Aircraft Accident/Incident Report

San Jose, California 95138
Thursday, June 15, 2000 12:25 PDT

During an aerobatic maneuver, the airplane impacted level terrain while in a descending, steep bank, right turn. On a clear day, the renter pilot acquired a parachute from the flight school and departed with the intent of performing aerobatic maneuvers during his pleasure flight. He had recently received a promotion at work. There were no communications with the pilot after he departed the airport. His route of flight, maneuvers performed, and altitudes utilized could not be determined. The airplane was not transponder equipped. About 50 minutes after takeoff, a witness observed the airplane between 400 and 500 feet above ground level in a medium bank descending right turn. The bank angle increased to about 60 degrees, and the witness lost contact with the airplane when his view became obstructed by ground objects/terrain. The accident site was located the following day. Wreckage was observed fragmented over a 115-foot-long path. The pilot was found lap-belted and shoulder harnessed in his seat with a fully stowed parachute. The cockpit door's emergency release pin assembly, which when utilized separates the entire door from the fuselage, was found seated. No evidence of any preexisting mechanical malfunctions or in-flight part separations were detected during the subsequent wreckage examination. The pilot had no physical limitations or reported physiological impairments. No evidence of drugs was found in toxicological specimens. The airplane was FAA certificated in the acrobatic category and was designed to withstand 6 positive and 5 negative Gs. The adverse effects of acceleration-induced G-force to a pilot's physiology while maneuvering within this range have been documented by the FAA and other organizations. Identified possible impairments include reduced vision to loss of consciousness (G-LOC). The effects of G-LOC may last 30 seconds and result in a loss of airplane control. A pilot who has recently been exposed to elevated G-loads may have increased tolerance to its effect. The pilot's flight record logbook indicated that he had not flown the Decathlon or performed aerobatics in 5 months.

The pilot's failure to maintain control of the airplane for undetermined reasons while intentionally performing an aerobatic maneuver.