The Joint Strike Fighter (JSF) is going to be the mass produced 5th generation aircraft of the 21st
century. Until 26 October 2001 there was an ongoing competition between Lockheed Martin (designer of
aircraft on the left, the X-35) and Boeing (designer of aircraft on the right, the X-32).
The winner of this competition will produce the F-16's replacement. Unlike the
F-22, the JSF will be a relatively low cost aircraft. The U.S. Air Force, U.S. Navy and Royal Navy, and the
US Marine Corps will use the JSF.
Overall the airframes will be alike with a few exceptions; the U.S. Air Force version will be a conventional takeoff multi-role fighter. The U.S. Navy's version of the JSF will be similar to the Air Force version except with a stronger internal structure, landing gear, and arresting hook to allow carrier landings. The U.S. Marine Corps and Britain's Royal Navy version (X-35B) will have a short takeoff and vertical landing (STOVL) capability thus allowing this version of the JSF to land almost anywhere. The JSF will use many of the advanced technologies employed in the F-22 yet still remain a low cost 5th generation fighter. It is scheduled to enter service in around 2012.
The Joint Strike Fighter (JSF) is a multi-role fighter optimised for the air-to-ground role, designed to affordably meet the needs of the Air Force, Navy, Marine Corps and allies, with improved survivability, precision engagement capability, the mobility necessary for future joint operations and the reduced life cycle costs associated with tomorrow's fiscal environment. JSF will benefit from many of the same technologies developed for F-22 and will capitalize on commonality and modularity to maximize affordability.
The 1993 Bottom-Up Review (BUR) determined that a separate tactical aviation modernization program by each Service was not affordable and cancelled the Multi-Role Fighter (MRF) and Advanced Strike Aircraft (A/F-X) program. Acknowledging the need for the capability these cancelled programs were to provide, the BUR initiated the Joint Advanced Strike Technology (JAST) effort to create the building blocks for affordable development of the next-generation strike weapons system. After a review of the program in August 1995, DoD dropped the "T" in the JAST program and the JSF program has emerged from the JAST effort. Fiscal Year 1995 legislation merged the Defense Advanced Research Projects Agency (DARPA) Advanced Short Take-off and Vertical Landing (ASTOVL) program with the JSF Program. This action drew the United Kingdom (UK) Royal Navy into the program, extending a collaboration begun under the DARPA ASTOVL program.
The JSF program will demonstrate two competing weapon system concepts for a tri-service family of aircraft to affordably meet these service needs:
USAF-Multi-role aircraft (primarily air-to-ground) to replace F-16 and A-10 and to complement F-22. The Air Force JSF variant poses the smallest relative engineering challenge. The aircraft has no hover criteria to satisfy, and the characteristics and handling qualities associated with carrier operations do not come into play. As the biggest customer for the JSF, the service will not accept a multirole F-16 fighter replacement that doesn't significantly improve on the original.
USN-Multi-role, stealthy strike fighter to complement F/A-18E/F. Carrier operations account for most of the differences between the Navy version and the other JSF variants. The aircraft has larger wing and tail control surfaces to better manage low-speed approaches. The internal structure of the Navy variant is strengthened up to handle the loads associated with catapult launches and arrested landings. The aircraft has a carrier-suitable tailhook. Its landing gear has a longer stroke and higher load capacity. The aircraft has almost twice the range of an F-18C on internal fuel. The design is also optimised for survivability.
USMC-Multi-role Short Take-Off & Vertical Landing (STOVL) strike fighter to replace AV-8B and F/A-18A/C/D. The Marine variant distinguishes itself from the other variants with its short takeoff/vertical landing capability.
UK-STOVL (supersonic) aircraft to replace the Sea Harrier. Britain's Royal Navy JSF will be very similar to the U.S. Marine variant.
The JSF concept is building these three highly common variants on the same production line using flexible manufacturing technology. Cost benefits result from using a flexible manufacturing approach and common subsystems to gain economies of scale. Cost commonality is projected in the range of 70-90 percent; parts commonality will be lower, but emphasis is on commonality in the higher-priced parts.
The Lockheed Martin X-35 concept for the Marine and Royal Navy variant of the aircraft uses a shaft- driven lift-fan system to achieve Short-Takeoff/Vertical Landing (STOVL) capability. The aircraft will be configured with a Rolls-Royce/Allison shaft-driven lift-fan, roll ducts and a three-bearing swivel main engine nozzle, all coupled to a modified Pratt & Whitney F119 engine that powers all three variants. The Boeing X-32 JSF short takeoff and vertical landing (STOVL) variant for the U.S. Marine Corps and U.K. Royal Navy employs a direct lift system for short takeoffs and vertical landings with uncompromised up-and-away performance.
Key design goals of the JSF system include:
Survivability: radio frequency/infrared signature reduction and on-board countermeasures to survive in the future battlefield--leveraging off F-22 air superiority mission support
Lethality: integration of on- and off-board sensors to enhance delivery of current and future precision weapons
Supportability: reduced logistics footprint and increased sortie generation rate to provide more combat power earlier in theatre
Affordability: focus on reducing cost of developing, procuring and owning JSF to provide adequate force structure
JSF's integrated avionics and stealth are intended to allow it to penetrate surface-to-air missile defenses to destroy targets, when enabled by the F-22's air dominance. The JSF is designed to complement a force structure that includes other stealthy and non-stealthy fighters, bombers, and reconnaissance / surveillance assets.
