Defence

Lockheed Martin has rolled out the last of six developmental F-35s to join the ground and flight test fleet by end-year.

The roll-out of the AF-1 – the second conventional takeoff and landing model, but the first completed in the weight-optimized configuration – rolled-out of Lockheed’s final assembly centre in Fort Worth on 19 December.

AF-1 joins a mix of CTOL and short-take-off-and-vertical landing (STOVL) models that have completed 86 flight tests so far.

Two days earlier, Lockheed rolled out AG-1, a ground test aircraft. AG-1 will be transported by cargo ship in late March to Brough, UK, for loads testing.

Lockheed also has completed assembly earlier this year of STOVL prototypes BG-1, BF-1 and BF-2.

The first flight test aircraft – AA-1 – rolled out in December 2006. AA-1 is several thousands pounds heavier than later models, as it began production before a 2004 weight savings programme was launched.