Graham Warwick/ATLANTA

UNIT FLYAWAY COST for some 3,000 production aircraft will be the deciding factor in the competition for the next phase of the Joint Strike Fighter (JSF) programme. The risk involved in developing and producing an aircraft for the cost quoted will be the second major factor, competitors believe.

Before the Joint Advanced Strike Technology (JAST) programme became the JSF, it was known, unofficially, as Joint "Affordable" Strike Technology. The "A" may have gone from the acronym, but affordability remains the programme's principal concern.

At a JSF symposium in Washington DC in June, organised by the American Helicopter Society, speaker after speaker addressed affordability first and the other JSF "pillars" - lethality, survivability and supportability - after. Keynote speaker Noel Longuemare, US principal undersecretary of defence for acquisition and technology, went as far as to say: "The JSF's overall mission is unique: to solve the budgetary problems in all services with one programme."

A frightening prospect, perhaps, for the three teams which submitted bids in mid-June for the $2 billion JSF concept-demonstration phase. Only two teams will win contracts to build and fly concept-demonstrator aircraft - the X-32 and X-35 - and only one will go on to the $16 billion engineering and manufacturing development phase scheduled to begin in 2001.

Indications are good that all three teams - Boeing, Lockheed Martin and McDonnell Douglas (MDC)/Northrop Grumman/British Aerospace - have submitted proposals which meet the JSF performance specifications and cost targets. "Each one is in first place," jokes JSF programme manager Rear Adm Craig Steidle.

Three distinctly different aircraft are on offer (see panels). Boeing is offering a high level of commonality (90%) between the three JSF variants - conventional take-off and landing (CTOL) for the US Air Force, carrier-capable CTOL (CV) for the US Navy and short take-off and vertical landing (STOVL) for the US Marine Corps and UK Royal Navy.

Lockheed Martin is emphasising the low technical risk attached to its JSF, largely the result of near-full-scale testing of its STOVL design, which includes a shaft-driven lift fan. MDC is offering a near-tailless design, meeting the STOVL requirement by the relatively simple expedient of installing a lift engine.

Under contracts to be awarded on 7 November, two teams will each build two concept demonstrators. The CTOL variant will be flown first, then it will be modified to represent the CV version for carrier-approach demonstrations. The second aircraft will represent the STOVL variant and will be used to demonstrate hover and transition handling qualities.

TARGETING COST

"Affordability: it's where we started; it's what we are all about," says Steidle. Unit flyaway cost targets are $28 million for the Air Force JSF, $31-38 million for the USN variant and $30-35 million for the USMC version. Latest estimates put the prices at $27.5 million for the basic CTOL aircraft, $32.3 million for the CV variant and $30.4 million for the STOVL version - an indication that the emphasis on affordability is paying off.

"We cannot afford to fail on JSF; it is critical to the future of tactical air," says Longuemare. "Three separate programmes are absolutely, totally unaffordable," he stresses. Nevertheless, the three US services are having to make difficult decisions to make the programme possible.

"The key issue is affordability. We have to be prepared to make hard cost/performance trade-offs," acknowledges Lt Gen George Meullner, principal deputy assistant secretary for acquisition for the USAF and former head of the JAST programme. As the biggest customer for the JSF, the USAF has the most to lose if it is not affordable. "We need over 2,000 aircraft to replace [Lockheed Martin] F-16s bought at high rates and which will age out at similar rates, beginning in 2007, with a steep drop-off after 2010," says Meullner. "We must meet the unit flyaway cost target or we cannot afford 2,000 aircraft.

"JSF must be affordable or our force structure will decrease," he warns. Meullner says the Air Force cannot afford to sustain its existing force structure, but needs it to meet US national policy objectives. "Our daily operations tempo does not permit us to reduce our forces, so it is imperative that we get off the line of increasing aircraft cost," he says.

COMPETING DEMANDS

At times, the USAF's need for affordability has seemed at odds with the USN's demand for capability. The former is the biggest customer, but the latter - which wants 300 aircraft only - has the most demanding mission. USAF concerns that the Navy's need for more stealth, range and payload will make the JSF unaffordable are being addressed by the prolonged process of drawing up the joint operational-requirements document (JORD), scheduled to be completed in 1999.

"JSF will be the Navy's 'Day One' strike aircraft, beginning in 2010," says Rear Adm Dennis McGinn, US Navy director of air warfare. The Navy's sees the JSF's role as attacking high-value targets and "rolling back" the enemy's integrated air-defences ahead of the MDC F-18E/F. Plans call for each carrier air-wing of 36 F-18Cs and 14 Grumman F-14s to re-equip with 36 F-18E/Fs and 14 JSFs by 2020.

