Australia's First Online Journal Covering Air Power Issues [ISSN 1832-2433]
F-22A Raptor Sukhoi PAK-FA and Flanker F-111 Aardvark F/A-18A Hornet Joint Strike Fighter Weapons Aerial Refuelling and Airlift Issues ISR and NCW Issues Regional Military Capability Growth Ballistic Missiles and Missile Defence Surface to Air Missile Systems / Integrated Air Defence Systems
Directed Energy Weapons and Electromagnetic Bombs Systems and Basic Technology Home - Air Power Australia Website Information Warfare, Information Operations and Electronic Attack Air Power and National Military Strategy Issues

Last Updated: Sun Aug 29 16:43:38 UTC 2010


Assessing
Joint Strike Fighter
Air Combat Capabilities
Air Power Australia Analysis 2008-08
  10th November, 2008

by Dr Carlo Kopp, SMAIAA, MIEEE, PEng
©  2008 Carlo Kopp



Given that the simulations cited by the Joint Strike Fighter program office and manufacturer disagree so dramatically against what is known about the capabilities of recent Flanker variants, and their supporting systems, there is a strong case to be made for all of these simulations to be fully audited by an independent body such as RAND or CSBA to determine whether representative adversary capabilities, tactics, doctrine and supporting systems were actually employed. Such disparities between assessments and fact parallel the findings of GAO in vendor and program office cost assessments in the Joint Strike Fighter program, reinforcing the case for a comprehensive Independent Verification and Validation effort on the program's activities. Depicted SDD Joint Strike Fighter Prototype AA-1 in flight. This aircraft is a 'non-representative prototype' which predates a series of structural and systems weight reduction measures.  (Imagery via Air Force Link).


Abstract


 Claims by the Joint Strike Fighter program office and manufacturer that the Joint Strike Fighter can outperform “Sukhois” in air combat operations are impossible to reconcile against what is known about recent developments in Sukhoi Flanker capabilities, and the known design limitations of the Joint Strike Fighter. This paper performs a critical analysis of these statements against known Russian technological capabilities, tactics and doctrine. The only conclusion which can be drawn is that the claimed simulations which yielded a "400 percent result" did not represent the variants of the Flanker which the Joint Strike Fighter will have to confront in operational service, and did not account for known Russian doctrine and capabilities intended to support these fighters. The only feasible explanation for such results is therefore that the simulated engagements were flown by Joint Strike Fighters against legacy Flanker variants with low power N-001 radars, 1980s generation missiles, warning systems, defensive jammers, and supporting systems. Therefore, a 2015 Joint Strike Fighter with its supporting systems is pitted against a 1980s threat without its supporting systems. Such results are only useful in assessing the effectiveness of the Joint Strike Fighter against some African or Middle Eastern nations and are clearly not representative of the Asia-Pacific environment post 2010. The reality is that the “threat environment” the Joint Strike Fighter will confront in the Asia-Pacific is very different to the environment expected and envisaged when the Joint Strike Fighter was conceived during the early 1990s. There have been significant technological advances in two metre band counter stealth radar, passive emitter locating systems, infrared sensors and high power-aperture X-band phased array radars. Moreover, DRFM jammers are proliferating, and Flankers now have the option of towed decoys like the KEDR, both diminishing the effectiveness of the AIM-120 AMRAAM which  is to arm the Joint Strike Fighter. For all practical purposes, technological evolution has rendered the concept of the Joint Strike Fighter obsolete before it has even completed Flight Test or entered full rate production. This is a clear case of failed technological strategy on the part of the Joint Strike Fighter planning staff. It is now abundantly clear that the Joint Strike Fighter is not going to be viable in Beyond Visual Range air combat, just as it was clear from the outset that it would never be a serious player in Within Visual Range air combat. Improvements in the capability and number of internally carried missiles will not turn this problem around, since the opposing sensor and weapons capabilities will continue to evolve over time. The remarkable claims about Joint Strike Fighter air combat performance made recently by the program executives and manufacturer's public relations staff can be explained only if the cited simulations were conducted against 1980s Sukhoi variants, devoid of the capabilities of contemporary and future Flanker variants. As such these claims clearly lack analytical rigour and cannot be taken seriously.