JSF requirements definition efforts are based on the principles of Cost as an Independent Variable: Early interaction between the warfighter and developer ensures cost / performance trades are made early, when they can most influence weapon system cost. The Joint Requirements Oversight Council has endorsed this approach.
The JSF's approved acquisition strategy provides for the introduction of an alternate engine during Lot 5 of the production phase, the first high rate production lot. OSD is considering several alternative implementation plans which would accelerate this baseline effort.
The focus of the program is producing effectiveness at an affordable price -- the Air Force's unit flyaway cost objective is $28 million (FY94$). This unit recurring flyaway cost is down from a projected, business as usual, cost of $36 million. The Concept Demonstration Phase (CDP) was initiated in November 1996 with the selection of Boeing and Lockheed Martin. Both contractors are: (1) designing and building their concept demonstration aircraft, (2) performing unique ground demonstrations, (3) developing their weapon systems concepts. First operational aircraft delivery is planned for FY08.
The JSF is a joint program with shared acquisition executive responsibilities. The Air Force and Navy each provide approximately equal shares of annual funding, while the United Kingdom is a collaborative partner, contributing $200 million to the CDP. CDP, also known as the Program Definition and Risk Reduction (PDRR) phase, consists of three parallel efforts leading to Milestone II and an Engineering and Manufacturing Development (EMD) start in FY01:
Concept Demonstration Program. The two CDP contracts were competitively awarded to Boeing and Lockheed Martin for ground and flight demonstrations at a cost of $2.2 billion for the 51-month effort, including an additional contract to Pratt & Whitney for the engine. Each CDP contractor will build concept demonstrator aircraft (designated X-32/35). Each contractor will demonstrate commonality and modularity, short take-off and vertical landing, hover and transition, and low-speed carrier approach handling qualities of their aircraft.
Technology Maturation. These efforts evolve key technologies to lower risk for EMD entry. Parallel technology maturation demonstrations are also an integral part of the CDP / PDRR objective of meeting warfighting needs at an affordable cost. Focus is on seven critical areas: avionics, flight systems, manufacturing and producibility, propulsion, structures and materials, supportability, and weapons. Demonstration plans are coordinated with the prime weapon system contractors and results are made available to all program industry participants.
Requirements Definition. This effort leads to Joint Operational Requirements Document completion in FY00; cost/performance trades are key to the process.
|Contractor||two competing teams:|
|Service||U.S. Air Force||U.S. Marine Corps
U.K. Royal Navy
|Variants||Conventional Takeoff and Landing (CTOL)||Short Takeoff and Vertical Landing (STOVL)||Carrier-based (CV)|
|Unit Cost FY94$||$28M||$35M||$38M|
|Propulsion||Baseline: Pratt & Whitney F119-PW-100 derivative from F-22 Raptor|
Alternate Engine: General Electric F120 core
|Empty Weight||~22,500 lbs||~24,000 lbs|
|Internal Fuel||15,000 lbs||16,000 lbs|
|Payload||13,000 lbs||17,000 lbs|
|Maximum Takeoff Weight||~50,000 lbs|
|Wingspan||36 feet||30 feet|
|Combat Radius||over 600 nautical miles|
|First flight (Date Deployed)||1999 (2008)|
|Inventory Objectives||U.S. Air Force
|U.S. Marine Corps
642 aircraftU.K. Royal Navy
text by: John Pike (FAS.org)
The Joint Strike Fighter project may be the largest and most important military aircraft program of the early 21st century, and both the military and contractors have placed large stakes on its outcome. While Boeing's competing X-32 is of unusual configuration, the Lockheed approach tends to resemble its larger cousin, the F-22. The advanced engine derived from that used on the F-22 is fed by two side intakes mounted beneath swept wings of similar platform to the F-22. As with the Boeing entrant, three variants are being studied: the conventional takeoff and landing (CTOL) X-35A for the US Air Force, the short takeoff and vertical landing (STOVL) X-35B for the US Marines and UK Royal Navy, and the carrier-based (CV) X-35C for the US Navy. Also like the X-32, Lockheed has constructed two prototypes for evaluation. The initial X-35A will be used for early flights before being modified and fitted with a second engine. This additional engine, a shaft-driven lift-fan system plus roll control jets along the wings, is coupled to the primary engine to provide the lift for vertical flight. Once complete, this modified airframe will be redesignated X-35B for completion of the STOVL portion of the evaluation process. During the three-month conversion process, the bulk of test flights will be assumed by the X-35C demonstrator for the Navy. This model features an enlarged wing of greater span and area for larger fuel capacity as well as enlarged horizontal tails and flaperons for greater control effectiveness during low-speed carrier approaches. While Boeing has adopted a direct lift STOVL design based on that used in the Harrier, Lockheed has opted for a different approach in meeting the vertical flight requirements. Inspired by the Russian Yak-141, the X-35B incorporates a separate lift fan that is powered by the F119 engine but provides an independent source of thrust in hover. While the Boeing design is more conventional, Lockheed argues that their strategy is better in the long term since it offers more room for growth as the aircraft evolves. The winner of the JSF contest will be announced on 26 October 2001.
