What happened
A flight conducted for crew coordination training, administered by Flight Safety International for the foreign airline Aer Lingus, resulted in an accident in the ocean. The aircraft was occupied by one instructor and two foreign pilots.
Prior to the accident, radar data indicated the aircraft was heading northeast while maintaining a constant altitude of 3,500 feet. The aircraft then turned east, at which point its ground speed decreased to 53 knots. Following this turn, the aircraft began a right turn at a rate of 125 degrees per minute. As the aircraft turned south, the ground speed further reduced to 37 knots. The aircraft then entered a descent that increased to a rate of 8,000 feet per minute. Witnesses observed the aircraft spinning left in a nose-down attitude before it impacted the ocean.
The investigation
The investigation found no evidence of pre-impact part failure or malfunction. Post-impact evidence showed that neither engine was operating at the time of impact. The flaps were extended to 10 degrees, the main landing gear was extended, and the nose gear was in transit.
Findings
The aircraft manufacturer reported that a spin may cause an interruption of fuel to the engines by exceeding carburetor limitations. It was noted that intentional spins were prohibited for this operation. The aircraft's visual maneuvering speed (VMC) was 56 knots and its stall speed was 54 knots.