Air Force Releases F-15D Crash Report

A newly released Air Force report of a deadly July 30 crash during an exercise at Nellis Air Force Base, Nev. reveals the perils of flying for the military.

"A combination of human factors and aircraft anomalies caused a spin" of a two-seat F-15D Eagle, according to an Air Combat Command accident investigation board report released yesterday.

The pilot in command, Lt. Col. Thomas Bouley, was killed. An observer pilot, a Royal Air Force flight lieutenant, sustained minor injuries.

The pilot "momentarily exceeded a technical order maneuvering limitation that is in place when the F-15D has fuel in the external wing tanks," according to an Air Force statement. "Additionally, spatial disorientation resulting from the aircraft spin hampered recovery and was also cited as a cause."

The statement continued:

"When the pilot momentarily exceeded limitations, the aircraft departed from controlled flight due to the 'left yaw/roll phenomenon,' an aerodynamic anomaly that affects some F-15D's with two external fuel tanks. The departure, when coupled with an external wing tank fuel imbalance, resulted in the F-15 going into a spin.

"Through simulations, investigators concluded that once in this spin, recovery was delayed by a radome, or nose cone, imperfection. Although the nose cone was too damaged to analyze, simulations provided substantial evidence that a radome anomaly aggravated the aircraft's spin recovery.

"The violent and prolonged spin left the pilot spatially disoriented, which hampered the dive recovery, necessitating ejection."

The observer pilot, sitting in the F-15's back seat, was ejected first. The pilot, who did not survive, was ejected .4 seconds later.