|First Flight||(X-35A) 24 October 2000|
||winning design to become operational about 2008|
||(X-35A) $28 million|
(X-35B) $35 million
(X-35C) $38 million
|Length||(X-35A) 50.50 ft (15.41 m)|
(X-35C) 50.80 ft (15.50 m)
|Wingspan||(X-35A) 32.78 ft (10.00 m)|
(X-35C) 43.00 ft (13.12 m)
(X-35C) 29.83 ft (9.10 m) folded
|Height||13.33 ft (4.07 m)?|
|Wing Area||(X-35A) 450 ft2 (41.8 m2)|
(X-35C) 540 ft2 (50.2 m2)
|Empty||about 22,000 lb (9,980 kg)|
|Max Takeoff||about 50,000 lb (22,680 kg)|
|Fuel Capacity||internal: 6,103 kg|
external: 4,423 kg
||about 15,000 lb (6,805 kg)|
|Powerplant||one Pratt & Whitney F119-611 turbofan and one Rolls-Royce/Allison shaft-driven lift-fan|
|Thrust||(PW) about 35,000 lb (155 kN)|
|Max Level Speed||at altitude: Mach 1.5|
at sea level: unknown
|Initial Climb Rate||unknown|
|Range||(X-35C) 1,620 nm (3,000 km)|
|Gun||one 20-mm cannon|
|Mountings||2 internal weapons bays and external hardpoints (only for non-stealthy missions)|
|Air-to-Air Missile||AIM-120 AMRAAM|
|Air-to-Surface Missile||unknown AGM-65 Maveric, AGM-88 HARM, AGM-84 Harpoon|
|Bomb||up to two 1,000 lb (455 kg) bombs (internally) or two 2,000 lb (900 kg) bombs, presumably JDAM|
|X-35A||Multi-role conventional takeoff (CTOL) fighter for US Air Force; 1 built|
|X-35B||Multi-role short takeoff and vertical landing (STOVL) fighter for US Marines and UK Royal Navy equipped with lift fan; X-35A to be converted to X-35B for STOVL tests|
|X-35C||Navalized (CV) fighter similar to X-35A but with larger wings for increased fuel capacity as well as larger horizontal tails and control surfaces; 1 built |
| KNOWN OPERATORS:
||not in service|
text: Aircraft Museum (aerospaceweb.org)
ANALYSIS: Lockheed-Martin F-35 Joint Strike FighterCarlo Kopp, PEng
(Australian Aviation, May/June 2002, p 28-32, p24-27.)
©2002, Aerospace Publications, Pty Ltd, Canberra.
July 15, 2002
Part 1 A Cold War Anachronism?
Judging from the media rhetoric in early January this year, one could almost be forgiven for believing that the Joint Strike Fighter (JSF) was the anointed replacement for Australia's F/A-18A and F-111 fleets - no doubt to the annoyance of many in Defence who are immersed in the complexities of AIR 6000 capabilities definition. The reality of the Joint Strike Fighter is much less sparkling as many would like us to believe. In this month's analysis we will explore some of the issues.
The new LM F-35 Joint Strike Fighter has the distinction of being a `first' in more than one respect. It is the first combat aircraft to leverage the massive US Air Force research & development investment in the F-22 family of aircraft. It is also the first attempt since the 1960s TFX (F-111) program failure to produce a fighter which can meet the needs of all three US services with fighter fleets, as well as the needs of export clients. As the Joint Strike Fighter program includes both conventional, carrier capable and STOVL variants, it is the first ever attempt to create a fighter which spans three very distinct deployment regimes. Finally, it is the first attempt to produce a very low cost aircraft with genuine stealth characteristics.
With the prospect of around 3,000 Joint Strike Fighters for the US services, replacing the F-16A-D, A-10A, F/A-18A-D and AV-8B, and the potential to render all European fighter offerings wholly uncompetitive in the large F-16 and F/A-18 replacement markets, the hope of US manufacturers and their congressional supporters is that the Joint Strike Fighter will become the next F-16 and secure the US industry with an unbeatable advantage in the future `commodity' fighter market. Greed is a powerful motivator in the Joint Strike Fighter program and one which is likely to see most of the obstacles to this aircraft, and its inherent limitations, ignored in the quest for market dominance.
The history of the Joint Strike Fighter (formerly the Joint Advanced Strike Technology - JAST) program is by any measure colourful, its earliest origins tracing back to technology demonstration programs for a Harrier follow-on for the US Marine Corps and multirole fighter for the US Air Force (refer AA December 2001 and http://www.jsf.mil/). The shrinking US aerospace industrial base soon saw significant congressional pressure applied for the initial technology demonstration goal to be extended into a production fighter program. In its current shape the Joint Strike Fighter program could lead to the production of around 3,000 Joint Strike Fighter variants replacing US Air Force F-16Cs, A-10s, US Navy F/A-18Cs, and US Marine Corps and RAF/RN Harrier variants. The lead service in the Joint Strike Fighter program remains the US Air Force.
From the very outset the principal aim of the Joint Strike Fighter program was to produce a low cost mass production strike aircraft which exploits the latest avionic/computer, stealth and production technologies. Given the incessant political threats of F-22 program cancellation held over the US Air Force through most of the 1990s, limiting the air superiority capabilities of the Joint Strike Fighter was a political imperative - moreso given that air superiority capabilities such as high thrust/weight ratio and sustained supersonic cruise are not very compatible with very low unit cost. If the Joint Strike Fighter were to be too snappy a performer in the air superiority game, the F-22 would have been promptly axed thereby shifting USD 20B or more of production costs back by at least a decade much to the delight of vote buyers in the US Congress.
