X-Planes: Boeing X-45

On 1 August 2004 one person at one ground station controlled two combat aircraft in flight at once [Boeing X-45] [Cosentino 2008]. On 3 December the two X-45As, with the call signs Stingray 01 and Stingray 02, flew in coordination under a single pilot-operator for more than an hour [Two Boeing X-45A unmanned jets continue coordinated flights], and in February 2005 they attacked simulated air defences as a team, the ground pilot authorising the first attack [Boeing X-45]. That ratio, one to two, is the entire argument of the programme reduced to a number, and this article is about that number. This is the forty-sixth article in the X-Planes series, following the X-1, the X-2, the X-3, the X-4, the X-5, the X-6, the X-7, the X-8, the X-9, the X-10, the X-11, the X-12, the X-13, the X-14, the X-15, the X-16, the X-17, the X-18, the X-19, the X-20, the X-21, the X-22, the X-23, the X-24, the X-25, the X-26, the X-27, the X-28, the X-29, the X-30, the X-31, the X-32, the X-33, the X-34, the X-35, the X-36, the X-37, the X-38, the X-39, the X-40, the X-41, the X-42, the X-43, and the X-44.

Two airframes flew sixty-four times between May 2002 and July 2005, and the record of those flights is extensive. They released a weapon, hit a target, flew in formation, replanned in flight and finally prosecuted a multi-target attack under changing operator priorities [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. The vehicle is documented and its software is not, so the article dimensions what the software had to deliver rather than describing it.

The keystone is not aerodynamic and the literature it comes from is not aeronautical. The quantity that decides whether an unmanned combat aircraft is worth building is the number of vehicles one operator can supervise, and the relation that governs it was written by people studying robots rather than aeroplanes [Olsen and Wood 2004, Fan-out, measuring human control of multiple robots]. At a ratio of one the aeroplane has saved nothing but the pilot’s life. Everything else the concept promises, in crew cost, in persistence and in the willingness to risk the airframe, arrives only when the ratio exceeds one, and the X-45A showed an unmanned combat aircraft doing it.

The Research Question

The binding unknown was whether autonomy could raise the number of aircraft one person can supervise above one.

That question needs stating carefully, because it is easy to state it in a way that is either trivially true or unfalsifiable. A remotely piloted aircraft has a ratio of one by construction, since an operator who never looks away has a neglect time of zero and

\[NT = 0 \qquad \Longrightarrow \qquad FO = \frac{0 + IT}{IT} = 1\]

The pilot has moved from the cockpit to a container and is committed to that airframe for the whole sortie, and what has been bought is that no crew is aboard to be lost. Those are real and they are not the argument that was being made. The argument being made was that unmanned aircraft would be cheaper to operate in numbers, and that argument is arithmetic about people.

The X-45’s own programme documents put it in the language of affordability and effectiveness rather than of ratios, describing a networked system of high performance unmanned air vehicles to prosecute combat missions affordably [X-45 Unmanned Combat Air Vehicle, NASA]. This article assumes that people, more than airframes, dominate the cost of an operational fleet, and on that assumption the ratio is the mechanism by which an unmanned aircraft affects it.

For the second vehicle the question was different and smaller. The X-45C replaced the X-45B that had been planned as the operational prototype [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and its stated aims were greater range and loiter, a larger payload, carrier suitability and affordable stealth [X-45C, GlobalSecurity]. It is treated here as the answer to a design question, and most of the length goes to the X-45A, where the research was.

Programme Origin

The programme began as a study of whether an unmanned strike aircraft was possible at all. In the late 1990s the Defense Advanced Research Projects Agency began to examine the idea, and in March 1999 Boeing received a contract to build two X-45A technology demonstrators for ground attack, electronic warfare, surveillance and other operations in high-risk airspace [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles].

The first airframe was completed in September 2000 and did not fly for twenty months, undergoing extensive ground testing, including low and high speed taxi tests, during 2001 and early 2002 [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. It arrived at Dryden in November 2000 and the second in May 2001 [X-45 Unmanned Combat Air Vehicle, NASA]. A twenty-month gap between a finished airframe and a first flight indicates where the risk was, and it was not in the airframe.

The first flight was on 22 May 2002, lasting fourteen minutes and reaching 195 knots at 7,500 feet [X-45 Unmanned Combat Air Vehicle, NASA] [Boeing X-45A Unmanned Combat Air Vehicle begins flight testing, Boeing]. The second vehicle followed in November [Second Boeing X-45A completes first flight, Boeing]. The sixth flight, in December 2002, was the first on which the aeroplane raised its landing gear, on a flight of forty minutes at the same speed and altitude [X-45 Unmanned Combat Air Vehicle, NASA]. That pace measures how deliberately the envelope was opened.

The vehicle is one of a class of unmanned combat aircraft [Unmanned combat aerial vehicle], and it was developed from research gathered on Boeing’s Bird of Prey [Boeing X-45]. An earlier unmanned reconnaissance aircraft built by Lockheed Martin and Boeing is the DarkStar that the previous article used to calibrate a thrust lapse.

In parallel the Navy was building its own. Two contracts for carrier-based demonstrators were awarded in June 2000, to Boeing for the X-46 and to Northrop Grumman for the X-47, both of which are articles still ahead in this series, and in April 2003 the Air Force and Navy efforts were combined into a joint programme that became Joint Unmanned Combat Air Systems, J-UCAS [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. The X-45B and the X-46A were both cancelled before any airframe was built, and the joint programme’s vehicles were the X-45C and the X-47B.

The programme was funded to continue. Boeing received 767 million dollars in October 2004 for the J-UCAS capability demonstration [Boeing awarded 767 million dollars for the J-UCAS capability demonstration programme], and a full-scale X-45C model was shown at Farnborough that July [Boeing X-45C full-scale model makes its debut at Farnborough].

It ended in January 2006. J-UCAS was cancelled in favour of separate Air Force and Navy programmes, the Air Force turning toward a new manned long-range bomber. The Navy carried the effort forward as a carrier demonstrator competition, and in August 2007 selected the X-47B, terminating the navalised X-45C [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. The reasons were institutional, and the record shows no technical failure behind them.

Sizing From First Principles

The demonstrated result is a ratio, and a ratio has a relation behind it.

The Quantity That Decides Whether the Aeroplane Pays

Let the fan-out be the number of vehicles one operator can supervise. The term and the relation come from human-robot interaction, where the problem of one person and many machines was posed and measured before it was posed for aircraft [Olsen and Wood 2004, Fan-out, measuring human control of multiple robots]. The idea is older than the aircraft application and descends from a literature on teleoperation and process supervision [Sheridan, Telerobotics, automation and human supervisory control].

Let $NT$ be the neglect time, meaning how long a vehicle can be left alone before it needs attention, and $IT$ the interaction time, meaning how long the operator must spend on it once it does. An operator cycling around a set of identical vehicles can serve them all if and only if the time spent away from any one of them covers the others. Serving $N$ vehicles takes $N$ interaction times, and each vehicle can wait for at most its neglect time plus the interaction it then receives, so

\[N \, IT \le NT + IT\]

and the largest $N$ satisfying it is the fan-out,

\[FO = \frac{NT + IT}{IT}\]

Neglect tolerance is measured rather than assumed in that literature, by putting an operator in a multitasking environment and observing how long each machine survives unattended [Crandall et al 2005], and the measurement framework the field settled on is itself a published object [Steinfeld et al 2006].

The operator’s committed time follows immediately and is the quantity an air force buys.

\[\frac{\text{operator hours}}{\text{vehicle hour}} = \frac{1}{FO} \qquad u = \frac{IT}{NT + IT} = \frac{1}{FO}\]

The operator’s utilisation and the reciprocal of the fan-out are the same number. A fully occupied operator is therefore a fan-out of one by definition, and no amount of interface work changes that.

The cost argument the programme was making follows from it in one line. With $C_{a}$ the cost of putting an airframe over the target and $C_{c}$ the crew cost of a manned sortie,

\[C = C_{a} + \frac{C_{c}}{FO}\]

Only the second term responds to autonomy. An unmanned aeroplane at a fan-out of one has removed the risk to the crew and none of the crew cost. That arithmetic underlies the opening claim that the ratio is the whole argument.

The relation says something the words do not. Fan-out is not a property of the operator or of the interface alone. It is a ratio of two times, and autonomy enters it in exactly one place, by extending the neglect time. An aeroplane that can be left alone for longer can be one of more.

Inverting It for the Ratio the X-45A Demonstrated

One operator and two vehicles bounds the ratio from below, and the relation then bounds the autonomy from below. An operator who directed two vehicles has shown a fan-out of at least two, so

\[FO = \frac{NT + IT}{IT} \ge 2 \qquad \Longrightarrow \qquad NT \ge IT\]

The X-45A could be neglected for at least as long as it took to attend to it. That is the least autonomy the vehicle can have had, expressed as a ratio, and none of the sources used publishes the ratio in any form. With a switch cost the same demonstration yields a stronger bound, since $(NT + IT)/(IT + SC) \ge 2$ gives $NT \ge IT + 2\,SC$, so any time the operator lost in moving between the two vehicles was covered by neglect time as well. What the demonstration does not bound is the ratio from above. No source reports one operator attempting three X-45As, so the flights cannot say whether a third could have been supervised, and they give neither time in seconds.

The same question was being asked of aircraft specifically within three years of the demonstration, and the answers arrived through operator capacity models rather than through flight tests [Cummings et al 2007] [Cummings and Mitchell 2008]. The scheduling strategy the operator adopts turns out to matter as much as the autonomy does [Cummings and Mitchell 2007], and the bare relation has no term for it.

It is a modest number and it was a genuine achievement. A vehicle that may need attending to as much as half the time is not autonomous in the sense the word is now used. But the comparison is not with a modern system. It is with a ratio of one, the ratio of the armed Predator then in service, since its ground station crew for one aircraft was a pilot and two sensor operators [General Atomics MQ-1 Predator].

What a Higher Ratio Demands

The relation is unforgiving about what a better ratio costs. Rearranging,

\[\frac{NT}{IT} = FO - 1\]

fan-out	required $NT/IT$	improvement over the X-45A, at most
2	1	the demonstrated bound
3	2	2 times
4	3	3 times
8	7	7 times
16	15	15 times

The improvement needed is linear in the fan-out and is measured against a demonstrated ratio of at least one, so a fleet ratio of eight is not four times harder than the demonstrated two. It is up to seven times harder, and exactly seven times only if the X-45A was flown at its limit, which the record does not show. The autonomy and the interface have to carry all of it between them, since the relation has no other term, and the metrics that introduced neglect time state the design goal as reducing interaction effort without diminishing task effectiveness [Goodrich and Olsen 2003, Metrics for evaluating human-robot interactions].

The table states the argument for autonomy as arithmetic rather than as enthusiasm, and it also locates where the effort has to go. Halving interaction time and doubling neglect time are worth the same amount, and the first is an interface problem while the second is an autonomy problem.

Adding the Switch Cost

An operator moving between vehicles pays for the move. Later work presents a feasibility test for a team that applies when the cost of switching attention between robots or tasks can become prohibitive, and establishes that switch costs can be high and that different tasks impose different ones [Goodrich, Quigley and Cosenzo 2005, Task switching and multi-robot teams]. The form used here adds a switch cost $SC$ to the denominator, since the time spent re-establishing context is time not spent on any vehicle,

\[FO = \frac{NT + IT}{IT + SC}\]

switch cost	fan-out at $NT = 3\,IT$
0	4.00
0.25 $IT$	3.20
0.50 $IT$	2.67
1.00 $IT$	2.00

A switch cost of half the interaction time removes a third of the fan-out. At a full interaction time it removes half, taking a system designed for four back to the two the X-45A demonstrated without any change to the vehicle at all. Interface design is therefore not a detail of this problem, it is one of its two terms, and the ground station is as much the article under test as the aeroplane.

The relation also stops describing one operator once there are several, and the multi-operator case is not the single-operator one multiplied, since operators specialise and hand work to each other [Cummings et al 2012]. This article stays with the single-operator case because the X-45A demonstrated that case.

The Two Aircraft

The X-45A and the X-45C are not the same design scaled, although the numbers make them look like it.

	X-45A	X-45C
span	10.3 m	14.9 m
length	8.08 m	11.9 m
gross mass	5,530 kg	16,600 kg
thrust	28.0 kN	31.0 kN
speed	Mach 0.75	Mach 0.85
ceiling	35,000 ft	40,000 ft
mission radius	497 nm	1,296 nm
internal payload	680 kg	2,040 kg

The table follows the directory and the sources disagree on the X-45A’s design point [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. GlobalSecurity says the X-45A was designed to achieve Mach 0.8 at 40,000 feet with a flight duration of about ninety minutes [X-45 Unmanned Combat Air Vehicle, GlobalSecurity], against the directory’s Mach 0.75 and 35,000 foot ceiling. Nothing below depends on the X-45A’s speed or ceiling.

The two aircraft carry the same payload fraction, and the rest of the table follows from that fact.

\[\frac{m_{\text{payload}}}{m_{\text{gross}}} = \frac{680}{5{,}530} = 0.12297 \qquad \frac{2{,}040}{16{,}600} = 0.12289\]

They agree to four significant figures, and their ratio is 0.99940. Nothing in the sources suggests it was intended, and the arithmetic confirms it happened.

The mass then scales as very nearly the cube of the span, which looks like geometric similarity and is not.

\[m \propto b^{\,n} \qquad n = \frac{\ln \left( m_{2} / m_{1} \right)}{\ln \left( b_{2} / b_{1} \right)} = \frac{\ln \left( 16{,}600 / 5{,}530 \right)}{\ln \left( 14.9 / 10.3 \right)} = 2.977\]

The same exponent computed from the payloads instead of the masses gives 2.976. The two agree, and the agreement explains the scaling.

\[\frac{\ln \left( 2{,}040 / 680 \right)}{\ln \left( 14.9 / 10.3 \right)} = 2.976 \qquad \frac{m_{\text{payload},2}}{m_{\text{payload},1}} = 3.0000\]

The payload was tripled exactly, the payload fraction was held, and the gross mass therefore tripled too. The span then followed from the mass rather than the mass from the span.

It is not geometry and it is not a coincidence either. The X-37 measured 1.924 against the Shuttle orbiter and the X-38 measured 3.507 against the X-24A, and in both cases the exponent said something about the design. Here the X-45C kept a similar centre body and took a wing planform like that of the naval X-46A, and the two aircraft are therefore not geometrically similar [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], so an exponent of three describes a held payload fraction. It does not describe a shape. A scaling exponent that arrives from the mission rather than from the geometry looks identical in the arithmetic and means something entirely different, and this series has warned before against reading an exponent as a property of the technology.

What is not similar at all is the performance.

\[\frac{T}{W} = \frac{T_{\text{SL}}}{m \, g} \qquad \left. \frac{T}{W} \right|_{\text{X-45A}} = \frac{28{,}000}{5{,}530 \times 9.80665} = 0.516 \qquad \left. \frac{T}{W} \right|_{\text{X-45C}} = 0.190\]

A factor of 2.71. The X-45C is three times the mass on ten percent more thrust, because it is an operational aeroplane carrying three times the payload two and a half times as far, and the demonstrator was a lightly loaded airframe on a proportionally large engine. Geometrically similar in mass and nothing like each other in the air.

A Thrust Figure That Looks Wrong and Is Not

The X-45C’s quoted thrust looks wrong. The engine is given as a General Electric F404 variant at 7,000 pounds force [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and the F404 family’s dry rating is nearer 11,000 with an augmented rating of 17,700 [General Electric F404]. The X-45A’s own engine is a Honeywell F124 of 28 kilonewtons [Honeywell and ITEC F124], a non-augmented turbofan of the class used in trainers and light attack aircraft. Parsch himself warns that his figures may be inaccurate, since the data given by several sources show slight variations [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles].

The test available is whether the low figure can hold the vehicle’s stated ceiling. At the ceiling the thrust available equals the drag, so

\[T_{\text{avail}}(h, M) = \frac{W}{L/D} \qquad \Longrightarrow \qquad \frac{L}{D} = \frac{W}{T_{\text{avail}}}\]

with the installed thrust following the corrected mass flow of a fixed engine, the standard corrected-parameter machinery of engine performance [Mattingly, Aircraft engine design] [Cumpsty, Jet propulsion],

\[T_{\text{avail}} = T_{\text{SL}} \, \frac{p}{p_{\text{SL}}} \, \frac{\left( 1 + 0.2 M^{2} \right)^{3.5}}{\sqrt{\left( T / T_{\text{SL}} \right) \left( 1 + 0.2 M^{2} \right)}}\]

At 40,000 feet and Mach 0.85 the weight is 162.8 kilonewtons and the three candidate ratings give

sea-level rating	available at the ceiling	lift to drag ratio it demands
7,000 lbf as published	9,964 N	16.3
11,000 lbf, the dry class	15,658 N	10.4
17,700 lbf, augmented	25,195 N	6.5

A clean subsonic flying wing of this size reaches sixteen to eighteen [Torenbeek, Synthesis of subsonic airplane design] [Filippone, Advanced aircraft flight performance] [Raymer, Aircraft design, a conceptual approach], so the published figure is admissible and the suspicion does not survive. What the check produces instead is better than the error would have been, because it pins a quantity no source used here publishes. The X-45C must have achieved a lift to drag ratio of at least 16.3 to meet its specification.

The demand of 16.3 is near the top of that range and the configuration is the reason to take the top seriously rather than the middle. A tailless aeroplane trims without a tail, so its efficiency and its static stability are set together, and the literature treats that coupling as the configuration’s defining aerodynamic question [Kashiwagura and Shimoyama 2018]. Drag reduction on such an aeroplane is pursued through the same surfaces that trim it [Cusher and Gopalarathnam 2012]. A clean flying wing can therefore reach a ratio a conventional aeroplane of the same size would not, and the figure is sensitive to how the aeroplane is trimmed. This supports the admissibility of the published thrust and it does not establish the ratio, which remains a lower bound derived from the published ceiling.

The bound is not an artefact of the exact ceiling.

assumed ceiling	assumed Mach	required lift to drag
35,000 ft	0.85	12.9
40,000 ft	0.80	17.1
40,000 ft	0.85	16.3
40,000 ft	0.90	15.6
45,000 ft	0.85	20.8

The 40,000 foot rows are all admissible and the 45,000 foot row is not, since 20.8 lies above the sixteen to eighteen that the sources cited above give for a clean subsonic flying wing of this size. The thrust figure and the ceiling figure therefore pin each other, and the pair is self-consistent at the ceiling the sources quote. Two figures that corroborate is a weaker result than an error would have been and a truer one.

Dependent Systems

The Configuration and the Crosswind Question

The X-45A is tailless, with trailing-edge elevons and a yaw thrust vectoring nozzle, and has no vertical surfaces. In the absence of vertical surfaces yaw was controlled by thrust vectoring [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles] together with oppositely deflected outboard elevons, in what NASA’s account of the design calls a crow mix [Cosentino 2008], and the flight controls are all-electric except for the nose wheel steering and the brakes [X-45 Unmanned Combat Air Vehicle, GlobalSecurity]. The absence of a fin is a signature decision before it is an aerodynamic one [Knott, Shaeffer and Tuley, Radar cross section], and the configuration has a documented history far older than the jet age [Wooldridge, Winged wonders, the story of the flying wings]. The stability the fin would have supplied is replaced by feedback [Etkin and Reid, Dynamics of flight] [Nelson, Flight stability and automatic control] [Anderson, Fundamentals of aerodynamics].

That is close to the configuration the previous article in this series derived could not meet an operational crosswind landing requirement. It found that the required vector angle for a crosswind of fixed speed depends on Mach number alone, that at equal throttle the approach is the easiest case in the envelope, and that the approach binds anyway because the throttle is nearly closed. And then the X-45A landed sixty-four times [Cosentino 2008].

The two results are compatible, and the arithmetic accounts for it. The demand goes as the dynamic pressure times the sideslip a fixed crosswind produces, and the authority goes as the thrust the approach leaves available. Neither the wing area nor the yaw derivative of the X-45A is given in any source used here, so the comparison is made against the F-22 case the previous article computed, in which the airframe terms appear in both and the throttle does not.

The thrust an approach requires is the one relation in this comparison that does not involve the wing at all. On a glide slope $\gamma$ at a lift to drag ratio $L/D$,

\[\frac{T}{W} = \frac{1}{L/D} - \sin \gamma \qquad \Pi = \frac{W}{T_{\text{SL}}} \left( \frac{1}{L/D} - \sin \gamma \right)\]

which for the X-45A at a landing lift to drag ratio of nine on three degrees gives $\Pi = 0.114$. The approach speed and the sideslip a crosswind produces do involve the wing, through

\[V_{\text{app}} = 1.3 \sqrt{\frac{2 m g}{\rho \, S \, C_{L,\max}}} \qquad S = \frac{b^{2}}{A\!R} \qquad \beta = \arctan \frac{V_{c}}{V_{\text{app}}}\]

and the demand the vectoring must meet is the product of the dynamic pressure and that angle,

\[D \equiv q \, \beta = \tfrac{1}{2} \rho V_{\text{app}}^{2} \arctan \frac{V_{c}}{V_{\text{app}}}\]

The comparison is then a ratio of ratios, in which the airframe constants of the previous article’s case appear in both halves and cancel.

\[\text{margin} = \frac{\Pi / \Pi_{\text{F-22}}}{D / D_{\text{F-22}}}\]

	X-45A	F-22, from the previous article
approach thrust fraction	11.4 percent	7.2 percent
sideslip in a 15 m/s crosswind	10.1 deg	11.0 deg
demand index, relative	1.09	1
available thrust, relative	1.58	1
net margin, relative	1.45	1

The X-45A is better off by a factor of 1.45 because of the throttle. It is a light aeroplane on a proportionally large engine, so the thrust that a three degree approach requires is a larger share of what the engine can produce, and the vectoring authority scales with that share.

The wing area does real work, so the conclusion is tested across the plausible range.

aspect ratio	wing area	wing loading	approach speed	net margin
3.0	35.4 m²	156 kg/m²	121 kn	1.98
4.0	26.5 m²	209 kg/m²	139 kn	1.71
5.5	19.3 m²	287 kg/m²	163 kn	1.45
7.0	15.2 m²	365 kg/m²	184 kn	1.28

Every row leaves the X-45A better off than the F-22, so the conclusion does not depend on the assumed wing. The thrust fraction does not move at all across that table, because it follows from the glide slope and the lift to drag ratio rather than from the wing, and only the demand column responds.

The rest of the reconciliation is the previous article’s own caveat and not a new argument. That article said explicitly that a vehicle landing into wind on a long runway at a test range faces a much weaker requirement than an operational fighter does. The X-45A is such a vehicle, flying at Edwards [X-45 Unmanned Combat Air Vehicle, NASA] with the option of waiting for the wind. So the earlier conclusion survives, the X-45A is not a counterexample to it, and the margin by which it is not a counterexample has been computed rather than asserted.

The vectoring-only model also understates the X-45A’s yaw authority. NASA’s account of the design records that oppositely deflected outboard elevons were used for yaw stability and control alongside the nozzle [Cosentino 2008], which the previous article’s model of a thrust-vectored tailless aeroplane does not include. No source gives the authority those surfaces add, so they strengthen the conclusion without changing the computed margin.

The Weapons Bay

An internal bay is a hole in a low observable aeroplane, and opening it is the moment the aeroplane stops being one. The X-45A carried a bay of 680 kilograms capacity, explicitly to test all phases of weapons handling and deployment [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and the X-45C was to carry 2,040 kilograms, being two GBU-31 Joint Direct Attack Munitions [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles].

In March 2004 the X-45A released a weapon for the first time [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and in April it hit a target with an inert satellite-guided bomb [Boeing unmanned combat aircraft makes aviation history]. The autonomy claim in that milestone is narrower than it is usually reported. The operator gave three commands, being target confirmation, arm and release consent, and the aircraft then performed the manoeuvres, the bay door operations and the release sequence autonomously under human supervision, dropping a 250-pound Small Smart Bomb from its internal bay at 35,000 feet and Mach 0.67 [Boeing unmanned combat aircraft makes aviation history]. The release was autonomous in the sense that the aeroplane executed it without a pilot flying the aeroplane, and the decision to attack that target was made by a person. The distinction matters and is kept throughout, because the later milestones moved the line and the record marks where.

The Command Link

A supervised aeroplane needs a link, and the link’s properties set the interaction time in the fan-out relation directly. A high-latency or low-bandwidth link raises the time an operator needs to understand a situation and to act, which lowers the fan-out for a fixed autonomy.

The coupling is not qualitative, and writing it down fixes what a latency figure would be worth. A round trip of $\tau$ each way is added to every interaction, so

\[IT = IT_{0} + 2\tau \qquad \Longrightarrow \qquad FO = \frac{NT + IT_{0} + 2\tau}{IT_{0} + 2\tau + SC}\]

Latency appears in the numerator and the denominator and does not cancel, because it lengthens the interaction without lengthening the neglect.

That effect was measured in 1963, thirty-nine years before this aeroplane flew. Sheridan and Ferrell put a transmission delay into a remote manipulation task and found the operator’s completion time growing with it in a way practice did not remove [Sheridan and Ferrell 1963], and four years later the same authors named the response to it, which was to stop transmitting movements and start transmitting intentions [Ferrell and Sheridan 1967]. Supervisory control was invented as an answer to latency, and the X-45A is an aeroplane built on that answer. Taking a ten second interaction and a neglect time three times it,

one-way latency	fan-out	cost
0 s	4.00	none
0.25 s	3.86	3.6 percent
0.5 s	3.73	6.8 percent
1 s	3.50	12.5 percent
2 s	3.14	21.4 percent

A satellite round trip costs a fifth of the fan-out on those assumptions, and a line-of-sight link costs almost nothing. These figures are computed from assumed times and observe nothing, yet they explain why a supervised combat aircraft wants its operator within line of sight or its autonomy raised to compensate.

This is the sharpest coupling in the article and the public record does not quantify it for this aeroplane. NASA’s review of the test site shows ultra high frequency, L-band and fighter data link command and control channels and L-band telemetry for the demonstration [Cosentino 2008], and none of the sources this article uses gives a latency figure, a bandwidth figure or a link budget for any of them. The relation shows what such a figure would buy and the sources do not give it, so the gap is recorded and no value is assumed.

