GODDARD DICK SIM BENSEN B-8M

Full Narrative

On August 13, 2022, about 1248 Pacific daylight time, an experimental amateur-built B-8M gyroplane, N532KB, sustained substantial damage when it was involved in an accident near Corona, California. The pilot sustained minor injuries. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that, while in the traffic pattern at the Corona Municipal Airport (AJO), Corona, California, 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 the hard landing. The gyro contacted the dirt and the gyroplane flipped onto its side before the rotor blades came to a stop.
The pilot reported that a visual inspection conducted after the accident indicated that the motor mount had sheared near the engine mounting bolts, causing it to drop several inches and allowing the propeller to strike the keel tube, severing the right rudder cable. Further postaccident examination of the engine mount revealed failure surfaces at each end of the steel tube weldment. Further examination exhibited a thumbnail shaped fatigue crack originating at the toe of the weld fillet that attached the washer to the steel tube. The fatigue crack exhibited ratchet marks indicating multiple origins. The rest of the fracture surface outside of the fatigue crack exhibited fracture features consistent with overstress.
A review of the maintenance records indicated that the last inspection was completed on February 01, 2020.