The USN portrays the JSF as leading the air-to-ground and air-to-air assault, supported by F-18E/Fs equipped for electronic warfare, defence suppression and stand-off attack. After enemy air-defences are dismantled, the aircraft would be switched to a more conventional role, operating alongside F-18E/Fs carrying precision-guided munitions.

Survivability is a key USN concern: "We need reduced signature to meet future threats," says McGinn. The USAF, which sees the JSF supporting stealthy Lockheed Martin F-117s and Lockheed Martin/Boeing F-22s, will settle for "...an affordable degree of stealth decided by cost trades," Meullner says. "[The Air Force] JSF is not necessarily a first-day-of-war aircraft...[but] it needs to be survivable," he acknowledges.

Steidle says that the programme office wants "supportable low-observables" which can be maintained easily on carriers. The external lines of each team's JSF variants are near-identical, designers relying on shaping - including aligning all leading and trailing edges - to achieve the basic radar cross-section reduction. The USN variant will receive additional low-observable surface treatment during manufacture.

RANGING FURTHER

Range is another Navy concern, with a required combat radius of at least 1,100km (600nm) carrying two 900kg Joint Stand-Off Weapons and two Advanced Medium-Range Air-to-Air Missiles (AMRAAMs) internally. The USAF is seeking a 850-1,100km radius with two 450kg Joint Direct Attack Munitions and two AMRAAMs internally. All variants will be able to carry external stores on four underwing stations.

"All three JSF designs have good range performance," says Meullner, who adds that the USAF wants "adequate" range to reduce the need for air-refuelling tankers. The differing bomb sizes specified by the two services has complicated design of the JSF weapons bays, but McGinn says that the USN "-has a continuing requirement for two 2,000lb [900kg] bombs. We think it is a very important requirement."

Steidle says that the Navy "-will not compromise" on its requirement to carry two 900kg bombs internally. "It has to do with the first-day-of-war target set," he says, adding: "It's easier to start the design at 2,000lb, then roll back to 1,000lb." McGinn agrees: "Payload is at the heart of the aircraft. Build the aircraft to carry the payload, then you can pack more in as new, smaller weapons emerge."

A JSF programme official says that a high-yield 450kg bomb with the blast/fragmentation effect of a 900kg weapon has been demonstrated under the J1000 programme, "...but the question is, how many will you have in the inventory?" Lockheed Martin has one weapons-bay design for all JSF variants, while MDC has resorted to "expandable bays" - the doors on the centre-fuselage bay can be reconfigured to accommodate the larger-diameter 900kg weapons. MDC's side bays, meanwhile, will each house one 450kg bomb in place of the AMRAAMs they usually house.

Boeing's side bays will each house one 900kg bomb and one AMRAAM - except in the STOVL variant, where the bays have been shortened to make room for the lift nozzles. The shortened bays will still accommodate the two 450kg bombs and two AMRAAMs required by the USMC.

BACKING STOVL

With the exception of its STOVL capability, the USMC's JSF variant will be similar to that of the USAF. "The Marine Corps has deliberately followed the Air Force because, once the aircraft are airborne, their roles are identical," says Lt Gen Harry Blot, US Marine Corps deputy chief of staff for aviation.

The JSF is important because it "-will be the Marine Corps' only strike aircraft. It is vital the aircraft appears in 2007. We can nurse our existing aircraft until then," Blot says. The USMC does not want any more MDC AV-8Bs or F-18s, he maintains, "-and we have over 600 strike aircraft to replace", making it the second largest JSF customer.

Blot staunchly defends the need for STOVL capability. "The Marine Corps uses aircraft instead of heavy artillery. That means the aircraft have to be there," he says, explaining that the 27min air-support response time possible in Vietnam with conventional aircraft was "unacceptable", compared with the 7min now achieved with the STOVL AV-8B. "The Marine Corps has gone down the route of STOVL...we cannot back off," he argues.

The Royal Navy's requirement "...is very, very similar to that of the US Marine Corps," says Air Vice Marshal Peter Norriss, head of fast-jet procurement at the UK Ministry of Defence. The STOVL JSF is the "principal candidate" for the UK's Future Carrier-Based Aircraft (FCBA) requirement to replace the BAe Sea Harrier, which reaches the end of its useful life in 2012, Norriss says.

"We have reached the end of the line for the Harrier, and reached the point where we can take the next step - to supersonic advanced STOVL," Norriss believes. The UK wants a multi-role offensive/defensive aircraft. Required roles include supersonic deck-launched intercept, offensive air-support, stand-off anti-ship attack and reconnaissance. Required characteristics include "...balanced signature reduction, good endurance and good supportability," he says.

There are "two major constraints", Norris says: affordability and compatibility with the Royal Navy's Invincible-class aircraft carriers. "It is vital to all of us that the programme delivers an affordable aircraft," he says, adding privately that he is impressed with the flyaway cost figures being projected.

