Boeing B75N1 N56200 accident near Winslow, Arizona

Probable cause

The partial loss of engine power during takeoff initial climb in high-density altitude conditions for reasons that could not be determined because a postaccident examination of the airplane and engine revealed no anomalies.

NTSB analysis

The private pilot reported that, earlier in the day, she had flown three flights, totaling about 5 hours of flight time, which included uneventful takeoffs from two airports with a higher density altitude than that which existed at the accident airport; the calculated density altitude at the time of the accident was about 7,223 ft.

The pilot reported that, before takeoff for the accident flight, she conducted an engine run-up and pretakeoff checks, which included leaning the mixture to account for the density altitude. She also conducted a static-power check, which was in the normal range. The pilot reported that, during takeoff for the personal cross-country flight, the airplane accelerated and climbed out normally with the tachometer indicating 2,250 rpm. As the airplane climbed to about 50 ft above ground level, the engine began to lose power, and the airplane started to descend. The pilot turned the airplane left to maintain clearance from obstacles and verified the throttle, mixture, propeller, fuel, and carburetor heat settings. Subsequently, the airplane struck the ground and rolled about 20 ft, the right main landing gear impacted vegetation, and the airplane cart-wheeled. The pilot reported that, just before landing, she observed the tachometer indicating 2,000 rpm.

It is likely that the engine's partial loss of power, in combination with the high-density altitude, prevented the airplane from being able to maintain a positive climb rate during takeoff. Postaccident examination of the airplane and engine run did not reveal any evidence of any preexisting anomalies that would have precluded normal operation; therefore, the reason for the partial loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR16LA106 for the full record.