Primary finding
Probable cause
A nosewheel shimmy on takeoff, which resulted in the failure of the nosewheel landing gear and a loss of control.
Investigator assessment
Analysis narrative
The pilot, who was also the builder, was conducting flight testing on the newly built gyrocopter. He reported that he spun the rotor up to about 110 rpm and was attempting to accelerate the rotor to flight rpm by moving down the runway. The pilot added that he was going about 25 mph when the nosewheel hit a bump in the runway and started to shimmy. He immediately reduced the throttle to slow down; however, the nosewheel strut failed, and the gyrocopter turned left, rolled over, and came to rest on its right side. During the rollover, the rotor blades and fuselage sustained substantial damage.
Source record
Factual narrative
The pilot, who was also the builder, was conducting testing on the newly built gyrocopter. He reported that he spun the rotor up to approximately 110 rpm and was attempting to accelerate the rotor to flight rpm, by going down the runway. The pilot added that he was going about 25 mph when the nosewheel hit a bump in the runway and started to shimmy. He immediately reduced the throttle to slow down; however, the nosewheel strut failed, the craft turned left, and came to rest on its right side. During the rollover, the rotor and fuselage sustained substantial damage.