Lockheed Martin has reported a spike in flight activity for the F-35 Joint Strike Fighter programme so far this year, despite having encountered a technical problem that kept some of its aircraft on the ground for between four and 15 days during March.
"Lightning II test jets made considerable flight-test progress during the first quarter of 2011, conducting 199 test flights versus a plan of 142," the company says in a 4 April programme update.
Unlike last year, the company's at-risk F-35B (below) has led the way, with short take-off and vertical landing aircraft having flown 101 sorties. This total was up over 60% from a stated target of 62 flights during the three-month period, and also included 61 vertical landings, against only 10 achieved in the whole of 2010.
© Lockheed Martin
Conventional take-off and landing F-35As were flown 82 times, against a planned 62, while the small fleet of F-35C carrier variant aircraft completed 16 flights; two more than scheduled.
The 199 total was achieved despite a 9 March setback, which led to a temporary halt of all flight activities after CTOL aircraft AF-4 suffered an electrical power shutdown. The incident was attributed to excess oil left in one of the aircraft's generators, which resulted in over-heating.
In all, Lockheed says that F-35s had been flown a total of 753 times between December 2006 and 31 March. This total includes the 410 flights recorded by its test fleet last year.