A US Air Force Accident Investigation Board (AIB) has concluded that an internal fire caused by electrical arcing due to a chafed wire led to the loss of a Lockheed Martin F-22A Raptor at Tyndall AFB, Florida, on 15 November 2012.

According to the USAF, a chafed positive generator-feeder wire arced and burned through an adjacent hydraulic line. That caused the generator to go offline, the report says.

 Raptor crash Tyndall - US Air Force

US Air Force

"When the [mission pilot] attempted to restart the generator, the ensuing arc ignited the misting hydraulic fluid and started a fire in the [aircraft's] left airframe-mounted accessory drive bay," the AIB report says. "The fire compromised critical [mishap aircraft] electrical and hydraulic systems that control the F-22A flight control surfaces, and led to an unrecoverable situation."

The AIB also found that weather contributed to the accident, because cloud cover did not allow for a visual traffic pattern.

While the pilot survived, the aircraft - tail number 00-4013 - was a complete loss. The total cost of the damage was just under $150 million, the AIB report concludes. The USAF now has 184 production Raptors and two test airframes.

Source: Flight International