F-35 Engine Fire Investigation Results

F-35 Engine Fire Investigation Results

F-35 Engine Fire Investigation. United State Air Force investigation blamed a Lockheed Martin F-35A fire on September 2016 at Mountain Home AFB, Idaho, in high tailwinds, according to an accident report released by the service this week.

Winds as high as 30kt blew during as the Pratt & Whitney F135 engine started a start sequence, forcing hot air into the Honeywell integrated power pack input. As air temperatures rose inside the IPP - a mini motor that supplies power and starts the engine - a series of failures occurred.

The lower air density produced insufficient torque needed for the engine, which slowed down the rotation of the turbine section.

At the same time, the fuel continued to supply the engine at an increased speed, which stimulated an engine fire that exploded from the exhaust. The tailwind extended the fire through the aircraft and caused significant damage to a portion of the aft section of the aircraft. Fire surrounded the engine's exhaust nozzle, also damaging several nozzle segments.

The pilot escaped but suffered minor injuries, including burns to the head, neck, face and ears, according to the report. The service has not yet determined the total costs, but estimates that the damages caused by the planes will cost more than 17 million dollars.

The report also blames the pilot's lack of knowledge and training for tailwind conditions during engine starting. A pilot checklist included a warning that strong tailwinds during engine starting could cause an IPP fault, but the checklist did not warn about the tailwind limit.

The highly automated start-up of the F-35A engine also led pilots to believe that the aircraft handled most of the start-up procedures and pilots assumed there were no problems if the quadrants were green, according to the report.

"The preponderance of the evidence shows if there was an expectation of engine start problems with a tailwind, the pilot could have relied less on the automation of the aircraft, and may have identified an abnormal start of the engine before," writes the Colonel Dale Hetke of the USAF, the investigation. "This vague awareness led to inadequate training for engine starts with a tailwind. Training also led to complacency and over-reliance on aircraft automation."

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