Choosing Plan B: Reviewing the UK's Choice of Joint Strike Fighter

Elizabeth Quintana

23 March 20127 Minute Read

As the full ramifications of the austerity measures become clear, the UK may be reconsidering the choice of F-35 variant which it will buy under its Joint Combat Aircraft programme. For costs and operational reasons, Variant B is the logical choice.

By Elizabeth Quintana, Senior Research Fellow, RUSI

In 1995, the UK had opted to join the Joint Strike Fighter programme as a level 1 partner in order to fulfil the requirements of the Royal Air Force for a replacement of the Tornado aircraft and Royal Navy for a replacement to the Harrier, which was amalgamated in the Joint Combat Aircraft programme.

Until October 2010, the UK was committed to buying the B- variant (Short Take Off Vertical Landing or STOVL) of the Joint Strike Fighter (JSF), which is currently being developed for the US Marine Corps and Italian Navy. Rather dramatically, the 2010 Strategic Defence and Security Review revealed that the UK would switch to the C variant, requiring catapults and arrestor gear to operate from a ship. This variant would not only provide greater range and bomb capability but it would also in principle allow UK aircraft to land on US and French aircraft carriers (and vice versa) which would increase interoperability between the navies. At the time, the through-life cost of the C variant of the JSF was estimated to be cheaper by twenty-five per cent,[1] although the review recognised there would be an additional cost of integrating the 'cats and traps' onto the new British Queen Elizabeth class carriers, which would incur an additional £400 million. At present, the UK is the only international partner buying a C variant.

To B or not to B?

However, in 2011, the B variant of the JSF ran into engineering problems and subsequently was at risk of cancellation as the US Department of Defense looked to make large budget cuts. Up until that point, the B variant had been ahead of the A and C variants in its test and evaluation schedule but was put on probation in January 2011 by Defense Secretary Gates who delayed the programme by two years and threatened to cancel it altogether if problems could not be resolved. According to Aviation Week,[2] Secretary Panetta lifted the probation earlier this year as the programme matured in five key areas: structural shortcomings in the STOVL bulkhead, flutter in the auxiliary inlet door, problems in the lift-fan clutch, unexpected wear and tear on the drive shaft, and heating on the roll-post actuator. Two B variant aircraft have also just successfully completed sea trials on board USS Wasp completing seventy-two short take offs and landings and moving the programme forwards another step.

In the meantime, problems with the Electro-Magnetic Arrestor Launch System (EMALS) and F-35 C arrestor gear are making the C variant increasingly unattractive. EMALS will replace conventional steam powered launch systems for the F-35 on board the new US Ford Class carriers and the British Queen Elizabeth class carriers, which is good news for the British as the Elizabeth Class carriers are not nuclear-powered and so would not naturally be producing steam as a by-product. It is, however, still a relatively immature piece of technology. EMALS has proved that it can launch aircraft (on land) but there are problems with the arrestor gear.

Owing to the stealthy design of the aircraft, the C variant has to store the arrestor hook internally during flight and therefore the hook sits nearer to the main landing gear than on other carrier landing aircraft, such as the F-18, which will also be using this system. This means there is more chance that the hook will fail to catch the wire. The hook will be redesigned and tests are on-going and the US has offered to pay for any additional modifications, so the costs will not be passed onto the UK. However, any delays to the Ford Class carrier could mean that the UK will be the first country to integrate EMALS onto a ship, with all the technical problems and costs associated with it. This may explain in part why the UK's initial estimate of £400m cost has already escalated to £1.8 billion. Interestingly, the UK has not committed to spend any money on the new EMALS system. Although it has issued an official request for the system, no contract has yet been signed. According to the Daily Telegraph, up to £40 million is said to have been spent by the programme office in the UK on initial feasibility studies. It seems, therefore that at present if the UK was to switch back to the B model it would be rather more cost-effective than buying the C variant and certainly less risky.

There are operational reasons why the C variant may be less desirable. First, the UK has a history of operating STOVL aircraft and so currently has the expertise to exploit this capability. In Afghanistan, British Harriers allowed the RAF to operate in and out of Camp Bastion well before a proper runway was put in. In addition, HMS Ark Royal operated US Marine Corps Harrier aircraft off its flight deck in 2007 so there is a history of interoperability with this type of aircraft too. Secondly, the STOVL aircraft would also be able to use the first Queen Elizabeth Class carrier, Queen Elizabeth II, which with the decision to install cats and traps has been down-graded to a Landing Helicopter Deck (LHD) Amphibious Assault ship. Thirdly, aircraft with arrestor hooks can get stuck on the flight deck blocking the deck for other aircraft wishing to land, this means that naval aircraft always return with fuel in case they need to loiter; modified combat aircraft are also available near the carrier to provide tactical tanking in an emergency.

The US Navy plan to use F-18s as their tactical tankers, which means the UK would need to either buy F-18s (with all the through-life costs of maintaining a separate platform) or foot the bill to design and install a drogue refuelling system on four of the C model aircraft it purchases. STOVL aircraft do not require tactical tankers because they can land on another part of the deck if an aircraft is in the way. Finally, the C variant will require additional training costs for both the pilots and deck crew as arrestor landings are more demanding for the pilot and support crew can be seriously injured or killed if the wire whips out over the deck. Landings therefore need to be performed on a regular basis in order to maintain currency and an efficient deck.

B is the most cost effective

Squeezing finances, a maturing B variant and uncertainties over the EMALS programme may mean that for the UK, the B variant may now prove to be a more cost-effective solution. This is a programme in development and there is a long way to go with each variant before the problems are ironed out and the final price tag negotiated, particularly since the in-service costs will dwarf the costs of buying the aircraft. The UK is not the only country to re-examine its contribution to this programme. Both Canada and Japan have stated that they retain the right to back out of the programme if the cost becomes too great.

What is sure, the UK remains committed to buying JSF aircraft whatever the final variant choice. The fifth generation stealth fighter represents a step change relative to existing fourth generation fighters and, as a tier one partner, the programme continues to be important to the UK both industrially and in terms of future revenue to the government.

Comparisons

F-35B	F-35C

STOVL	CATOBAR
15.57m long	15.67m long
4.57m high	4.72m high
10.67m wingspan	13.11 wingspan
Empty weight 32,000lbs	Empty weight 34,800lbs
Internal fuel capacity: 13,500lbs	Internal fuel capacity: 19,750lbs
Thrust-to-weight ratio: 0.81	Thrust-to-weight ratio: 0.69
F-135-PW-600 (uninstalled thrust rating: 38,000lb max, 26,000mil, 40,000 vertical)	F-135-PW-100 (uninstalled thrust rating: 40,000lb max, 25,000mil)
Radius of action >450nm	Radius of action: >600nm
Range: >900nm	Range: >1200nm
Max. take off mass 50300lb	Max. take off mass 66000lb
Max. landing mass 36000lb	Max. landing mass 44000lb
Max stores load at take off 15000lb	Max stores load at take off 18000lb
Smaller internal weapons bay	Longer internal weapons bay, but same number of munitions
Shorter range - some fuel space of C is given over to the lift fan for the STOVL propulsion system	25% lower lifetime cost than B
Fatigue-testing stopped at 6% in 2011 following bulkhead crack	Fatigue testing not yet started
Maximum g-rating: 7.0	Maximum g-rating: 7.5
Larger wing/tail control surfaces
	Larger leading-edge flaps
	Foldable wingtip sections
No landing hook	Landing hook