Pakistan Military Watch

Lockheed Martin has clarified reports by a senior Pentagon official June 1 that the Short Takeoff and Vertical Landing version of the F-35 Lighting II Joint Strike Fighter continues to encounter difficulties in flight testing.

While the Bethesda, Md.-based company has discovered several problems with the STOVL version of the jet during flight testing, none has caused the test schedule to slip, a senior Lockheed official said.

The Pentagon official told reporters that STOVL problems had helped cause the program's breach of the Nunn-McCurdy statute that caps per-unit cost growth on weapons.

The problems include ones that affect the lift fan doors and jet engine actuator nozzle. A packaging problem bent pins in the rudder pedals as they were shipped to Lockheed, according to the official.

The official would not elaborate on these "discoveries" or the fixes that have been developed for them.

"When you do flight test, the desire is" to discover any possible problems with the aircraft, the official said June 2. "We've done well and we're ahead of plan; so you try to discover as many things as you can, so it's really a tribute to the test program to exercise the jet in a manner where you could discover anything that could be improved."

He reiterated Lockheed's claims that the program is back on track following this spring's restructuring of the program that came in the wake of the Nunn-McCurdy breach.

The program has completed 93 test flights in 2010, three more than planned, the official said.

Numerous problems that arose during the development of the STOVL jet contributed to what eventually became a two-year delay in the jet's development program. The restructuring cut this delay by half.