Indeed as recently as a year ago the US Air Force had to defend the F-22 against repeated political attacks, most of which clearly illustrated the almost total technical illiteracy of the F-22's critics. Invariably the argument is that the F-22 is `too big, too costly, too capable' or `built around Cold War needs, thus irrelevant to the modern environment' and that a Joint Strike Fighter can do the job well enough.
The US Air Force crafted the basic definition of the Joint Strike Fighter - its size, performance, load carrying ability and target cost around its principal tactical strike fighter, the Lockheed-Martin F-16CG/CJ. In the mid 1990s US Air Force force structure model the F-15C flew air superiority and air defence tasks, the F-111F, F-15E and F-117A performed the `deep strike' penetration tasks, with the latter used in more heavily defended environments. The venerable Fairchild-Republic A-10A Thunderbolt was used for battlefield interdiction and close air support, together with the F-16CG. Defence suppression was performed by the F-16CG, in concert with AGM-130 firing F-15Es, after the retirement of the formidable F-4G Weasel. In this model targets fall into two distinct bands - those within a 400 NMI radius of friendly runways, and those at 600 NMI and beyond.
This force structure model evolved during the latter part of the Cold War, and combined a relatively diverse mix of fighter capabilities. With the 1970s F-111F, A-10 and F-117A, 1980s F-15C/E and F-16C and a mix of weapons with lineages back to the 1960s, this model was a cumulative aggregation of almost three decades of technology and evolving doctrine. This was the force structure which the US Air Force applied with such devastating effect against the SovBloc modelled Iraqi defences in 1991 and it proved itself convincingly.
There is however one important division which can be drawn through this force structure model - size. With the exception of the small single engine single seat F-16, all of these aircraft are large twin engine fighters designed to push the performance envelope in their respective categories.
The ubiquitous F-16 was a uniquely Cold War phenomenon. With NATO and the Warsaw Pact geographically poised along either side of the Iron Curtain, presenting each other with a concentration of force and targets unprecedented in history, significant imperatives existed for both sides to saturate the theatre with high performance fighters. Whoever won the air superiority game over Central Europe held the decisive advantage in the Cold War standoff. Fighter combat radius and endurance over the target are not issues when the geographical environment puts the two largest military forces on the planet head-to-head across a single frontier.
The Light Weight Fighter (LWF) contest saw the GD YF-16 take the laurels and decisive build numbers over the YF-17. The production F-16A was a day-VFR light weight air combat fighter designed for exceptional transonic agility and good supersonic dash performance when clean, armed with Sidewinders and an internal gun. Its principal role was to destroy enmasse the Soviet and allied Warpac strike fighter fleets in close air combat, and then swing into day-VFR battlefield air interdiction and close air support to eradicate Soviet/Warpac land forces, the latter role to be shared with the F-15A, F-4E and F-111D/E/F. With the Soviet/Warpac fighter fleets dominated by the MiG-21, MiG-23/27 and Su-7/17/22 series, the F-16s would have enjoyed a decisively target rich environment.
With the impending retirement of the F-4E Phantom II, the US Air Force needed a substitute to fill the tactical fighter bomber role. The F-16C, equipped with the LANTIRN Terrain Following Radar and FLIR/laser targeting podset, was to fill this niche. With European theatre geography and threats driving this need, the radius of the F-16 airframe was yet again not an issue.
When the Soviet Empire collapsed, the US Air Force was forced into a massive downsizing program. Under significant budgetary pressure, the remaining F-4E and F-4G aircraft were retired, followed by the F-15A, much of the F-16A fleet and early model F-111A/D/E/G aircraft. By the mid to late nineties, the US Air Force fighter fleet comprised primarily the F-15C, F-16C variants, the F-15E and a small number of F-117As. Most of the massive B-52 fleet was retired and the buy of B-2A `batwing' bombers was chopped from 132 to 60 and then finally 21.
Expectations during this period were that the principal strategic problems the US would confront would be troublesome nations in the Balkans and the Middle East, with ethno-religious conflicts between smaller nation states dominating agenda. In this environment problem nations would be unable to threaten US basing, and the enormous political clout during the `Pax Americana' period would see easy access to basing. Concurrently the US Congress showed little interest in the defence budget, and the US Air Force faced the prospect of an aging and increasingly expensive to run fighter fleet, in a strategic environment where air superiority and safe in-theatre basing were virtually guaranteed.
This was the environment which shaped the Joint Strike Fighter program - a situation in which combat radius, endurance over the target, air superiority performance and availability of in-theatre basing were not principal design imperatives. Cost and industrial base survival pressures were the foremost drivers in the Joint Strike Fighter program. The US Air Force needed a cheap mass production bomb truck to provide a one-for-one replacement of its aging F-16C inventory. The US aerospace industry needed another F-16A with which to saturate export markets and retain their eroding market position against the Dassault Rafale and Eurofighter Typhoon.
Perhaps the greatest misconception about the Joint Strike Fighter program is that it represents a `repeat scenario' when compared to the YF-16/F-16A program - a low cost highly agile air superiority fighter designed to exploit cutting edge technology to provide a shorter ranging supplement to the top end twin engine large fighter (then F-15A, now F-22A) of the period. This misconception misrepresents the central design objectives of the Joint Strike Fighter program against the Light Weight Fighter program, and also ignores the decisive role shift in the F-16 fleet.