The ongoing debate surrounding the Joint Strike Fighter has seen some remarkable claims made recently by the F-35 program executive officer, Maj. Gen. Charles R. Davis, and the Lockheed Martin executive vice president of F-35 program integration, Tom Burbage. The central argument in these claims by the program executives is that the Joint Strike Fighter will outperform Russian designed “Sukhois” in air combat operations, indeed the opening statement in the manufacturer's media release claims “F-35 Lightning II is at least 400 percent more effective in air-to-air combat capability than the best fighters currently available in the international market.”

However, remarkable claims require remarkable evidence, and to date no such evidence has been forthcoming either from the program office or the manufacturer. Historically, when Joint Strike Fighter advocates have been challenged to provide the supporting assumptions and methodology that were used to compare Joint Strike Fighter capabilities to potential adversary aircraft, the answer has invariably been “this is classified so we cannot tell you”. That in itself is a dubious claim, insofar as such analyses generally involve classification of exact results, but not necessarily classification of how the assessment was performed and which adversary capabilities were assessed.

The most interesting of the recent claims are that the “F-35 enjoys a significant Combat Loss Exchange Ratio advantage over the current and future air-to-air threats, to include Sukhois,” made by Maj. Gen. Charles R. Davis, F-35 program executive officer, and that “the Lockheed Martin F-35 Lightning II is at least 400 percent more effective in air-to-air combat capability than the best fighters currently available in the international market” made by the manufacturer’s public relations office. Both claims were justified by reference to “U.S. Air Force air-to-air combat effectiveness analysis” and “Air Force's standard air-to-air engagement analysis model, also used by allied air forces to assess air-combat performance, pitted the 5th generation F-35 against all advanced 4th generation fighters in a variety of simulated scenarios.”

Importantly, these claims did not specify whether the results were for Within Visual Range (WVR) or Beyond Visual Range (BVR) air combat, or some mix of the two. Which variants of the Sukhoi Flanker, or other types assessed, were also not disclosed. The reader was left to infer that the simulations covered a mix of engagement types, and all aircraft types which the Joint Strike Fighter might confront in combat.

If we consider real world air combat scenarios, there are a wide range of variables which can be applied to constructing a scenario. Some basic considerations include:

  1. Support by Airborne Early Warning & Control aircraft. Did both sides have such support, or did only one side have it, or did neither?
  2. Support by surface based Early Warning or Acquisition radars. Did both sides have such support, or did only one side have it, or did neither?
  3. Support by airborne or surface based passive emitter locating systems. Did both sides have such support, or did only one side have it, or did neither?
  4. Support by aerial refuelling tanker aircraft. Did both sides have such support, or did only one side have it, or did neither?
  5. Intraflight and offboard sensor networking support. Did both sides have such support, or did only one side have it, or did neither?
  6. Standoff jamming support of ground based and AEW&C radar systems, and networks. Did both sides have such support, or did only one side have it, or did neither?
  7. What was context of the simulated air combat engagements? Was the Joint Strike Fighter performing a Defensive Counter Air (DCA) Combat Air Patrol (CAP), a rapid alert runway launched intercept, an Offensive Counter Air (OCA) sweep into hostile airspace, or was it defending itself from interceptors when attacking a ground target?
  8. Were these simulated engagements “One versus One”, “Two versus Two”, “Many versus Many”, or did they involve “One versus Two”, “Two versus One”, etc in force ratios?

These considerations, which represent assumptions about Joint Strike Fighter weapon types and payloads, and assumptions about adversary aircraft types, tactics, employment, radar design, missile design, and supporting radar and sensor system design, will all have a large impact on the results of any simulation. Therefore, the “exchange ratio”, or how many “hostiles” are killed versus “friendlies” lost, can vary significantly depending upon how these variables are set up.

In any aerial clash between two fighter forces, contemporary thinking is to engage and destroy as many opposing fighters as possible at Beyond Visual Range, such that an advantage in numbers can be gained when the surviving enemy fighters close to visual range. At that point, the objective is to gain firing opportunities at visual range before the opponent does, again to inflict losses on the enemy as quickly as possible.

