NTSB Factual Report

On January 10, 2004, about 1155 Pacific standard time, a Fleet 2 bi-wing airplane, N606M, veered off of the runway, and came to rest inverted at the Fresno-Chandler Airport, Fresno, California. The pilot was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, sustained minor injuries; the airplane sustained substantial damage. The personal local flight departed the Fresno-Chandler Airport, about 1145, to perform touch-and-go takeoffs and landings. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot reported in the Pilot/Opertor Aircraft Accident Report (NTSB Form 6120.1/2), that a few days prior to the accident he performed maintenance on the throttle. After loosening the throttle friction locks, he forgot to tighten them. During the landing roll, he removed his hand from the throttle control, and it went into the "wide open" position. The airplane veered to the right, and then to the left, before coming to rest inverted. The pilot stated that there were no mechanical failures or malfunctions during the flight.

The Federal Aviation Administration inspector interviewed a witness to the accident. The witness stated that while he was taxing out of his hangar, he observed the airplane yawing from side to side, trying to establish a landing attitude on runway 30L. The left wing hit the ground and the airplane veered left, departing the runway. The airplane struck soft dirt, and nosed over.

NTSB Probable Cause

the pilot's failure to set the throttle friction lock, which resulted in the inadvertent application of the throttle, followed by a loss of directional control.