In its day the F-16A was perhaps the nastiest close-in air combat fighter in existence, requiring careful tactics by even the top end F-15A air superiority fighter. While the F-16C Block 40/50 is heavier, it is still a respectable air combat fighter even if a dubious bomb truck. The F-16's central design optimisation was the transonic dogfight, reflected in thrust/weight ratio, wing loading, turn rates, climb rates and acceleration. In these parameters it was competitive against the best in the field, even if it could not compete with the thrust/weight ratio, wing loading, climb rates and acceleration of the F-15A.
The Joint Strike Fighter's central design optimisation is in-theatre strike, battlefield interdiction and close air support, reflected in forward sector stealth, internal weapons/fuel capacity and cruise efficiency in clean configuration. In these parameters it outperforms the incumbent F-16C and F/A-18A/C, while providing relatively similar air superiority performance to these types. Against the current yardstick for air superiority performance, the F-22A, the Joint Strike Fighter is a non-contender - its 35 degree class transonic wing and 1:1 thrust/weight ratio are adequate for self-defensive purposes but not in the league for rapidly establishing air supremacy.
Just as the joint Tactical Fighter eXperimental (TFX) or F-111A/B program was cast at an early stage into a conceptual mold of a high speed long range bomb-truck, the Joint Strike Fighter has been cast into the mold of an incrementally improved F-16C / F/A-18C class light bomb-truck, exploiting stealth and modern avionics to provide a survivability edge over its predecessors. The TFX program crashed and burned on the evolving needs of the US Navy, who wanted more air superiority performance and lower carrier landing weights.
Some critics of the Joint Strike Fighter argue that it will `inevitably go the route of the TFX' experiencing cost growth, weight growth and performance loss as it undergoes development and its respective end users load it up with desired design extras to meet their specific needs. Indeed US reports suggest repeated political clashes in recent years, as the US Marine Corps and Navy sought performance and capability improvements which conflicted with US Air Force unit cost targets. Given that the maritime users of the Joint Strike Fighter do not have an F-22 equivalent to gain the high ground in an air battle, it is not inconceivable that we might see downstream disagreements in the Joint Strike Fighter program as these players try to fill this crucial gap in their basic capabilities.
The broader strategic issue for the Joint Strike Fighter will be its basic sizing in a world environment which sees two mutually supporting strategic trends - `problem nations' acquiring ballistic missiles, both mobile and semi-mobile, weapons of mass destruction, and a concurrent trend to implementing `shoot-and-scoot' SAM/AAA air defence tactics. In air power theoretic terms, the use of `shoot-and-scoot' SAM/AAA and ballistic missile/WMD technologies represent an `anti-access' strategy. Such strategies aim to deny the use of nearby runways by threatening ballistic missile or WMD attacks on runways as well as hosting nations, while providing a persistent and highly mobile air defence threat (A good summary of emerging ballistic missile capabilities in this area is at: www.fas.org/nuke/guide/iran/missile/index.html).
Prior to the 11th September, long term US Air Force envisaged a two tier force structure model: the Global Strike Task Force (GSTF) , an Air Expeditionary Force comprising 48 x F-22A and 12 x B-2A, would break the opponent's air defences and launch high tempo attacks on critical command/control/communications, WMD sites and ballistic missile forces. As the opponent's defences would crumble, a `sustainment' Air Expeditionary Force, comprising the Joint Strike Fighter, B-1B and B-52H, would then hammer the opponent to collapse. This model makes two implicit assumptions - the enemy cannot bombard friendly runways with ballistic missiles, and these runways are close enough to permit a viable sortie rate (missions/day) by the Joint Strike Fighter and F-22.
If the opponent chooses to play the ballistic missile bombardment game, then this model does get into some difficulty, since the 400-600 nautical mile range of evolved Scud class missiles presents difficulties for the Joint Strike Fighter - nearby nations might deny basing access and bases which are made available might be shut down by ballistic missile strikes. This is less of an issue for the supercruising F-22, as with decent tanker support it can sustain a high sortie rate from a much greater distance - the F-22 can transit to targets at roughly twice the speed of contemporary fighters and the Joint Strike Fighter.
This was a principal strategic argument against the whole concept of the Joint Strike Fighter prior to the September 11th events. Since then we have seen a pivotal shift in bombardment tactics, with long endurance `loitering bombardment' used to successfully engage and destroy fleeting and highly mobile ground targets. This in turn mitigates against smaller fighters and decisively favours aircraft which have larger bomb loads and endurance. The argument that Afghanistan was a `one-off' does not hold up to scrutiny - a campaign against Iran, Iraq, the PRC or more than one African problem nation could see the very same geographical problem issues arise yet again. Well spoken diplomacy is no match against the threat of domestic terrorism across porous Third World borders, or ballistic missile attacks with conventional or even WMD warheads - all being convincing disincentives to the basing of a US-led Air Expeditionary Force.
Whether one is hunting a high technology Russian mobile SAM system, a mobile ballistic missile system, or a bunch of terrorists in a four wheel drive or BTR-60, the inevitable reality is that the best technique is `loitering bombardment' which is not the forte of smaller fighters - including the Joint Strike Fighter.