The long history of aerial combat shows that the highest numbers of kills were accrued by pilots who practiced surprise ambush tactics against unsuspecting opponents, and avoided close combat manoeuvring engagements. The very same history shows that pilots flying escort or air defence patrols scored, on average, much fewer kills.

Many historical case studies have revealed frequent and ongoing arguments between fighter pilots seeking to fly independently to maximise opportunities for kills, and those whom they were tasked with protecting, who sought to tether the fighters to their vulnerable assets – be they bombers or surface targets. This dichotomy is one of the unwanted realities of aerial war – wiping out the opponent's air force favours independent fighter operations, and ambush tactics, yet keeping critical surface and airborne assets alive requires that fighters orbit close to these assets to defend them from attacks.

Once fighters are committed to protecting an airborne or surface based asset, they will have no choice other than to patrol a volume of airspace between those assets and the approaching enemy force. The unavoidable geometrical reality is that the area in which they are operating will be therefore well known to the enemy, the instant the location of the asset is known to the enemy.

What follows in turn is a set piece engagement scenario, where the defender plays to keep the attacker away from the defended assets, and the attacker plays to overwhelm or bypass the defenders.

In the contemporary air combat game this set piece scenario unfolds in three phases:
  1. Initial detection and mutual positioning of fighters.
  2. Beyond visual range missile launches, some of which succeed and some of which fail.
  3. Surviving fighters merge and engage at visual range. Some fighters survive in close combat, some are killed.
The only circumstance where the defending fighter does not need to engage in close combat is where all of the approaching attackers are destroyed early, in Beyond Visual Range combat.

These realities are also key factors which have determined the design foci in the Russian Sukhoi Flanker family of fighters, especially the most recent variants. The Flankers are designed to deliver large salvoes of Beyond Visual Range missiles to kill as many defending fighters as early as possible, and force evasive manoeuvring upon the survivors to “spoil” their entry geometry once the Flankers close to visual range and merge. The Flankers are built to excel in close combat, exploiting the refined aerodynamic design of the aircraft, thrust vectoring capability, and high thrust to combat weight ratio.

The notion that air combat will be wholly confined to Beyond Visual Range combat presupposes that an adversary will agree to play this game, even if it is not to their advantage. Real adversaries do not play in this fashion, and never have.

The claim that the Joint Strike Fighter is “at least 400 percent more effective in air-to-air combat capability” therefore needs to be carefully tested against the realities of modern air combat. The notion that an aircraft with unspectacular aerodynamic performance, very limited missile payload, and strongly compromised stealth, is at least half as good as the top tier F-22 is remarkable by any measure. More so since the Joint Strike Fighter lacks the supersonic cruise capability, radar peak power, subsonic and supersonic agility, and all aspect penetration orientated stealth capabilities of the larger F-22.

If we assume that the cited 400 percent is an “exchange ratio” as the statement expects us to infer, it could apply to Beyond Visual Range combat or a mix of Within Visual Range and Beyond Visual Range.

However, the claim cannot apply to Within Visual Range combat alone since all Flankers have better manoeuvring capability in close combat, and like the Joint Strike Fighter are equipped with Helmet Mounted Display/Sight technology. Even if we assume they are both equipped with identical missile types, the Flanker's superior agility and performance, and larger payload of missiles, would result in a decisive advantage over the Joint Strike Fighter. The RAND presentation's observation that the Joint Strike Fighter is “double inferior” to the Flanker in close combat is an unavoidable reality of the Joint Strike Fighter's inferior speed, acceleration, combat thrust to weight ratio, and much higher effective wing (ie lifting area) loading.

At present time the only air to air missile payload planned for the Joint Strike Fighter before 2018 is a pair of internally carried AIM-120 AMRAAM Beyond Visual Range missiles. British Joint Strike Fighter's are to have the option of carrying the ASRAAM Within Visual Range missile instead.

In close combat the best the Joint Strike Fighter can achieve against any Flanker is parity, or a 1:1 exchange ratio – trading one Joint Strike Fighter for every Flanker killed. This is as generous an assessment as is possible, given what we know about the Joint Strike Fighter's aerodynamic performance inferiority relative to the Flanker.

