Primary finding
Probable cause
The inflight loss of the engine’s air filter which collided with the propeller which resulted in a vibration.
Investigator assessment
Analysis narrative
While on the downwind leg of the airport traffic pattern, the pilot heard a noise from the engine or the rotor and felt the gyroplane momentarily “shudder.” The pilot performed a precautionary landing and the gyroplane touched down hard, bounced, and rolled on its right side. The gyroplane sustained substantial damage to the main rotor and fuselage. A postaccident examination of the gyroplane revealed that the air filter, which is mounted to the engine, was not located at the accident site. It is likely that the air filter separated from the gyroplane which resulted in the shudder felt by the pilot. An examination of the gyroplane and engine revealed no other anomalies that would have precluded normal operations.
Source record
Factual narrative
On July 11, 2023, about 1800 central daylight time, a Magni M24 gyroplane, N123PS, was substantially damaged when it was involved in an accident near Mineral Point, Missouri. The pilot and passenger received minor injuries. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, while on the downwind leg of the airport traffic pattern, he heard a noise from engine or rotor felt a momentary “shudder.” The pilot performed a precautionary landing to a field. During the landing, the gyroplane touched down hard, bounced, and rolled on its right side. The gyroplane sustained substantial damage to the main rotor and fuselage. A postaccident examination of the gyroplane revealed that the air filter, which is mounted to the engine, was not located at the accident site. No other anomalies were detected with the airframe or engine when examined by the Federal Aviation Administration. Following the accident, the pilot returned to the accident site and conducted a grid-search to locate the air filter. Unable to locate it, he thought the air filter likely came loose and departed the gyroplane on the downwind leg, which struck the propeller and would have produced the loud noise and brief shudder that he encountered.