The U.S. Air Force grounded its fleet of Lockheed Martin-built F-35 Joint Strike Fighters earlier this month — for the 3rd time in less than year.
In October 2010 the company grounded the fleet of 20 F-35s purchased by the US military after discovering a software glitch during simulation tests. The glitch could cause the fuel pump to shut down at altitudes over 10,000 feet.
On Tuesday, August 2, Lockheed Martin released another grounding order for the same fleet after the Internal Power Package (IPP) failed standard engine tests.
The IPP is an important system, responsible for both starting the engine and acting as a back up electrical system for the two main generators. This IPP system saved a plane and pilot this past March when the main power generators shut down during tests--while the aircraft was still in flight. Fortunately, the pilot was able to land the plane safely as the IPP allowed the flight control system to continue operating until landing. That incident also resulted in grounding of the fleet.
The F-35 fleet is able to undergo ground tests, but Lockheed Martin reports that “further reviews are required prior to lifting the suspension of flight operations.”
The Joint Program Office has not given a date for when flight testing can resume, or when the jets will be prepared to leave the ground.
U.S. Air Force photo