Sunday, 24 April 2011

Fast Forward ‘Fast Transients’: John Boyd, the F-22 and F-35 in 2016

Air Power Australia - Australia's Independent Defence Think Tank

Air Power Australia NOTAM

13th December, 2010
© 2010 C. L. Mills

Contacts:Peter Goon
Carlo Kopp

Mob: 0419-806-476Mob: 0437-478-224

First prototype of the T-50 PAK-FA during an early test flight, January 2010. Intended to replace the Flanker series, the T-50 PAK-FA improves upon the superlative aerodynamic and kinematic performance of the Flanker, but adds competitive Very Low Observable capability, until recently unique to United States designs (Sukhoiimage).

For any Nation to protect its sovereignty, it must control the airspace over its territory. If that Nation intends to project power, it must control the airspace over its trade routes, areas of its National interest, and at times the airspace of its enemies.

The current weapons system that enable air control are Surface-to-Air Missiles (SAMs) and Air Combat Fighters. The capability of advanced SAMs such as the Russian S-300V, S-300PMU2, S-400 and planned S-500 series continues to expand rapidly. SAMs are best employed as denial and defensive weapons. Air Combat Fighters are inherently more flexible and deployable, and can control vast amounts of airspace, and in hours and minutes, can change the area of operations to defeat threats and dominate new areas. Whether an Air Combat Fighter is Inhabited or Uninhabited is immaterial. Whether or not it is effective is vital.

John Boyd’s gift to the Western World in the 1960’s was the reasoning which led to the development, design and large-scale production of Air Combat Fighters that would dominate any airspace that the US designated. In the late Cold War period, the USSR responded with effective Air Combat Fighters of its own, but being more committed to defending its sovereignty, had a greater emphasis on SAMs.

What was John Boyd’s intellectual basis for this achievement? If we search his brief paper ‘New Conception Air-to-Air Combat’ dated 4 August 1976, the progenesis is clear. His ‘Original Purpose’ was to reduce the ambiguity associated with the relative importance (in air combat) of turn radius, turn rate and/or ‘G’ in air combat manoeuvring. He used the concept of ‘Energy-Manoeuvre’ envelopes of an armed F-4E and then examined simulations and ‘Real World’ situations where the following air combat pairs were examined1:
  • F-100 vs F-86H
  • F-5A vs F-86H
  • F-105 vs MiG-17 (1965)
  • Harrier vs All Comers
  • YF-16/17 vs F-4E
His conclusion was the victor would be the aircraft (and skilled pilot) ‘that has a higher energy rate for any turn rate/radius or a high(er) turn rate/ lower turn radius for any energy rate, within the battle area’. Put simply, victory goes to the aircraft that out-manoeuvres the enemy, gets into a position where its weapons can kill, and can then egress safely, all while denying its enemy any kill opportunities.

These observations should be put into the context of the weapons of the day. While air-to-air missiles were being rapidly developed at the time, they presented a miserable level of reliability in the harsh tropical environment of Vietnam, they had a limited ability to deal with aircraft maneuver, and mediocre seekers that limited successful engagements in both range and target aspect. John Boyd had grown up in the era of the aircraft-mounted gun or cannon, and his mastery of the F-100 and what was to become ‘Energy Maneuvering’ earned him the name of ‘Forty Second Boyd’ – an ability to change from imminent defeat to victory in 40 seconds. Now in the hot seat, Boyd would ‘hose’ his victim from behind with simulated gun fire.

He took these lessons into the Pentagon and applied them to the internecine politics of the Military-Industrial-Complex (MIC). John Boyd had a keenly focused and simple-minded attitude to the world – he wanted his country to win any battle in which it became embroiled. To do so, he knew the Armed Services needed superior weapons – those effective at engaging and convincingly defeating the enemy. His view often crossed the agendas of those in the MIC, and he was very forthright and aggressive in confronting those who blocked his path, completely regardless of their rank and position. This attitude did not aid his career advancement.