Structure and Affordability

No source this article uses describes the X-45A’s structure. Affordability was a stated programme objective rather than a consequence, and the flight control paper states the programme’s aim as exploiting the freedom of relocating the pilot outside the vehicle to enable a new paradigm in aircraft affordability [Davidson 2004]. GlobalSecurity puts the X-45 unmanned combat air vehicle at 10 to 15 million dollars apiece, about a third of the 45 million dollars it gives for the Joint Strike Fighter [X-45 Unmanned Combat Air Vehicle, GlobalSecurity]. That figure is a projection for an operational aircraft. The demonstrator’s cost does not appear in it. The cited sources give no cost figure for the demonstrator airframe, so the objective is recorded without being evaluated.

The Flight Test Record

Sixty-four flights over thirty-eight months [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles].

\[\dot{n} = \frac{64}{38} = 1.68 \ \text{flights per month}\]

That rate reflects what was under test. The record runs in software blocks [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and a T-33 carried the vehicle’s management system computers in flight before the X-45A first flew, and the arrangement allowed each mission to be rehearsed on it to validate the mission plan and train the team [X-45 Unmanned Combat Air Vehicle, NASA], serving for software checkout and mission planning verification [Cosentino 2008]. A programme that flew more often would have been testing something else.

The record, as the directory [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles] and NASA [X-45 Unmanned Combat Air Vehicle, NASA] give it, is set out below.

date	milestone
May 2002	first flight, 14 minutes, 195 kn at 7,500 ft
November 2002	second vehicle flies
December 2002	landing gear raised in flight for the first time
February 2003	Block 1 complete, being taxi, takeoff, landing, navigation and basic communication
November 2003	Block 2 testing begins, including communication with manned aircraft
March 2004	first weapon released
April 2004	target hit with an inert satellite-guided bomb
August 2004	two vehicles in coordinated flight under one operator
October 2004	Block 3 begins, including in-flight mission replanning
July 2005	programme complete after 64 flights

The final mission deserves quoting in full, because the ratio was earned on it. It included detecting and avoiding multiple simulated threats, determining which of several possible targets to attack, replanning after the operator changed target priorities, and conducting the attacks with one or two aircraft [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles].

Read against the fan-out relation, every clause of that sentence is an attempt to raise neglect time. Detecting and avoiding threats without asking is neglect time. Choosing among targets is neglect time. Replanning after the operator changed priorities is the opposite. It is an interaction, the sole clause that describes the operator doing something. The mission was designed so that the operator contributed a priority change instead of a control input, and that division of labour defines supervision.

Both airframes survived and both are in museums, one at the National Museum of the United States Air Force [Boeing X-45A J-UCAS, National Museum of the United States Air Force] and one in the Military Unmanned Aerial Vehicles exhibit at the National Air and Space Museum [Military Unmanned Aerial Vehicles exhibit, National Air and Space Museum]. No airframe was lost, and NASA records the sixty-four research flights as safe and successful [Cosentino 2008].

Comparison With Ground Prediction

The sources this article uses hold no numerical pair of a ground prediction and a flight result for this aeroplane, and that absence is the first finding. They include no test report, flight log or software specification for the X-45A. The seven research papers whose titles name the aeroplane are where such a pair would be sought, as The Source Base below records, and the abstracts of four of them and the full text of a fifth describe the testing without giving its numbers. The aeroservoelastic paper records the one ground prediction these sources show being revised by test before flight. Its flight control filters were first designed from structural and aerodynamic models, initial structural mode interaction testing prompted a post-test investigation of both the models and the analysis, and the filters were redesigned from the improved models before the flight results it summarises [Reichenbach 2003]. The flight control paper reports flight test results for the system that controlled the vehicle through taxi, takeoff, flight and landing during envelope expansion [Davidson 2004], the formation paper presents flight results for the guidance behind formation taxi and flight [Brinker and Barker 2005], and the first flight paper summarises the test accomplishments up to and including the first flight [Wise 2003]. NASA’s account of the design records that the shape passed through computational fluid dynamics analysis, design refinement and wind tunnel testing before the flight article was built [Cosentino 2008], and gives no figures either. The first flight on 22 May 2002 lasted fourteen minutes and reached 195 knots at 7,500 feet [X-45 Unmanned Combat Air Vehicle, NASA] [Boeing X-45A Unmanned Combat Air Vehicle begins flight testing, Boeing], and it can be reported but not compared with a stated prediction.

What the record does show is where the prediction was done, and it was done on the ground at length. The first airframe underwent extensive ground testing, including low and high speed taxi tests, during 2001 and early 2002 [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], and autonomous ground taxi was demonstrated on 24 October 2001 [Cosentino 2008]. Dryden engineers designed the ground control laws for taxi, takeoff and landing relying heavily on simulation models, and ran ground vibration tests to update the analytical models and calculate the flutter margins [X-45 Unmanned Combat Air Vehicle, NASA], exciting the airframe with three 50 pound shakers and measuring it with 176 accelerometers [Cosentino 2008]. The landing gear was not raised in flight until the sixth flight, and the T-33 surrogate allowed each mission to be rehearsed first [X-45 Unmanned Combat Air Vehicle, NASA]. The inert satellite-guided bomb that hit its target in April 2004 [Boeing unmanned combat aircraft makes aviation history] is the flight result that any ground separation analysis would be judged against. No such analysis appears in the sources cited, so the hit confirms that whatever prediction was made was adequate and is silent on the margin by which it was.

The one prediction this article can set against a flight result is an analytical one from outside the programme. The previous article in this series derived that a tailless aeroplane yawed by thrust vectoring could not meet an operational crosswind landing requirement, and the X-45A then landed sixty-four times in a tailless configuration yawed in part by thrust vectoring [Cosentino 2008]. The two are compatible and the reconciliation is argued under Dependent Systems above, where an approach thrust fraction of 11.4 percent against 7.2 percent for the F-22 case leaves the X-45A better off by a factor between 1.28 and 1.98 across the plausible wing, and where the test range’s option of waiting for the wind carries the rest. That comparison sets a prediction beside a flight count and not beside flight data, since no crosswind, sideslip or nozzle deflection from any X-45A landing has been published.

The keystone result reverses the usual direction of comparison. The fan-out relation was posed and measured in human-robot interaction before it was posed for aircraft. The metrics that founded it measure a robot’s autonomy by its neglect time and the attention it demands by free time and fan-out [Goodrich and Olsen 2003, Metrics for evaluating human-robot interactions], principles of efficient interaction were compiled from evaluations of neglect tolerance and interface efficiency [Goodrich and Olsen], and the fan-out equation was then defined and validated experimentally [Olsen and Wood 2004, Fan-out, measuring human control of multiple robots]. No ground estimate of the X-45A’s own neglect time or interaction time is among the sources used for the flight to confirm. The flight returned the ratio, one operator to two vehicles first in August 2004 [Boeing X-45] and for more than an hour in December [Two Boeing X-45A unmanned jets continue coordinated flights], and the derivation in Sizing From First Principles works backward from that ratio to a neglect time at least equal to the interaction time. Here the flight is the measurement and the relation supplies the inference, and the operator capacity models that took up the question for aircraft arrived after the demonstration rather than before it [Cummings et al 2007].

For the X-45C the comparison is empty, because the aeroplane never flew as the X-45C, its prototype airframe flying only in April 2011 as Boeing’s Phantom Ray [Boeing Phantom Ray]. Its specification gave a ceiling of 40,000 feet on an engine rated at 7,000 pounds force, and the thrust check in The Two Aircraft shows that the pair is self-consistent only if the aeroplane reaches a lift to drag ratio of at least 16.3. That bound is a prediction derived from a specification, and flight never returned a number to set beside it.

What the Data Changed

The X-45A settled that the ratio can exceed one, and nothing since has settled how far.

Whether the demonstrated fan-out of two has since been exceeded for armed aircraft in operational service is not settled by the sources this article uses, and the article assumes neither answer. The armed aircraft in service when the X-45A flew was crewed on the ground by a pilot and two sensor operators for each aircraft [General Atomics MQ-1 Predator], a ratio of one.

The configuration propagated and the programme did not. The X-47B flew the tailless low observable planform with internal carriage from a carrier, and the planform has appeared repeatedly since [Northrop Grumman X-47B]. J-UCAS itself was cancelled in January 2006 before either competitor’s vehicle had flown, in favour of separate service programmes and, for the Air Force, a manned bomber [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. Flight testing of both systems had been expected to begin in 2007 [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles], a Boeing release of April 2004 scheduled the first X-45C flight for mid-2006 [Boeing unmanned combat aircraft makes aviation history] and one of December 2004 for early 2007 [Two Boeing X-45A unmanned jets continue coordinated flights], and the X-45C never flew as such. The X-47B first flew on 4 February 2011 [Northrop Grumman X-47B].

The clearest thing the programme changed is what a demonstrator is expected to demonstrate. The X-45A’s milestones are software blocks and not envelope points. The aeroplane was the test rig and the flight control laws were the fixture.

That shape is now the normal one, and the test community has said so. The operational test lessons drawn from unmanned aircraft while the X-45A was flying already treat the system, more than the airframe, as the article under test [Carr et al 2003], and a decade later the problem had been named as a standing challenge for test and evaluation in general, beyond any one programme [Clark et al 2014] [Yeh 2018]. What makes an autonomous aircraft hard to test is that its behaviour is a function of a situation and not of a flight condition, so an envelope point does not bound it and a block of software has to be argued about instead.

The Contemporary Literature

Cluster	Records
Human supervisory control and the span of control	1,390
Autonomy, mission management and onboard decision making	853
Multi-vehicle coordination and cooperative control	718
Tailless configurations and their control effectors	499
Flight control law design and handling qualities	472
Aircraft conceptual design, sizing and mass estimation	281
Propulsion, inlet integration and installed performance	269
Unmanned combat aircraft and the strike mission	248
Aerodynamics of the configuration	230
Suppression of enemy air defences and time-critical targeting	209
Internal weapons carriage and store separation	200
Automatic takeoff, landing and carrier recovery	179
Low observable design and signature	179
Flight test technique, instrumentation and simulation	171
Verification, validation and the certification of autonomous software	128
Airspace integration, detect and avoid and the regulation of unmanned flight	123
Unmanned aircraft in history, doctrine and military employment	120
Programme, acquisition and the cost of a demonstrator	101
Datalink, latency and beyond-line-of-sight command	87
Navigation, sensing and onboard computing for unmanned aircraft	59
Airframe structure, composites and affordability	53
Total	6,569

The survey below maps the field these vehicles sit in and is kept separate from the curated sources that carry the argument. Every record comes from Crossref or from the Technical Reports Server of the National Aeronautics and Space Administration, NASA, is admitted under the subject rule that The Source Base states, and is assigned to exactly one cluster.

The survey draws on two literatures and not one. The keystone relation comes from human-robot interaction, where the papers carry no aeronautical vocabulary whatever, so a survey admitting only the vocabulary of aircraft would contain none of them.

What the Shape of the Survey Says

The autonomy clusters together outweigh the aerodynamic ones, as suits this subject. Autonomy and mission management, multi-vehicle coordination, human supervisory control, and verification of autonomous software hold 3,089 records between them, against 230 for the aerodynamics of the configuration. An aeroplane whose risk sat in its software has a literature whose mass sits there too.

The median publication year is 2015 and 50.8 percent of dated records are from 2015 or later. The subject did not stop when the programme did. It moved to a different community, and the recent weight is in autonomy and cooperative control, where records from 2015 or later make up 64.6 percent of the cluster on autonomy and 67.3 percent of the cluster on multi-vehicle coordination, against 35.8 percent for the aerodynamics of the configuration.

Nine hundred and ninety-eight records predate 2000 and they are not decoration. Supervisory control was posed as a problem of remote manipulation in the 1960s, long before an aeroplane needed it [Sheridan and Ferrell 1963] [Ferrell and Sheridan 1967], and the relation at the centre of this article descends from that work.

The datalink cluster holds 87 records, fewer than all but two others, and the smallness does not look like an artefact. The likeliest reason is that military link performance seldom reaches the open bibliographic record, and only fifteen research titles in the whole survey pair a latency or a delay with an unmanned aircraft, by the count in The Source Base. This limits the survey without showing a gap in the field, and it is also the single place where this article’s coupling between the link and the fan-out cannot be supported from the literature.

Reading the survey against this article’s conclusions instead of its topics asks a different question. A conclusion is not a topic, and a survey assembled around a subject can be silent on the thing the subject was used to argue.

The survey supports the aeronautical conclusions unevenly. The crosswind comparison inherited from the X-44 article rests on 245 records on yaw control without a fin, and the flight test methodology behind the claim about software blocks on 58. The lift to drag ratio that the thrust figure pins rests on only twenty-nine, because most published work on that ratio concerns airfoil sections, induced drag theory and configurations other than the flying wing, which the subject rule excludes, and the range of sixteen to eighteen that the bound is tested against is sourced to textbooks. The conclusions about supervision sit on between eleven and thirty-one records each, fewer than either well-served aeronautical conclusion, and the cause is vocabulary. The question of how many vehicles one operator can hold is named by phrases that also name a much larger literature about photogrammetry, path planning and crop estimation. The vocabulary does not discriminate, a different condition from a subject being unstudied, and no choice of search terms repairs it.

The sharpest instance sits underneath the question this article leaves most open. Whether a ratio of two has since been exceeded for armed aircraft in service is a question about reported operator to vehicle ratios, and the survey holds eleven records that use that vocabulary. Four of the eleven are a different subject wearing the same words, being the organisational span of control that asks how many subordinates a commander may hold. That question is the ancestor of this article’s question and not an instance of it. They are kept and not removed, because the lineage is real and a reader is better served by seeing it named than by finding the cluster quietly smaller.

Human supervisory control and the span of control

This is the cluster the article’s keystone comes from, and most of it is not an aeronautical literature. It holds human-robot interaction, the fan-out relation and its successors, neglect time and interaction time, operator workload and situation awareness, levels of automation, trust in automation and the out-of-the-loop problem, together with teleoperation under transmission delay, which is where the latency term in the section headed Dependent Systems comes from. Of its 1,390 records, 315 name an aircraft, a drone, a helicopter, an aerial or uninhabited vehicle, aviation, flight, a pilot, a cockpit, air traffic or airspace in their titles, so a survey admitting only the vocabulary of aircraft would miss more than three-quarters of it, which is why this survey admits the vocabulary of supervising a machine as a second route onto the subject.

Autonomy, mission management and onboard decision making

What the X-45A’s software blocks were actually delivering. Mission management architectures, onboard replanning, contingency handling, deliberative and reactive planning, and the long argument about what autonomy means when the word is used as a selling point. The programme’s milestones were all software milestones after the first year, and this is the field those milestones were drawn from.