The revived argument in the US promoting new build B-2C `batwings' and an F-111/FB-111A class `regional bomber' illustrates this important shift in the bombardment paradigm - and the increasing long term exposure of close-in based Air Expeditionary Forces to MRBM attacks. The argument pits direct operational needs for striking radius, sortie rates and bomb loads in difficult to export or non-exportable top tier assets against the limited yet highly exportable and thus potentially profitable JSF.
Part 2 Sizing up the Joint Strike Fighter
The public rhetoric surrounding the Joint Strike Fighter is no less deceptive to the uninitiated as the public rhetoric surrounding many of the other current production types being bid for AIR 6000. In all instances we hear the `latest avionics technology' and `stealth performance' as key attributes of a `modern high tech fighter' designed to `meet the threats of the future'.
In comparing the Joint Strike Fighter against the Eurofighter Typhoon, Dassault Rafale, F-16C/B60 and F/A-18E/F, the Joint Strike Fighter will have a decisive advantage in its very modern integrated avionic architecture, which is modelled on that of the F-22A but built using militarised commercial computing technology. With a battery of GigaHertz clock speed processors, high speed digital busses with around 1,000 times the throughput of the Mil-Std-1553B busses in the teen series and Eurocanard fighters, it is no contest - the Joint Strike Fighter is in an unbeatable position. While growth versions of the teen series and Eurocanard fighters might see a similar integrated avionic architecture in the post 2010 period, this is unlikely to be a revenue-neutral design change.
Against all of these contenders, the Joint Strike Fighter has an unassailable survivability advantage in its use of evolved second generation stealth technology, again derived from the F-22A technology base. With a forward sector radar cross section cited to be `close to the F-22' the Joint Strike Fighter will present a challenging target to forward sector radar guided threats.
As a bomb truck, the Joint Strike Fighter falls into a similar payload class to these players, but with the important distinction that it carries its bombs or missiles internally, and it has an internal fuel capacity similar to that of these competing aircraft loaded up with external fuel tanks. In practical terms this means that the Joint Strike Fighter can carry a similar load of fuel and bombs without the critical transonic regime drag penalty of external stores. Therefore it can carry the same bomb load further using a similar fuel load. Claims that the X-35 demonstrator exceeded the Joint Strike Fighter combat radius requirement should come as no surprise - the cited figure of 600+ nautical miles is credible and a distinct gain over the F-16C and F/A-18A/C. This radius is however unlikely to be achievable if the F-35 is heavily loaded with external stores, since it will like its competitors incur a major drag penalty.
Claims that the Joint Strike Fighter is an `F-111 class bomb truck' are scarcely credible, especially if the F-111 is armed with internal JDAMs or `small bombs' - a variable geometry wing and 34,000 lb of internal fuel is impossible to beat in the bomb trucking game. The comparison of a clean F-35 against an F-111 loaded with external BRU-3A/Mk.82 is not representative of what a post 2020 F-111 weapons configuration would look like. The only decisive system level advantage the Joint Strike Fighter has against the F-111 is its use of second generation stealth technology - no radar cross section reduction on the F-111 will make it competitive against this type. In terms of avionics, if the RAAF retains the F-111 post-2020 then Joint Strike Fighter generation technology would most likely find its way into the Pig and thus render this comparison meaningless.
As an air combat fighter the Joint Strike Fighter is more difficult to compare, since the differences against the teen series and Eurocanards are less distinct. In terms of achievable radar performance its small aperture radar will fall broadly into the same class as its direct competitors. While transonic turn rate performance figures remain classified, the F-35 is a 9G rated fighter and is thus apt to deliver highly competitive transonic close-in dogfight performance against the teen series and Eurocanards. The empty weight of the F-35, at 26,500 - 30,000 lb is deceptive insofar as it must be compared against a conventional competitor's weight including external pylons and empty fuel tanks - nevertheless it is in the empty weight class of an F-15 or F/A-18E rather than F-16C or F/A-18C.
With a nominal payload of 2,000 lb of AAMs the USAF F-35 yields a combat thrust/weight ratio around 1.1:1 which is competitive against a modestly loaded F-16, F/A-18A/C or Eurocanard, but with a typically better combat radius or combat gas allowance - however it is not in the class of an F-15C let alone F-22A. Therefore the F-35 should provide competitive acceleration and climb performance at similar weights to the F-16, F/A-18A/C or Eurocanards. With the upper portions of the split inlets likely to produce good vortices, the F-35 should provide respectable high alpha performance and handling, especially if flight control software technology from the F-22A was exploited fully.
Where the F-35 is apt to be less than a stellar performer is in the supersonic Beyond Visual Range combat regime, which is the sharp end of air superiority performance. This is primarily a consequence of the wing planform design which is in the 35 degree leading edge sweep angle class, thus placing it between the sweep of the F/A-18A/C and F-16A/C. Wing sweep in this class is good for transonic bomb trucking and tight turning, but incurs a much faster supersonic drag rise with Mach number against the supersonic intercept optimised wing planforms seen in the F-15, Typhoon, Rafale and indeed the F-22A. The important caveat is that the teen series and Eurocanards wear a hefty supersonic drag penalty from carrying external missiles and drop tanks, whereas the F-35 will have a clean wing in this regime.
In the absence of published hard numbers for supersonic acceleration, energy bleed and persistence performance, the only reasonable conclusion is that the F-35 is likely to be competitive against the teen series and Eurocanards in combat configuration but decisively inferior to the F-22A.
