Amateur-built BENSEN B-8M N532KB accident near Corona, California

Probable cause

The fatigue failure of the engine mount resulting in a loss of engine power and directional control while maneuvering.

NTSB analysis

The pilot of the gyroplane reported that, while in the traffic pattern and shortly after a turn onto the final approach leg, he heard and felt a “bang” and the engine lost power. The pilot attempted to maintain airspeed; however, the gyroplane entered a descending, slow spin. The pilot was able to flare just before landing hard in a flat attitude. The gyroplane contacted the dirt and flipped onto its side before the rotor blades came to a stop.

Postaccident examination of the engine mount revealed fatigue cracks exhibiting ratchet marks with multiple origin points emanating from the toe weld that secured two washers onto the steel tube. When the engine mount failed, it dropped several inches and allowed the propeller to strike the keel tube, severing the right rudder cable and causing a loss of directional control while maneuvering.

Text from the NTSB. Open the NTSB docket for WPR22LA302 for the full record.