853 records. [A multi-sensor fusion system 1994] [Aburime] [Adhikari 2021] [Adhikari 2021] [Agbeyibor et al 2024] [Agent-Based Autonomous System Verification 2023] [Agte et al 2026] [Ahner et al 2006] [Ainvestigation of Computer Vision 2024] [Akanbi and Ayomoh 2025] [Al-Salah and Zein-Sabatto 2020] [Albaker and Rahim 2011] [Albert and Imsland 2017] [Alharasees et al 2023] [Alijani and Osman 2021] [Alonso da Silva 2019] [Alsayed et al 2022] [Alvarez et al 2020] [Alves et al 2019] [Ambroziak and Ciężkowski 2021] [Ambroziak and Gosiewski 2015] [Ambroziak et al 2025] [Amelin et al 2013] [Ancel et al 2019] [Ancel et al 2024] [Andersen et al 2026] [Anderson and Milutinovic 2013] [Anderson et al 2008] [Anderson et al 2018] [Angermuller and Hall 2003] [Architecture Framework for Unmanned] [Arcile et al 2020] [Arkin 2010] [Arkin 2010] [Arkin and Ulam 2012] [Arkin et al 2012] [Ashokkumar 2023] [Assaad] [Athanasiadou et al 2026] [Aurandt] [Automation and Autonomy in 2016] [Autonomous Control of Unmanned 2012] [Autonomous Control of Unmanned 2019] [Autonomous Heading Sensors Navigation 2020] [Autonomous Navigation of Unmanned 2021] [Autonomous Systems Architectures 2023] [Autonomous unmanned aircraft RandD 1994] [Autonomous vehicle control with] [Autonomous vehicle position control 1993] [Autonomous vehicles] [Autonomous vehicles 2025] [Awni 2007] [Awni and Tuzcu 2011] [Allen et al] [Babel 2014] [Babel 2018] [Bai and Meng 2022] [Balakirsky et al 2005] [Banks et al 2007] [Bao et al 2025] [Barbier and Chanthery 2004] [Bardhan et al 2017] [Barhydt et al 2003] [Barlow 2004] [Barnhart 2012] [Baser et al 2013] [Bassett] [Bateman et al 2005] [Batinovic et al 2022] [Beeharry and Ramful 2024] [Ben Ludington 2006] [Ben-Asher 1992] [Benders 2018] [Benders et al 2018] [Benders et al 2020] [Berrios et al 2018] [Bestaoui and Dicheva 2010] [Bestaoui and Lakhlef 2013] [Bestaoui Sebbane 2015] [Bhandari et al 2026] [Bhatt et al 2018] [Bi 2020] [Biagini et al 2018] [Bingo 2018] [Blauensteiner and Fahrnberger 2024] [Blidberg 2003] [Bogdanowicz 2018] [Bouchard et al 2026] [Boyko and Girgidov 2021] [Brajovic et al 2018] [Brinker 2004] [Brock et al] [Brockett et al 2002] [Barrows et al 2025] [Bryant et al 2015] [Buffington 2002] [Bui 2025] [Bulka and Nahon 2017] [Burgos and Bhandari 2016] [Burns et al 2007] [Burstein et al 2003] [Buysse et al 2025] [Bürkle et al 2010] [Calhoun et al 2016] [Calhoun et al 2021] [Callow et al 2010] [Candela et al 2017] [Cappuzzo et al 2022] [Carmeli et al 2022] [Carryer] [Casavola and Garone 2008] [Castano and Xu 2019] [Castanon and Cassandras 2010] [Castillo-Effen and Visnevski 2009] [Castillo-Effen et al 2009] [Cetin and Yilmaz 2013] [Cetin et al 2010] [Chambers et al 2016] [Chamseddine et al 2014] [Chandra and Ghosh 2019] [Chang et al 2023] [Chao et al 2010] [Chapter 3 Autonomous UAVs 2021] [Chen 2022] [Chen 2022] [Chen 2022] [Chen and Duan 2016] [Chen et al 2002] [Chen et al 2014] [Chen et al 2017] [Chen et al 2022] [Chen et al 2025] [Childers 2007] [Chiou et al 2021] [Chitrakaran et al 2006] [Cho and Jung 2026] [Choi et al 2018] [Choi et al 2021] [Chou et al 2021] [Christianos 2022] [Ciećko and Grunwald 2017] [Cisler et al 2019] [Civil Regulation Of Autonomous 2024] [Clare et al 2012] [Clark et al 2014] [Clement et al 2024] [Clough] [Clough 2002] [Clough 2003] [Cobleigh 2002] [Conde et al 2011] [Consiglio 2016] [Consiglio et al 2016] [Cooper and Ravela 2024] [Cordeiro et al 2019] [Costello and Xu 2023] [Cotting 2010] [Cowlagi et al 2016] [Crowe et al 2019] [Crum et al 2004] [Cummings and Guerlain 2004] [Cutler 2018] [D’Amato et al 2019] [Dai et al 2025] [Daibing et al 2012] [Dang et al 2023] [Dapena et al 2017] [Darling] [Dasarathy 1980] [David 2023] [Zahn et al] [de Bruin and Jones 2016] [Deng et al 2016] [Dennis et al 2016] [Deonandan et al 2010] [Deuel 2022] [DeVries and Paley 2013] [Di Marzo Serugendo 2016] [Dibley et al 2007] [Diddi] [Diget et al 2022] [Dimitrakopoulos et al 2021] [Ding et al 2013] [Ding et al 2021] [Djang and Lopez 2009] [Doherty et al 2014] [Doherty et al 2021] [Doherty et al 2023] [Doman 2015] [Dong 2024] [Dong et al 2019] [Drusinsky et al 2022] [Du et al 2022] [Du et al 2023] [Duan and Luo 2016] [Duan and Zhu 2018] [Duan et al 2021] [Duplouy] [Duraklar 2024] [Durdu et al 2018] [Durst and Gray 2014] [Durst et al 2013] [Edwards et al 2006] [Effect of operator experience 2016] [Ghazi et al 2024] [El-Sayed and ElHelw 2012] [Ellis and Durak 2020] [Enright et al 2005] [Ergezer and Leblebicioglu 2013] [Erkin et al 2022] [Ancel et al] [Eubank and Atkins 2011] [Evolution of Autonomous Vehicles 2024] [Zortul et al 2020] [Fagbemi et al 2019] [Falco and Gilpin 2021] [Fan 2017] [Fan et al 2019] [Fan et al 2021] [Farhat and Babri] [Farmani et al 2014] [Feng et al 2020] [Ferreira and Tejeda 2011] [Filyashkin 2025] [Flämig and Schiffmann 2024] [Forrai et al 2025] [Forsmo et al 2013] [Foughali] [Franco and Bezzo 2020] [Frank and Aaseng 2016] [Frau 2022] [Fravolini et al 2007] [Frazzoli et al 2003] [Fregene et al 2010] [Freund and Dierks 1995] [Friedrich et al 2024] [Frost et al 2020] [Frost et al 2012] [Fu et al 2014] [Fu et al 2019] [Fu et al 2019] [Fukuda and Takimoto 2014] [Gallo Olalla] [Gao et al 2024] [Garcia and Casbeer 2017] [Gardi et al 2015] [Garland and Alterman 2004] [Gautam et al 2014] [Gebreyohannes et al 2020] [Geister et al 2017] [George and Ghose 2009] [Gertman et al 2007] [Getir Yaman et al 2025] [Geurts et al 1993] [Giacomin and Hemerly 2022] [Gomez and la Cour-Harbo 2021] [Gong et al 2023] [Gopalswamy and Rathinam 2018] [Gosiewski and Ambroziak 2013] [Graham et al 2023] [Gramajo and Shankar 2016] [Gu and Enoiu 2023] [Gunawardana and Alonso 2013] [Gunetti et al 2013] [Göttfert et al 2022] [Hagele and Soffker 2017] [Hajiyev et al 2015] [Hamidani and Kunz 2018] [Hang and Guo 2026] [Hang et al 2025] [Hangal et al 2015] [Hansen and Blanke 2012] [Hanson et al 2002] [Hao and Quan 2021] [Hashim 2020] [Hastbacka 2003] [Healey and Kim 2005] [Heaton et al 2012] [Herbst and Klöckner 2014] [Herrnberger et al 2005] [Hertel et al 2022] [Hess and Flick 2004] [Hess et al 2010] [Hinchey et al] [Hirsch and Schroeder 2012] [Hirsch and Schroeder 2014] [Ho et al 2017] [Hopchak et al 2022] [Horn et al 2014] [Horn et al 2015] [Horowitz et al 2014] [Hota and Ghose 2014] [How et al 2008] [Hu Zhu et al 2016] [Huang 2004] [Huang 2007] [Huang 2008] [Huang and Liu 2018] [Huang et al 2004] [Huang et al 2005] [Huang et al 2007] [Huang et al 2007] [Huang et al 2009] [Huang et al 2010] [Huang et al 2017] [Huang et al 2020] [Huang et al 2022] [Huang et al 2025] [Hui et al 2017] [Hui et al 2017] [Ibrahim et al 2020] [Iglesis et al 2021] [In-flight demo of multiple 2007] [Insaurralde 2015] [Institute For Defense Analyses Alexandria Va 2008] [Iqbal et al 2026] [Jabr et al 2022] [Jain and Weiskircher 2014] [Jameson et al 2009] [Jamshed et al 2025] [Jaulmes et al 2009] [Shively] [Jenks 2026] [Jessee et al 2017] [Ji and Zhao 2019] [Ji et al 2016] [Jia et al 2026] [Jia et al 2026] [Jiaju Wu et al 2016] [Jiang and Wang 2010] [Jiang Wang et al 2006] [Johnstone and Arntz 1990] [Jun and D’Andrea 2003] [Jung and Ariyur 2013] [Jung and Nag 2020] [Jung and Oh 2022] [Jung et al 2022] [Jung et al 2024] [Senthil Kumar and Shanmugam 2023] [Kahn et al 2010] [Kaidan 2026] [Kala and Warwick 2011] [Kalyan et al 2015] [Kamel and Oussama 2021] [Kanayama and Hartman 1990] [Kang and Prasad 2013] [Kang and Xi] [Karagiannis and Astolfi 2007] [Karas] [Kargar and Kyrki 2022] [Karr et al 2004] [Karásek et al 2026] [Katake and Choi 2010] [Kaupp and Makarenko 2008] [Kawamura and Azimov 2022] [Kawamura et al 2023] [Ke et al 2009] [Keke et al 2014] [Kemeny 2023] [Kendoul 2013] [Kendoul et al 2013] [Keviczky and Balas] [Khaksar et al 2016] [Khan et al 2018] [Khanafseh and Pervan 2007] [Kim et al 2022] [Kim et al 2024] [Kim et al 2025] [Kimmett et al] [Kimmett et al 2002] [Kisačanin 2017] [Klöckner 2014] [Koh and Paranjape 2020] [Konert and Balcerzak 2021] [Kontarev and Belik 2026] [Koo and Sastry 2003] [Kopeikin et al 2013] [Kotov 2006] [Krishnamurthy and Ward 2000] [Kukla 2026] [Kulatunga et al] [Kulatunga et al 2006] [Kurnaz et al] [Kusnirakova and Buhnova 2023] [König et al 2023] [Kügler and Holzapfel 2020] [L.P and Ghosh 2020] [Lacaze 2012] [Lampazzi and Pankok Jr. 2022] [Lan 2026] [Lancovs 2017] [Lauzon et al 2006] [Lavretsky 2002] [Lawrence et al 2008] [Lee 2014] [Lee 2026] [Lee and Ji 2022] [Lee and Kim 2020] [Lee and Kim 2025] [Lee et al 2019] [Lee et al 2025] [Lee et al 2026] [Lee et al 2026] [Leonard et al 2012] [Leylek and Costello 2010] [Li 2023] [Li and Chen 2003] [Li and Ersal 2021] [Li et al 2012] [Li et al 2022] [Li et al 2024] [Li et al 2024] [Li et al 2025] [Li et al 2025] [Li et al 2025] [Li et al 2025] [Li et al 2025] [Lin and Saripalli 2014] [Lin and Wang 2026] [Lin et al 2024] [Linne 2022] [Liu] [Liu 2017] [Liu and Dai 2010] [Liu and Valavanis 2026] [Liu et al 2018] [Liu et al 2020] [Liu et al 2021] [Liu et al 2023] [Liu et al 2023] [Liu et al 2023] [Liu et al 2025] [Liu et al 2025] [Lomuscio 2021] [Lou and Zhang 2013] [Lowe et al 2026] [Lu et al 2025] [Lungu et al 2022] [Luo et al 2025] [Luo et al 2025] [Löbl et al 2018] [Fravolini 2006] [Ma et al 2018] [Ma et al 2026] [Madej 2024] [MahmoudZadeh et al 2018] [MahmoudZadeh et al 2018] [Maitland and McPhee 2018] [Malhotra et al 2025] [Mammadov and Gueaieb 2014] [Mangonneaux] [Martin et al 2015] [Martins et al 2017] [Martínez et al 2013] [Marupudi et al 2026] [Marwaha et al 2009] [Mas et al 2017] [Masaoka and Hashimoto 2024] [Mata and Insa 2024] [Matalonga et al 2022] [Mathur and Atkins 2025] [Matsumaru et al] [Matsumoto et al 2015] [Matsuno and Andreeva-Mori 2023] [Maza et al 2014] [McCormick 2019] [McEneaney and Singh 2004] [McGee and Hedrick 2006] [McManus and Walker 2006] [Meakin 2021] [Mejias 2014] [Mejias and Fitzgerald 2013] [Mejias et al 2021] [Mekala et al 2016] [Melekhin and Khachumov 2021] [Mengying et al 2017] [Merchant 2005] [Mersha et al 2020] [Mezali et al 2022] [Mian et al 2013] [Miller et al] [Miller et al 1999] [Miller et al 2023] [Miloradović et al 2019] [Mission Planning, Simulation and 2006] [Mohseni and Nielsen 2018] [Monckton et al 2007] [Montazeri et al 2021] [Moon and Kim 2003] [Morris et al 2005] [Moshkina and Arkin 2008] [Muhammad 2021] [Mukherjee et al 2023] [Murillo and Lu 2008] [Musau et al 2023] [Mwaffo et al 2024] [Mоchalov 2022] [Narayan 2013] [Neogi et al 2021] [Navickiene et al 2025] [Navigation Control and Signal 2025] [Navigation of autonomous systems 2020] [Nawaj et al 2024] [Nazar and Sadik 2014] [Neace et al 2017] [Nejat and Benhabib] [Nelson and Cox 1990] [Neural networks in autonomous 1994] [Nguyen et al 2018] [Nguyen 2018] [Niendorf et al 2012] [Niendorf et al 2013] [Nikolaidis et al 2025] [Nospes and Stutz 2022] [Nospes and Stütz 2023] [Ntakolia et al 2022] [O’Rourke et al 1999] [Obaideen et al 2024] [Ogorzalek et al 2019] [Ogunbodede et al 2019] [Oktay and Eraslan 2024] [Ollero et al 2007] [Opening up civil airspace 2007] [Ordoukhanian and Madni 2019] [Orhan et al 2026] [Owlia] [Ozalp et al 2013] [Ozerdem 2023] [Padmanabhan and Suresh 2015] [Panerati et al 2026] [Panigrahi and Tripathy 2025] [Papa 2023] [Papa et al 2026] [Parasuraman et al 2026] [Parr et al 2023] [Pastor et al 2009] [Pastor et al 2012] [Patel 2025] [Patel et al 2011] [Patel et al 2021] [Patil] [Paul and Liu 2006] [Rajagopal et al] [Pedrozo 2022] [Pelletier et al 2025] [Pelletier et al 2025] [Peng et al 2016] [Peter et al 2015] [Pfaender et al 2004] [Pham] [Pieniążek 2003] [Pippin 2014] [Pohudina et al 2022] [Ponda et al 2012] [Pouya and Saghafi 2009] [Powell 2001] [Primatesta 2025] [Primatesta et al 2018] [Primatesta et al 2021] [Proctor 2023] [Prohorov et al 2025] [Qamar and Cheok 2023] [Qi et al 2021] [Qu et al 2011] [Qu et al 2013] [Quan et al 2026] [Quayzin and Arbaretier 2009] [Querry] [Rakotonarivo et al 2022] [Ramasamy et al 2015] [Ramos et al 2011] [Ranasinghe and Shen 2009] [Randieri et al 2025] [Rasche et al 2010] [Rasmussen et al 2016] [Rasmussen et al 2018] [Rastgoftar and Atkins 2017] [Ratnabala et al 2025] [Razi] [Redfield and Lennon 2026] [Ren and Beard 2006] [Ren and Chen 2006] [Ren et al 2025] [Reyner and Liem 2026] [Reynolds et al 2010] [Ridder and HandUber 2005] [Rigatos and Busawon 2018] [Ring and Tenorio 2010] [Roberto Mati 2006] [Robustness Against Deception in 2007] [Rocha et al 2023] [Rochford et al 2025] [Rochford et al 2026] [Ross et al] [Ross et al 2005] [Rowe] [Royset 2009] [Rozier et al 2015] [Rucco et al 2015] [Rudas and Haidegger 2021] [Rudnick and Schulte 2016] [Ruff and Calhoun 2013] [Ryan 2012] [Rydzewski and Czarnul 2021] [Rysdyk et al 2005] [Kailash and Sornalakshmi 2023] [Sabatini et al 2014] [Safeer and Costello 2026] [Safety Assurance Objectives for] [Safety Assurance Objectives for] [Safety Assurance Objectives for] [Safety Assurance Objectives for] [Saffre et al 2022] [Sahawneh and Beard 2017] [Samal 2026] [Emerson et al 2026] [Sampedro et al 2016] [Sankararaman 2017] [Sankararaman and Teubert 2017] [Sanni et al 2021] [Santamaría Barnadas] [Savage et al 2006] [Savuran and Karakaya 2015] [Savuran and Karakaya 2015] [Schacht-Rodriguez et al 2019] [Scheidt 2014] [Scheidt et al 2026] [Scherer and Singh 2011] [Schieferdecker 2007] [Schmitt and Schulte 2015] [Schmitt and Schulte 2015] [Schopferer and Adolf 2014] [Schopferer and Benders 2020] [Schopferer and Pfeifer 2015] [Schopferer et al 2018] [Schrage 2023] [Schroeder and Treutterer 1992] [Schumann et al 2013] [Schumann et al 2015] [Schumann et al 2019] [Scrapper et al 2016] [See et al 2017] [Segor et al 2025] [Seibel and Farines 2002] [Seitzer 2003] [Sellner et al] [Seok 2019] [Shah 2026] [Shaham] [Shanshan et al 2020] [Sharkey 2010] [Sharma and Jain 2024] [Shaw and Bevly 2018] [She et al 2024] [Shet 2020] [Shetiya et al 2024] [Shi and Zhang 2022] [Shi et al 2012] [Sieber et al 2023] [Singh 2000] [Singh and Kamal 2025] [Sinha and Kumar 2024] [Sislak et al 2007] [Smith and Willcox 2005] [Smith et al 2026] [Soliday et al 2001] [Song et al 2023] [Song et al 2026] [Sonmez et al 2015] [Sorton and Hammaker 2005] [Sprengart et al 2017] [Stambler et al 2018] [Stanley 2005] [Stecz and Chodnicki 2022] [Study on Deep Learning 2023] [Su and Wang 2018] [Sun and Pack 2016] [Sun and Zhang 2013] [Sun and Zhang 2013] [Sun et al 2022] [Sun Xun and Zhang Xinguo 2012] [Sundar and Rathinam 2012] [Survivability of Unmanned Autonomous 2016] [Sánchez López] [Tan et al 2018] [Tandale et al 2005] [Tang 2025] [Tang and Jiang 2025] [Tang et al 2008] [Tang et al 2011] [Tang et al 2022] [Tankasala et al 2022] [Taraba et al 2018] [Taranto and Abdulrahim 2023] [Target Tracking and Navigation 2025] [Tarhan et al 2014] [Tellez guzman] [The algorithm of the 2020] [The Case for Ethical 2016] [The Ethics of Autonomous 2016] [Theissing and Schulte 2013] [Thomessen and Nagarajan 2026] [Tian et al 2024] [Tinoco] [Tkachenko and Hrebeniuk 2025] [Tomczyk and Gruszecki 1999] [Torens et al 2014] [Torens et al 2018] [Torkjazi and Raz 2026] [Torno et al 2014] [Toupet and Mettler 2006] [Toward Intelligent Robot Systems 1989] [Tošić 2023] [Tošić Predrag and Vilalta Ricardo 2010] [Tsoukalas et al 2026] [Tsourveloudis and Doitsidis 2025] [Tsukerman et al 2017] [Tunc and Hariri 2022] [Tweedale Jeffrey 2012] [Unmanned Autonomous Vehicle 2016] [Unmanned Systems Terminology Based] [Unnikrishnan and Prasad 2004] [Usach Molina] [Vachon et al 2002] [Vachon et al 2003] [Valasek et al 2002] [Valavanis 2017] [Valavanis and Vachtsevanos 2014] [Valavanis and Vachtsevanos 2014] [Valenti Clari et al] [Van den Bergh et al 2016] [Van Manen et al 2025] [Vanualailai et al 2013] [Venugopalan et al 2012] [Vepa 2020] [Vepa 2026] [Verification and Validation of 2017] [Verification of Autonomous Systems 2026] [Verifying Autonomous Systems 2023] [Dulchinos et al] [Vidan 2016] [Vilchis Medina et al 2017] [Virgil Petrescu 2019] [Visnevski and Castillo-Effen 2010] [Wagner et al 2025] [Wallar et al 2014] [Waltz et al 1983] [Wang and Liu 2012] [Wang and Wang 2020] [Wang et al 2010] [Wang et al 2012] [Wang et al 2014] [Wang et al 2018] [Wang et al 2020] [Wang et al 2022] [Wang et al 2023] [Wang et al 2024] [Wang et al 2025] [Wang et al 2025] [Wang et al 2026] [Waterson 2019] [Weatherington and Wilson 2003] [Webster et al 2012] [Weiskopf et al 2002] [Weyrer and Rinner 2018] [Wickramasuriya et al 2026] [Wilson et al 2015] [Wise and Lavretsky 2009] [Wittels et al 2025] [Wotawa 2012] [Wu and Chen] [Wu and He 2022] [Wu and Mueller 2018] [Wu et al 2009] [Wu et al 2018] [Wu et al 2020] [Wu et al 2022] [Wu et al 2023] [Wu et al 2025] [Xi and Baras 2006] [Xi and Liu 2020] [Xiao and Li 2023] [Xie et al 2019] [Xiong et al 2022] [Xu 2018] [Xu 2018] [Xu et al 2017] [Xu et al 2020] [Xue and Jiang 2022] [Yadav and Bhargava 2026] [Yadav and Tanner 2021] [Yan and Tan 2013] [Yan et al 2018] [Yan et al 2018] [Yan et al 2022] [Yang et al 2014] [Yang et al 2018] [Yang et al 2020] [Yang et al 2024] [Yang et al 2025] [Yang et al 2025] [Yao et al 2023] [Yavnai 2003] [Yeh 2018] [Yel and Bezzo 2019] [Yeşilbaş 2025] [Yi et al 2023] [Yomchinda 2015] [Yoon et al 2009] [You and Shim 2010] [Yu 2017] [Yu and Dingcheng 2023] [Yu et al 2021] [Yu et al 2021] [Yuan] [Zakharin and Ponomarenko 2019] [Zhai et al 2024] [Zhang and Hwang 2017] [Zhang and Hwang 2019] [Zhang and Liu 2011] [Zhang and Liu 2018] [Zhang and Zhao 2020] [Zhang et al 2011] [Zhang et al 2020] [Zhang et al 2020] [Zhang et al 2023] [Zhang et al 2026] [Zhao and Huang 2018] [Zhao and Zhu 2016] [Zhao and Zhu 2016] [Zhao et al 2018] [Zhao et al 2019] [Zhao et al 2021] [Zhao et al 2026] [Zheng et al 2020] [Zheng et al 2026] [Zhihao and Ruyi 2011] [Zhikai 2026] [Zhipu Jin and Bertozzi 2007] [Zhipu Jin et al 2006] [Zhipu Jin et al 2006] [Zhou et al 2017] [Zhou et al 2022] [Zhou et al 2023] [Zhou et al 2024] [Zhou et al 2024] [Zhou et al 2025] [Zhu and Wang 2011] [Zhu et al 2018] [Ziye et al 2023] [Zokowski 2020] [Zou et al 2024] [Çoban 2023]

Multi-vehicle coordination and cooperative control

The other half of the fan-out problem, approached from the machine’s side. Cooperative control, task allocation, consensus, distributed decision making, formation flight and swarm coordination. Autonomy raises the fan-out by raising neglect time, and this cluster is where the algorithms that do so live. Eighteen records sit here because particle swarm optimisation shares the word swarm, and they are kept because their subjects, most of them path planning, are on this article’s subject.

718 records. [A Swarm of UAVs 2023] [Abas et al 2013] [Abdallah and Lesser 2006] [Abdessameud and Tayebi 2013] [Abdessameud and Tayebi 2013] [Abdessameud and Tayebi 2018] [Abdessameud et al 2012] [Abramson et al 2007] [Abzal et al 2026] [Adaptive Backstepping Consensus Control 2026] [Aguiar 2024] [Ahn 2020] [Ajorlou et al 2011] [Alarcon Herrera and Chen 2012] [Alejo et al 2013] [Ali Dehghani and Bagher Menhaj 2016] [Ali et al 2025] [Alighanbari and How] [Allen et al 2002] [Aloboud and Kurdi 2025] [An and Kim 2025] [Andriole] [Antony et al 2024] [Anum et al 2022] [Arogeti and Ailon 2023] [Ashokaraj 2005] [Atkinson 2003] [Avetisyan et al 2023] [Baek and York 2020] [Bailey 2008] [Bakirci and Ozer 2023] [Baliyarasimhuni and Beard 2007] [Ballam] [Bayraktar et al 2004] [Bayraktar et al 2004] [Behjat et al 2019] [Belkadi et al 2015] [Belta 2012] [Belta 2012] [Benini et al 2011] [Bereg et al 2015] [Bian et al 2018] [Binetti et al 2013] [Blake 2002] [Bogdan 2015] [Bolting et al 2017] [Borah 2022] [Borrelli et al 2006] [Braasch 2006] [Burdakov et al 2016] [Butler and Hays 2015] [Cabral et al 2023] [Cai and Zhao 2026] [Cai et al 2018] [Cai et al 2021] [Cai et al 2023] [Carmel and Markovitch 1999] [Catak et al 2025] [Cebeci] [Cetin and Yilmaz 2014] [Chalmers et al 2004] [Chandler et al 2003] [Chapa-Garcia et al 2016] [Chapter 13 Consensus in 2016] [Chaudhary et al 2022] [Chen and Niu 2026] [Chen and Wang 2015] [Chen and Zhao 2019] [Chen et al 2016] [Chen et al 2016] [Chen et al 2017] [Chen et al 2017] [Chen et al 2020] [Chen et al 2022] [Chen et al 2022] [Chen et al 2024] [Chen et al 2024] [Chen et al 2026] [Cheng et al 2014] [Cheng-Lin and Fei 2015] [Chepizhenko et al 2023] [Chethan and Kar 2022] [Chopra and Ghose 2022] [Cloutier 2010] [Consensus Algorithms for Double-integrator 2008] [Consensus Algorithms for Rigid 2008] [Consensus Algorithms for Single-integrator 2008] [Consensus Tracking of Multi-Agent 2020] [Consoli 2016] [Control of cooperative unmanned] [Cooper and Schierman 2014] [Crosscombe and Lawry 2016] [Cui et al 2022] [Cunningham and Roberts] [Hanson et al 2002] [D’Andrea 2008] [Dahlquist et al 2023] [Dai and Cochran 2009] [Dai et al 2011] [Dam] [Damien 2009] [Darbha et al 2013] [Darrah et al 2005] [Darvish et al 2018] [Dawkins et al 2018] [De Cubber et al 2023] [de Oliveira et al 2016] [de Sousa et al 2004] [de Vries and Subbarao 2011] [Decision Making and Health 2010] [Deghat et al 2018] [Dehghani and Menhaj 2016] [DeJarnette-Crumsey et al 2022] [del Ser et al 2024] [DeLima and Pack 2008] [Delle Fave et al 2012] [Deming and Perlovsky] [Deng and Fang 2025] [Deng et al 2025] [Derkach and Chudnov 2025] [Devi et al 2017] [Ding] [Ding et al 2021] [Distributed Decision Making 1990] [Diyachuk and Chekareva 2025] [Doan] [Dobrokhodov 2011] [Doherty et al 2013] [Dong and Geng 2014] [Dong and Gu 2026] [Dong et al 2009] [Dong et al 2011] [Dong et al 2024] [Donkels and Voigt 2019] [Du 2024] [Du et al 2012] [Du et al 2016] [Duan 2013] [Duan and zhang 2020] [Duan et al 2018] [Dyvak et al 2024] [Egerstedt et al 2014] [Egorov and Shpilman 2022] [El-Ferik 2020] [Emile et al 2020] [Enright et al 2014] [Ergezer and Leblebicioglu 2012] [Eun and Bang 2004] [Eun and Bang 2006] [Eun and Bang 2009] [Evaluation of Failure-Free Indicators 2024] [Fabra Collado] [Fagnani 2013] [Fahimi 2005] [Fang et al 2025] [Farmani et al 2015] [Farzaneh] [Fatima and Wooldridge 2001] [Feng et al 2013] [Feng et al 2021] [Feng et al 2023] [Fierro et al] [Fischhoff and Johnson 1996] [Fitzpatrick 2013] [Floriano et al 2019] [Foo et al 2006] [Foo et al 2007] [Formation and adjustment of 2018] [Frazzoli 2002] [Frederick et al 2001] [Frederick et al 2001] [Frederick et al 2001] [Frederick et al 2001] [Frische and Ludtke 2013] [Frommknecht and Surynek 2024] [Fyfe and Johnson] [Ganapathi Subramanian et al 2023] [Gao and Li 2019] [Gaynor and Coore 2014] [Geng et al 2014] [George et al 2010] [Ghose 2010] [Giles et al 2021] [Gionfra et al 2017] [Gkesoulis and Psillakis 2020] [Glazunov 2017] [Global Consensus of Multi-Agent 2014] [Gomez et al 2020] [Goncharenko et al 2019] [Gong et al] [Gong et al 2022] [Gruber et al 2015] [Gu and Veloso 2006] [Gu et al 2023] [Guan et al 2012] [Guijarro Reyes et al 2018] [Guo et al 2019] [Guo et al 2019] [Guo et al 2019] [Guo et al 2021] [Hafez and Kamel 2016] [Hafez et al 2015] [Hafez et al 2017] [Hammarbäck 2022] [Han] [Han and Chesi 2013] [Han et al 2009] [Han et al 2017] [Han et al 2019] [Han et al 2021] [Han et al 2022] [Haoran et al 2015] [Haque et al 2013] [Hari et al 2020] [Health Monitoring and Adaptation 2010] [Hentout et al 2019] [Heonyoung Lim et al 2008] [Hino and Tsuchiya 2013] [Horn et al 2009] [Hou et al 2021] [Hou et al 2025] [Hu] [Hu et al 2019] [Hu et al 2024] [Hu et al 2025] [Huang et al 2017] [Huang et al 2018] [Huang et al 2018] [Huang et al 2018] [Huang Huang and Qinghe Wu 2010] [Huhn et al 2009] [Huo et al 2021] [Hussain et al 2025] [Hutchins et al 2010] [Im and Kim 2023] [Incze et al 2015] [Iskandarani et al 2014] [İnan and Ceylan 2024] [Jaimes et al 2008] [Jain et al 2017] [Javed et al 2025] [Jia 2016] [Jia and Gao 2026] [Jia et al 2016] [Jian Chen et al 2006] [Jianan Wang and Ming Xin 2013] [Jiang and Jiang 2008] [Jin 2016] [Jing and Chen 2020] [John and Sundaram 2025] [Joshi and Mehta 2024] [José Olivieri De Souza] [Kabanov and Mitin 2025] [Kaduk et al 2023] [Kalra and Martinoli] [Kalra et al 2017] [Kalwa 2009] [Kalwa 2009] [Kang et al 2019] [Karaman et al 2014] [Karimoddini et al 2014] [Karteek et al 2017] [Kaur et al 2026] [Kelner and Ziółkowski 2020] [Kenyeres and Kenyeres 2021] [Khamseh et al 2014] [Khan and Khorasani 2010] [Khan et al 2025] [Khan et al 2025] [khan et al 2025] [Khaneghaei et al 2026] [Khelifi and Butun 2022] [Kim and Bang 2016] [Kim and Morrison 2013] [Kim et al 2015] [Kim et al 2019] [Kim et al 2020] [Kimathi and Lantos 2022] [Kladis and Tsourveloudis 2020] [Kladis et al 2011] [Kocaman 2026] [Kok and Rajendran 2020] [Korecki and Hoika 2026] [Korsah G. Ayorkor et al 2010] [Krizek et al 2022] [Kucuksayacigil 2023] [Kumar et al 2021] [Labella et al] [Lau and Naeem 2012] [Leonard et al 2013] [Li and Han 2014] [Li and Jiang 2008] [Li and Ma 2020] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li and Zhisheng 2017] [Li et al 2006] [Li et al 2017] [Li et al 2020] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2021] [Li et al 2024] [Li et al 2024] [Li et al 2025] [Li et al 2025] [Li et al 2025] [Li et al 2026] [Li Qin and Zhongping 2006] [Lian and Deshmukh 2009] [Liang et al 2014] [Lin 2002] [Lindsay and Sun 2020] [Liu] [Liu and Bucknall 2018] [Liu and Hao 2023] [Liu and Li 2025] [Liu and Liu 2016] [Liu and Liu 2016] [Liu and Liu 2016] [Liu and Liu 2016] [Liu and Sun 2021] [Liu and Zhao 2016] [Liu et al 2015] [Liu et al 2018] [Liu et al 2018] [Liu et al 2020] [Liu et al 2020] [Liu et al 2022] [Liu et al 2022] [Liu et al 2022] [Lu and Chen 2026] [Luo et al 2011] [Luo et al 2025] [Lv et al 2026] [Lyshevski 2018] [Lyu et al 2016] [Ma and Qi 2023] [Ma et al 2013] [Ma et al 2023] [Malhotra et al 2024] [Malhotra et al 2026] [Manikandan and Sriramulu 2022] [Mann et al 2023] [Mansouri et al 2015] [Matlock et al 2009] [Vaughan and Kelley] [McIngvale and Dudley 1990] [McInnes 2003] [McLain and Beard 2004] [McLain et al 2000] [Merino et al] [Merino et al 2014] [Mesbahi 2015] [Meyer and Schulte 2020] [Miao et al 2015] [Miao et al 2017] [Miller 2006] [Mingfeng Zhang and Liu 2012] [Mingfeng Zhang and Liu 2013] [Misra et al 2019] [Missing-Value] [Mo et al 2025] [Modares et al 2019] [Mohamed et al 2013] [Monwar et al 2018] [Moon et al 2014] [Moore 2011] [Morando et al 2024] [Morral et al 2014] [Morris and Rouse 1986] [Mukherjee] [Mukherjee and Namuduri 2019] [Mukhopadhyay] [Multiple Heterogeneous Unmanned Aerial 2007] [Mwanandiye 2023] [Na et al 2023] [Nangia and Palmer 2007] [Nangia and Palmer 2007] [Nazarov et al 2021] [Negron et al 2010] [Newcomb and Ning 2019] [Nguyen et al 2024] [Ni et al 2024] [Nigam 2014] [Nigam and Kroo 2008] [Nikolos and Tsourvelouds] [Nunes et al 2017] [Ogbebor and Meng 2021] [Oh et al 2017] [Ok and Ozsoyeller 2025] [Okolo et al 2014] [Ondracek et al 2015] [Orozco et al 2026] [Osman et al 2006] [Osumi et al] [Ousingsawat 2006] [Overview of Consensus Algorithms 2008] [Overview of Distributed Decision-Making 2016] [Pack and York 2008] [Pack et al] [Pack et al 2005] [Page 2025] [Pandey] [Pandey and Jha 2023] [Park and Kim 2026] [Path Planning for Multiple 2010] [Paul et al 2025] [Peng Cheng and Kumar 2008] [Peterson and Paley 2009] [Phadke et al 2024] [Pinon et al 2022] [Pinto Neto] [Pippin and Christensen 2013] [Plett et al] [Popov et al 2022] [Poudel and Moh 2022] [Proskurnikov and Zabarianska 2024] [Qin et al 2021] [Qiu] [Qu and Girard 2010] [Giele et al 2015] [Rabbath and Léchevin 2010] [Ragi and Chong 2013] [Ramasamy et al 2023] [Rasmussen and Chandler] [Rasmussen and Kingston 2015] [Rasmussen and Schumacher 2007] [Rasmussen et al 2002] [Rasmussen et al 2006] [Rayes and Çetin 2025] [Redundant Robots Control Using 2021] [Ribichini and Frazzoli 2003] [Richards et al 2002] [Ridley et al 2014] [Roberge et al 2024] [Roberts and Ferrazano 2004] [Robinson et al 2021] [Robust consensus control of 2020] [Robust consensus control of 2020] [Rojo-Rodriguez et al 2019] [Ronchieri and Innocenti 2007] [Rosa and Belo 2021] [Rosa et al 2015] [Roth and Schulte 2022] [Roth and Schulte 2022] [Roussos et al 2008] [Ru and Subbarao 2017] [Sadraey 2018] [Sadraey 2025] [Saeed Mirza] [Safe Coordinated Maneuvering of 2016] [Saif et al 2014] [Sakaguchi and Ushio 2018] [Sakamaki et al 2017] [Salamat and Tonello 2017] [Samiei and Sun 2020] [Samiei et al 2019] [Saska et al 2013] [Sauter et al 2005] [Scheidt et al] [Schneeweiss 1999] [Schneeweiss 2003] [Schneeweiss 2003] [Schumacher 2010] [Schweim et al 2024] [Sease et al 2023] [Second-Order Consensus of Continuous-Time 2021] [Seo et al 2020] [Shaferman and Shima 2015] [Shahid et al 2022] [Sharma et al 2012] [Shen et al 2014] [Sherstjuk 2015] [Sherstjuk et al 2019] [Shi and Yu 2023] [Shi et al 2022] [Shima et al 2014] [Shin et al 2017] [Shively et al 2011] [Shiyan et al 2016] [Shiyou et al 2011] [Shmelova and Bondarev 2019] [Shmelova et al 2025] [Shobeiry] [Sidorov et al 2014] [Silva] [Silva and Branco 2025] [Silva et al 2012] [Singh et al 2007] [Singh et al 2013] [Singh et al 2023] [Singh et al 2024] [Skantzikas et al 2024] [Song] [Song et al 2020] [Sperling et al 2008] [Spritzer] [Spry et al] [Stanković et al 2010] [Steiner et al 2019] [Stojkovic and Katic 2017] [Su et al 2024] [Sujit and Beard 2007] [Sujit and Beard 2009] [Sujit and Ghose] [Sujit et al 2006] [Sujit et al 2008] [Sulak et al 2017] [Sun et al 2024] [Sundar et al 2017] [Sunil et al 2026] [Tahir 2024] [Taj et al 2025] [Taj et al 2025] [Tancredi et al 2013] [Tang et al 2022] [Tao et al] [Teague et al 2008] [Teo et al 2004] [Thakra et al 2025] [Thakra et al 2025] [The Control of Multiple 2026] [Thomassey and Arlen 2021] [Tian et al 2025] [Timis and Dulf 2024] [Tousi and Khorasani 2014] [Trotsyuk and Lesohorskyi 2026] [Tsang] [Tse Min Chen and Luo] [Tsourdos et al 2010] [Turner 2018] [Unmanned Aerial Vehicle Collaboration 2026] [Unmanned Aerial Vehicles Swarm 2025] [Valavanis 2005] [Van Dyke ParunaK et al 2002] [Van Dyke Parunak et al 2005] [Vandermeulen et al 2019] [Varada] [Vemprala and Saripalli 2018] [Viana et al 2015] [Voigt et al 2019] [Volovoda 2024] [Wan et al 2024] [Wang] [Wang 2019] [Wang and Hong 2010] [Wang and Li 2016] [Wang and Liu 2011] [Wang and Wang 2017] [Wang and Xin 2012] [Wang and Yin 2021] [Wang and Zhang 2022] [Wang and Zhe Gao 2014] [Wang et al] [Wang et al 2016] [Wang et al 2017] [Wang et al 2017] [Wang et al 2018] [Wang et al 2018] [Wang et al 2019] [Wang et al 2019] [Wang et al 2020] [Wang et al 2020] [Wang et al 2020] [Wang et al 2020] [Wang et al 2021] [Wang et al 2021] [Wang et al 2021] [Wang et al 2022] [Wang et al 2023] [Wang et al 2024] [Wang et al 2024] [Wang et al 2024] [Wang et al 2025] [Wang et al 2025] [Wang et al 2026] [Waslander 2013] [Watanabe 2013] [Watson et al] [Weiss 2010] [Wellman 2000] [Wen et al 2013] [Wen et al 2023] [Weng et al 2014] [Whitzer et al 2016] [Wilde and Alonso-Mora 2023] [Wolfe et al 1996] [Wolfe et al 2020] [Wu and Han 2019] [Wu et al 2023] [Wuwer et al 2025] [Xiangyu Wang and Shihua Li 2015] [Xiaohong et al 2025] [Xie et al 2020] [Xie et al 2026] [Xie et al 2026] [Xie et al 2026] [Xie et al 2026] [Xie et al 2026] [Xie et al 2026] [Xiong et al 2024] [Xu and Carrillo 2015] [Xu and Zhu 2025] [Xu et al 2011] [Xu et al 2013] [Xu et al 2020] [Xu et al 2021] [Xu et al 2024] [Xu et al 2025] [Xuanyuan et al 2022] [Xue et al 2024] [yaghoubi 2024] [Yan and Zheng 2006] [Yan et al 2022] [Yan et al 2026] [Yang and Wang 2020] [Yang and Wang 2022] [Yang et al 2012] [Yang et al 2016] [Yang et al 2022] [Yang et al 2024] [Yang et al 2025] [Yang et al 2025] [Yang et al 2025] [Yang et al 2026] [Yao et al 2018] [Yao et al 2024] [Yasar et al 2006] [Ye 2025] [Yen-Chen Liu 2013] [Yin et al 2022] [Yin et al 2023] [Yinqiu Wang et al 2013] [Yongming Yang et al 2009] [Yongxing Hao et al] [Yoo 2018] [Yoo et al 2021] [Yoon and Kim 2017] [Yoon and Kim 2019] [Yoon et al 2022] [York and Pack 2011] [York et al] [Young Hwan Chang et al 2011] [Yu] [Yu et al 2015] [Yu et al 2018] [Yu et al 2022] [Yu et al 2023] [Yu et al 2023] [Yu et al 2024] [Yue et al 2022] [Zarzhitsky et al 2009] [Zeng and Hu 2014] [Zhai et al 2009] [Zhai et al 2026] [Zhang] [Zhang 2006] [Zhang 2015] [Zhang 2020] [Zhang 2026] [Zhang and Chen 2016] [Zhang and Mehrjerdi 2013] [Zhang and Parker 2012] [Zhang and Xu 2026] [Zhang and Zhai 2021] [Zhang et al 2016] [Zhang et al 2017] [Zhang et al 2017] [Zhang et al 2017] [Zhang et al 2020] [Zhang et al 2020] [Zhang et al 2020] [Zhang et al 2021] [Zhang et al 2022] [Zhang et al 2022] [Zhang et al 2024] [Zhang et al 2024] [Zhang et al 2025] [Zhao] [Zhao 2013] [Zhao and Wang 2019] [Zhao and Wang 2023] [Zhao and Zhou 2023] [Zhao et al 2024] [Zhao et al 2025] [Zheng et al 2004] [Zheng et al 2014] [Zheng et al 2019] [Zheng et al 2026] [Zhiqiang and Wu 2017] [Zhong and Cao 2022] [Zhou and Qin 2024] [Zhou and Qin 2025] [Zhou et al 2020] [Zhou et al 2024] [Zhou et al 2024] [Zhou et al 2025] [Zhu and Mao 2021] [Zhu and Qin 2023] [Zhu and Wen 2019] [Zhu et al 2017] [Zhuoning Dong et al 2016] [Zi’ang 2025] [Zou et al 2021] [Özcan and Thomas-friedrich 2026] [Švancara and Barták 2019]