Another factor in the BVR game is radar performance, limited by the power/aperture of the radar design. While hard numbers on the F-35's radar are yet to be published, what is available suggests an 800-900 element phased array which is in the class of the F-16C/B60, F/A-18E/F and Eurocanards but well behind the massive 2200 element APG-77 in the F-22A. With a superior processing architecture to the F-16C/B60, F/A-18E/F and Eurocanards the Joint Strike Fighter is very unlikely to have inferior radar performance, but may not have a decisively large detection range advantage either.
If used as an air defence interceptor and air superiority fighter, the F-35 will deliver similar capabilities to the F-16C/B60, F/A-18E/F and Eurocanards at similar weights - its limitations in thrust/weight ratio and thus climb rate/acceleration, and wing optimisation for transonic regimes, will limit its ability to engage high performance supersonic threats by virtue of basic aerodynamic performance. Its small radar will also put limitations on achievable BVR missile engagement ranges, although this will be mitigated by very good forward sector stealth performance. A threat with a large infrared search and track set may however get a firing opportunity in a high altitude clear sky engagement. The radar performance bounds will also present similar limitations to those seen with the F-16C/B60, F/A-18E/F and Eurocanard series when hunting for low flying cruise missiles - without close AWACS support the F-35 may not be very effective in this demanding role.
It is worth noting that the F-35 is not an all-aspect stealth design like the F-22A and YF-23 which have carefully optimised exhaust geometries and thus excellent aft sector radar cross section. The axisymmetric F-135 nozzle is not in this class and thus the F-35 is clearly not intended for the deep penetration strike role of the F-22A.
Attempting to make an all encompassing comparison of the F-35 against current fighters is fraught with some risks, insofar as the design will further evolve before production starts and many design parameters, especially in avionics, may shift. In terms of basic sizing and performance optimizations probably the best yardstick is that the F-35 is much like a `stealthy but incrementally improved F/A-18A/C' which closely reflects the similarity in the basic roles of the two types - strike optimised growth derivatives of lightweight fighters.
The F-35 is clearly out of its league against the F-22A in all cardinal performance parameters, with the exception of its bomb bay size which is built to handle larger weapons than the F-22A. Disregarding stealth capability and baseline avionics, the F-35 is also out of its league against the F-111 in the bomb trucking role by virtue of size and fixed wing geometry.
All of these analytical arguments are essentially contingent upon the JSF meeting its design performance and cost targets. This remains to be seen since the JSF is arguably the highest technological risk program in the pipeline at this time. Key risk factors derive from its reliance upon `bleeding edge' technology to achieve the combination of capability for its size and cost. There are no less than five areas of concern: the COTS derived avionic system departs from established technology and is in many respects a repeat of the F-111D Mk.II avionics idea; the reliance upon software goes well beyond established designs and software systems with many millions of lines of code are not renowned for timely deliveries; any durability problems with the hot running F135 engines would be handled by derating which cuts into an already marginal thrust/weight ratio; differing needs and expectations by the JSF's diverse customer base could cause divergence in program objectives and cost blowouts in `common' areas; the sheer complexity of what the JSF project is trying to achieve in melding untried technologies with diverse missions could create unforeseen problems in its own right. Until we see production JSFs coming off the production line, it remains a high risk option.
The Joint Strike Fighter is a most curious blend of the F-22 technology base, state-of-the-art avionics and Cold War era strategic thinking - in its own way as much a Cold War anachronism as the Eurocanards. Insofar as one of its prime design aims is to shoot down the Eurocanards in the commercial dogfight, it represents an instance of an anachronistic fighter sizing strategy and associated cost structure becoming a principal design driver over achievable combat effect and long term strategic usefulness.
2.1 Joint Strike Fighter vs A6K
With the F-35 being the holy grail of budget minded force planners throughout the West, it has developed some followers in the Canberra defence establishment, especially amongst players who see little importance in the RAAF's established doctrinal and strategic thinking or developing regional environment. Indeed, if we pretend that the PRC doesn't exist and India's strategic competition with the PRC in the region doesn't concern us, and that cruise missiles are not the hottest selling item across the wider region, then the F-35 becomes an attractive proposition - a cheap to buy, cheap to run, stealthy hi-tech fighter which is an incremental improvement over the RAAF's somewhat anaemic F/A-18A Hornet.
As a bomb truck, disregarding stealth performance, the F-35 falls into the gap between the F/A-18A and F-111. As an air combat fighter, it will offer modest performance gains over the F/A-18A HUG and the advantage of stealth. In the eyes of many this is apt to be a `good compromise' at a `good price'.
These arguments may appear superficially reasonable, but are based upon a number of premises which are not reasonable. Regional strategic issues may have disappeared from the press and TV bulletins but remain as they were a year ago:
1.The regional arms race has yet to show signs of abating, and with the War on Terrorism forcing the US to make significant political concessions to China and India we should expect to see both players doing their best to shop for Russian (and Israeli) technology while world attention is focused elsewhere.
2.Shifting tactics in nations opposed to the West will see mobility become the basic tactic for evading air power, given that Afghanistan has proven yet again that bunkers, caves and tunnels are no defence against air power. Loitering bombardment will become the baseline tactic for defeating mobility, demanding larger fighters.
3.Mobile ballistic missiles and cruise missiles are the most rapidly proliferating weapon class in Asia today, and given their value in implementing `anti-access' strategies against Western air power, and political coercion, this is unlikely to change soon. Korea has made a successful business out of the export of extended range Scud derivative technology.
