Lightning II, (formerly the Joint Strike Fighter) was selected to meet the UK's Joint Combat Aircraft requirement for a survivable, stealthy, multi-role, all-weather, day and night, fighter/attack air system, able to operate from land and sea. Using secure links, the aircraft will operate as an ISTAR (Intelligence, Surveillance, Target, Acquisition and Reconnaissance) platform.

Once in service we would expect the Lightning to be capable of undertaking air interdiction operations, making low or medium level attacks using precision-guided, freefall or retarded bombs. Close air support missions against targets in the forward edge of the battle area and fleet air defence patrols in the area of vessels that require protection from enemy air attack.

Although the US Company Lockheed Martin is the prime contractor, the UK is a Level 1 partner with the US Government and a number of British companies, including BAE Systems and Rolls-Royce are participating. These UK companies have had extensive involvement in building and developing the aircraft. Under current plans, about 15 per cent of the aircraft will be manufactured in the UK, securing about 25,000 jobs.

The UK's first three Lightning II aircraft are currently participating in the US Test and Evaluation programme at Elgin Airforce Base in the US. Frontline aircraft are expected to be delivered from 2015 onwards, with an initial operating capability from land in 2018, followed by first of class flights from HMS Queen Elizabeth later that year. In March 2013, the MoD confirmed that RAF Marham would be the main operating base for Lightning II.

Decisions on the overall order for Joint Strike Fighters will not be made until the Strategic Defence and Security Review in 2015. However, most analysts believe that there will be an initial UK order for about 50 aircraft. Current cost estimates vary, but there seems to be a reasonable consensus that around a unit cost of between £100 - 125 million per aircraft. Current  expectations are that the aircraft will remain in service until at least 2040.