The UK, as the only major partner in the international Joint Strike Fighter (JSF) team, will decide which variant it will acquire next year.

Earlier this year the UK committed to the systems development and demonstration (SDD) phase, pledging $2 billion - or about 8% of the cost.

It will spend another £600 million ($870 million) on integrating Lockheed Martin's F-35 into the UK armed forces.

Sir Robert Walmsley, UK Ministry of Defence chief of defence procurement, says the extra funding will include integrating and clearing UK weapons on the aircraft and integrating it into the UK command and control infrastructure.

Walmsley says the MoD is committed to "winner takes all" and will not insist on any company joining the Lockheed Martin team. Nor, he says, will the MoD push for a UK final assembly line.

The UK plans to order 150 F-35s and will select either the CV aircraft carrier version or the short take-off and vertical landing (STOVL) variant. Walmsley says the 150 number is "not firm" but the final total will "not be half and not be double [the 150]".

Walmsley says there will be no differences between the aircraft ordered for the RAFand RN as the assets will be operated by Joint Force Harrier.

If the order were split, says Walmsley, "it would be sad to lose the commonality across the force and would raise costs".

Selection of the variant will be considered alongside the CV(F) future aircraft carrier and the Future Organic Airborne Early Warning aircraft which will also operate from the ships. Selection of the JSF variant will drive the carrier design.

Walmsley says that, with selection of the F-35, operational studies can now start to be undertaken, including the acoustic and thermal impact of the STOVL varient's lift-fan on the flight deck.

Air Cdre Peter Giles, Defence Procurement Agency JSF team leader, says training is also a consideration as it is relatively simple to work up pilots for STOVL carrier operations over a short period at times of crises, but CV pilots would have to maintain currency as it is more difficult to work up quickly to carrier operations.

Source: Flight International