Cessna 340A N121CB accident near Hayward, California

Probable cause

The pilot’s sudden incapacitation from effects of a previously undiagnosed underlying heart disease, which resulted in his loss of control of the airplane and subsequent impact with terrain.

NTSB analysis

The pilot had just removed the airplane from his hangar and started both engines. While setting up the avionics, the pilot was suddenly incapacitated, and the airplane began to move across a taxiway. The passenger attempted to wake the pilot, but the airplane continued across a taxiway intersection and into the runway safety area before it collided with a swale. The nose landing gear collapsed and both wings sustained substantial damage.

Postaccident medical examination of the pilot attributed the loss of consciousness to an episode of abnormal heartbeat due to a previously undiagnosed underlying heart disease. Thus, the pilot’s sudden incapacitation from effects of previously undiagnosed heart disease likely caused the accident. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for WPR24LA003 for the full record.