If the cited 400 percent applies to a 50:50 mix of Within Visual Range and Beyond Visual Range engagements, then it follows that to achieve a 4:1 ratio, the Joint Strike Fighter must achieve a 7:1 exchange ratio in Beyond Visual Range engagements. That is effectively claiming that it can almost match the F-22 regardless of the fact that it lacks all of the F-22's additional performance, sensor and stealth capabilities, and it carries at best one half the missile payload of the F-22, and at worst one quarter.

That a Joint Strike Fighter which is optimised for subsonic combat at medium to low altitudes can almost match the F-22 in air combat exchange ratios against advanced Flankers like the Su-35BM or Su-35-1 presents a clear non-sequitur.

The only way a simulation can produce this type of result is if the adversary aircraft are operated in a completely asymmetric environment, with pilots and operational planners who actively cooperate in getting themselves killed by:
  1. Not using known Russian Beyond Visual Range air combat doctrine;
  2. Flying single aircraft sorties rather than sections of four or more aircraft;
  3. Turning off the advanced DRFM jamming equipment intended to spoof the AMRAAM and Joint Strike Fighter's APG-81 radar;
  4. Turning off the InfraRed Search Track system and Missile Approach Warning System;
  5. Turning off the Sukhoi intra and inter-flight networks which allow sharing of target data;
  6. Not using jamming equipment to disrupt the networks supporting the Joint Strike Fighter;
  7. Turning off the Flanker's Irbis-E or Zhuk ASE high power-aperture fire control radar;
  8. Turning off the Flanker's Khibiny Emitter Locating System;
  9. Not carrying a representative payload or mix of missiles;
  10. Not using thrust vectoring to evade the AMRAAM missile;
  11. Not using supersonic cruise to deny the Joint Strike Fighter firing opportunities;
  12. Not deploying supporting two metre band VHF radars which can detect the Joint Strike Fighter;
  13. Not deploying supporting passive Emitter Locating Systems;
  14. Not deploying supporting AEW&C aircraft;
  15. Not using the R-172/R-100 “AWACS-killer” missile to drive away or kill the AEW&C and tanker aircraft supporting the Joint Strike Fighter.
The only logical conclusion which can be drawn is that the claimed simulations which yielded the 400 percent result did not represent the variants of the Flanker which the Joint Strike Fighter will have to confront in operational service, and did not account for known Russian doctrine and capabilities intended to support these fighters.

The only feasible explanation for such results is therefore that the simulated engagements were flown by Joint Strike Fighters against legacy Flanker variants with low power N-001 radars, 1980s generation missiles, warning systems, defensive jammers, and supporting systems. In other words, a 2015 Joint Strike Fighter with its supporting systems is pitted against a 1980s threat without its supporting systems. Such results are only useful in assessing the effectiveness of the Joint Strike Fighter against some African or Middle Eastern nations and are clearly not representative of the Asia-Pacific environment post 2010.



Su-35BM cockpit layout. At this time there are three discrete generations of the Flanker. The first generation was deployed during the 1980s and is represented by the baseline Su-27S/SK Flanker B, Su-27UB/UBK Flanker C. Direct derivatives of the first generation Flanker include the smart weapons capable Su-27SMK, Su-30MKK/MK2 and Chinese clone J-11B. Second generation Flankers are the Su-30MKI and Su-30MKM and the Su-27K/UB/Su-33/33UB which incorporate additional capabilities such as thrust vectoring and phased array radars. The third generation of Flankers is exemplified by the Su-35BM and new production Su-35-1 which expand on second generation features, but include high power-aperture phased array radars, advanced Infrared Search Track systems, advanced networking, 200 nautical mile class "counter-ISR" missiles, and are fully digital (Sukhoi).

Flanker capability is a moving target as the aircraft and its systems have rapidly evolved over the last two decades. This chart compares graphically the peak power aperture product estimates for the Flanker radars, and the APG-79, which considered superior to the Joint Strike Fighter's APG-81. The latter is depicted with some provision for growth. Hybrid array technology used in the BARS and Irbis E provide similar total noise figure for the antenna-receiver design to that of AESA designs like the APG-79. Growth JSF APG-81 radars will be similar to the APG-79. Block upgrades to the BARS to convert it into an Irbis E configuration will not present difficulties as the latter is an uprated derivative of the former.


