F-35B STOVL JSF “on probation”

Further, the number of F-35s to be built in the lot 5 LRIP (low rate initial production) batch which is currently under negotiation will be reduced from 42 aircraft to 32, adding risk to Lockheed Martin’s plans to ramp up its production rates, to achieve planned in service dates, and to get the per unit cost of the aircraft down to target levels.

While Gates didn’t reveal plans for a rescheduling of the JSF program, which was expected to be announced in February, he did reveal the US Navy would buy an additional 41 F/A-18E/Fs and refurbish more F/A-18A-D classic Hornets to “fill the gap created from the slip in the JSF production schedule. ” The F-35 program did meet many of its flight test goals in 2010, but also missed a few key targets at the same time.

In total, the program completed 410 test flights in 2010, more than the planned 394. The F-35A fleet based at Edwards AFB exceeded its planned flights and more importantly, the number of test points by a healthy 50 per cent, while the lone F-35C based at NAS Patuxent River completed 125 per cent of its planned test points.

But it is in the F-35B test fleet where the program came up short, with the four aircraft falling 15 per cent behind the planned test points schedule in 2010, due to reliability problems and the discovery of aerodynamic issues with the aircraft’s auxiliary engine inlet doors located on top of the centre fuselage. Cracking was also found in a fuselage bulkhead of an F-35B ground test article well before the expected fatigue life had been reached, indicating there may be a structural weakness in the design.

Those issues kept the fleet grounded at their Patuxent River base at various times during the year.

Further, only one of the F-35Bs, BF-1, had completed just 10 vertical landings since last March, and these were suspended in September after the airflow problems with the auxiliary inlet doors were found. Plans had called for 43 vertical landings to be done before shipborne trials aboard the USS Wasp could commence in March 2011, and with vertical landings planned to restart in January, the Wasp trials have now been rescheduled for August or September.

2010 was capped off with an eleventh hour first flight of the fourth CTOL F-35A development aircraft, AF-4, from Forth Worth on December 30, while F-35B BF-5 first flew in January (see photos), making a total of 10 development aircraft now flying, comprising the four CTOL jets, five F-35B STOVLs, and a single F-35C CV carrier variant.

Two more development F-35s are yet to fly and remain in extended post production preflight work periods at Fort Worth.