Tailless configurations and their control effectors

The configuration, and the thread this article inherits from its predecessor. Tailless and flying wing aerodynamics, elevons, split drag rudders, control allocation among redundant effectors, and yaw by thrust vectoring. The X-45A flew the configuration the previous article in this series analysed and found wanting for an operational fighter, and it flew it sixty-four times.

499 records. [Acosta et al 2015] [Adams et al 1994] [Adler and Martins 2023] [Adler and Martins 2024] [Agenbag et al 2009] [Ahmed et al 2025] [Ahuja et al 2026] [Ale Isaac et al 2023] [Alex 2014] [Ali et al 2012] [Ali et al 2020] [Ali et al 2024] [Ali et al 2025] [Ali et al 2026] [Alipour et al 2022] [Almuina Pica et al 2022] [Altunkaya and Özkol 2025] [Alviani et al 2022] [Alyanak and Pendleton 2014] [Amanuddin and Dey 1980] [Ammar and Trépanier 2014] [An analysis of gap 1981] [Ang and Ng 2026] [Arya et al 2026] [Asaro and Vos 2025] [Asaro et al 2025] [Atesoglu and Ozgoren 2011] [Atesoglu and Özgören 2008] [Atmaca et al 2026] [Bainsla et al 2021] [Banerjee 1984] [Banerjee 1988] [Banerjee 1988] [Barker and Balas 1999] [Barnhouse et al 2025] [Begin 1983] [Bergman 1979] [Berry 1998] [Bie et al 2017] [Benson and Orr] [Bishop 1961] [Bolitho and Jacob 2008] [Boskovic and Mehra 1999] [Boskovic and Mehra 2000] [Boskovic et al] [Bourdin et al 2007] [Bradley et al 2012] [Brinker and Wise 1998] [Brinker and Wise 1999] [Brinker and Wise 2000] [Brodsky and Luby 2013] [Buch and George M. 2010] [Buffington 1997] [Buffington 1999] [Buffington 1999] [Buffington et al 1993] [Buffington et al 1994] [Bursey and Dickinson 1990] [Calise 2000] [Calise et al 1998] [Cameron and Princen 2000] [Capone and Mason 1986] [Carlsson 2003] [Carlsson 2005] [Carlsson and Kuttenkeuler 2003] [Cen et al 2014] [Chan et al 2024] [Chen et al 2026] [Chi et al 2022] [Chudoba and Cook 2003] [Cohn et al 1985] [Colgren and Loschke 2008] [Collins et al 2004] [Collins Jr 2005] [Cong et al 2023] [Control Allocation and Flight 2016] [Control Surface Sizing Criteria 2010] [Cornelius and Lucius 1993] [Corona-Sanchez and Rodriguez-Cortes 2015] [Costes 1988] [Cox et al 1949] [Cunha et al 2018] [Cusher and Gopalarathnam 2006] [Cusher and Gopalarathnam 2012] [Dae-yeon Won and Tahk 2008] [Dakka and Johnson 2019] [Davis and Hines 1976] [de Becdelievre and Kroo 2021] [Deere 2003] [Deere et al 2003] [DeLaurier 2022] [Denieul] [Denieul et al 2018] [Deslich et al 2021] [Durmus 2021] [Durmuş 2025] [Dwyer and Lutze 1993] [Eberhardt and Ward 1999] [Ebrahimi Fakhari et al 2024] [Elenin 2021] [Ericsson and Beyers 2002] [Erwin et al 1964] [Esker and Sedrick 1972] [Experimental investigation of synthetic 2023] [Fernandes and Maldonado 2024] [Fernando 2018] [Firdaus Mohamad et al 2010] [Flamm et al 2006] [Flow Field Investigation of 2023] [Formation of aerodynamic outline 2008] [Friedl 2001] [Friehmelt 1996] [From Tube and Wing 2013] [Frost et al 2009] [Gal-Or 1994] [Gal-Or 2003] [Gamble and Inman 2016] [Gang et al 2019] [Gao and Smith 2020] [Gao et al 2011] [Gauvrit-Ledogar et al 2018] [Gebbie et al 2005] [Gill 1973] [Gill 1974] [Gillard et al 1997] [Gingerich et al 2026] [Goldberg et al 2017] [Granasy 1995] [Gregory et al 2007] [Ground testing of X-48B 2007] [Gu et al 2008] [Guiler] [Guiler and Huebsch 2005] [Guiler and Huebsch 2005] [Guo et al] [Gupta 2025] [Gupta 2026] [Guruswamy 1991] [Guruswamy 1992] [Hammett et al] [Hammond et al 1995] [Handa and Srinivas 2022] [Hansmann and Stumpf 2025] [Hansmann and Stumpf 2026] [Harley et al 2009] [Harris and Harris 1997] [Hauser 1999] [Hauser and Jadbabaie] [He et al 2023] [Hirano et al 2019] [Hiroyuki Takano et al 2007] [Hoffler et al 1988] [Hong and Ma 2016] [Hou et al 2022] [Howard et al 2002] [Huang and Wei 2025] [Huang et al 2025] [Huber 1995] [Huber 2022] [Huber et al 2012] [Huijts and Voskuijl 2015] [Humphreys-Jennings et al 2019] [Hunter and Deere 1999] [Imlay 1986] [In-Flight Thrust Determination for] [Iniguez de Heredia and Friehmelt 2005] [Isaac et al 2024] [Ishrak et al 2024] [Islam et al 2024] [Izquierdo] [Jackson 2023] [Jadbabaie and Hauser 2002] [Jiang et al 2019] [Jiayu et al 2024] [Jiguang Li et al 2016] [Jiméneze and Icaza 2000] [Jo et al 2015] [Jo et al 2016] [Johnston 2016] [Jun 2023] [Jung Hoe and Nik Mohd 2014] [Jyothi et al 2006] [Jyothy and John Wessley 2023] [Kale and Pendharkar 2021] [Karimi Kelayeh and Djavareshkian 2024] [Karpuk et al 2020] [Karpuk et al 2023] [Kashiwagura and Shimoyama 2018] [Kazarin et al 2017] [Keidel et al 2019] [Keidel et al 2020] [Kentfield 1975] [Khadiv et al 2025] [Kikkawa and Uchiyama 2017] [King and Schnelker 1970] [Klafin 1988] [Kleemann et al 2020] [Kok et al 2010] [Kolonay and Eastep 2006] [Kolonay et al 2004] [Kowal 2002] [Kumar and Khalid 2017] [Kumar et al 2020] [Kumaran et al 2021] [Kwiek 2019] [La Rocca et al 2002] [Larkin and Coates 2017] [Latif et al 2017] [Lee et al 2018] [Lemko and Molodchyk 2015] [Li and Cai 2026] [Li et al 1996] [Li et al 2014] [Li et al 2016] [Li et al 2017] [Li et al 2018] [Li et al 2026] [Liebeck 2003] [Liebeck 2004] [Liebeck 2008] [Lim et al 2025] [Lin et al 1998] [Lin et al 2021] [Liu and Hu 2014] [Liu and Zhang 2022] [Liu et al 2021] [Liu et al 2026] [Loechert et al 2018] [Lu and Wu 2009] [Lucena and Goncalves 2020] [Miller and Pei] [Luo et al 2025] [Lyu et al 2023] [Lyu et al 2023] [Lyu et al 2024] [Nasir et al 2022] [Ma and Wang 2009] [Ma et al 2019] [Mader and Martins 2010] [Madhanraj et al 2025] [Mahantesh Katagi et al 2015] [Maimako et al 2026] [Malcolm and Ng 1990] [Mansor et al 2019] [Mardanpour and Hodges 2013] [Mardanpour and Hodges 2013] [Mardanpour and Hodges 2014] [Mardanpour and Hodges 2015] [Mareca Rios et al 2023] [Marques 2013] [Mascraenhas 2020] [Mason and Crowther 2004] [Matamoros and de Visser 2018] [McKeehen 1998] [McKeehen et al 1997] [Meckstroth and Blake 2015] [Meckstroth and Ordóñez 2020] [Meckstroth and Ordóñez 2020] [Meheut et al 2012] [Meng et al 2020] [Merceruio] [Metin et al 2023] [Michal 1998] [Miller 1983] [Mioduska 2016] [Modeling and Control for 2015] [Mohamad et al 2012] [Mohan and Kumar 2023] [Mohan and Kumar 2024] [Mohan and Kumar 2025] [Montgomery and Hunsaker 2022] [Morris 1992] [Morris and Tigner 1995] [Morris et al 2014] [Mukhopadhyay 2005] [Murray 1949] [Muñoz] [Myatt et al 1998] [Nangia and Palmer 2002] [Nasir et al 2010] [Nasir et al 2012] [Nazim et al 2026] [Neely et al 2007] [Nguyen et al 2025] [Nie et al 2020] [Niestroy 2025] [Niestroy et al 2017] [Nieto-Wire and Sobel 2007] [Nieto-Wire and Sobel 2009] [Oganyan and Loginov 2025] [Okonkwo and Jemitola 2022] [Okonkwo and Smith 2016] [Oosedo et al 2022] [Orhan and Subbarao 2021] [Osedo et al 2023] [Pan and Huang 2018] [Pan and Huang 2019] [Paranjape and Chung 2010] [Parello] [Park et al 2015] [Park et al 2016] [Park et al 2017] [Pastír and Čičváková 2020] [Pate 2013] [Paudel 2016] [Paul et al 1997] [Paulus et al 2013] [Pedro and Tshabalala 2017] [Pedro and Tshabalala 2017] [Peigin and Epstein 2006] [Peigin and Epstein 2006] [Peng et al 2014] [Peterson and Grant 2011] [Potsdam et al 1997] [Prisacariu 2019] [Protz and Sparks 1998] [Qi et al 2017] [Qi et al 2018] [Qian and Alonso 2021] [Qin 2002] [Qin et al 2005] [Qin et al 2007] [Qu et al 2017] [Rahman et al 2025] [Rahulin 2025] [Rajput et al 2014] [Rajput et al 2015] [Ramprasadh and Devanandh 2015] [Ranjan et al 2026] [Reigelsperger et al 1995] [Reist and Zingg 2015] [Reist and Zingg 2016] [Reist et al 2022] [Resta et al 2021] [Rezazadeh Movahhed and Ali Hamed 2021] [Richter et al 2021] [Richter et al 2022] [Riethausen 2026] [Ro 2006] [Rojas Carvajal and Amitay 2023] [Rojas Carvajal and Amitay 2025] [Rojas Carvajal et al 2022] [Rossetti and Beblo 2022] [Rui et al 2007] [Ruseno 2021] [Saephan and van Dam 2006] [Saephan and van Dam 2006] [Sanders 1997] [Sanghi et al 2022] [Santoso et al 2008] [Saucez] [Saucez and Boiffier 2012] [Scalera and Durham 1999] [Schirmer and Capone 1989] [Schuette et al 2018] [Scuderi 2022] [Sgueglia] [Sharma and Hosder 2024] [Shayan and Van Kampen 2021] [Shearwood et al 2019] [Shearwood et al 2020] [Shearwood et al 2020] [Shearwood et al 2021] [Shearwood et al 2023] [Shi and Ma 2023] [Shi and Wu 2022] [Shi et al 2020] [Shuang et al 2016] [Shuang et al 2017] [Shukla et al 2026] [Siddiqui et al 2025] [Silva] [Simon et al 1993] [Sineglazov and Karabetsky 2013] [Sinha 2026] [Snell] [Snow 1990] [Song et al 2014] [Soundararajan 2022] [Soundararajan and Sridhar 2024] [Sparks] [Sparks and Sparks 1997] [Staelens et al 2007] [Stalford and Hoffman 1989] [Staub et al 2019] [Stenfelt and Ringertz 2009] [Stenfelt and Ringertz 2010] [Stenfelt and Ringertz 2013] [Strykowski et al 1996] [Sun et al 2024] [Sung et al 2026] [Suresh et al 2013] [Susanto and Ahdan 2020] [Syed et al 1990] [Syed et al 1992] [Tan et al 2014] [Tang et al 2026] [Tanveer and Ahmad 2023] [Tanveer and Ahmad 2023] [Taylor 1988] [Taylor and Yoo 2011] [Teel 1999] [Teel 1999] [Tingting and Aijun 2014] [Tipton et al 1996] [Tomac and Stenfelt 2014] [Torenbeek 1991] [Torenbeek 2016] [Tournes and Johnson 1999] [Tournes et al 1997] [Traas et al 2026] [Tsuchiya et al 2022] [Ul Haq et al 2026] [Valeriu 2011] [Variable mode turbofan jet 2002] [Vashistha et al 2014] [Velicki and Thrash 2010] [Verstraete et al 2012] [Vile et al 2019] [Vile et al 2019] [Voss 2018] [Voß 2019] [Vugts et al 2023] [Wang and Feng 2026] [Wang and Wang 2012] [Wang and Wang 2012] [Wang and Zhao 2025] [Wang and Zhou 2007] [Wang et al 2014] [Wang et al 2019] [Wang et al 2020] [Wang et al 2021] [Wang et al 2021] [Wang et al 2024] [Wang et al 2025] [Wang et al 2025] [Warsop et al 2019] [Watanabe et al 2023] [Weekley et al 2021] [Wei et al 2025] [Weisman and Valasek 2010] [Weisshaar 1973] [Weyl 1944] [Weyl 1945] [Weyl 1945] [Weyl 1945] [Weyl 1945] [Weyl 1945] [Whitaker and Gowadia 1994] [Whiting 1996] [Wildschek 2014] [Williams and Vittal 2002] [Williams et al 2025] [Wing and Asbury 1991] [Wisnoe et al 2010] [Xi and Zhao 2017] [Xie et al 2011] [Xin et al 2019] [Xu and Yu 2025] [Xu and Zhou 2015] [Xu and Zhou 2016] [Xu et al 2019] [Xu et al 2019] [Xue et al 2021] [Yan et al 2014] [Yan et al 2025] [Yeo et al 2015] [Yerly et al 2016] [Yingsong et al 2015] [Yoon et al 2014] [Yu et al 2023] [Yu et al 2024] [Yue et al 2009] [Zhang 2020] [Zhang and He 2026] [Zhang and He 2026] [Zhang and Meng 2019] [Zhang and Zhao 2023] [Zhang et al 2010] [Zhang et al 2013] [Zhang et al 2014] [Zhang et al 2017] [Zhang et al 2018] [Zhang et al 2020] [Zhang et al 2023] [Zhang et al 2025] [Zhao et al 2021] [Zhao et al 2021] [Zhao et al 2023] [Zhao et al 2026] [Zhou et al 2022] [Zhou et al 2023] [Zhou et al 2024] [Zhu et al 2016] [Zhu et al 2020] [Zihan et al 2017] [Zmijanovic] [Zurriati et al 2011] [Zwerneman and Eller 1994]

Flight control law design and handling qualities

What replaces the pilot’s hands. Control law design, stability augmentation, gain scheduling, adaptive and robust control, and the handling qualities framework that an unmanned aeroplane inherits without inheriting the pilot who defined it. A handling quality is a statement about a human being, and this cluster is where the field works out what the term means when there is nobody aboard. Of its 472 records, 232 concern unmanned aircraft by their titles, and none of those names a rotorcraft or a vertical takeoff type.

