Incident Details
During a flight, one of the passengers, who was a single-engine rated pilot, occupied the right front seat. Upon arrival at the destination, the pilot initiated an Instrument Landing System (ILS) approach. However, before landing, a full deflection of the localizer course deviation indicator (CDI) was observed, and the pilot executed a go-around. Approximately 15 seconds later, the pilot released the control yoke, leaned back against the seat, and began to convulse.
Passenger Takes Over
The passenger, who was a rated pilot, assumed control of the aircraft and notified air traffic control (ATC) of the situation. ATC provided vectors for landing. Initially, the passenger was unable to disengage the autopilot. At one point during the flight, the pilot's hand pulled the left engine mixture control to the idle cutoff position; the passenger restored engine power by repositioning the mixture control.
Landing and Aftermath
The passenger landed the airplane. During the landing roll, the passenger did not have access to the brake system, and the aircraft rolled off the left side of the runway onto grass. No damage occurred to the airplane. Subsequently, the pilot was pronounced dead. A post-mortem examination listed the cause of death as coronary atherosclerosis/hypertensive heart disease. According to the pilot's wife, he had no prior complaints suggestive of heart disease.