Report: 6 factors led to Nev. F-15 crash - Air Force News | News from Afghanistan & Iraq - Air Force Times

Report: 6 factors led to Nev. F-15 crash

The cause of an F-15 crash last year in Nevada remains unknown, although investigators found six factors contributed to the accident, according to a report released Friday.

The F-15C crashed on Oct. 24 after the pilot entered an uncontrolled spin during a defensive turn. The pilot, whose name was not provided in the report, managed to eject before the crash on the Nevada Test and Training Range, which destroyed the $32 million aircraft.

Investigators found six things — linked with several different segments of the accident — that played a contributing role in the crash.

The first three involved the initial departure from controlled flight: aircraft structural imperfections that include problems with the radome, a failure to adequately discuss Advanced Handling Characteristics topics prior to flight and misapplication of flight controls by the pilot — likely due to insufficient briefing on Advanced Handling Characteristics.

Issues with the radome — a dome covering a radar or antennae — can be invisible to the naked eye and include issues such as bent or misaligned nose caps or cuts and blisters in the rain erosion boot, which can cause problems with the aircraft yawning at high angles of attack, according to the accident investigation. Imperfections have been estimated to be present in more than half of F-15 radomes, the head of the aircraft investigation board wrote in his assessment.

“Further, during a recent post-mishap survey of Nellis [Air Force Base, Nev.,] radomes, I observed many radomes with imperfections similar to those documented in engineering studies,” Lt. Col. Dylan Wells wrote.

Other problems that led to the crash include a misperception of operational conditions by the pilot, which led to the departure from planned flight turning into a spin. The misperception could have occurred because the pilot either failed to recognize departure cues or failed to apply corrective action properly or quickly enough, according to the report.

The pilot also failed to attain or maintain full control surface authority, which might have helped the pilot recover from the spin before reaching an altitude where he needed to eject.

Finally, “Air Force-accepted risk placed the [aircraft] in a regime with decreased ability to recover by recommended ejection altitudes from the start,” according to the report.

To fully understand aircraft capabilities — especially in air-to-air dominance platforms such as the F-15C — pilots need to operate in regimes that are typically 20,000 feet above sea level, the report states. But spin testing and recoveries in a controlled environment typically begin above 30,000 feet.

“A correct assessment of risk was made by the supervisors to allow the [mission], especially since it is rare that events would align to prohibit recovery,” it states. “But they can align as evidenced by this mishap. Tactical aviation must balance risks and not all risks can be fully mitigated.”