472 records. [Ficola 2006] [Ablesimov and Sarapina 2013] [Adams 1972] [Adoghe] [Advanced Control Techniques for 2023] [Aerospace - Flight Control] [Aerospace - Vehicle Management] [Aerospace Vehicle Flight Control 1965] [Agha et al 2019] [Air Force Test Pilot School Edwards Afb Ca 1969] [Air Force Test Pilot School Edwards Afb Ca 1990] [Aircraft Dynamics and Classical 2015] [Aircraft Flight Control 2014] [Aircraft Flight Control Systems] [Aircraft flutter control system 2011] [Aircraft lateral-directional handling qualities 2011] [Aircraft longitudinal handling qualities 2011] [Akopov et al 2020] [Altuğ and Türkmen 2021] [Ananda 2016] [Anderson 1984] [Appa et al 1998] [Applebaum] [Applebaum and Ben-Asher 2004] [Application of dynamic flight] [Autopilot Design Using Successive 2012] [Autopilot, Flight Director, and] [Azimov and Allen 2017] [Bachelder and Aponso 2020] [Bachelder and Aponso 2020] [Bachelder and Aponso 2023] [Bailey 1984] [Ballouz and Chang] [Baughman and Longeauay 2015] [Bayrak 2026] [Beaufrere 1988] [Beh et al 2018] [Bertrand et al 2007] [Bertrand et al 2007] [Bestaoui et al 2003] [Bingaman 2012] [Bischoff 1981] [Blight et al 2018] [Boothe 1971] [Bouadi] [Boudreau 1976] [Bradshaw et al 1985] [Braun et al 2014] [Brown 2009] [Burcham and Burken 1994] [Burnashev and Zbrutsky 2019] [Burris and Bender 1969] [Burton and Kneeland 1981] [Capello et al 2011] [Ceren and Altuğ 2011] [Chai Xue et al 2010] [Chan] [Chapter 5 Unmanned Vehicle 2024] [Chavez and Vogel 2003] [Chen 2009] [Chen et al 2025] [Chetty and Raol 1992] [Chetty et al 2002] [Chin et al 1987] [Chiu] [Chowdhury and Keshmiri 2024] [Chowdhury et al 2021] [Citurs 1984] [Cjoplin et al 1996] [Clifford 1968] [Conceptual and Preliminary Design 2017] [Control System Elements Sensors 2026] [Control systems of unmanned 2012] [Cook 1997] [Cook 2007] [Cook 2013] [Cord 1989] [Cotton 1974] [Cox and Cotting 2005] [Crespo et al 2010] [Crespo et al 2010] [Cully and Boller 1973] [Cunis] [Cunningham et al 2011] [Dahleh and Tsitsiklis 2002] [Dayuan et al 2013] [Demarchi and Haning 1978] [Design Guidelines for Aircraft] [Dlapa 2020] [Dmitriev et al 2020] [Dobos-Bubno and Hartsook 1977] [Dotson et al 2020] [Dołęga et al 2017] [Drewiacki et al 2016] [Duggan and Bhandari 2021] [Dussart et al 2018] [Efremov et al 1998] [El Mobaraky et al 2026] [Enciu 2019] [Enns 1990] [Eraslan and Oktay 2023] [Erdogan et al 2017] [Fajar and Arifianto 2018] [Fang 2025] [Fantin Irudaya Raj 2022] [Farhadi 2017] [Farhadi and Kortunov 2017] [Farhadi et al 2017] [Feedback Flight Control 2026] [Felisiak 2026] [Fell et al 2015] [Ferreres and Puyou 2006] [Figueiredo Prudencio] [Flanagan et al 2019] [Flanagan et al 2020] [Flight Control 2015] [Flight Control Actuation Systems 2025] [Flight control system design 2011] [Flight Control Systems 2022] [Flight Dynamics of Elastic 2014] [Flight Envelope Awareness/Protection] [Flying Qualities 2003] [Fosdick 1970] [Franklin 1970] [Franklin 1971] [Franklin and Miller 1967] [Gai et al 2020] [Gainer 1963] [Galaguz 2013] [Ganguli et al 2005] [Gao et al 2021] [Gao et al 2021] [Gao et al 2021] [Gao et al 2021] [Gao et al 2021] [Gao et al 2021] [Garcia-Hernandez et al 2017] [García-Hernández et al 2018] [Gaylor 1984] [Ge] [Ge and Liu 2023] [General Electric Co Schenectady Ny 1952] [Gibson 1990] [Girish et al 2014] [Graham 1986] [Gratton 2018] [Gray 2008] [Gray 2009] [Gray and Kemper 2009] [Greene and Kunz 2015] [Greene et al 2014] [Gregory et al 2011] [Gresham et al 2022] [Gu et al 2019] [Gubbels et al 2002] [Ha 1990] [Hajiyev et al 2015] [Hajiyev et al 2015] [Hajiyev et al 2015] [Hajiyev et al 2015] [Hajiyev et al 2015] [Hajiyev et al 2015] [Hall and Boothe 1972] [Handling qualities 2000] [Handling Qualities Analysis 2008] [Handling Qualities and Control 2017] [Harris et al 2000] [Hart 1956] [Hart 1968] [Hartmann et al 1979] [Heald 1955] [Hernandez Ramirez and Nahon 2020] [Hess 1981] [Hess 2009] [Hess and Peng 2018] [Himich and Kineyko 1981] [Hodgkinson 2003] [Hodgkinson et al 1990] [Hoh 1988] [Hoh and Mitchell 2018] [Holzapfel and Sachs 2004] [Hongyan and Xiaoyong 2026] [Horn et al 1998] [How et al 2014] [Hu et al 2026] [Huang and Zhang 2020] [Härkegård 2009] [Immanuel and Johnson 2005] [Initial flight test of 1989] [Integrated Flight Instruments and] [Introduction The Flight Control 2017] [Islam et al 2020] [Ito et al 2016] [Jacklin et al 2006] [Jafari et al 2017] [Jagadish and Chang] [Jain 2015] [Jansen 1980] [Jebakumar et al 2019] [Jeffrie and Rolston 1972] [Jenney et al 1982] [Jianhong and Yanxiang 2026] [Jihui 2019] [Johnston and Hogge 1974] [Joosten et al 2023] [Junfeng et al 2020] [Kahn 2010] [Kang and Hedrick 2006] [Kannan et al 2014] [Karpel 1990] [Karshakov 2013] [Kerr et al 2009] [Kikkawa and Uchiyama 2017] [Kim and Kunz 2016] [Kineyko 1982] [Kitsios et al 2020] [Klipa and Sydorenko 2015] [Klyde et al 1997] [Klyde et al 2003] [Klyde et al 2018] [Kobayashi and Takahashi 2011] [Kong et al 2024] [Kotikalpudi et al 2014] [Kotikalpudi et al 2018] [Kotikalpudi et al 2020] [Kreerenko 2025] [Krüger et al 2010] [Kubica and Livet 1994] [Kumar et al 2024] [Lanteigne and O’Reilly 2020] [Larson 1986] [Lateral Control Power Rolling 2003] [Lateral Directional Fractional Order 2012] [Lavretsky 2014] [Lee et al 2003] [Lee et al 2023] [Leggett and Cord 1994] [Levin et al 2019] [Leylek and Costello 2015] [Li 2025] [Li and Xu 2020] [Li et al 2017] [Li et al 2019] [Li et al 2021] [Li et al 2023] [Li et al 2023] [Liang et al 2024] [Liao et al 2026] [Lin and Liu 1998] [Liu 2018] [Liu 2024] [Liu and Li 2021] [Liu et al 2009] [Liu et al 2025] [Low 2010] [Lu 2024] [Lu et al 2011] [Luo et al 2011] [Luo et al 2022] [Ma] [Malaek et al 2006] [Malyar and Shcheholskyi 2026] [Manning and Gleason 1992] [Maria-Agneta and Stef 2011] [Martínez-Ramírez and Rodríguez-Cortés 2022] [Matthews and Yi 2019] [Maurya et al 2021] [McCUISH 1994] [McCuish and Caldwell 2018] [McFarlane et al 2008] [McKenzie 1973] [McMaster and Schenk 1973] [Mehta et al 2006] [Menon et al 2013] [Mercadante et al] [Merheb] [Miller and Franklin 1968] [Modeling the Aircraft 2015] [Montgomery 1971] [Moshu Qian and Zhifeng Gao 2016] [Movahhed and Hamed 2024] [Murch 2008] [Myers and Walsh 1988] [Napolitano et al 2001] [Nardi 1970] [Natesan and Bhat 2005] [Natesan et al 2008] [Nemati and Montazeri 2018] [Nguen et al 2017] [Noble and Bhandari 2017] [Northrop Aircraft Inc Hawthorne Ca 1952] [Ogren et al 1974] [Oland and Kristiansen 2013] [Olivares Méndez] [Owashi et al 2017] [Oz 1998] [Ozimina et al] [Paine 1950] [Panza and Mak 2003] [Park et al 2001] [Pei et al 2025] [Peni et al 2013] [Peterson 2025] [Pisano and Lawrence 2009] [Place et al 1974] [Pontillo et al 2026] [Primary Flight Controls by] [Prokopiev et al 2023] [Prokopyev and Sofronova 2021] [Péni et al 2015] [Qian et al 2019] [Quantitative Design Requirements for 2017] [Raol and Singh 2023] [Rasitha et al 2015] [Reid et al 1994] [Reinhardt and Johansen 2019] [Research and Design of 2022] [Rezazadeh Movahhed and Hamed 2026] [Rickard 1978] [Ridgely et al 1985] [Rinde 1969] [Moore et al] [Robinson] [Robot and Uav Control 2016] [Rogalski 2018] [Rogalski et al 2020] [Rogalski et al 2021] [Rohlf et al 2012] [Roscoe et al 1975] [Royer et al 2009] [Ru and Subbarao 2017] [Ruflin and Grantham 1984] [Rustenburg 1972] [Rysdyk 2003] [Sachs 1999] [Sadien] [Salahudden et al 2020] [Salahudden et al 2020] [Salman and Anavatti 2012] [Sanfilippo 1970] [Sarabakha] [Sarigul-Klijn and Huber 2006] [Schmidt 1983] [Schmidt 1986] [Schmidt 2016] [Schmidt et al 2019] [Schreadley 1977] [Schwanz 1972] [Seckel 1964] [Seckel 1964] [Seckel 1964] [Seiferth and Heller 2017] [Sferrazza et al 2017] [Shao et al 2024] [Shen et al 2017] [Shore and Bodson 2004] [Simms 2023] [Simplício et al 2018] [Sims] [Sims and Biezad 2010] [Simsek and Tekinalp 2015] [Simulation Requirements for Flight 2017] [Sinha and Ananthkrishnan 2017] [Smirnov and Smirnova 2018] [Smith 1977] [Smith 1991] [Smith and Geddes 1979] [Smith et al 1971] [Snell 1993] [Soares 2007] [Soares 2007] [Song 2008] [Song and Chen 2011] [Sorial 1984] [Souanef 2022] [Souanef 2024] [Steer 2003] [Stengel and Miller 1978] [Stern 1984] [Subbarao et al 2015] [Sugino et al 2019] [Szabolcsi 2018] [Szabolcsi 2018] [Szabolcsi 2018] [Ta et al 2014] [Tang] [Tantrairatn and Veres 2015] [Tekinalp and Prach 2013] [Teofilatto 2001] [Thomasson 1995] [Tischler and Tobias 2016] [Tiwari] [Tiwari 2010] [Tomczyk 2014] [Tonon and Belluati 2018] [Tunik and Nadsadna 2017] [Tunik et al 2013] [UAV Control 2016] [Unmanned Aerial Vehicle Dynamics 2016] [Unmanned Aerial Vehicle Path 2014] [Urnes and Yeager 1991] [Ursu et al 2018] [Valasek et al 2009] [Valasek et al 2012] [Van Cuong Nguyen and Damm 2012] [Van Gool and Weingarten 1981] [Vehicle Management Systems] [Velasco Carrau] [Vepa 2016] [Vepa 2023] [Vepa 2023] [Vepa 2023] [Vepa 2026] [Vepa 2026] [Vepa 2026] [Verba 2021] [Vukobratović and Stojić 1986] [Wadley et al 2003] [Wang and Zhang 2017] [Wang et al 2020] [Wei Ren and Beard 2004] [Weinstein et al 1986] [Weiss 1983] [What’s under the skin?] [Wichgers] [Wilburn] [Williams 2004] [Williams-Hayes 2005] [Wong et al 2019] [Wood 1984] [Wu 2018] [Wu 2018] [Wu and Mora-Camino 2012] [Xiaowei Zhang et al 2016] [Xie et al 2026] [Xin et al 2023] [Xu 2009] [Xu 2016] [Xu et al 2013] [Xu et al 2026] [Yaghini 2025] [Yamamoto et al 2023] [Yan 2017] [Yan et al 2025] [Yang] [Yang et al 2009] [Yanushevsky 2011] [Yanushevsky 2026] [Yanushevsky 2026] [Yao et al 2023] [Yeom 2017] [Yi Zhu et al 2016] [Yin et al 2023] [Yu et al 2023] [Yuan and Wang 2020] [Yue et al 2017] [Zbrutsky et al 2024] [Zeyada et al 1998] [Zhang et al 2017] [Zhang et al 2019] [Zhang et al 2020] [Zhang et al 2021] [Zhao et al 2017] [Zhiping and Fang 2013] [Zhou 2025] [Zhou 2025] [Zhu et al 2024] [Zogopoulos-Papaliakos et al 2020] [Zolotas 2023] [Zou et al 2017] [Zou et al 2022] [Çoban and Oktay 2018]

Aircraft conceptual design, sizing and mass estimation

The discipline the section headed The Two Aircraft borrows its arithmetic from. Conceptual design, initial sizing, mass and weight estimation, payload fractions and the sizing loop, for combat, military and unmanned aircraft, for blended wing body designs of any class, and as general methods. A mass exponent near three that arrives from a held payload fraction is the kind of result this literature exists to explain, and the section headed The Source Base records how thinly the survey treats scaling across size itself.

281 records. [Abdelrahman et al 2009] [Abdullahi et al 2026] [Aircraft Characteristics 2022] [Aircraft Components and Subsystems 2011] [Aircraft Components and Subsystems 2011] [Aircraft Conceptual Design 2012] [Aircraft Design A Conceptual 2024] [Aircraft Design Fundamentals 2012] [Aircraft Design Optimization 2013] [Aircraft Sizing, Engine Matching 2010] [Aircraft Weight and Center 2010] [Aircraft Weight Distribution 2012] [Aircraft Weights Data 2010] [Al-Shamma et al 2017] [Alder et al 2023] [Alsahlani et al 2017] [Altman 2015] [Analysis of the relationship 2024] [Anton et al 2010] [Argrow 2016] [Ascani 1974] [Aspects of Airframe Design 2010] [Aubeelack] [Autry and Victorazzo 2019] [Badra et al 2023] [Badyagin et al 1979] [Bagdatli et al 2019] [Bahamonde Jacome and Elham 2017] [Bai et al 2014] [Ball 1966] [Ballhaus 1954] [Barlow 1929] [Barlow 1999] [Barton] [Basgall et al 2020] [Bateman et al 2007] [Berci and Torrigiani 2020] [Bindolino et al 2010] [Bischof et al 1994] [Braafladt et al 2020] [Brandt 2018] [Brown and Vos 2018] [Bråmå 1987] [Buddhamatya et al 2026] [Burton and Hoburg 2018] [Butler et al 1999] [Bye 1993] [Cai et al 2022] [Camatti et al 1998] [Capristan and Welstead 2017] [Capristan and Welstead 2018] [Carreyette 1950] [Cavagna et al 2009] [Cavagna et al 2010] [Cavagna et al 2011] [Chai et al 1995] [Chakraborty and Mishra 2021] [Chakraborty et al 2014] [Chaussee and Dervault 2013] [Coen and Foss 1986] [Coen and Foss 1985] [Component analysis of unmanned 2010] [Computer-Aided System of Aircraft 2018] [Control authority assessment in 1993] [Crossley 2004] [Crossley et al 2011] [Dannenhoffer 1981] [Dantas de Jesus Ferreira and Secco 2021] [Daoud 2017] [de Oliveira 2007] [Dergachev and Temicheva 2023] [Design of the Well-Tempered 2013] [Design of Unique Aircraft 2024] [Du Cray et al 2025] [Eisler] [Elham and Bahamonde Jacome 2016] [Espinosa Barcenas et al 2022] [Essari 2018] [Essari 2018] [Essari and Ghatus 2023] [Fielding and Vaziry-Z 1995] [Fioriti 2014] [Franco et al 2019] [Frommer and Crossley 2005] [Frulla 2021] [Führer et al 2016] [Galloway 1989] [Gates 1949] [Gaynutdinov et al 2020] [Geiger 2002] [Generic Aircraft Design Flowchart 2017] [Giles 1995] [Giles et al 1972] [Glīzde] [Golombek et al 2025] [Golombek et al 2026] [Goyal 2026] [Greene and Sobieszczanski-Sobieski 1982] [Grinsted 1949] [Gudmundsson 2014] [Gudmundsson 2014] [Gudmundsson 2014] [Gudmundsson 2022] [Gudmundsson 2022] [Gundlach 2012] [Gundlach 2014] [Gómez Rodríguez] [Hammond 1986] [Hannon et al 2008] [Hannon et al 2011] [Harasani 2010] [Hayase 1974] [Hayase 1974] [Hays 1989] [Heinemann 1954] [Henry et al 2021] [High altitude reconnaissance aircraft 1989] [High-Altitude Long-Endurance HALE Sensor 2026] [Hiyama 1974] [Hiyama 1974] [Hoburg and Abbeel 2014] [Hon et al 2022] [Horvath and Wells 2018] [Howe 2000] [Howe 2000] [Howe 2000] [Hung et al 2010] [Incorporating agility flight test 1994] [Information Model of Aircraft 2021] [Ingram et al 2015] [Initial Unmanned Aircraft Sizing 2014] [Initial Unmanned-Aircraft Sizing 2012] [Jagtap et al 2024] [Jagtap et al 2025] [Johnson 1985] [Kao et al 2018] [Karabacak and Turan 2020] [Karagoz et al 2019] [Karali et al 2026] [Kaymal 2016] [Kim and Lee 2018] [Kim et al 2018] [King] [Krengel et al 2019] [Kretov 2020] [Kretov 2021] [Kuprikov and Markin 2018] [Kuprikov et al 2019] [Lappos 2020] [Larsen 1966] [Laughlin et al 2013] [Lenz and Crossley 2009] [Liscouet-Hanke and Huynh 2013] [Liseitsev 2025] [Liu and Elham 2019] [Liu and Wu 2003] [Livne 1999] [Love and Argrow 2021] [Luu 2025] [Ma et al 2022] [Martin and Crossley 2002] [Martı́nez-Val and Hernández 1999] [Mastin et al 1996] [Mavris and DeLaurentis 1995] [McDonald 2013] [McGettrick 1995] [Measures of Wing Area 1990] [Meyer et al 2009] [Min Tint 2018] [Mistree 1987] [Mody et al 2010] [Mokotoff et al 2025] [Mokotoff et al 2026] [Moorhouse and Jenkins 1975] [Most 2016] [Most and Stroup 2021] [Myklebust and Gelhausen 1993] [Nam and Mavris 2018] [Nam et al 2005] [Neufeld 2021] [Neufeld et al 2011] [Nigam et al 2015] [Nugent and Girard 2003] [Oole 1993] [Oyama 2021] [Palaia et al 2025] [Palusamy and Sivier 1993] [Parker 1986] [Patterson 1989] [Patterson et al 2012] [Perez and Behdinan 2002] [Preliminary Fuselage Sizing and 2010] [Preliminary Sizing of the 2010] [Putting It All Together 2004] [Putting It All Together 2015] [Qi and Song 2023] [Rajaram et al 2018] [Raymer 1992] [Raymer 1998] [Raymer 2004] [Raymer 2012] [Raymer 2012] [Raymer 2018] [Raymer 2019] [Raymer 2024] [Raymer and Crossley 2002] [Rentema et al 1998] [Richez and Bostock 2026] [Rodriguez and Liscouët-Hanke 2025] [Roelofs et al 2021] [Rosenthal 1947] [Roskam 1985] [Roskam 1986] [Roth et al 2002] [Rufino et al 2024] [Sanghi 2003] [Schneider and Strohmayer 2023] [Schwartz 1988] [Scott 2021] [Semke 2016] [Semke 2021] [Sensmeier and Samareh 2005] [Siegers and Smith 1995] [Singh et al 2016] [Skillen and Crossley 2005] [Skillen and Crossley 2008] [Solvey 1951] [Sorensen et al 1979] [Sponholz] [Sreeletha et al 2019] [Staack] [Stamm and Woods 2024] [Stanford 2021] [Straub 1973] [Stringer et al] [Subramaniam et al 2012] [Sun 2014] [Suzdaltsev et al 2016] [Svoboda 1999] [Swift et al 1990] [Switzky 1962] [Takahashi 2022] [Takahashi and Donovan 2010] [The Design of Classical 2012] [The Wing Structure and 2013] [Toll 1980] [Tong and Naylor 2008] [Torenbeek 1971] [Torenbeek 1972] [Torenbeek 2013] [Turevskiy et al 2007] [Unmanned Aircraft Geometry and 2014] [Unmanned-Aircraft Geometry and Configurations 2012] [Useful Aircraft Design Data] [Useful aircraft design data 1999] [Van Haver and Vos 2015] [Verstraete et al 2018] [Wakayama 1998] [Wampler et al 1988] [Wang and Shi 2023] [Ward 1983] [Wauters 2022] [Wells et al 1999] [Welstead and Crouse 2014] [Werner-Westphal et al 2008] [Whitford 1992] [Whitford 1994] [Why Should We Design] [Wildermuth et al 1974] [Wildermuth et al 1974] [Wilkinson et al 1974] [Wilkinson et al 1976] [Woelk 1989] [Worked Manned Aircraft Detail 2017] [Xie and Haberland 1999] [Xie et al 2019] [Xun et al 1993] [Zhang et al 2006] [Zhao et al 2014] [Ziemer et al 2011] [Ünal et al 2023]

Propulsion, inlet integration and installed performance

The engine and what the airframe does to it. Turbofan cycle and installed performance, embedded inlet integration, pressure recovery and specific fuel consumption. The article uses this literature for one purpose, being to test whether a published thrust figure can hold a published ceiling.

269 records. [A Current Assessment of] [Adkins and Sherwood 1996] [Ahren 1981] [Ahuja and Mavris 2021] [Ahuja and Mavris 2022] [Air brakes and thrust 1965] [Aircraft Engine Efficiency and 2018] [Aircraft engine thrust reverser 1998] [Airfoil static-pressure thrust 1990] [Allard 1982] [Amin and Hollweger 1983] [Amin and Richards 1984] [Andersen and Bagby 1965] [Anderson 1983] [Anderson and Othling 1976] [Appendix E Aircraft Engine 2002] [Appendix I Mixed Flow 2002] [Armstrong and Miller 1967] [Assessment of the Inlet/Engine] [Atesoglu and Özgören 2006] [Atesoglu and Özgören 2007] [Atesoglu and Özgören 2009] [Babu 2021] [Baer-Riedhart 1981] [Bagby and Andersen 1966] [Ball 1991] [Baranwal and Mahulikar 2016] [Beale 2018] [Beale et al 2006] [Becker et al 2015] [Bents et al 1998] [Berrier 1983] [Berrier and Mason 1983] [Berrier and Re 1978] [Bert 1999] [Binder and Carbonneau 2012] [Bird] [Bloy 1996] [Bloy 1998] [Bolonkin 2005] [Boretz 1985] [Boytos 1969] [Braman et al 1983] [Bridges 2008] [Bridges 2010] [Brown and Sun 2017] [Bruening et al 2000] [Bruening et al 2001] [Bucsan et al 2017] [Burcham 1971] [Burcham et al 1981] [Burger 1983] [Campbell and Ellis 1971] [Carlson and Mack 1980] [Chamberlain 1969] [Chandrakar et al 2022] [Chapman 2020] [Chen et al 2015] [Chen Xuyi and Xiaoying Zhang 2015] [Chennuru et al 2023] [Cler 1995] [Climbing Flights of Turbojet 1995] [Coates et al 2019] [Compton and Burgess 2021] [Cotter 1968] [Cousins 2004] [Covert 1984] [Cruising Flights of Turbojet 1995] [Csavina 1976] [Csavina and Denney 1991] [Cunis et al 2018] [D Thrust Data for 2006] [da Fonseca Filho et al 2019] [Davidson 1964] [Davis et al 2001] [Dean 1978] [Deere 1998] [Derbel and Beneda 2025] [Design and Development of 1989] [Dyson and O’Donnell 1970] [El-Sayed 2016] [El-Sayed 2026] [Ergöçmen and Tilki 2023] [Exley 1991] [Feng and Jin 2016] [Forliti et al 2002] [Foy 1983] [Frosst et al 2024] [Fuqun et al 1985] [Gal-Or 1992] [Gal-Or 1994] [Gas Turbine Engine Inlet] [Gilbart et al 2023] [Glezer et al 1985] [Goeing et al 2024] [Goetz et al 1978] [Gridley and Walker 1996] [Griffis et al 2008] [Grois et al 2024] [Gudmundsson 2022] [Hah et al 2015] [Hale et al 2004] [Haq and Huang 2022] [Harley et al 2012] [Harris 1984] [Hawkes and Obye 1993] [Herrick 1985] [Herrick 1988] [Herrick 1989] [Hiley et al 1975] [Hill 1970] [Hou et al 2024] [Huey] [Hughes and McDonald 1965] [Hughes and Ray 1985] [Hunt and Gowadia 1981] [Inlet / Engine Compatibility] [Inlet, Duct, and Nozzle 1998] [Inlets and Inlet/Engine Integration 1989] [Integrated flight/propulsion control 1985] [Invernizzi and Lovera 2018] [Jackson 2010] [Jagtap et al 2025] [Jente 2022] [Jet Thrust Measurement In 2003] [Johns 2002] [Joshi 1985] [Katz 1971] [Kauser and Burcham 2001] [Kc et al 2019] [Kelly et al 2021] [Khailany et al 2025] [Khalid 2016] [Kidman et al 2013] [Kim et al 2020] [Kim et al 2026] [Klepper et al 2017] [Kowalski et al 1991] [Kozu and Yashima 1989] [Krase 1967] [Kunwar et al 2024] [Kurkov et al 1975] [Kurzke 2006] [Labonte 2017] [Lecuyer 1970] [Lee and Boedicker 1985] [Lee et al 2018] [Lennard and Fasching 1982] [Levy et al 2007] [Li and Tiniakov 2026] [Li et al 2018] [Li et al 2018] [Li et al 2025] [Lian and Wu 2018] [Lindermeir 1994] [Liou and Lee 2012] [Liu et al 2024] [Lowe et al 2020] [Lucas et al 2014] [Maghsoudi et al 2020] [Malaek and Parastari 2001] [Malan and Brown 1994] [Marshall 1973] [Mathur 1998] [Mattingly 1998] [Mattingly and Heiser 1986] [Maywald and Beale 1991] [McGuigan 1970] [Milford and Migdal 1967] [Military Aircraft and Engine 2021] [Miller and Hamstra 1996] [Miller and Migdal 1970] [Mixed Flow Turbofan Engine 2018] [Moorhouse and Citurs 2018] [Morton 2014] [Morton et al 1991] [Most and Feasey 2021] [Munroe et al 2021] [Murman et al 2000] [Naterer and Glockner 2001] [Nelson 1986] [Nelson and Dix 2003] [Nevo et al 2025] [Oelberg and Rodrigues 2018] [Pan Song and Wei Minxiang 2008] [Papageorgiou et al 2022] [Patterson et al 1991] [Pelz et al 2016] [Peters 1980] [Poland and Schwanebeck 1970] [Porter 1984] [Potts and Bons 2020] [Pourtakdoust et al 2009] [Propulsion 2017] [Propulsion 2024] [Propulsion System Thrust Sizing 2010] [Propulsion Systems 2012] [Propulsion Systems 2014] [Propulsive Thrust by Jet 1995] [Rahman and Whidborne 2010] [Ramachandra et al 1979] [Ramachandra et al 1982] [Ramette and Corde 1992] [Rasimarzabadi et al 2023] [Rauh and Anders 1986] [Remiger et al 2024] [Review of Inlet/Airframe Integration 1986] [Rhoades 1973] [Rodgers 2001] [Rooney and Wilt 1985] [Rosenberg and Esker 1980] [Rosenberg and Schuch 1983] [Rosenberg and Schuch 1985] [Roth and Mavris 2001] [Rowe and Sussman 1971] [Sadraey 2024] [Sedgwick 1975] [Semakov and Semakova 2023] [Sforzini 1970] [Shmilovich 1988] [Shmilovich 1990] [Shoemaker 1981] [Shuo et al 1995] [Solies 1994] [Suh 1990] [Sussman 1968] [Svoboda 2000] [Symposium on Advanced Flow 2003] [T. V. et al 2024] [Takahashi 2005] [Tan and Mavris 2024] [Tasic et al 2018] [Thrust and Drag Modeling 2021] [Thrust-to-Weight Ratio and Wing 2024] [Tindell et al 1982] [Trapp and da Motta Girardi 2010] [Turan 2012] [Turbine Engine Inlet Design 2010] [Turbofan engine components 1998] [Turbofan Engine Performance under 2017] [Ulizar and Pilidis 1997] [Urban et al 2023] [Van Der Hoeven 1981] [Van Deusen and Mardoc 1972] [Vectored thrust 1992] [Wallace and Bowers 1982] [Wang and Wang 2022] [Wang et al 2022] [Wei et al 2023] [Williams and Stevens 2006] [Wygonik 2013] [Xiao and Liang-Wei 1985] [Xingjian et al 1985] [Yaeger 1977] [Yahsi et al 2023] [Yalcin 2017] [Yanik et al 2014] [Yildirim Dalkiran and Toraman 2020] [Yong et al 2014] [Yong et al 2020] [York et al 2018] [Younes and Hickey 2020] [Yu Kun et al 2020] [Zelenak 1994] [Zhao et al 2022] [Zhongwei and Shiying 1985] [Zimbelman and Rouser 2025] [Zirka et al 2021] [Şöhret et al 2015]

Unmanned combat aircraft and the strike mission

The vehicle class, as distinct from the far larger literature on unmanned aircraft in general. Armed unmanned aircraft, strike mission analysis and the operational arguments for and against them. This cluster is deliberately narrow, because the civil small aircraft literature now dwarfs the combat one and would otherwise swamp the survey. Four records in this cluster name the X-45A in their titles, on its first flight, its aeroservoelastic design and test, its flight control design and test, and the formation taxi and flight of the two vehicles.

