Accident Overview
While in cruise flight at 19,000 ft mean sea level (msl), the pilot declared an emergency to air traffic control, reporting that the airplane had lost engine power and needed to divert. The pilot chose to divert to an airport approximately 5 miles south of the aircraft's position.
Sequence of Events
Archived automatic dependent surveillance-broadcast (ADS-B) and commercial flight track data indicated that a descent from 19,000 ft began and the aircraft proceeded directly to the airport, circling once while descending. The last data point showed the airplane at 1,250 ft msl (about 750 ft above ground level) and about 1 mile north of the approach end of the runway. From the cruise altitude to the last data point, approximately 12 minutes and 45 seconds elapsed, yielding an average descent rate of about 1,392 ft per minute.
Witnesses located about 1/4 mile south of the runway end on a miniature golf course noticed that the propeller was not turning. They reported seeing the airplane in a “really hard” left bank; the nose dropped, and it impacted the ground in a near-vertical attitude. The airplane came to rest along a road about 200 ft south of the airport property. The fuselage and both wings sustained substantial damage.
Pilot Actions and Checklist Adherence
Based on the location of the runway relative to the golf course, it is likely that the pilot initiated the left bank to avoid bystanders on the ground and inadvertently exceeded the wing’s critical angle of attack, resulting in an aerodynamic stall.
The airplane was equipped with an engine trend monitor (ETM) that captured events including engine start, operating limit exceedances, and power checks. The ETM recorded a power check at 19,100 ft. About 3 minutes 32 seconds later, an engine off event was logged. Further, a logon message consistent with power being cycled was recorded at 3,542 ft, 9 minutes 52 seconds later. No start attempts were recorded between the engine off event and power loss to the unit.
A postaccident examination of the airframe, engine, and accessories revealed no mechanical malfunctions or anomalies that would have precluded normal operation. Although it could not be determined whether a restart attempt would have been successful, the data were consistent with a restart not being attempted.
Both the engine failure and power off landing checklists instructed the pilot to establish airspeed at 90 knots; however, groundspeed data adjusted for winds aloft indicated this did not occur. The power off landing checklist also instructed the pilot to be about 1,500 ft above the airport on the downwind leg, but data showed the airplane was about 5,000 ft above the airport on that leg. The rapid descent from 5,000 ft on the downwind leg to about 750 ft above ground level on the final leg resulted in an unstabilized approach.
Probable Cause
The probable cause was the loss of engine power for reasons that could not be determined and the pilot’s failure to maintain control of the airplane, which resulted in an aerodynamic stall and spin. Contributing to the accident was the pilot’s failure to establish and maintain a proper glidepath.