Faulty Component Doomed QF-4

A defective pitch-rate controller led to the crash of a QF-4 remotely piloted aircraft at Tyndall AFB, Fla., last July, announced Air Combat Command. The airplane went down just eight seconds after takeoff on July 17, 2013, according to ACC’s accident investigation board report, released on Feb. 12. The QF-4’s Attitude Heading Reference System, which controls the aircraft’s up and down movement, sent incorrect inputs for the airplane’s horizontal pitch to the autopilot system, causing the QF-4 to pitch up and down rapidly, states ACC’s release. The remote pilot executed the proper emergency checklist items, but was unable to stabilize the aircraft, which pitched down 33 degrees and impacted the ground. The impact destroyed the QF-4, along with one infrared flare-dispensing pod and 120 flares, states the release. The crash also caused runway and barrier damage. The loss of hardware and runway damage amounted to nearly $4.6 million. The QF-4, a full-scale aerial target, was assigned to Tyndall’s 82nd Aerial Targets Squadron. Earlier this month, a QF-4 crashed in New Mexico. (AIB report; caution, large-sized file.)