Piper J3C-65 N42522 accident near Hartford, Wisconsin

Probable cause

The flight crew’s exceedance of the airplane’s critical angle of attack during a simulated engine failure during initial climb after takeoff, which led to an aerodynamic stall/spin and loss of control. Contributing to the severity of the occupants’ injuries was the airplane’s lack of shoulder harnesses.

NTSB analysis

The pilot receiving instruction reported that they had performed about 10 practice takeoffs and landings before the accident takeoff. On the accident takeoff, when the airplane reached an altitude of 400-500 ft above ground level (agl), the instructor said, “engine failure, turn around for 09”. The pilot receiving instruction later reported that it was unclear from the instructor’s statement whether it was an actual or a simulated engine failure. Both pilots were on the flight controls at the time and started a turn when the airplane entered a “graveyard spin”. The pilot receiving instruction remembered about 1 to 2 seconds of the spin and had no further recollection of the accident.

Examination of the flight controls and engine did not reveal any preimpact anomalies that would preclude normal operation. Based on the surviving pilot’s description and the airplane damage signatures, the airplane was in a nose-low, left-wing low attitude at impact. It is likely that the airplane entered an inadvertent stall/spin when the critical angle of attack was exceeded. The surviving pilot was not sure if the airplane’s engine had actually lost power or if the flight instructor was simulating an engine emergency. The lack of engine-related mechanical anomalies and the pilot training purpose of the flight suggest that it was likely a simulated emergency scenario initiated by the flight instructor.

The airplane was not equipped with shoulder harnesses and only lap seat belts were installed. Regulations did not require shoulder harnesses to be installed at the time it was manufactured. However, at the time of the accident, several manufacturers offered shoulder harnesses kits that could be retrofitted to the airplane under supplemental type certificate.

The investigation determined that the injuries to the occupants were consistent with the use of only lap seat belts. The availability of shoulder harnesses would likely have reduced the severity of the injuries.

Text from the NTSB. Open the NTSB docket for CEN21FA345 for the full record.