248 records. [Ananyev 2019] [Ananyev 2019] [Acharya et al 2004] [Ahn et al 2023] [Aircraft Payload Limits for 1970] [Akhdan Fadhil et al 2022] [Aleisa et al 2023] [Aleisa et al 2023] [Aleksandrovich and Nikolayevich 2020] [Alexopoulos et al 2014] [Allouani et al 2023] [Anderson 1999] [Angell 2009] [Armstrong 2025] [Aslan and Erkin 2023] [Aslan and Oktay 2023] [Aslan and Ozkok 2024] [Baba et al 2002] [Bacci et al 2019] [Bagul et al 2020] [Balasubramanian et al 2026] [Banks 2000] [Bishop et al 2000] [Bookstaber 2000] [Booz 1998] [Bozov 2023] [Brinker and Barker 2005] [Brown 1998] [Cao et al 2013] [Casey-Maslen 2018] [Casey-Maslen 2018] [Casey-Maslen 2018] [Casey-Maslen 2018] [Casey-Maslen et al 2018] [Chang et al 2022] [Chapa 2017] [Chaplin and Birch 2012] [Chiesa et al 2000] [Choi et al 2010] [Chung and Ghee 2006] [Ciolponea 2022] [Cox 2009] [Cummings and Schütte 2012] [Cummings et al 2003] [Cummings et al 2008] [Cummings et al 2018] [Da Ronch et al 2018] [Davidson 2004] [Dickes et al 2002] [Digman 2009] [Dong et al 2017] [Dong Kangsheng et al 2016] [Drones and Unmanned Smart 2020] [Dungan and Clark 1994] [Elkhoury 2008] [Elkhoury and Rockwell 2004] [Elkhoury et al 2005] [Eom 2023] [Eremenko 2006] [Ernest and Carroll 2016] [Ernest and Cohen 2016] [Evaluating The Use of 2015] [Faied and Girard 2008] [Faisal and James 2025] [Fan et al 2017] [Feng et al 2020] [Fielding and Nilubol 2003] [Flow Control and High-Lift 2016] [Fouad et al 2024] [Franke 2016] [Frink et al 2012] [Fu et al 2015] [Fu Li et al 2008] [Gangl et al 2013] [Ganglin 2009] [Gao et al 2025] [Ge et al 2024] [Gern et al 2001] [Ghee 2002] [Ghee 2003] [González 2023] [Gordnier et al] [Gordnier et al 2006] [Gordnier et al 2007] [Greaney 2010] [Grzesik and Sobolewski 2014] [Gu et al 2012] [Guo et al 2023] [Guo et al 2024] [Haider et al 2022] [Han et al 2024] [Hanif and Sasongko 2019] [Hansu Dai and Jihong Zhu 2010] [Heyns and Borden 2017] [Hinchman 2002] [Hitzel 2018] [Hoholis et al 2016] [Hong et al 2004] [Huang et al 2019] [Huang et al 2023] [In et al 2007] [İşci and Günel 2021] [Jiang et al 2025] [Jones et al 2006] [Jones et al 2023] [Jordan] [Jung et al 2014] [Kar et al 2025] [Keleş 2024] [Khalatov et al 2023] [Khalid 2023] [Klein 2002] [Kumar 2020] [Kumar et al 2026] [Lewis 2002] [Li and Fan 2018] [Li et al 2020] [Li et al 2022] [Li et al 2022] [Li et al 2024] [Liersch and Bishop 2018] [Lima Filho et al 2021] [Lin and Liu 2015] [Liu et al 2019] [Liu et al 2023] [Liu et al 2023] [Liu et al 2025] [Longino 1994] [Lynn and Gursul 2006] [Ma et al 2024] [Marques 2014] [Matsushima 2001] [Maynell 2010] [van Rooij et al 2019] [Minglang et al 2018] [Mishra et al 2022] [Mousazadeh et al 2016] [Nadler 2015] [Nangia and Palmer 2011] [Nangia et al 2010] [Nangia et al 2018] [Nguyen et al 2009] [Nguyen et al 2013] [Nuriwati and Sasongko 2019] [Ol 2006] [Ordaz et al 2004] [Ortiz et al 2021] [Pan et al 2020] [Panahi et al 2021] [Petterson 2006] [Pradeep 2002] [Prymirenko et al 2022] [Pu and Yu 2024] [Qinkun Xiao et al 2006] [Ramin et al 2022] [Reich et al 2016] [Reichenbach 2003] [Remotely Piloted Vehicles and] [Renehan 1997] [Reorganization for the Era 2008] [Rinehart 2026] [Ruetten 2018] [Ruetten et al 2012] [Ruetten et al 2014] [Sathe and Pant 2010] [Schulzke 2016] [Schütte et al 2012] [Sepulveda et al 2018] [Shi et al 2018] [Shillito 1977] [Sijabat and Indriyanto 2021] [Strawser 2010] [Strawser 2013] [Sun et al 2021] [Sun et al 2025] [Surma and Barczyk 2020] [Talley and Mavris 2006] [Talley et al 2004] [Tang et al 2019] [Tekinalp and Cavus 2012] [The Current and Future 2002] [The Evolution of UCAV 2002] [The Future of Uass 2023] [Tianyuan and Xiongqing 2009] [Tomac et al 2012] [Twesme and Corzine 2003] [Uass in Warfare and 2023] [Vallespin et al 2011] [van Rooij and Cummings 2018] [van Rooij et al 2018] [Venetsky et al 2003] [Vicroy et al 2012] [Vicroy et al 2018] [Voss et al 2011] [Wan et al 2025] [Wang and Tian 2025] [Wang et al 2010] [Wang et al 2016] [Wang et al 2019] [Wang et al 2019] [Wang et al 2020] [Wang et al 2023] [Wang et al 2026] [Wang et al 2026] [War and Risk Non-Lethal 2016] [Weapon configuration, allocation and 2018] [Weaponised Unmanned Air Systems 2013] [Wei et al 2023] [Weizmann 2018] [Wills 2015] [Wills 2015] [Wilt et al 2022] [Wise 2003] [Woo et al 2022] [Woolvin 2006] [Wu et al 2019] [Wu et al 2026] [Wyatt 2003] [Wyatt 2021] [Xiaole 2020] [Xie et al 2026] [Xu et al 2024] [Xuan et al 2022] [Yagci and Nikbay 2022] [Yang 2024] [Yang and Yee 2022] [Yao et al 2018] [Yin et al 2020] [Yin et al 2022] [Yin et al 2025] [Yoon et al 2026] [You 2026] [Yue et al 2025] [Yun et al 2020] [Zhang and Duan 2013] [Zhang et al 2005] [Zhang et al 2014] [Zhang et al 2016] [Zhang et al 2022] [Zhang et al 2024] [Zhen-ning et al 2020] [Zhou et al 2015] [Zhou et al 2022] [Zhuang 2024] [Zimper and Hummel 2014] [Zimper and Hummel 2018] [Zátureczká 2023] [Çoban and Oktay 2018]

Aerodynamics of the configuration

The flow the vehicle lives in. Lift, drag and the lift to drag ratio of tailless, flying wing, blended wing body and delta planforms and of combat and unmanned aircraft, their vortex flows, the cruise, range, ceiling and takeoff performance of fixed-wing aircraft, lateral-directional and crosswind behaviour, and the wind tunnel and flight techniques that correlate prediction with flight. The X-45’s aerodynamic record is thin because the aerodynamics were not the point, the configuration having been chosen for signature and the programme’s risk having sat in the software, and one record in this cluster names the X-45 planform.

230 records. [Abed 1989] [Aerodynamic Performance 2012] [Aerodynamics and Airframe Configurations 2010] [Aircraft Cruise in Steady 2011] [Aircraft Cruise in Steady 2011] [Aircraft Operating Envelope 2010] [Aircraft Performance 2026] [Aircraft Performance Methods 2010] [Aircraft Range and Endurance 2011] [Aircraft Range and Endurance 2011] [Aircraft Stability Derivatives 1998] [Aircraft Steady Longitudinal Flight 2011] [Aircraft Steady Longitudinal Flight 2011] [Almosnino 2016] [Andrew and Cahn 1967] [Andrews 1969] [Aubeelack et al 2023] [Axelson 1975] [Bagwell 2006] [Bazuhair 2018] [Berens 2003] [Bertelrud et al 1988] [Beyers and Ericsson 2001] [Bilimoria 1989] [Boschetti et al 2007] [Boschetti et al 2008] [Bray et al 1992] [Bulat and Minin 2018] [Cacciola et al 2023] [Cai et al 2014] [Cameron and Cameron 1997] [Carter et al 2009] [Cavanaugh and Holifield 1995] [Collins 1982] [Cook et al 2004] [Coppin et al 2018] [Cosentino 2007] [Cosentino 2008] [Cruise and Climb of] [Cruise and Drag Performance 2021] [Deepa et al 2016] [Design and Fluid Flow 2015] [Deulgaonkar et al 2020] [Doig et al 2013] [Drake 1964] [Drake 1965] [Durmus 2021] [Elisov et al 2018] [Elkhoury 2016] [Erickson 1980] [Erturk and Gomec 2020] [Fairuz Izzuddin Romli et al 2023] [Figliola 2004] [Figliola 2005] [Flight Envelope 2021] [Flight Envelopes 2012] [Flight Performance of Aircraft 1998] [Flight-test evaluation of engine 1985] [Florance et al 2003] [Foss 1944] [Fu et al 2024] [Gabor et al 2016] [Gan et al 2017] [Gastaldo and Ahuja 2026] [Gc] [Gebbie et al 2007] [Gern 2012] [Ghee and Taylor 2000] [Ghee and Taylor 2004] [Gilbert and Parsons 1976] [Gilmore et al 2002] [Glīzde 2017] [Goetten et al 2018] [Graham and Luskin 1946] [Gratton 2018] [Gray and Zingg 2024] [Grigor’ev 2023] [Grove et al 2000] [Gryte et al 2018] [Guo et al 2018] [Hale and Steiger 1978] [Hale and Steiger 1979] [Hale et al 2026] [Henchey et al 2016] [Hicks and Moulton 1988] [Hiller 2002] [Hitzel 2013] [Hoe et al 2012] [Howard et al 1989] [Howe 2000] [Huang and Hanff 1996] [Iliff 1977] [Innocenti et al 1998] [Jaganraj and Velu 2019] [Jameson 2009] [Jeong and Bae 2022] [Johnson 1972] [Jung and Lowenberg 2005] [Kang et al 2026] [Kanistras et al 2017] [Karkehabdi 2005] [Katz and Roglin 2000] [Khan and Nahon 2015] [Kim and Lee 2000] [Kim and Liou 2019] [Knaus 1981] [Knaus 1983] [Kotikalpudi et al 2015] [Krumenacker and Pellicano 1992] [Kunlo 1959] [Kwiek et al 2026] [Lamar 1977] [Lamar et al 1980] [Lampropoulos et al 2025] [Langan and Samuels 1999] [Lawson and Barakos 2010] [Lee and Batina 1991] [Lee and Franz 1976] [Lee and Kim 2024] [Leylek and Costello 2012] [Li and Qin 2020] [Li and Tiniakov 2026] [Li and Wang 2003] [Li et al 2023] [Liebeck 2002] [Liebeck et al 1998] [Limitations and Flight Envelope 2017] [Linnell 1963] [Lopes Tumelero et al 2022] [Lowenberg 2010] [Lyu and Martins 2013] [Lyu and Martins 2013] [Lyu and Martins 2014] [Madden 1958] [Martinez-Val and Perez 1992] [Matheny and Panageas 1981] [Mathioudakis et al 2020] [McAndrew et al 2014] [McConnell 2004] [McMichael and McKay 1995] [McParlin and Adamczak 2003] [Menon 1986] [Methods for Drag Determination 2003] [Milillo 1972] [Miller and Koch 1985] [Moeller and Rediniotis 2002] [Mohaghegh 2025] [Mora 2017] [Musa et al 2026] [Niewald and Parker 2000] [Nix et al 2009] [Oelker and Friehmelt 1998] [Ohme 2009] [Oktay et al 2018] [Oktay et al 2018] [Oorebeek and Babinsky 2014] [Ossmann 2016] [Nishanth et al 2019] [Pambagjo et al 2001] [Panagiotou and Yakinthos 2017] [Panagiotou et al 2021] [Patel et al 2006] [Payne 1980] [Piloted Aircraft Performance 2004] [Polhamus 1983] [Poole 2010] [Prasad 2025] [Preliminary Aerodynamic and Stability 2017] [Prilliman and Slingerland 1966] [Qiu et al 2024] [Reist and Zingg 2013] [Reist and Zingg 2014] [Ren et al 2025] [Richardson 1976] [Rogerson 1960] [Roman et al 2000] [Roman et al 2003] [Roysdon and Khalid 2010] [Roysdon and Khalid 2011] [Rubio Pascual and Vos 2020] [Ryu et al 2022] [Sachs and Christodoulou 1987] [Sachs et al 1993] [Saltzman et al 1999] [Sears 1980] [Seckel 1964] [Selecting the Planform and 2010] [Selig 2010] [Sforza 2018] [Sforza 2020] [Sharma et al 2012] [Shelton et al 2006] [Shevchenko et al 2017] [Si et al 2024] [Simon 1992] [Snyder 1990] [Stalford 1979] [Su and Cesnik 2009] [Su and Cesnik 2010] [Tahir et al 2026] [Takahashi 2011] [Takahashi 2013] [Takahashi 2026] [Tan] [Tardaguila et al 2023] [Tijdeman et al 1979] [Traub 1995] [Traub 2022] [Tuncer and Platzer 1998] [Ueno et al 2002] [Valiyff and Arjomandi 2009] [Vallone] [Völker et al 2023] [Wagenmakers 2020] [Wakayama 2000] [Wakayama and Kroo 1998] [Wang and Zhou 2022] [Wang et al 2026] [Welterlen and Leone 1996] [Wild 2021] [Wittenberg 2001] [Xi and Yan 2014] [Xu and Feng 2025] [Young 2010] [Yuan 2026] [Zhang 2024] [Zhang et al 2026] [Zhao and Kapania 2019] [Zhou and Wang 2023] [Zountouridou et al 2023]

Suppression of enemy air defences and time-critical targeting

The mission the vehicle was built for and the one that sets its clock. Suppression of enemy air defences, emitter location, time-critical targeting, the kill chain, threat evaluation and jamming. A mobile emitter that shuts down sets a deadline, and whether the loop closes inside it is the question the mission poses to the autonomy.

209 records. [Adrian 2007] [Adrian 2008] [Advancing Network Securing Strategies 2023] [Agate et al 2019] [Agee] [Agee and Calabretta 1990] [Air Defense Radar Design 2009] [Al-Rabi 1990] [Amar and Weiss 2008] [An Air Defense System 1995] [Andrews and Gordon 1981] [APPENDIX 1. The Suppression 2017] [Army War Coll Carlisle Barracks Pa 1982] [Asadov et al 2010] [Bader 1990] [Barkdoll et al 2002] [Becker 1992] [Benameur 2001] [Berle 1986] [Bezel 2015] [Biederman et al 1994] [bin Hussin et al 2025] [Bo Yang et al 2008] [Boardman et al 2017] [Borden 1987] [Bozsóki 2014] [Cahyana et al 2024] [Cakir and Kaya 2013] [Cakir et al 2013] [Cakir et al 2013] [Canavan 1993] [Cao and Li 2020] [Cen and Feng 2022] [Chan et al 2012] [Chen and Fowler 2010] [Chen Yongguang and Sun Zhongkang] [Chestnut 1982] [Christopherson 1999] [CIA, Directorate of Intelligence] [Constancias et al 2013] [Dale Groutage 1978] [Darrah et al 2006] [de Sousa and Thoma 2018] [Deergha Rao and Reddy 1994] [Deitchman 2019] [Druzin and Gorevich 2020] [Du and Dilkes 2018] [Electronic Warfare 2010] [Elmes et al 2008] [Fang et al 2010] [Farlik 2015] [Farlik and Tesar 2018] [Feng et al 2020] [Fletcher et al 2007] [Fonseca 2017] [Foucault et al 2020] [Fowler] [Fowler 2001] [Fowler 2001] [Fowler et al 2010] [Fraenkel 2000] [Fu et al 1988] [Fu et al 1988] [Fu et al 2007] [Fucci and Zuzolo 1969] [Gabriel] [Gabriel 1989] [Gaver and Jacobs 1998] [Gething 1987] [Glasgow and Bell 1999] [Gonçalves et al 2020] [Gorodnov 2025] [Griffin and Duck 2002] [Groot et al 2008] [Ground and Airborne RF 2025] [Hanley 1987] [Hao et al 2025] [Harding] [Harrington et al 2021] [Hawkley et al 2005] [Hazinedar 2015] [Heilenday 2000] [Horrigan 1990] [Hsiung and Wichmann] [Hu and Fowler 2008] [Hu and Wen 2013] [Huang et al 2008] [Huie and Fowler 2010] [Huie and Fowler 2011] [Huie and Fowler 2015] [Jiangang et al 2006] [Jo et al 2024] [Kaidenko and Kravchuk 2021] [Kara 2016] [Karako and Dahlgren 2024] [Khalaf-Allah 2021] [Khalaf-Allah 2022] [Kim et al 2021] [Kindley 2015] [Kintz and Gupta 2012] [Kriel and Yarlagadda] [Kudriashov et al 2018] [Kumar et al 2025] [Lee et al 2012] [Liang and Liang 2011] [Liang and Qin 2013] [Lineage of Electronic Warfare 2013] [Liu and Jia 2014] [Liu et al 2010] [Liu et al 2014] [Ma et al 2023] [Mabrouk et al 2022] [Mahapatra 1980] [Marshal 2026] [Masters 1981] [Mathematical standard of MUSIC 2013] [Mattila et al 2014] [Matuszewski and Dikta 2017] [Matuszewski and Kraszewski 2021] [Matuszewski and Kraszewski 2026] [Mellen et al 2003] [Mishra et al 2004] [Morley 2013] [Mustopa 2022] [Nagel and Farmer 1980] [Navarro et al 2018] [Ohm and Marple 2009] [Pack et al] [Paim Gonçalves et al 2024] [Paradowski] [Paradowski] [Pollard and Gould 1998] [Pourhomayoun and Fowler 2010] [Pourhomayoun and Fowler 2011] [Pourhomayoun and Fowler 2011] [Pourhomayoun and Fowler 2014] [Prasetiyo et al 2024] [Purvis 2003] [Purvis et al] [Qiang Wang et al 2008] [Raju and Prahlada 1997] [Rao 1987] [Raps et al] [Ren and Fowler 2009] [Rutkowski et al 2015] [Sands 2009] [Santos 2023] [Saudi Land-Based Air Defenses 2009] [Schatzman 2015] [Schmidt 1986] [Sea and Air Defenses 2005] [Seavoy et al] [Shaw Y. Ong and Pierson] [Shengli Wang et al] [Singh 2025] [Small Uncrewed Aircraft Systems 2025] [Smith et al 1999] [Song et al 2015] [Stegall 2001] [Suminsby 2002] [Sutherland 1979] [Sviestins] [Tanergüçlü et al 2010] [Tang et al 2017] [Tang et al 2017] [The Israeli air force 2020] [The U.S. Air Force 2025] [Thomas 2003] [Timenes 1964] [Tkachenko 2015] [Tkalcevic and Stein] [Toussaint et al 2007] [Tuncer and Cirpan 2022] [Tuyen 2025] [Tzoreff and Weiss 2017] [Novikov 2023] [Vandermeersch et al 2005] [Vichnyakova and Kukhtenko 1998] [Vishnyakova and Kukhtenko 1996] [Volkov et al 2025] [Waddell 1961] [Wang and Wang 2026] [Wang et al 2008] [Wang et al 2012] [Wang et al 2012] [Weber and Huang 2010] [Wenhua Li and Peiguo Liu] [Wu and Fowler] [Wu and Fowler 2006] [Xu et al 2012] [Xu et al 2013] [Xu et al 2014] [Xu Yaowei et al] [Yang and Xu 2022] [Yannone] [Yi et al 2017] [Yiyu and Zhongkang] [Yu et al 2008] [Zhang and Luo 2013] [Zhang and Shen 2023] [Zhang et al 2011] [Zhang et al 2012] [Zhang et al 2020] [Zhang et al 2021] [Zhang et al 2025] [Zhao et al 2016] [Zhao Juanjuan 2016] [Zhong et al 2006] [Zou et al 2009]

Internal weapons carriage and store separation

A bay is a hole in a low observable aeroplane and opening it is the moment it stops being one. Internal carriage, store separation, cavity flow and acoustics, and guided weapon delivery accuracy. The X-45A released a weapon from an internal bay in 2004, the release sequence performed autonomously under human supervision [Boeing unmanned combat aircraft makes aviation history], and no ground separation analysis for it is among the sources used.

200 records. [A Study on the 2007] [Abderrahmane et al 2019] [Ahuja et al 2025] [Aircraft store separation motion 1980] [Allee 1980] [American Airpower in World 2008] [Anderson and Teope 2017] [Arunajatesan et al 2009] [Atwood 1994] [Bacci and Saddington 2022] [Bacci and Saddington 2024] [Bacci and Saddington 2026] [Bacci et al 2026] [Bamber 1961] [Ben-Gida 2022] [Ben-Gida 2023] [Berger and Meyer 1974] [Berglind and Tysell 2010] [Berglind and Tysell 2011] [Billingsley et al 1979] [Black 1968] [Black and Picklesimer 1971] [Blakeley and Diamond 1991] [Boman 2009] [Burke 2013] [Byreddy et al 2003] [Byreddy et al 2005] [Cain et al 1999] [Calise et al 1975] [Carlson 1974] [Carlson et al 1995] [Carter 2012] [Carter and Lind 2012] [Carter and Lind 2012] [Cavallo et al 1999] [Cenko 1992] [Cenko 2025] [Cenko and Madson 1993] [Cenko et al 1981] [Chakravarthy and Szema 1991] [Chan and Zhu 1999] [Chapman 1998] [Chen 1990] [Chen and Cenko 1990] [Cheng et al 2023] [Chin and Gable 1983] [Chow and Marconi 1989] [Ciaponi and Harris] [Clark 1975] [Coley 2024] [Considerations for Safe Store] [Crisalli et al 1979] [Davids and Cenko 2001] [Davis and Welterlen 2003] [Davis et al 2009] [Debasis Chakraborty 2023] [Demir 2018] [Deslandes and Seifert 2000] [Dillard and Nelms] [Dougherty and Kuan 1989] [Dudley and Torres 2007] [Dudley and Westmoreland 2004] [Estimated CEP of Weapon 1970] [Faruqi 2010] [Finney 2010] [Glaze et al 1999] [Gong and Wang 2019] [Gonzalez and Denny 1970] [Gonzalez-Martino et al 2023] [Gough and Carlson 1979] [Hall et al 1973] [Hallberg and Godiksen 2007] [Hao et al 2024] [Harding and Barton 2007] [Harish et al 2006] [Heltsley and Cline 1979] [Heltsley et al 1981] [Hetreed et al 2018] [Hiwale et al 2017] [Hoffren and Salminen 1999] [Janardhan and Grandhi 2003] [Janardhan and Grandhi 2004] [Janardhan et al 2003] [Janardhan et al 2005] [Jiang et al 2024] [Johnson et al 2008] [Jolly and Coley 2026] [Joshi 1998] [Kaykayoglu 1996] [Kim et al 2015] [Kinstler et al] [Kohiyar et al 1992] [Kraft 1994] [Kraft and Lofthouse 2011] [Krekeler et al 1999] [Kugler 2007] [Lackey et al 2011] [Lan et al 1994] [Lasek and Sibilski 2002] [Lawrence and Fensky 1996] [Le et al 2005] [Lee 2010] [Leondes and Rankine 1972] [Lewis and Mills 1973] [Lijewski and Lijewski 1997] [Lijewski and Suhs 1992] [Lijewski and Suhs 1994] [Liu et al 2016] [Lohner and Baum 1991] [Loupy et al 2018] [Maddox 1980] [Madson and Talbot 1996] [Mani et al] [Marcum 2001] [Massengill 1993] [Maury et al 2017] [McCormick et al 2023] [Mebarki et al 2020] [Mills et al 2002] [Moyer 1992] [Moyer and Cenko 1994] [New applications of engineering 1994] [Newman and Baysal 1992] [Nichols 2008] [Nichols and Westmoreland 2006] [Nichols and Westmoreland 2007] [Outten and Kumar 2025] [Pegoda et al 2025] [Peters et al 2021] [Qi et al 2025] [Recording Store Separation Safe 2022] [Reed and Curry 1969] [Rizk et al 2002] [Roe] [Rokita et al 2012] [Rosen 1988] [Ross and Voss 1976] [Sainio and Krandel 1993] [Savery and Coder 2024] [Schmit and Raman 2006] [Schmit et al 2005] [Schuck et al 2003] [Seiner et al 2008] [Seo et al 2023] [Shalaev et al 2003] [Shankar and Malmuth 1980] [Shankar and Malmuth 1981] [Shaw and McGrath 1996] [Shaw and Smith 1977] [Shaw et al 1987] [Shaw et al 1988] [Shaw et al 2001] [Sheta et al 2015] [Sheta et al 2015] [Sheta et al 2017] [Sickles et al 2008] [Simulation of Store Separation 2014] [Sinha and Garg 2018] [Sinha et al 2000] [Sinha et al 2001] [Smith et al 2002] [Smyth 1972] [Snyder et al 2003] [Snyder et al 2010] [Song 2021] [Song and Ai 2021] [Song et al 2022] [Spahr 1974] [Spahr 1975] [Spahr 1987] [Srinivasan 2000] [Stallings 1982] [Stanek 2002] [Stanek 2003] [Stanek 2007] [Sundaram and Wu 1983] [Tait et al 2009] [Talbot and Moyer 1993] [Tamer 2021] [Tembhurnikar et al 2021] [Teng and Yu 2023] [Tian et al 2023] [Tipton and Hodson 1979] [Türk and Güleren 2025] [Unalmis et al 2001] [Van Buren et al 2015] [Veazey 2004] [Weapon Delivery Systems] [Weapons Carriage and Guidance 2006] [Welterlen 2000] [Wilcox 1991] [Wingfield and Venema] [Wolfe et al 2024] [Yang et al 2012] [Yi et al 2020] [Yoo and Meade 2005] [Zhang et al 2026] [Zhu et al 2018] [Zhu et al 2021] [Zugel 2003]

Automatic takeoff, landing and carrier recovery

Where an unmanned aeroplane earns or loses its case. Automatic takeoff and landing, carrier approach and recovery, arresting gear, catapults and aerial refuelling. The X-45A’s first software block was taxi, takeoff and landing, which is this literature’s problem in its simplest form.