The MiG-35 Zhuk AE AESA multimode radar designed by Phazotron is the first Russian AESA design. An enlarged variant is in development, intended to deliver similar power aperture performance to the F-22's APG-77 and F-15C's APG-63(V)3/4, strongly outperforming the APG-81 in the Joint Strike Fighter (RSK MiG).




In the simplest of terms, the Joint Strike Fighter is "outgunned" when confronting the Flanker in air combat. With two to possibly four missiles carried, the Joint Strike Fighter confronts an adversary armed with up to 12 missiles (above, from www.jsf.mil, below KnAAPO).






2005 SDD Threshold Weapons. Early F-35s will carry only two internal missiles, either the AIM-120 AMRAAM or ASRAAM. While growth to four missiles remains planned, timelines have not been disclosed to date (www.jsf.mil).

The Joint Strike Fighter cannot achieve a high exchange ratio against an aircraft like the Su-35BM or Su-35-1 for a number of very good reasons:
  1. The advent of advanced high mobility 2 metre band VHF "counter stealth" radars, such as the NNIRT Nebo SVU, Rezonans NE, KBR Vostok E and CETC JY-27 will deny much of the concealment provided by the limited stealth design of the Joint Strike Fighter. The manufacturers of the Vostok E for instance claim a detection range of ~40 nautical miles against the F-117A Nighthawk, or other types with similar VHF band RCS, in a jammed environment, and 190 nautical miles in an unjammed environment.
  2. Advances in Emitter Locating System technology, ground based and airborne, will provide an opponent with early warning and location of the Joint Strike Fighter if its frequency hopping APG-81 radar is employed any other way than sporadically. Such systems include the surveillance component of the electronic warfare suite on the Su-35BM, and the well known 85V6 Orion/Vega, Kolchuga and CETC YLC-20.
  3. The advent of advanced InfraRed Search Track and Emitter Locating systems on the Flanker will deny the element of genuine surprise to a Joint Strike Fighter pilot. Lighting up the APG-81 radar, lighting the afterburner, or launching a missile will give the Joint Strike Fighter's position away, no differently than a submarine launching a torpedo.
  4. The advent of intra-flight and wide area networking capabilities in the Flanker permit much more flexible tactics against the Joint Strike Fighter, but also the use of non-radiating attacks where the Flanker prosecutes the engagement against the Joint Strike Fighter using only tracking data produced by sensors on the ground or other aircraft.
  5. The advanced Flankers are built to cruise supersonically and that presents the lower performance Joint Strike Fighter with genuine challenges in positioning for a shot within the performance envelope of the AMRAAM missile. The instant the afterburner is engaged, the Joint Strike Fighter is exposed and compromised to the Flanker's InfraRed Search Track sensor.
  6. Once the Joint Strike Fighter launches its missile, the Flanker pilot has the option of using his DRFM jammer, or towed decoy to defeat the AMRAAM, as well as using his thrust vectoring to outmanoeuvre the AMRAAM. The AMRAAM is not designed to turn like a Python 4/5, AIM-9X, ASRAAM, or digital R-74.
  7. Once the Flanker detects the Joint Strike Fighter, Russian doctrine is to launch a salvo of two, three or four missiles, with a mix of different seeker types, to complicate defensive manoeuvre by the victim. With its dependency on frequent afterburner use for high performance manoeuvres the Joint Strike Fighter is especially vulnerable to newer heatseeking missiles. An exhaust can be shielded and cooled, an afterburning exhaust plume cannot.

The reality is that the “threat environment” the Joint Strike Fighter will confront in the Asia-Pacific is very different to the environment expected and envisaged when the Joint Strike Fighter was conceived during the early 1990s. There have been significant technological advances in two metre band radar, passive emitter locating systems, infrared sensors and high power-aperture X-band phased array radars. Moreover, DRFM jammers are proliferating, and Flankers now have the option of towed decoys like the KEDR.