Nonetheless, Boyd was very successful, and is considered the ‘Father of the F-15’, the United States' Air Combat Fighter that dominated the skies for decades. He made a profound contribution to the lightweight fighter, the F-16, which gave the USA an effective low-cost ‘second tier’ aircraft, useful in battles not requiring the zenith of air combat ability, and where geography did not require it to operate over larger distances with large payloads.

A concise summary of John Boyd is: gifted, committed, uncompromising. This personality often leads to misconceptions about John Boyd’s views of particular aircraft. While he shaped the design of the F-15 into a highly effective Air Combat Fighter, in his view, it was materially deficient in being overweight and lacking internal fuel, and was correspondingly critical of the final result. In assessing John Boyd’s contribution to control of the air, one must measure his achievements but equally so measure his statements – he always sought the pinnacle of capability in close air combat at expense of all other roles. He had a similar view of the F-22A Raptor, which he considered inadequate, but this aircraft remains the dominant Air Combat Fighter globally, decades later.

Let us now indulge in some informed speculation. What would John Boyd make of the current crop of fighters, weapons and where their evolutionary development is taking future air combat?

The pace of development of Air Combat Fighters and weapons is surprisingly (to many US observers at least) frenetic, especially in those nations playing ‘catch-up’ to reach parity and then wrest air superiority from the United States. Russia is currently in the lead, Europe has some competent Air Combat Fighters and China is only a few years behind and gaining rapidly.

John Boyd would undoubtedly be impressed with contemporary short-range air-to-air missiles: AIM-9X, AA-11 Archer (R-73 & 74), ASRAAM, Darter-A, IRIS-T and Python 4/5, many of which can be fired along a line-of-sight from a Helmet-Mounted-Sight or Display. He would recognize in a flash that these missiles are simply an extension of his Energy Maneouvering concept, extending the close air combat battlespace from a few hundred yards to over ten nautical miles in range, with the endgame killing maneuver being shifted from the aircraft to the missile. Contemporary missiles have multiple times the range and endgame turning capability of the AIM-4 and AIM-9 variants Boyd worked with throughout his career.

He would also be undoubtedly impressed with the development of long range, multi-spectral sensors, and the way data flowing from these sensors and between Air Combat Fighters becomes information and knowledge of the battlespace. The same could be said of contemporary long-range air-to-air missiles, extending the battlespace to more than 200 nautical miles around each Air Combat Fighter fortunate enough to have access to such weapons.

With his knowledge that the early AIM-9s could be easily outmaneuvered by agile Air Combat Fighters, he might be less impressed with those contemporary Beyond-Visual-Range missiles that can be defeated by maneuver, deceived by decoys or confused by electronic countermeasures. He would no doubt, in his classic strident way, insist on the development of more effective long-range weapons. After all, what is the point of having sensors that generate a clear knowledge and understanding of the battlespace, only to be frustrated by an enemy that can easily avoid such missiles, or worse still, an enemy that has a similarly clear picture of the battlespace, but weapons that are effective, unavoidable killers?

He would also instantly understand a point that is lost on many contemporary air combat commentators and analysts – that the Air Combat Fighter with the ability to gets its missile into a firing position first and then egress without taking return fire will be the victor. The aphorism ‘let the missiles do the turning’ is at best a half-truth. Even if agile missiles are in the air at the same time, superior positioning at the firing point can result in the enemy's missiles killing us while forcing our missiles to miss - we lose aircraft, pilots and the fight.

How, from John Boyd’s view of the world, should future air war be waged? This is a verbatim citation from his ‘Fast Transients’ briefing1:

Fast transients … suggest a new conception for air-to-air combat and for waging war.


ACTION: Exploits operating and technical features to:
  • Generate a rapidly changing environment (quick / clear observations, fast tempo, fast transient, quick kill);
  • Inhibit an adversary’s capacity to adapt to such an environment (suppress or distort observations);
GOAL: Un-structure adversaries with a hodge-podge of confusion and disorder by causing him to over and under react because of activity that appears to be uncertain, ambiguous orchaotic.


