By Marina Malenic

An “anomaly” discovered during durability testing of the Pratt & Whitney [UTX] F135 engine will not delay the F-35 Joint Strike Fighter’s flight test schedule, a top Pentagon official in the aircraft program office said yesterday.

Pratt announced on Sunday that an F135 engine was damaged during testing on Friday. The F135 is the primary engine for all three F-35 variants in development.

Air Force Maj. Gen. C.D. Moore, the deputy executive program officer for the F-35, told reporters at the Air Force Association’s annual meeting at National Harbor that he is not concerned about completing the flight-test schedule as planned.

“Because of the amount of durability testing we have already done, this incident is not of great concern,” Moore said.

He said government and industry officials were in the midst of analyzing Friday’s engine damage to determine its cause. He was unable to narrow down the possible causes at this time.

Critics of a single-engine plan could seize on Friday’s difficulties as further evidence that a second development effort is needed. Congress has continued to fund an alternate engine being developed by General Electric [GE] and Rolls-Royce, despite Pentagon assurances that it was not needed. President Obama singled out the alternate engine as an example of wasteful spending when presenting his Fiscal 2010 budget earlier this year.

GE and Rolls recently offered the Pentagon a fixed price contract, thereby taking on more of the financial risk associated with the project. Pratt has said it will respond in kind with a better offer to the government this week.

Meanwhile, a critical test for the Marine Corps’ short takeoff, vertical landing (STOVL) variant of the aircraft has once again been delayed, according to Moore. The first vertical landing is now expected to take place at Patuxent River Naval Air Station, Md., in October or November. The exercise was expected to take place in May before being bumped to September.