Aircraft

A key test article for the Lockheed Martin F-35 Joint Strike Fighter programme has returned to flight after a nearly year-long hiatus.

The BF-1 flight-test aircraft, which will demonstrate the F-35B's short take-off and vertical landing (STOVL) capability, completed a 1h flight on 4 September at Fort Worth, Texas, Lockheed says.

The return-to-flight event for BF-1 had been expected for several months since the aircraft was grounded after 22 September 2008.

Lockheed installed a redesigned turbine blade after the original Pratt & Whitney design revealed concerns about early fatigue cracking. Plans to resume flight-testing by December 2008 were delayed to June, and finally to early September. Lockheed blamed the latest delays on a series of frustrating technical issues.

BF-1 is one of two aircraft that is scheduled to ferry to NAS Patuxent River, Maryland, by the end of the month. The goal is to complete a series of flight tests leading to the first vertical landing in October, a major milestone in the early phases of the STOVL aircraft's flight test programme.

However, BF-1 still has to complete another 11 flight tests at Fort Worth before it can be transferred to Patuxent River, Lockheed says.

© Luca Peruzzi