4.The cumulative total of Su-27/30 orders in Asia still remains around the 500 aircraft mark, representing an environment where a 600 nautical mile class subsonic combat radius is not a decisive strategic advantage against the Sukhoi's similar or better radius performance.
5.Turmoil in the Middle East is likely to see long term growth in alternative sources of oil and gas, accelerating development in Australia's Timor Sea and North West Shelf energy industries - and Australia's strategic vulnerability as a result.
6.Uncertainties in the RAAF gaining basing access in South East Asia during a regional crisis remain. While the War on Terrorism may have shifted the focus of Australia's regional interactions, the reality is that much of the region is culturally Muslim and whatever the outcome of the war, political sensitivities in the region will be exacerbated over the nearer and longer term.
The sad reality is that the regional strategic drivers remain as is - they are a consequence of the ongoing economic and military growth in Asia. While India's current relationship with the West has thawed, this situation may not persist over coming decades - the strategic timeline which concerns A6K planning.
What the War on Terrorism will produce, other than major strategic changes in the Middle East and Central Asia, is an increased move to mobility in Asian armed forces as the Afghan campaign is understood fully. It is also apt to produce a longer term demand for coalition campaign forces to support the US in expeditionary warfare.
If we make the assumption that A6K will aim to field only new technology fighters with a very long term development future, then the only relevant candidates are the F-22 and F-35 - both stealthy and using the latest generation avionic architectures and engines.
Numerous strategies exist - with or without F-111 replacement - for implementing the A6K program. If the F-111 is to disappear in 2015-2020, then the choices are a single type replacement using only the F-22, or only the F-35, or some Hi-Lo mix of the F-22 and F-35. If the F-111 is to be stretched beyond 2020, then the F/A-18A could be replaced with either the F-22 or the F-35. This provides no less than 5 possible force structure models, each with different funding needs and capability mixes. Which is best? That depends on the priorities of the observer.
The case for a mix of F119 powered F-111s and F-22s was argued in some detail in AA late last year and presents a robust case in capabilities, with the benefit of significant domestic spending but the drawback of some developmental risk. The case for an F-22 and F-35 mix depends crucially on the perceived importance of bomb-trucking performance vs survivability of the F-35 against the F-111. The F-35's stealth advantage must be weighed against the F-111's superior ability to haul big loads over big distances - with an F-22 escort to kill opposing fighters and SAMs the survivability argument may prove narrower than many may think. A mix in which transonic F-35s escort supercruising F-111s is arguably non-viable and is merely a new technology reimplementation of the existing F/A-18 and F-111 mix.
The alternatives of single type total force replacements with the F-22 or F-35 also raise interesting issues. While the F-35 at this time carries larger bombs than the F-22, it is a decidedly inferior performer in the air combat game and the deep penetration strike game. With supercruise capability in a baseline bombing role using `small bomb' payloads the supercruising F-22's higher sortie rate at longer ranges suggests that one F-22 can perform a similar workload to a pair of F-35s, with the caveat that two or more F-35s will be needed to perform the air defence coverage of a single F-22. In terms of deterrent credibility and potency in combat, the F-22 is unbeatable, in terms of political whining from air power detractors of every ilk, it is a guaranteed magnet (deja vu - F-111 1967?). Conversely, a pure F-35 force structure is apt to leave important capability gaps in air superiority, cruise missile defence and deep penetration strike, while pushing up total numbers and thus aircrew demands - the latter likely to be a major long term issue with ongoing demographic shifts.
A key factor in any F-22 vs F-35 contest is that the F-35 order book is full, but the F-22 buy was hatcheted from around 750 down to 332 thus providing significant incentives for an export sale of an aircraft which would be exclusively available, like the F-111 during the 1960s, only to close and trusted allies of the US. US sources suggest a revived build of 750 F-22s would push the unit cost down to USD 74M, similar to an F-15E.
Which of these strategies proves to be most attractive to Australia's leadership is yet to be seen - and if the government is serious about the A6K effort this will not be known until a decision is reached around the middle of the decade.
What is clear at this stage is that the fighter market is stratifying in a manner without precedent - two decades ago a buyer had more than one choice in any given size/weight/performance class. By 2010 this will be untrue - in non-stealthy fighters there is apt to be only the F/A-18E/F and Typhoon with different weights, aerodynamics and mission avionic capabilities, and in stealthy fighters the F-22 and F-35 which are much more diverse in capabilities than their teen series predecessors, the F-15 and F-16. Therefore a choice of fighter will determine the choice of strategy/doctrine since different classes of fighter provide distinctly different possibilities - and limitations - in roles and missions.
One might ask the question of whether the `classical' model of a fighter competition is even relevant any more? With the only gains from the competitive process likely to be in ancillary benefits such as domestic support programs - aircraft prices being largely fixed by the domestic markets of the manufacturers - one might seriously contemplate the primary focus of the A6K evaluation being in assessing the ability of particular fighter types or mixes/numbers thereof to perform the intended roles, rather than the historical game of playing manufacturers off to secure the best pricing package.
In the context of A6K, the F-35 Joint Strike Fighter is most notable in terms of the roles and missions it cannot do well, rather than those it can. If air superiority and long range strike are the long term priorities which government policy ostensibly declares them to be, then the F-35 may not be the best choice for replacing the F/A-18A or the F-111, either singly or in a mix.