Compatibility with the UK's small STOVL carriers has challenged the JSF design teams, particularly the limit on wing-span imposed by the elevators on Invincible-class ships. Boeing's STOVL variant lacks small wingtip extensions included on the USAF and US Navy versions, while Lockheed Martin's Royal Navy variant has folding wingtips "weighing around 100lb". Wing folding is a feature of both Navy and STOVL variants of MDC's design.

The Invincible class is scheduled to be replaced some time after the FCBA enters service and, although the Royal Navy would like larger ships, Norriss believes that the JSF will influence the design of any new carriers - an indication that the UK, like the US Marine Corps, is committed to the STOVL variant.

The UK's 10% stake in the JSF programme is the result of a $200 million investment in the concept-development phase. This stake has bought the UK the position of full collaborative partner, and won it the ability to influence the JSF requirements. Norriss expects the UK's Staff Requirement (Air) 6464 for the FCBA to be "very, very close" to the eventual JSF JORD.

UK involvement in the JSF development phase will depend on successful flight-demonstration - and affordability - of the STOVL variant and will be subject to a review of FCBA requirement, he cautions. Nevertheless, Norriss is "-confident JSF is the most viable solution to RN needs".

He is less certain whether the JSF can meet the Royal Air Force's Future Offensive Aircraft (FOA) requirement to replace the Panavia Tornado GR4 strike aircraft around 2015-2018. "We do not necessarily assume an aircraft will emerge from this programme as the FOA...although it is a possibility," he acknowledges. Although the JSF is an obvious candidate to replace the RAF's BAe Harrier GR7 STOVL attack aircraft, "-we do not need to address the GR7 replacement yet", Norris says.

The JSF is regarded as the natural successor to the F-16 on the export market and existing F-16 operators are prominent among the several countries which have been briefed on the programme. Norway has requested "informed-customer" status, requiring a minimum 0.2% investment, giving it access to data enabling it to make a timely decision on replacing its F-16s early next century.

It is not yet clear whether UK involvement in JSF development will be based on its 10% concept-demonstration stake or its smaller share of the production off-take - 80-100 aircraft. Concept-demonstration contractors are required to provide "equitable workshare" to UK companies, possibly winning them a place on the production programme, but UK officials on the JSF programme say that they would prefer to leave UK-industry participation to "competitive forces", rather than risk drawing the attention of the US Congress.

The US Congress has finally woken up to the potential of the JSF programme - particularly its almost $100 billion procurement price-tag - and recently fired a warning shot across the US Department of Defense's bows when a key subcommittee barred any spending on the STOVL variant. The block is likely to be voted down before the JSF budget is approved, but the point has been made - the US Congress wants greater oversight of a programme which started out as a technology demonstration and has become a major procurement.

Steven Madey, staff member to the Senate Armed Services Committee, warns that the US defence budget is unlikely to increase. "The pressure is building [in Congress] to look at tactical aviation overall. The central question is, how much of the present programmes can we afford? If the procurement budget does not go up, something will have to give," he says, adding, ominously: "There is already talk of fewer F-18s and F-22s."

Both the USAF and the USN portray the JSF as complementary to their existing programmes - the air-superiority F-22 in the case of the USAF and the multi-role F-18E/F for the Navy. Meullner describes the USAF JSF as "an air-to-ground workhorse, not a leading-edge air-supremacy aircraft [like the F-22]"." McGinn, meanwhile, pictures the USNs small fleet of JSFs as the means by which a larger force of less-stealthy F-18E/Fs can penetrate enemy air-defences.

The USMC, for its part, does not want any strike F-18E/Fs because the aircraft are limited to operating from conventional carriers or runways. Blot says that a Congressional block on funding for the STOVL JSF would be a "critical blow" to its modernisation plans.

In late May, the Pentagon finally designated the JSF a major acquisition programme, giving the Congress greater oversight. Madey believes that the key to the JSF's survival "-will be its ability to survive attacks from present programmes". After the year 2000, as cuts to balance the US budget begin to bite, "-only cost-effective, widely supported programmes will survive", he predicts.

BURYING TFX

As the US Congress gets to grips with the JSF programme, one tantalisingly similar acronym is likely to be heard again and again - TFX. The Tactical Fighter Experimental (TFX) was the Pentagon's last - and disastrous - attempt to develop a joint-service combat aircraft. The TFX eventually entered service with the USAF as the General Dynamics F-111 strike aircraft, but the US Navy's air-defence version was cancelled and replaced by the F-14.

"We tried something similar [to JSF] before, and ended up with something that did everybody's job poorly," says Longuemare. "We are on a different track this time. With TFX, we held too many needed variables constant. Technology and management have matured, and today we can address past shortfalls.

Source: Flight International