  • Quick/Clear Scanning Sensors
  • Suppressed/Distorted Signatures
  • Quick and Precise Performance
  • Supercruise
  • Rapid energy Gain and Loss coupled with Hi Turn Rates and Low Turn Radii
  • Hi Pitch Rates / Hi Roll Rates / High Yaw Rates coupled with ease of control
  • Kill Mechanism
  • Quick shoot weapons and fire control system
  • Off Boresight (to which we should add Range)

He who can handle the quickest rate of change survives

(and kills?)

John Boyd’s few words contain a wealth of concepts essential to success in future air combat.

We can survey the current and future Air Combat Fighters being developed and test them against John Boyd’s criteria for success. If our possible adversaries are developing air combat capabilities that we cannot match, then it becomes imperative to fill those gaps, and the design concept for the Next Generation Air Combat Fighter becomes clear.

Fast Transients Criteria:

Air Combat Fighters in IOC Order




F-35 JSF


Observations (in the Battlespace)


Signature Suppress

Activity: (In the Battlespace) (Quick/ Precise Performance)


Rapid Energy Change

Extreme Agility & ControlA

Kill Mechanisms:

Quick Shoot Weps

Quick Shoot Fire Control

Off Boresight/Weps Range

A - Extreme Agility: Agility = Manoeuvrability + Controllability which equals ability to rapidly change energy state plus ability to control such changes precisely and accurately, at will.

B - If the F-35 remains an active program and the current trend of creeping schedule delays persists, there is no guarantee that the F-35 full capability IOC would be any time before an evolved F-22 variant could achieve IOC.

John Boyd died on the 9th March 1997 – far too young as he could have contributed so much more to the development of air combat capabilities. In particular, the way Information and Communications Technology could have improved the lethality and survivability of the future Air Combat Fighter.

Reviewing the contents of Table 1, an extension, particularly in the ‘Kill Mechanisms’ area, is how Information and Communications Technology can add combat effect to an Air Combat Fighter. We are all familiar with ‘Bitching Betty’ who attempts to keep us out of the dirt. Now it is time for Marvelous Marilyn (MM) to keep fighter pilots alive in a fast, furious and lethal close air combat engagement. Monitoring all the incoming data, MM would advise and coax in a mellifluous voice; “John, S-400 SAMS at 70 miles, turn onto 210 to bypass. Four Su-35S at 2 O’Clock – time to arm the missiles.” And becoming strident when danger approaches: “Incoming missile, break left and down NOW! … Missile past, snap onto 150 and fire two LRAAMs at Sukhois 2 and 4 – I have selected them for you.”

This is of course none other than the DARPA “Pilot's Associate” Artificial Intelligence “Augmented Cognition System” envisaged for the F-22A Raptor during the Advanced Tactical Fighter definition effort. It was never implemented as the computer technology of two decades ago was far too slow and bulky for it to fit into a fighter aircraft. The same is no longer true due to Moore's Law driven exponential growth2.

Here is a word of caution about the Pilot’s Associate: it won’t turn a sow’s ear into a silk purse, so if an air combat aircraft does not have ‘the right stuff’ in terms of combat kinematics, the Pilot’s Associate will only be able to warn its master of imminent immolation. This is a fictitious vignette of a future deadly air combat engagement being monitored in PACOM HQ:
A video feed splashes into the screen of the Operations Room, showing images of Chuck looking desperately left and right, trying to spot the missiles inbound from each side. The horizon gyrates wildly as he attempts to find an exit, but they have him skewered. Marilyn speaks, this time in a chilling voice: “Chuck, I warned you to egress, but you over-rode my advice. You cannot avoid these missiles, so I’m sending a video stream to HQ so your wife and children can see your last moment. Goodbye.” A brief blast rocks the frame, and silence on the blank screen casts a pall over the Operation Room.
Conversely, in an aircraft with superb ‘Activity’ (extreme and extreme plus agility), the combination of sensor fusion and assistance from Artificial Intelligence can ramp up the tempo of the close air combat battle, and hopefully move much faster than the adversary. As a meta-action, the US will need to be ‘quick’ to develop an operational “Pilot's Associate” Artificial Intelligence in that Sukhoi has competitive aircraft in the Su-35S and the T-50 PAK-FA, and have implied publicly that their pilots will be assisted with an advanced fire control and flight control system, under the watchful purview of what is being called the Electronic Pilot”.