Depicted an Su-35 Flanker E (KnAAPO Image)

This is a by-product of the systematic focus in Russian, former Soviet republic, and Chinese industry and research communities on developing technology to defeat the principal technological monopoly of the US military, that is, stealth. While these advances are not strong enough to nullify the top end stealth designs, such as the B-2A and F-22A Raptor, and may never be, they are now rendering the “economy stealth” design of the Joint Strike Fighter susceptible to detection. For all practical purposes, technological evolution has rendered the concept of the Joint Strike Fighter obsolete before it has even completed Flight Test or entered full rate production. This is a clear case of failed technological strategy on the part of the Joint Strike Fighter planning staff.

Central to the Joint Strike Fighter's weaknesses in air combat is its limited payload of internally carried missiles, which simply compounds the problems arising from the Joint Strike Fighter's inferior aerodynamic performance relative to advanced Russian designed fighters. The baseline for the Joint Strike Fighter is a payload of only two AIM-120 missiles, with long term growth to four internal missiles feasible. The claim that six 'superpacked' missiles might be carried remains to be demonstrated.



QF-4 drone. In combat the AIM-120 AMRAAM has delivered kill probabilities of the order of ~50 percent against targets which cannot be considered challenging either aerodynamically or electronically. The standard drone against which the AIM-120 has been tested, including the latest AIM-120D prototypes, is the QF-4, which is not capable of replicating the performance of any Flanker variant, especially not second generation Flankers with thrust vectoring, and third generation Flankers with supersonic cruise and thrust vectoring (US DoD).

The limited number of missiles carried exacerbates the problems arising from the limited ability of even later variants of the AIM-120 to deal with high G manoeuvring targets, equipped with advanced DRFM jammers. The AIM-120 was conceived to defeat massed raids by Soviet era tactical strike aircraft, which had limited manoeuvre performance and poor defensive systems, and could thus be picked off easily. While the seeker and propulsion in the AIM-120 have evolved considerably since the AIM-120A, its basic aerodynamic design and flight profile are not adequate to kill a high G manoeuvring late model Flanker. Claims that the AIM-120 has killed manoeuvring targets in trials should be assessed carefully, since the US has no drone aircraft which can aerodynamically match the supercruising thrust vectoring and extremely agile late model Flanker.

While seeker improvements, and derivative AIM-120 designs equipped with other seekers, such as derivatives of the AGM-88 and AIM-9X designs, would overcome the susceptibility of the active radar seeker to DRFM jammer technology, they cannot overcome the inherent aerodynamic limitations of the AIM-120 airframe design when confronting high G manoeuvring targets.

Where a missile's ability to kill a target is uncertain, the basic strategy to overcome this limitation is to fire salvoes of two, three or four missiles against a single target. The Russians have adopted this model with the later Flanker variants, typically carrying up to twelve Beyond Visual Range missiles. This permits six two round salvoes, four three round salvoes or three four round salvoes for an especially difficult target.

With two, maybe four missiles, the Joint Strike Fighter cannot play this game, and will never be able to do so.

It is now abundantly clear that the Joint Strike Fighter is not going to be viable in Beyond Visual Range air combat, just as it was clear from the outset that it would never be a serious player in Within Visual Range air combat. Improvements in the capability and number of internally carried missiles will not turn this problem around, since the opposing sensor and weapons capabilities will continue to evolve over time.

The remarkable claims about Joint Strike Fighter air combat performance made recently by the program executives and manufacturer's public relations staff can be explained only if the cited simulations were conducted against 1980s Russian Sukhoi variants, devoid of the tactics, sensors, weapons and supporting systems contemporary and future Flanker variants will employ. As such these claims clearly lack analytical rigour and cannot be taken seriously.

JSF Limitations - Click for more ...



Imagery Sources: Author; www.jsf.mil, US DoD.


Air Power Australia Analyses  ISSN   1832-2433


Support Air Power Development in Australia - Click for more ...



Artwork, graphic design, layout and text © 2004 - 2010 Carlo Kopp; Text © 2004 - 2010 Peter Goon; All rights reserved. Recommended browsers. Contact webmaster. Site navigation hints. Current hot topics.
Site Update Status: $Revision: 1.591 $ Site History: Notices and Updates / NLA Pandora Archive