What happened
On February 5, 2016, a North American F-51D, registration N551JP, crashed approximately 6 miles southwest of Maricopa, Arizona. The flight, which was for personal use, had departed from Stellar Airpark in Chandler, Arizona, earlier that morning. The aircraft was being operated by a commercial pilot with a passenger.
Witnesses near the accident site observed the airplane performing acrobatic maneuvers, including what one person described as a "regular loop." During the maneuver, witnesses reported seeing the airplane enter a nose-down spiral. While the engine was heard running during the descent, some witnesses noted the engine sound changed from full power to a lower power setting. The aircraft impacted the terrain at an elevation of approximately 1,274 feet, resulting in 2 fatal injuries.
The investigation
Investigators examined the wreckage and found the fuselage and wings were largely consumed by a post-impact fire. The aircraft's engine was found to be mostly intact, and the examination of the airframe and engine revealed no mechanical failures that would have prevented normal operation. Flight control continuity was established from the cockpit to the center portion of the cabin.
A performance study using airport surveillance radar tracked the aircraft's flight path. The data showed the airplane climbed from 5,700 feet to 7,700 feet mean sea level (msl). To reach this altitude, the aircraft required a significant nose-up pitch and a climb rate exceeding 8,000 feet per minute. The study indicated that the airplane's airspeed decreased significantly at the top of this climb.
Toxicological testing on the pilot found ethanol in the muscle and liver; however, the levels were not consistent with impairment and were likely the result of postmortem production. Additionally, a review of the pilot's medical history, including a previous stroke and atrial fibrillation, showed no evidence that his medical condition contributed to the accident.
Findings
- The airplane likely experienced an accelerated stall and entered a spin at the top of a climbing maneuver.
- The pilot's attempt to recover from a power-on spin involved closing the throttle, which was consistent with witness reports of a change in engine sound.
- The aircraft's flight manual warns that power-on spins are extremely dangerous and that recovery can require a loss of 9,000 to 10,000 feet of altitude.
- Because the aircraft's maximum recorded altitude was 7,700 feet msl (approximately 6,426 feet above ground level), there was insufficient altitude available to complete the recovery.