Primary finding
Probable cause
The pilot’s improper adjustment of the prerotator motor, which resulted in its failure to disengage and the subsequent loss of aircraft control during takeoff.
Investigator assessment
Analysis narrative
The pilot, who was also the owner of the of amateur-built gyroplane, stated that he adjusted the prerotator motor pressure plate before the flight by moving it closer to the clutch to improve rpm. During takeoff, the gyroplane rolled right, and he was unable to maintain control. The gyroplane subsequently impacted the ground and cartwheeled, which resulted in substantial damage to the rotor, mast, and cabin. The pilot further stated that, due to his adjustment, it was likely that the prerotator did not disengage, which resulted in increased right torque and the inability to control the gyroplane during takeoff.
Source record
Factual narrative
The pilot, who was also the owner of the of amateur-built gyroplane stated he adjusted the prerotator motor pressure plate prior to the flight by moving it closer to the clutch to improve rpm. During takeoff, the gyroplane rolled right and he was unable to maintain control. The gyroplane subsequently impacted the ground and cartwheeled, which resulted in substantial damage to the rotor, mast, and cabin. He further stated that due to his adjustment, it was likely that the prerotator did not disengage, resulting in increased right torque and the inability to control the gyroplane during takeoff.