With the competition now catching up with the baseline F-22A Raptor, and the F-35 not being designed to ever be capable of ‘fast transients’, it is time to make the Next Generation Air Combat Fighter a capability development emergency.

What are the options? The logic is stark:
  1. A Pilot’s Associate will not rescue aircraft like the F/A-18E/F and the F-35 Joint Strike Fighter from a shortage of the kinematic ‘right stuff’ for future, high intensity, fast transient air combat;
  1. With potential adversaries having imminent access to air combat aircraft such as the Su-35S and the T-50 PAK-FA, there is insufficient time to start with a ‘blank sheet’ and produce a superior Air Combat Fighter without an air combat capability gap of a decade or more;
  1. The F-22A remains the air dominant Air Combat Fighter, but its days of uncontested superiority are numbered as the T-50 PAK-FA matures and is deployed operationally.
The F-22A provides the technological ‘springboard’ that the USA needs to develop an Air Combat Fighter that will dominate the T-50 PAK-FA. The USA can avoid medium-term, high-risk air combat capability shortfalls by switching Air Combat Fighter production funding to the only proven and viable air dominance fighter – the F-22A3.

Taking such action immediately would provide top-cover for the also urgent and necessary evolutionary development of the Super Raptor – the “F-22E”. We can take advice from John Boyd’s work to produce an Air Combat Fighter that has all the characteristics of his ‘Fast Transients’ concept, extrapolated into the near future.

If the USA is not to surrender the future dominance of airspace of its choice, and avoid the risk of dominance of its airspace to foreign intruders, the “F-22E Super Raptor” is the only option available. Current thinking that would see massive re-design effort applied to the F-35A and C variants of the Joint Strike Fighter with commensurate cost and schedule blow outs in the program should be seen for what it is - nothing more a fool's errand4.

F-22A vs F-15C

An F-15C formates on an F-22A. The F-22A was intended to replace the US Air Force F-15C, and remains the only Western air combat fighter design kinematically competitive against new Russian designs (US Air Force photo).


1 Colonel John R. Boyd, USAF, Fast Transients, URI:

2 Banks S.B. and Lizza C.S., Pilot's Associate: A Cooperative, Knowledge-Based System Application, IEEE Expert: Intelligent Systems and Their Applications, Volume 6 Issue 3, June 1991, cite: “The Pilot's Associate program, a joint effort of the Defense Advanced Research Projects Agency (DARPA) and the US Air Force to build a cooperative, knowledge-based system to help pilots make decisions is described, and the lessons learned are examined. The Pilot's Associate concept developed as a set of cooperating, knowledge-based subsystems: two assessor and two planning subsystems, and a pilot interface. The two assessors, situation assessment and system status, determine the state of the outside world and the aircraft systems, respectively. The two planners, tactics planner and mission planner, react to the dynamic environment by responding to immediate threats and their effects on the prebriefed mission plan. The pilot-vehicle interface subsystem provides the critical connection between the pilot and the rest of the system. The focus is on the air-to-air subsystems.”; see also Pohlmann, L.D. And Payne, J.R., Aerospace and Electronic Systems Magazine, IEEE, August 1988, Volume: 3 Issue: 8

3 A good indication of how good the kinematic performance of the current F-22A Block 10/20 configuration is can be found in the test points being flown in ongoing test work on the aircraft:

4 Refer Joint Strike Fighter Air System Studies (IDIQ) Contract, Solicitation Number: N00019-11-R-0026, Agency: Department of the Navy; Office: Naval Air Systems Command; Location: NAVAIR HQ, URI:

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