Cessna 150M N66117 accident near Banning, California

Probable cause

The flight instructor's decision to continue the takeoff in gusting tailwind and high density altitude conditions, which significantly reduced airplane performance, and his subsequent exceedance of the airplane's critical angle of attack during the initial climb, which resulted in an aerodynamic stall at low altitude.

NTSB analysis

The flight instructor and student pilot were conducting an instructional flight. After completing airwork, they returned to the airport to perform touch-and-go takeoffs and landings. The student reported that the first landing was "hard" and that the wind was gusting; however, they continued the subsequent takeoff. He reported that, during the initial climb, the airplane drifted right of the runway centerline. The student pilot had the flight instructor take over control of the airplane and shortly thereafter, it impacted trees. A witness reported that, about 100 ft above ground level during the takeoff, the airplane began to lose altitude and the wings wobbled; it impacted trees near railroad tracks and a highway adjacent to the airport. Another witness described a similar sequence of events and stated that there was, "more than enough runway and overrun to abort but [the airplane] seemed to keep trying to climb until it finally crashed." Examination of the airplane and engine revealed no mechanical anomalies that would have precluded normal operation.

Wind conditions recorded by nearby weather reporting stations were consistent with an 8 knot gusting tailwind. Additionally, the density altitude about the time of the accident was 8,500 ft, which would have resulted in a reduced climb rate. It is likely that the combination of wind conditions and the density altitude greatly reduced the airplane's takeoff performance and that the instructor subsequently exceeded the airplane's critical angle of attack while attempting to climb the airplane, which resulted in an aerodynamic stall and a loss of control.

Text from the NTSB. Open the NTSB docket for WPR17FA118 for the full record.