179 records. [Abu-Jbara et al 2015] [Aircraft Automatic Approach and 1996] [Aircraft landing procedure 1998] [Amelin 2022] [Anderson 1996] [Application of quasi-object control 2008] [Approach to solving the 2025] [Ausonio et al 2022] [Banks and Paulson 1985] [Barman et al 2025] [Basak and Datta 2026] [Basov et al 1977] [Biertümpfel and Pfifer 2021] [Bihrle 1969] [Billec 1967] [Blackman and Eigenmann 1981] [Brodzinsky 1959] [Brown 2009] [Buell 1970] [Cao et al 2026] [Carter et al 2024] [Chaloff et al 1974] [Chen et al 2015] [Chen et al 2024] [Chernenko and Burnashev 2022] [Chessman 2022] [Chitrakaran et al 2005] [Choi et al 2015] [Clark 1965] [Connelly 1982] [Coombes et al 2013] [Coombes et al 2015] [Coombes et al 2017] [Coutard and Chaumette 2011] [Coutard et al 2011] [Crassidis and Mook 1991] [de Bonfim Gripp and Sampaio 2014] [de Oca and Flores 2020] [della Noce et al 2021] [Dermer] [Ding et al 2015] [Dobrzynski et al 2019] [Dong et al 2021] [Douglas Aircraft Co Long Beach Ca 1963] [Durand and Teper 1964] [Durand and Wasicko 1965] [Durand and Wasicko 1967] [Eaton and Chen 2015] [Farajollahi and Markazi 2010] [Ferrier et al 2015] [Gainutdinova et al 2022] [Garcia et al 2017] [Garg et al 2015] [Georghiou et al 1986] [Gibson et al 1968] [Godfrey 1953] [Gold 1974] [Grasso 1994] [Green and Findlay 2016] [Aerospace Design Co Inc Bedford Ma 1987] [Haitao and Yan 2021] [Han 2022] [Hann-Shing Ju et al] [Hansen et al 2004] [Hansen et al 2005] [Helliwell 1952] [Hess 2019] [Hess and Judd 1976] [Hoy 1963] [Instrument landing of aircraft 1940] [Jarry et al 2020] [Jiang et al 2018] [Joshi and Compton 1985] [Kalinov et al 2021] [Kansas Univ Lawrence 1952] [Kansas Univ Lawrence 1952] [Kaplan 1969] [Kaplan and Sargent 1970] [Kariya et al 2019] [Kariya et al 2020] [Katz 2017] [Ke et al 2014] [Khobin and Goncharenko 2021] [Kistyarev and Wang 2025] [Klochan et al 2015] [Kumar et al 2007] [Lara et al 2025] [Lee et al 2016] [Lehman 1964] [Lehman 1965] [Lehman 1966] [Li and Sun 2018] [Li et al 2025] [Liang et al 2020] [Ling 1970] [Liu et al 2011] [Liu et al 2016] [Liu et al 2022] [Liu et al 2025] [Liu et al 2025] [Liu Zhi and Wang Yong 2012] [Lorenzetti et al 1969] [Lorenzetti et al 2020] [Lowrance and Smith 1996] [Lungu and Lungu 2016] [Lungu et al 2016] [Lv et al 2011] [Lynch 2012] [Ma et al 2019] [Manjarrez et al 2018] [Martorella et al 1981] [McDonald 1980] [McDonald et al 2020] [Mejias et al 2009] [Meng and Li 2014] [Merrick 1971] [Misra and Bai 2018] [Mohammadkarimi and Nobahari 2018] [Muehter 1974] [Pal et al 2024] [Paletta et al 2013] [Parkinson et al 1970] [Patterson and Arena 2015] [Perry and Schneider 1984] [Pierson 1986] [Practice for Handling of] [Prasinos et al 2025] [Qayyum et al 2017] [Qi et al 2018] [Raja 2011] [Regulator with reference model 2022] [Rithirun and Sooraksa 2013] [Rosa et al 2007] [Ryan and Cummings 2016] [Sajjadi et al 2026] [Schallhorn 2020] [Sedlmair et al 2022] [Semakov and Semakov 2020] [Shakernia et al 1999] [Sollie et al 2024] [Specification for Design and] [Steinberg and Page 2001] [Su et al 2018] [Sun 2023] [Sun et al 2022] [Suresh et al 2018] [Tang and Lai 2020] [Tang 2013] [Theis et al 2017] [Theis et al 2018] [Thompson 1965] [Tian and Zhao 2012] [Trobaugh and Obrimski 1980] [Tseng and Epshteyn 2009] [Tweddale et al 2011] [UAV control with active 2023] [Vachon and Ray 2004] [Vechtel 2019] [Walker 1960] [Walker 1961] [Wang and Wang 2013] [Wang et al 2016] [Weingarten 1984] [Wenzel et al 2010] [Williams 1947] [Wolfe and Peters 1968] [Xiao et al 2024] [Xu et al 2017] [Yakimenko et al 2002] [Yaroshevsky and Kuzmin 2018] [Yin et al 2020] [Yuan et al 2025] [Zhang and Jia 2013] [Zhang et al 2022] [Zhang et al 2024] [Zhou et al 2020] [Zhou et al 2022] [Zhu and Qiu 2013] [Zou et al 2026]

Low observable design and signature

Why the aeroplane has that shape and no fin. Radar cross section, low observable planforms, serpentine inlet ducts, absorbing materials and infrared signature suppression. The premise is taken from this literature and nothing in it is computed here.

179 records. [Abdullah and Miao 2026] [Abdullah et al 2025] [Advanced Technology Related to 2020] [Airborne Hydraulic and Control] [Al-Ahmed and Fielding 1999] [Aldowesh et al 2015] [Aleisa et al 2024] [Altman 2008] [Alves et al 2007] [Andersson 2017] [Andersson 2017] [Aronstein 1996] [Bacci and Vagias 2023] [Bae et al 2017] [Ball and Atkinson 1998] [Baranowski 1982] [Baranwal and Mahulikar 2019] [Bhatt and Mahulikar 2022] [Bhatt and Mahulikar 2025] [Bo et al 2024] [Borison 1965] [Brown 1993] [Buckner 2000] [Cathcart and Sheffer 1988] [Chandra et al 2023] [Chaudhury and Chaturvedi 2007] [Chen and Liu 2018] [Cheng and Tsui 2022] [Chernyak 2018] [Chima et al 2010] [Cho et al 2016] [Choi et al 2019] [Choi et al 2023] [Chung and Tuan 2021] [Cogliandro 1986] [Correa et al 1981] [Desmarais et al 1986] [Doan et al 1995] [Dotseth 1970] [Edefur and Tormalm 2018] [Elton 1990] [Esparza 1979] [Forrester] [Frederickson et al 1967] [Fry 2008] [Fuhs 1984] [Future Air Force Needs 2006] [Gaitanakis et al 2020] [Garretson III 1986] [Gjessing 1997] [Gu et al 2014] [Gu et al 2017] [Guay et al 2017] [Guy et al 1995] [Hoehne and Luce 1969] [Houret et al 2025] [Huang et al 2025] [Hughes 1997] [Hughes 2017] [Hydraulic System Survivability for] [Infrared Signature Characterization] [Introduction to Radar Cross 2015] [Introduction to the Aircraft 1985] [Introduction to the Aircraft 2003] [Ishii et al 2016] [Jahangir and Baker 2017] [JanakiRam and Scruggs 1982] [Jenn 2024] [Jeong et al 2024] [Joy and Singh 2022] [Joy and Singh 2023] [Jylha et al 2019] [Kan] [Kao and Anderson 1981] [Kaushal 1995] [Kirk et al 2007] [Kirk et al 2009] [Knott 1993] [Knott 1993] [Knott 2004] [Knott et al 2004] [Kumar et al 2024] [Kurdyla 1963] [Kweon et al 2025] [Lee 2024] [Lekic et al 2015] [Li et al 2010] [Liu and Ji 2018] [Liu et al 2013] [Lu et al 2012] [Mahafza 2022] [Mahulikar et al 2022] [Mammadova et al 2025] [Marcus] [Marcus 2019] [Marenghi et al 2007] [Marty et al 2025] [Max Chung and Tuan 2021] [Military aircraft camouflage coating 2007] [Misovec et al] [Moon et al 2011] [Motevasselian and Jonsson 2009] [Norsell 2003] [Ochodnicky et al 2008] [Orhan 2020] [Ou Yang and Tsai 2020] [Pande et al 2022] [Papageorgiou et al 2018] [Paterson 1999] [Paterson and Paterson 1997] [Peixoto et al] [Persson 2017] [Persson and Bull 2016] [Peto et al 2016] [Pham and Sim 2002] [Piccirillo 1996] [Rabe et al 2004] [Radar Cross Section] [Radar cross section fundamentals 1979] [Radar Cross Section RCS 2000] [Radar Cross Section RCS 2003] [Radar Cross Section RCS 2005] [Radar Cross Section RCS 2016] [Radar Cross-Section Reduction Stealth 2016] [Ratnoo and Shima 2010] [Rooks et al 2002] [Rossi and Frasca 2020] [Rulf and Robertshaw 1987] [Ryapolov et al 2014] [Neethu and Sudhi 2023] [Sai Teja et al 2017] [Santos et al 2014] [Semenikhin and Chernokolpakov 2017] [Shaeffer 2004] [Shaeffer et al 2004] [Shi et al 2023] [Siegel and Lanterman 1963] [Singh and Jha 2015] [Singh et al 2015] [Singh et al 2016] [Soldani 2015] [Strattan 1978] [Su Donglin 2008] [Sullerey and Chandra 2008] [Sullerey et al 2006] [Sullivan and Reynolds 1988] [Sutrakar and Anjana 2025] [Sutrakar et al 2026] [Temporal, Spatial, and Compositional 2025] [Thompson and Komives 2019] [Toomay 1989] [Tsai et al 2016] [Tuley 2004] [van Schalkwyk and Smit 2017] [VanBlaricum 2020] [Varney 1979] [Vasilets et al] [Vinh et al 1994] [Vogel 2016] [Vogel and Junqueira 2017] [Volume 5 OGC CDB] [Volume 5 OGC CDB] [Walton 1994] [Wang et al] [Wang et al 2005] [Wang et al 2025] [Watanabe and Yamada 2021] [Williams 1990] [Williams and Beex] [Wong et al 2006] [Wright 1975] [Wu et al 2022] [Xu et al 2020] [Zdunek and Rachowicz 2014] [Zhang et al 2026] [Zhou and Huang 2020] [Zhou and Huang 2021] [Zohuri 2020] [Özdemi̇r 2020]

Flight test technique, instrumentation and simulation

How an aeroplane’s claims are checked in the air. Flight test planning and management, data reduction and system identification from flight data, envelope expansion, flutter testing, the instrumentation of small unmanned aircraft for test, and the simulation used alongside flight test, for research, combat and unmanned aircraft. It holds the operational test lessons that the section headed What the Data Changed cites, drawn from unmanned aircraft while the X-45A was flying.

171 records. [Air Force Flight Test Center Edwards Afb Ca 1974] [Air Force Flight Test Center Edwards Afb Ca 1974] [Air Force Test Pilot School Edwards Afb Ca 1990] [Aircraft Models 2012] [Aircraft Simulation Model 2022] [Albaker et al 2015] [Alford and Knarr 1999] [Allison 1972] [American Institute of Aeronautics and Astronautics 1992] [Appendix B Aircraft models] [Appendix E. Airframe Parameters 2012] [Armstrong 1977] [Arthurs and Valasek 2016] [Asselin 2021] [Ates et al] [Auborn et al 2003] [Bachelder et al 2004] [Bachelder et al 2011] [Bageshwar 2017] [Bailey et al 1962] [Belcastro et al 2017] [Benders and Koch 2019] [Bennett and Abel 1981] [Benyamen et al 2023] [Blevins et al 2018] [Bosworth and West 1986] [Brieger et al 2008] [Brown 2010] [Brown and Bradley 1981] [Brunner 1996] [Burnett 2002] [Bushey] [Buttrill and Verstynen 2014] [Caleffi and Belo 1993] [Canniff 1969] [Carico 1995] [Carr et al 2003] [Chapter 2. Exploring the 2005] [Chemaly and Weisshaar 1998] [Cheney 1988] [Clarke and Roskam 1982] [Communications Flight Test 2010] [Cronk 2007] [Danowsky et al 2017] [Dauphin et al 2025] [Deepa and Gupta 2023] [Dixon and Roberts 2008] [Dorobantu et al 2013] [Duke and Lux 1983] [Dunlap and Porter 1971] [Dynamic Lateral-Directional Stability Theory 2003] [Dynamic Longitudinal Stability Flight 2003] [Engelien 1994] [Exploring the Flight Envelope 2015] [Farhadi 2017] [Fechter and Mills 1988] [Fletcher 1994] [Flight performance of civil] [Flight Test 2017] [Flight Test Planning 2021] [Foch 1992] [Foch and Toot 1989] [Gera et al 1981] [Gray 2016] [Göktoǧan and Sukkarieh] [Harris et al 2016] [Hart 1992] [Hicks and Petersen 1988] [Hicks and Petersen 1989] [Hines et al 1995] [Hoffer et al 2013] [Holberg and Grabowsky 1981] [Howard and Bray 1992] [Howard et al 1990] [Howard et al 1991] [Howell 1988] [in’t Veld Alexander and Karwal Arun 2012] [Jackson 1995] [Jacobson 2012] [Jategaonkar 2000] [Johnson 2009] [Jordan 1974] [Jorris et al 2011] [Justin James Matt et al 2025] [Kay and Panagos 2004] [Kehoe 1988] [Kelly 1988] [Kennedy 1986] [Krings et al 2013] [Krishana et al 1997] [Kukreja 2007] [Kukreja 2007] [Lang 1981] [Lateral-Directional Stability Theory and 2003] [Lechniak and Melton 2017] [Level Flight Performance Jet 2003] [Longitudinal Control And Trim 2003] [Lorenzetti et al 2017] [Lu et al 2017] [Lykins and Keshmiri 2010] [Mallozzi et al 2014] [Marino 2001] [Masters 1981] [Matos et al 2026] [Mayfield and Smith 1978] [McClelland et al 2025] [McCrink and Gregory 2014] [McDaniel 2017] [McKinnis et al 2021] [Michalowski and Varano 2017] [Miller 1973] [Morger 1988] [Motyka 1975] [Nichols et al 1998] [Norlin 1995] [Padua and Preisighe Viana 2025] [Patel et al 2023] [Performance Evaluation by Flight 1995] [Petersen 1981] [Platz and Bounajem 1992] [Poltavsky and Akhobadze 2022] [Ratliff and Marquart 1995] [Rediess and Melton 1994] [Robertson and Hartfield 1992] [Roscoe et al 2001] [Rzucidło 2013] [Schumacher 1952] [Schweikhard 1983] [Seanor] [Selig 2014] [Sevcik and Oh] [Sevcik and Oh] [Shukla et al 2018] [Siddiqi and Abraham 1988] [Simpson 1972] [Simpson 1979] [Simulation in support of 1988] [Smith 1999] [Soltmann and Hall 2017] [Static Longitudinal Stability Flight 2003] [Stewart and Bauer 1983] [Sunil] [Svendsen 1994] [Swann et al 1981] [System In-Flight Testing 2010] [Süelözgen 2022] [Thornton and Lamy 1992] [Tischler 2018] [Tomczyk 2003] [Traven and Whitley 1995] [Van Bavel 2014] [Van Pelt 1981] [Verhaegen 1988] [Vincent and Franklin 1981] [Ward 1988] [Wardana et al 2021] [Westat Inc Rockville Md 2001] [Williams and Hartford 1987] [Williams and Hartford 1989] [Wingrove 1972] [Wolfe] [Wu and Liu 2021] [Xi et al 2023] [Xiaofei et al 2025] [Xu 2022] [Xu and Keshmiri 2021] [Yuma Proving Ground Az 2013] [Yuma Test Center Yuma Proving Ground Az 2008] [Zajdel et al 2024] [Zanette et al 2019] [Zhai et al 2023]

Verification, validation and the certification of autonomous software

The reason an autonomous combat aircraft is hard to field rather than hard to fly. Verification and validation, certification, run-time assurance, safety cases, formal methods and redundancy management. This literature concerns the distance between an aeroplane cleared to fly as a demonstrator and one cleared to enter service.

128 records. [Aiello et al 2010] [Air Force Safety Agency Kirtland Afb Nm 2000] [Aircraft Design and Certification 2014] [Airworthiness of unmanned aircraft 2018] [Ali et al 2026] [Almuthaybiri and Murphy 2025] [Alomar et al 2023] [Alomar et al 2024] [Assifuah and Jacob 2026] [Avram et al 2017] [Bateman et al 2018] [Belcastro et al 2017] [Birnbaum et al 2014] [Birnbaum et al 2015] [Bulusu et al 2022] [Burken and Larson 2009] [Cardili et al 2026] [Certification Considerations for Highly-Integrated] [Certification of Flight Crews 2000] [Certification of the basic 1973] [Certification of Unmanned Air 2023] [Clark et al 2013] [Clothier et al 2015] [Clothier et al 2017] [Cofer et al 2020] [Cook 2017] [Cook 2024] [Cook and King 2018] [Corraro et al 2003] [Corwin et al 1989] [Cybersecurity of Air Force 2015] [Dalamagkidis et al 2012] [Deckert 1981] [Demir and Seyfullah Babaarslan 2021] [Dunlap et al 2025] [Dvorak 1998] [Fuller 2020] [Fuller et al 2016] [Fuller et al 2017] [Funk 1964] [Gao et al 2021] [Gao et al 2021] [Ghaffari 2020] [Ghatas et al 2017] [Goodman et al 1981] [Grant et al 2017] [Guarro et al 2017] [Halefom et al 2021] [Hancioglu et al 2025] [Hardy 2026] [Hook et al 2016] [Hook et al 2018] [Hryshchenko et al 2019] [Huber et al 2025] [Humphrey 2012] [Hussain et al 2013] [Jacklin 2008] [Jacklin et al 2005] [Jacobsen and Marandi 2021] [Javaid et al 2015] [Lederer et al 1971] [Joos and Pfife 2012] [Joslin 2017] [Karyotakis et al 2021] [Kelley 1970] [Kiriakidis and Bharadwaj 2025] [Kirkendoll 2022] [Kirkendoll 2022] [Kotikalpudi et al 2020] [Krishnamoorthy] [Larsen 1980] [Laurent 2010] [Lee 2002] [Li et al 2026] [Liu et al 2021] [Llanes and Coogan 2023] [Lochow et al 2025] [Malik 2024] [Marx et al 1990] [Miao et al 2024] [Muniraj and Farhood 2017] [Mutuel 2013] [Nagarajan et al 2021] [Nelson 2003] [Nguyen and Jacklin 2010] [Operations of Unmanned Aircraft 2018] [Orrego and Mundy 2007] [Oztekin et al 2011] [Packard et al 2009] [Perez 2010] [Pimm 1976] [Practice for Application of] [Practice for Methods to] [Practices for Unmanned Aircraft] [Prokin and Prokin 2022] [Pyzynski 2020] [Ravaioli et al 2023] [Recommended Practice When Flight 2021] [Rosentrater] [Rozier 2008] [Salvano 2010] [Schierman et al 2008] [Schlautmann et al 2025] [Schneider 2010] [Schumann et al 2009] [Sleeman et al 2008] [Soares et al 2005] [Some Inadequacies of Current 2000] [Specification for Design, Construction] [Srikanthakumar et al 2011] [Standard Practice for Methods] [Standard Specification for Design] [Standard Specification for Positioning] [Stracquodaine et al 2016] [Sward] [Taylor et al 2021] [Torens and Adolf 2018] [Tran] [Tran et al 2020] [UAS Safety Assessment and] [Validation and Verification Process] [Wong et al 2014] [Xu et al 2025] [Yan and Shi 2024] [Yu et al 2018] [Zhang] [Čečrdle 2015] [čečrdle 2023]

Airspace integration, detect and avoid and the regulation of unmanned flight

The rules an unmanned aircraft must satisfy to share airspace with other aircraft. Detect and avoid, the integration of unmanned aircraft into controlled airspace, the air and ground risk of their operations, and the law and regulation of unmanned flight. None of it bound a demonstrator flying from a test range, and all of it binds a successor that leaves one.

123 records. [Aerospace series. Unmanned Aircraft] [Alieksieiev and Tsybov 2025] [Lacher et al] [Anicho et al 2024] [Argrow 2012] [Ayhan et al 2016] [Bartsch 2018] [Canolla et al 2017] [Castillo-Effen and Visnevski 2010] [Categorization and classification of] [Chapter 3U.S. Aviation Regulatory 2016] [Cho 2014] [Clothier and Walker 2014] [Conducting Unmanned Aircraft Flight 2015] [Consiglio et al 2019] [Corraro et al 2020] [Cour-Harbo 2018] [Current Manned Aviation Regulation] [D’Amato et al 2018] [Dalamagkidis et al 2008] [Wing et al 2022] [Wing et al 2022] [Davies et al 2018] [Domercant et al 2014] [Donohue 2017] [Du et al 2024] [Edwards and Mackay 2017] [Ells 2014] [Experiment results on test] [Eyrian] [Ferreira et al 2018] [Fortońska 2022] [Fulton et al 2011] [Gardi et al 2016] [Geffard et al 2021] [Geister and Geister 2013] [Guerin 2015] [Guide for Suggested Procedures] [Hartmann et al 2024] [Hartmann et al 2024] [Henderson 2022] [Highland et al 2020] [Horio et al 2017] [Hossain et al 2023] [Howell et al 2012] [Huang et al 2024] [Huber et al 2021] [Integrating Remotely Piloted Aircraft 2016] [Iqbal and Saleem 2018] [Jack and Hoffler 2014] [Jack and Kc 2020] [Jack et al 2015] [James et al 2020] [Japins et al 2020] [Jaussi and Hoffmann 2018] [Kallinen] [Kc and Jack 2020] [Kenny] [Knisely et al 2012] [Londner 2016] [Lourenço and Páscoa 2024] [Luxhoj and Morton 2011] [Mackie and Lawrence 2019] [Maki et al 2010] [Marshall 2010] [Masutti 2009] [McFadyen and Martin 2016] [McFadyen et al 2016] [Melnyk et al 2014] [Minwalla et al 2016] [Monk et al 2019] [Moses et al 2014] [Mutuel 2013] [Nguyen and Marion 2026] [Noth 2011] [Noth and Luke 2013] [Nysetvold and Salmon 2019] [Ogan 2014] [Oren and Kocyigit 2016] [Owen et al 2014] [Pappas 2016] [Park et al 2014] [Petrock and Huizenga 2006] [Peña et al] [Policy Issues of Remotely 2016] [Politi et al 2021] [Prats et al 2012] [Rainer 2014] [Rainer 2015] [Reitz and Crouse 2009] [Rudnick-Cohen et al 2019] [Schoenbein 2009] [Scott et al 2019] [Shah 2013] [Shively et al 2013] [Shively 2017] [Smith et al 2013] [Smith et al 2014] [Spanò Cuomo and Guglieri 2021] [Specification for Unmanned Aircraft] [Standard Terminology for Unmanned] [Stankunas and Ziliene 2003] [Status and challenges for 2018] [Stremel and Ahmad 2019] [Tabassum et al 2020] [Templin and Mohammad 2011] [Thoughts and Recommendations on] [Truxal and Scott 2024] [Unmanned Aircraft System risk-based 2018] [Unmanned aircraft systems airspace 2011] [Unmanned Aircraft Systems Regulation] [Unmanned and Uncontrolled The 2015] [Wang et al 2025] [Weibel et al 2011] [Weinert et al 2022] [Werner] [Wieland 2025] [Wigfield et al 2007] [Wolf 2013] [Wu et al 2017] [Wu et al 2018] [Yilmaz et al 2022] [Zeitlin 2009]

Unmanned aircraft in history, doctrine and military employment

The vehicle class as its users and historians describe it. Overviews and histories of unmanned aircraft, their military roles and doctrine, the organisation of the units that fly them, entries on fielded systems, and the argument over replacing manned aircraft. It includes an account of DarkStar, the reconnaissance ancestor named in the section headed Programme Origin.

Programme, acquisition and the cost of a demonstrator

Why the programme ended, which is the part of this story that is documented. Acquisition, cost estimation, technology readiness and the transition from demonstrator to programme of record. J-UCAS was cancelled in January 2006 and the reasons were institutional rather than technical, and the cluster holds one review of the flight test site processes and personnel of the X-45A demonstration programme.

101 records. [Adams and Hinders 1974] [Aerospace series. Programme Management] [Aircraft Cost Considerations 2010] [Aircraft Engine Life Cycle] [Akça 2022] [Alden 1993] [Alexander 1979] [Alford 2004] [An Examination of the 2008] [Anish Kaharkar 2013] [Arnold 1981] [Arnold 1983] [Barrett et al 2006] [Bell 1993] [Boito et al 2015] [Boito et al 2016] [Boness and Schwartz 1969] [Burris and Bender 1969] [Carlyle 1976] [Cheng et al 1990] [Connelly 1965] [Cosentino 2008] [Cost Analysis Improvement Group Washington Dc 1980] [Cost-Estimating Relationships for Aircraft 1972] [Coulter et al 2018] [Dantsker and Mancuso 2019] [Draper et al 1983] [Draper et al 2013] [Engblom and Decker 2016] [Erdman and Mitchum 2013] [Fanthorpe et al 2011] [Flight Test Programme 1970] [Friehmelt 2003] [Gao et al 2014] [Gilge 2010] [Glenn et al 2005] [Gould 1981] [Greer 2010] [Gregory and Kim 2022] [Gudmundsson 2014] [Gudmundsson 2022] [Gyazova et al 2020] [Hardy 1983] [Hawkes and White 2008] [Hewitson et al 2018] [Horowitz et al 2014] [Hudson et al 2018] [Jares and Valasek 2022] [Maddalon et al 2021] [Kenyon 1974] [Kundu et al 2002] [Laird 2009] [Lappas and Bozoudis 2018] [Litvinas and Dickerson 2013] [Martindale et al 1974] [Marx 1983] [Marx et al 1995] [Meitzler 1988] [Mirchandani 2020] [Moon 2025] [Morgenfeld 1992] [Nadsadna 2016] [Newcamp 2022] [O’Hanlon et al 2018] [Ozdoeva and Smolyakov 2020] [Palazzo and Rosenfeld 1983] [Parametric Flyaway Cost Estimating 2024] [Peterson and Finkenstadt 2011] [Pieciukiewicz et al 2024] [Potempa and Gentner 1988] [Rebikoff] [Reed et al 1982] [Roger et al 1974] [Rosenthal and Brandeau 1983] [Samoylovitch and Strelets 2000] [Samy et al 2010] [Scanlan et al 2006] [Schuetz 1982] [Sells and Crossley 2023] [Stahl et al 1984] [Stahl et al 2017] [Standard Practice for Development] [Stoll and Davis 1993] [The Aircraft Life Cycle 2013] [Thornton 1994] [Tihansky 1976] [Todd and Simpson 2019] [Trice 1989] [Valerdi 2005] [Wagner 1977] [Wallace et al 2000] [Wang et al 2021] [Warsop and Crowther 2019] [Watkins 2019] [Whitmore et al 1995] [Why do Aircraft Cost] [Xu et al] [Yates 1964] [Yilmaz 2013] [Zhao et al 2011] [Zhao Xiaojia et al 2015]

Datalink, latency and beyond-line-of-sight command

The link is what makes supervision possible and what makes it fragile. Datalinks, latency, beyond-line-of-sight satellite command, bandwidth, lost-link procedures and network-centric command and control. A small cluster for a large subject, which is consistent with military link performance seldom reaching the open bibliographic record.

87 records. [A Service-Oriented Framework for 2007] [Analysis of At-Altitude LTE 2019] [Baek and Lim 2018] [Bass 2006] [Bennett] [Billings and Durlach 2008] [Bostian and Young 2013] [Bouyoucef and Khorasani 2005] [Burns and Gouldie 2019] [Carney 2008] [Cooper 1959] [Cox and Wong 2019] [Development of the structure 2024] [Dimitrov 2025] [Dixon and Frew 2007] [Djuric 2001] [Dobronski 1988] [Farley 1990] [Ford et al 1998] [Frew and Brown] [Gray 2015] [Grisworld 2008] [Havir and Durbin 2004] [Hayashi et al 2022] [Henriksen 2007] [Hunn 2005] [Hunn 2006] [Ivancic et al 2019] [Jain et al 2011] [Jamrok] [Jinwen Liu and Matolak 2017] [Sakakeeny et al] [Sakakeeny et al] [Kainrath et al 2021] [Kashkevych et al 2026] [Kerczewski and Griner 2012] [Kerczewski et al 2013] [Kerczewski et al 2014] [Kerczewski et al 2016] [Khan 2021] [Kim et al 2015] [Kuhn 1984] [Larratt 2001] [Lee 2021] [Matolak 2012] [Mielke 2019] [Mostafa and Schnell 2016] [Mulkerin 2007] [Mund et al 2016] [Nichols 1998] [Okcu 2016] [Ono et al 2017] [Ostermann et al 2024] [Ozger et al 2018] [Peters 2002] [Podhradsky et al 2017] [Proctor and Johnson 2003] [Pugh et al 2020] [Purucker et al 2021] [Purucker et al 2024] [Reichstein et al 2022] [Reyes et al 2012] [Rupar et al 2021] [Sabuwala and Daruwala 2022] [Sadjadi 2004] [Saliy et al 2024] [Sarker and Nahhas 2018] [Schagaev and Kirk 2024] [Schalk and Becker 2021] [Shalkhauser et al 2014] [Soares Lira da Silva et al 2016] [Specification for Design of] [Spura et al 2005] [Sridharan et al 2024] [Stevenson et al 2015] [Sun et al 2017] [Towards a Data Link 2019] [Tsuji et al 2014] [Tsuji et al 2015] [Van Dyke et al 1990] [Wang et al 2017] [Yadav and Balakrishnan 2006] [Yuan et al 2026] [Zhang et al 2016] [Zolanvari et al 2018] [Zolanvari et al 2020] [Çuhadar and Dursun 2016]

What an unmanned aircraft needs in order to know where it is. Inertial and satellite navigation, vision-based and satellite-denied navigation, state estimation, sensor fusion and onboard computing. Neglect time is bounded by how long a vehicle can be trusted to know where it is, which ties this small literature to the keystone and not only to the avionics.

59 records. [Andert and Mejias 2015] [Avionics, Flight Software, and 2012] [Avionics, Flight Software, and 2014] [Azarskov and Dyvnych 2019] [Bekirov et al 2015] [Celik] [Center 1975] [Chelini and Farmer 1981] [Dolph et al] [Cordero et al 2014] [Cross] [D’Urso] [Ding et al 1998] [Distributed system of onboard 2025] [Dixon and Frew] [Du et al 2020] [Electro-Optical, Radio-Frequency, and Electronic 2016] [Fu et al 2015] [Garcia and Valavanis] [Guo] [Hajiyev et al 2015] [Hamnanaka 2018] [Hanna] [Humphrey and Humphrey 1997] [Gregory and Choong 2008] [Kannan et al] [Kozlov 2013] [Ludington et al] [Mammadov 2021] [Morales-Ferre et al 2020] [Mueller 2018] [Munguia et al 2016] [Neto et al 2024] [Ntousis et al 2025] [Opromolla 2020] [Ouyang et al 2024] [Paterson 1991] [Quist and Beard 2013] [Ramasamy 2015] [Rigatos 2012] [Sabatini et al 2015] [Sasiadek and Walker 2010] [Sepehri Boroujeni] [Sineglazov and Tsoba 2022] [Slapnicar] [Starkey et al 2026] [Thompson and Robertson 1990] [Tomczyk and Rogalski 2005] [Vasylenko 2017] [Viollet et al 2009] [Wang et al 2018] [Wang et al 2018] [Wigley and Jasiunas] [Zakharin and Ponomarenko 2017] [Zakharin and Ponomarenko 2017] [Zhang] [Zhang and Qin 2026] [Zhang et al 2025] [Écorchard et al 2017]

Airframe structure, composites and affordability

Affordability was a stated programme objective and not a consequence. Composite structure, sandwich construction, producibility, tooling and cost. No source this article uses describes the X-45A’s structure, so this cluster bears on the class of aircraft rather than on the aeroplane. Six records here concern aircrew fatigue rather than structural fatigue, and they are kept because operator fatigue is the term the section headed Where the Framing Breaks Down finds missing from the fan-out relation.

53 records. [Analysis and Design of 2020] [Ardema 2003] [Bail 2008] [Beaty et al 2016] [Bennett 1990] [Berryman et al 1976] [Bokuchava et al 2019] [Bonded Joints and Repairs 2016] [Calado et al 2019] [Crosby et al 2003] [Curran et al 2009] [Davis 1973] [Dehua and Changyou 1993] [Dotseth et al 1977] [Figge 1973] [Figge and Bernhardt 1975] [Glenn and Koch 1973] [Gore et al 2010] [Graeber 1988] [Green and Fernandez 1994] [Horton and Mayers 1965] [Kikukawa 2020] [Kordonowy and Toupet 2011] [Kosmatka and Panza 2002] [Kundu et al 2003] [Lammen et al 2014] [LeClair 2001] [Leone et al] [Li and Tiniakov 2026] [Mallis et al 2010] [Mallis et al 2023] [Marchinski 1974] [McCombs et al 1968] [O’Brien 1989] [Oakley et al 1997] [Ozyetis and Alemdaroglu 2014] [Practice for Design and] [Qian and Alonso 2018] [Ranson 1993] [Ridgard 2008] [Rothwell 2001] [Sensburg et al 1988] [Siegel 1972] [Skelly 1989] [Slobodyanin 2025] [Snell and Bartholomew 1982] [Srour et al 2021] [Toffol and Ricci 2023] [Walters et al 2002] [Weeks 2001] [Weisshaar 1978] [Wen] [Yang 2025]

Where the Framing Breaks Down

Five places.

The fan-out relation assumes homogeneous vehicles and independent tasks, and combat is neither. Two aircraft attacking the same target are coupled, so neglecting one is not independent of neglecting the other, and the relation’s derivation does not hold. The demonstrated ratio of two is therefore a measurement and the extrapolation to eight is a relation being used outside its assumptions, which is stated here rather than in a footnote.

Interaction time is treated as a property of the system and it is a property of a person on a day. The relation has no term for fatigue, for training, or for the difference between a test operator who helped write the software and a squadron operator who did not. Every fan-out in this article is therefore an upper bound.

The comparison with the F-22 approach borrows a computed case from another article and the two aircraft share no planform. What transfers is the throttle argument, which depends on the glide slope and the lift to drag ratio, and what does not transfer is anything depending on the wing or the yaw derivative. Only the part that transfers is used, and the sensitivity table exists to show that the conclusion does not need the rest.

Treating the X-45C as an answer rather than a question understates it. It was a substantial aeroplane that never flew under its own designation, and an article that gave it equal weight would be a different and more speculative one. The choice is defensible and it is a choice.

Whether the ratio has since been exceeded is the question this article is least able to settle, and it assumes neither answer. A negative answer would be a claim about an operational state of the art, and a bibliographic survey is a poor instrument for negative claims, since the absence of a published better ratio is equally consistent with nobody having achieved one and with nobody having published what they achieved. The survey holds eleven records in the vocabulary of reported operator to vehicle ratios and four of those are a different subject wearing the same words. The record therefore does not say whether the demonstrated two is a hard limit or a neglected opportunity, and a reader should treat that silence as a statement about the open literature and not about the world.

The Source Base

The argument rests on six documents and the rest of the reference list is a map of the surrounding literature.

One carries the relation. The fan-out paper defines the term, gives the relation and shows it can be measured empirically [Olsen and Wood 2004, Fan-out, measuring human control of multiple robots]. Everything done with the keystone comes from that relation and its later extension with a switch cost.

One carries the vehicle. The specialist designation directory gives the programme chronology, the software blocks, the milestone dates, the flight count, the configuration and the specifications of both aircraft [Parsch, Boeing X-45 and X-46, Directory of U.S. Military Rockets and Missiles]. It is a secondary source and it is the best one available, and it is the only source consulted that states plainly that the X-45A controlled yaw by thrust vectoring in the absence of vertical surfaces.

Two carry the demonstration. The contemporary reports of the coordinated flight [Two Boeing X-45A unmanned jets continue coordinated flights] and of the first weapon release [Boeing unmanned combat aircraft makes aviation history] establish the ratio and the date, which is the article’s keystone datum.

Two carry the aeroplane’s own numbers. The government and encyclopaedia entries supply the dimensions, the flight control actuation and the museum placements [X-45 Unmanned Combat Air Vehicle, NASA] [Boeing X-45].

The sources this article uses include no programme test report, flight log or software specification for the X-45A. The open literature does hold seven research papers whose titles name the X-45A or its planform, on its first flight, its aeroservoelastic design and test, its flight control design and test, its autonomous steering, the formation taxi and flight of the two vehicles, the flight test site processes and personnel of the demonstration, and the flow over the planform in a pitch-up [Reichenbach 2003] [Wise 2003] [Brinker 2004] [Davidson 2004] [Brinker and Barker 2005] [Cosentino 2008] [Elkhoury 2016]. Their abstracts are drawn on in the section headed Comparison With Ground Prediction, where four abstracts and one full text could be read and the papers on autonomous steering and on the pitch-up flow have no abstract available. The analysis in the sections headed Sizing From First Principles, The Two Aircraft and Dependent Systems does not depend on them, resting on published dimensions, a published ratio and a relation from a different field.

The research survey holds 6,569 records from Crossref and from NASA’s Technical Reports Server. Records from 2015 or later number 3,113, or 50.8 percent of the 6,125 dated records, records predating 2000 number 998, and the median publication year is 2015.

The Definition of Primary

Report primaries, meaning records with NASA and Defense Technical Information Center identifiers, number 519, or 7.9 percent of the 6,569 research records.

The definition of primary has to fit the subject and this article’s subject spans two fields. A NASA report is primary for the aerodynamics and a conference paper of the Association for Computing Machinery, ACM, is primary for the fan-out relation, and a definition admitting only the first would report this article’s keystone literature as entirely secondary. On that fitted definition, which adds the venues of the American Institute of Aeronautics and Astronautics, AIAA, of SAE International, of the ACM and of the Institute of Electrical and Electronics Engineers, IEEE, primary sources number 3,634 of 6,569, or 55.3 percent. The ACM count is 73, which is small in absolute terms and is the venue the keystone relation was published in.

Thin Subjects

Four subjects the argument rests on are thin in the survey, and each is thin for a different reason. Each is counted over the research titles that carry its terms.

subject	title terms	records
scaling laws across aircraft size	scaling law, scaling laws, scaling analysis, square-cube, geometric similarity, dynamic similarity, allometric, size effect, size effects	1
neglect time and interaction time	neglect time, neglect tolerance, interaction time, interaction times	4
manpower and crew cost	manpower, crew cost, crew costs, crew size, personnel cost, personnel costs, operator cost	3
latency on an unmanned aircraft’s link	latency, time delay, time delays, communication delay, communication delays, transmission delay or time-delayed, in a title that also names an unmanned aerial vehicle, an unmanned aircraft, a UAV, a UAS, a drone, a remotely piloted or uninhabited vehicle, or an aircraft	15

Scaling across aircraft size is a textbook subject rather than a journal one, and it is cited to books accordingly. Neglect time and interaction time belong to a small sub-community while the concepts they name are covered elsewhere in the survey, in the 1,390 records of the cluster on human supervisory control and in the 87 titles that name workload, so the thinness is in the vocabulary and not in the coverage. Manpower and crew cost are thin, and the likeliest reason is that much of the analysis that would answer them is defence work outside the open bibliographic record, which is the same limit this article records for its datalink cluster. Latency is not thin in general, since 236 titles name it, but only fifteen of them also name an unmanned aircraft, and 211 of the other 221 concern teleoperation, so the coupling in the section headed The Command Link rests on a relation and not on measurements of aircraft.

What the Survey Admits

A record is admitted only when a person reading its title finds it on this article’s subject, and the subject spans two fields. A title qualifies either in the vocabulary of aircraft or in the vocabulary of supervising a machine, being supervisory control, fan-out, neglect and interaction time, levels of automation, operator workload and the rest. Bare autonomy, operator, task or workload do not qualify a title, because every discipline that studies work uses them. Not every source the argument rests on qualifies by its title. Remote Manipulative Control with Transmission Delay, published in 1963, uses none of the modern terms for its own subject, having predated latency, teleoperation and supervisory control as terms of art, so a rule written in a field’s current vocabulary cannot reach that field’s origin, and that paper and the other foundational sources on which a relation or a claim here rests are admitted by name.

Many words this subject depends on also name something else, and a record that shares only such a word is excluded. Unmanned also names a civil small-aircraft literature in which the aircraft is a camera and the imagery is the subject, as in photogrammetry, precision agriculture, forestry, flood monitoring, heritage documentation, survey and inspection. It also names the aircraft as a telecommunications node, counter-unmanned work that treats the aircraft as a target, and unmanned ground, surface, underwater and marine vehicles. Autonomous vehicle also names road, rail and traffic vehicles. Supervisory control also names the discrete-event, process-plant and energy-management senses of control theory, in which no human operator appears. Fan-out also names a semiconductor packaging technology, and a chapter titled exactly Fan-Out Technology is recognisable as off subject only by the book it appears in, which is Flip Chip, Hybrid Bonding, Fan-In, and Fan-Out Technology. Radar cross section also names antenna engineering, and the letters SEAD also name a distance education seminar, a school programme and a vehicular network protocol. Correction, retraction and withdrawal notices, figure, table and supplementary-material records, peer-review reports, decision letters and journal front matter are excluded as well, because a survey counts research works and those are parts of works or editorial events rather than works. A review of a book, a reference or definition entry of two pages or fewer, a news item, the record of a whole conference volume and a second deposit of a document already in the survey, such as the preprint of a kept paper, are not admitted either, while an authored encyclopedia article of more than two pages and a textbook chapter are research works and are kept.

Also excluded is aeronautical and engineering work whose only link to this subject is a shared word or a distant application, among them hypersonic, rocket and missile engineering, propeller, electric and fuel-cell propulsion, noise, icing, airline and airport operations, maintenance and aircrew training, landing gear and other airframe subsystems, and the physical-contact and social branches of human-robot interaction. A title on a ground, surface or underwater vehicle is kept only where its subject is human supervision or the coordination of several vehicles.

For aeronautical work the vocabulary of aircraft is not sufficient, and such work is admitted only where it bears on a quantity the argument uses. Those quantities are the tailless, flying wing and blended wing body configuration, the lift to drag ratio, cruise, ceiling and thrust lapse of a jet aircraft, conceptual sizing and mass estimation, yaw by thrust vectoring and the crosswind approach, internal carriage and store separation, the correlation of ground prediction with flight, and the flight test of unmanned, combat and research aircraft. Rotorcraft and vertical takeoff aircraft are excluded except where the subject is their supervision, their cooperation, their onboard planning or the assurance of their autonomy, because the argument never uses that vehicle class. Excluded with them are the design, performance, handling and structure of civil transport, business, light and sport aircraft, flow physics and flow control on generic wings and airfoils, and configurations the argument never uses, such as joined and box wings, lighter-than-air craft, parafoils and micro air vehicles. So are afterburning, turboprop, high-bypass civil, electric, solar and hybrid propulsion together with the sizing of aircraft that carry them, the guidance, seekers and aerodynamics of missiles and munitions, anti-radiation missiles included, flight test instrumentation, ranges and facilities, civil low-altitude unmanned traffic management, and generic decision mathematics in which an unmanned aircraft is only the worked example. A tailless, flying wing or blended wing body design is admitted whatever its class or propulsion, because the configuration is the subject.

Some records of doubtful relevance are kept, and the cut on rotorcraft is by subject and not by platform alone. The supervisory-control and cooperative-control literatures use small rotorcraft as testbeds and those results transfer, so the survey holds nine research titles containing quadrotor or quad-rotor, on formations, swarms, collision avoidance, trajectory planning and run-time assurance. Radar absorbing material for aircraft radar cross section reduction is exactly on subject and is kept, while radar cross section reduction by metasurfaces, absorbers and antenna surfaces that names no aircraft is excluded as electromagnetic engineering, as is the radar cross section of a small drone treated as a target. A title on autonomy, guidance or control that names no platform is kept too, since nothing in it marks it as off subject. Human-factors studies of trust, workload and situation awareness in driving are kept because they measure the operator quantities the fan-out relation depends on, general sizing and weight-estimation methods are kept because the sizing argument does not depend on the engine, and the four records on the organisational span of control are kept for the reason the section headed The Contemporary Literature gives.

The survey has no residual cluster. Every research title belongs to a cluster named for what its titles are, and the smallest, on airframe structure, composites and affordability, holds 53 records.

Every research title has been read for relevance, so the off-topic share that remains is a matter of reading judgement.

Epistemic State

Historical Fact

Boeing received a contract in March 1999 for two X-45A demonstrators. The first airframe was completed in September 2000 and first flew on 22 May 2002, reaching 195 knots at 7,500 feet in a fourteen minute flight. The second flew in November 2002.

The X-45A was tailless with trailing-edge elevons and a yaw thrust vectoring nozzle, with no vertical surfaces, and carried an internal weapons bay of 680 kilograms capacity.

In March 2004 an X-45A released a weapon, in April it hit a target with an inert satellite-guided bomb, in August 2004 two X-45As flew in coordination under a single operator for the first time, and in December 2004 they did so for more than an hour.

The programme ended in July 2005 after 64 flights. J-UCAS was cancelled in January 2006. The X-47B won the Navy competition in August 2007 and the navalised X-45C was terminated.

Both X-45A airframes survive in museums.

Verified by Independent Derivation

The fan-out relation returns exactly two when neglect time equals interaction time, and at least two whenever neglect time is at least the interaction time.

The mass exponent of 2.977 was computed from the published spans and masses and is within one percent of the cube. The same exponent computed from the payloads is 2.976, and the two payload fractions agree to four significant figures at 0.12297 and 0.12289.

Primary sources stand at 3,634 of 6,569 research records, or 55.3 percent, on a definition fitted to a subject spanning two fields, and report primaries alone at 519 or 7.9 percent. Records from 2015 or later number 3,113, or 50.8 percent of dated records, and records predating 2000 number 998. Each of these counts follows from the reference list by the stated rules of The Source Base, so a reader holding the list can recompute it.

The lift to drag ratio the published thrust demands, 16.3, was computed from the standard atmosphere and a corrected-flow engine model, and the sensitivity across ceiling and Mach number was carried through.

The crosswind comparison was run across four assumed aspect ratios and the conclusion holds in every row.

Analysis

The X-45A’s demonstrated fan-out of at least two implies a neglect time at least equal to its interaction time, and at least the interaction time plus twice any switch cost, a minimum autonomy that no cited source states. The demonstration sets no upper bound.

A fleet fan-out of eight requires up to seven times the neglect-to-interaction ratio the X-45A is shown to have achieved, and a switch cost of half the interaction time removes a third of the fan-out.

The X-45C’s published thrust is consistent with its published ceiling and implies a lift to drag ratio of at least 16.3. The two figures pin each other and would not be consistent at 45,000 feet.

The X-45A’s approach carries 11.4 percent of maximum thrust against 7.2 percent for the F-22 case, leaving it better off in the crosswind comparison by a factor between 1.28 and 1.98 across the plausible wing.

Inference

The twenty-month gap between a completed airframe and a first flight locates the programme’s risk in the software. This is inferred from the chronology and is consistent with the milestone structure.

The flight rate of 1.68 a month indicates that the aeroplane was a test rig for the flight control laws rather than the article under test.

The X-45C is not a scaled X-45A despite a mass exponent of 2.977. The exponent comes from a held payload fraction and a tripled payload rather than from geometry, which is inferred from the two fractions agreeing and from the changed planform.

What the Record Does Not Settle

Every quantity in the fan-out relation for the X-45A except a lower bound on the ratio. Neglect time and interaction time were not published in seconds, so only a lower bound on their ratio is known, and the most vehicles one operator could have directed is not known at all.

The link’s latency, bandwidth and budget, which the article shows to be coupled to the fan-out and cannot evaluate.

The X-45A’s wing area, aspect ratio and yaw derivative. None appears in the sources used, so the crosswind comparison is a sensitivity table.

What the X-45C would have achieved, since it never flew as the X-45C.

Why J-UCAS was cancelled. The record shows institutional restructuring and a turn toward a manned bomber, and does not show a technical failure.

Whether a fan-out above two is achievable for armed aircraft at all. The programme opened that question and the sources this article uses do not close it.

On Sources Used With Reservation

No programme test report is among the sources used, the nearest being NASA’s review of the flight test site and its personnel, and the chronology rests on a secondary directory. It is careful, it is cited by others, and it warns about its own specification figures. Every specification in this article inherits that warning.

The museum page returns a bot-mitigation status to automated requests and its existence and title were confirmed by search rather than by retrieval.

On Information Postdating the Editorial Date

This article carries an editorial date of 20 November 2025 and is written from knowledge current at the time of writing, which includes the programme’s cancellation, the X-47B selection and two decades of subsequent unmanned aircraft development.

Out of Scope

The X-46, the next article in this series and Boeing’s separate naval demonstrator, cancelled before an airframe was built.

The X-47, which followed it and won the competition the X-45C lost. Both are treated where the series reaches them, and neither is cited here.

The suppression of enemy air defences mission in operational detail, including the emitter timing that would set the loop deadline, which the survey covers and the article does not compute for want of released figures.

Autonomy verification and certification, the reason an autonomous combat aircraft is hard to field rather than hard to fly, which deserves its own treatment.

The cost case, since no airframe or operating cost figure is among the sources used.

Conclusion

The Boeing X-45A is the aeroplane that showed an unmanned combat aircraft could make the ratio exceed one.

Its keystone is not aerodynamic and its governing relation was written by people studying robots. Fan-out is the number of vehicles one operator can supervise, it equals one plus the ratio of neglect time to interaction time, and at a fan-out of one an unmanned aeroplane has saved the pilot’s life and nothing else. In August 2004 one operator first flew two X-45As in coordination, and in December 2004 did so for more than an hour, which shows a fan-out of at least two and therefore a neglect time at least equal to the interaction time. No source used states that minimum autonomy in any form.

The relation is unforgiving about what more would cost. A fleet ratio of eight demands up to seven times that, a switch cost of half the interaction time removes a third of whatever is achieved, and whether the demonstrated two has since been exceeded for armed aircraft in service is not settled by the sources used. The relation specifies what exceeding it would take, and the record leaves open whether it has been done.

A third finding comes from dividing two numbers in the specification table. The X-45A and the X-45C carry the same payload fraction to four significant figures, being 0.12297 and 0.12289, and the payload was tripled exactly. The near-cubic mass scaling is therefore a consequence of a held payload fraction and not of geometry, a distinction the arithmetic alone cannot reveal.

Two further findings concern figures that look wrong and are not. The X-45C’s quoted thrust looks far too low for its engine family, and tested against the vehicle’s stated ceiling it turns out to be admissible and to pin the aeroplane’s lift to drag ratio at 16.3 or better, which no source used here publishes. The two figures corroborate rather than conflict, a weaker result than an error and a truer one. And the X-45A flew sixty-four times in a tailless configuration yawed in part by thrust vectoring, close to the one the previous article derived could not meet an operational crosswind requirement. It is not a counterexample. Its approach carries 11.4 percent of maximum thrust against the 7.2 percent of the case that article computed, leaving it better off by between 1.28 and 1.98 times across every plausible wing, and the rest is the caveat that article already stated, since a demonstrator at a test range may wait for the wind and an operational aeroplane may not.

What the programme changed is what a demonstrator is now expected to demonstrate. The X-45A’s milestones are software blocks, its flight rate of 1.68 a month is consistent with testing done largely on the ground and on a surrogate, and its airframe was a fixture for its flight control laws. The configuration propagated to the aircraft that followed and the programme itself was cancelled before its successor vehicle flew. The aeroplane that answered the question is in a museum, and the question it answered is still the one being asked.