American Aviation AA-1A N9261L accident near Cleburne, Texas

Probable cause

The canopy moving fully open during flight, which resulted in the pilot’s distraction and a subsequent aerodynamic stall/spin and loss of control.

NTSB analysis

The pilot and passenger were conducting a local sightseeing flight. A video uploaded to the passenger’s social media, recorded about 6 minutes after takeoff, showed the pilot with his left hand on the control yoke, a tablet connected to the yoke, and a cell phone in his right hand. The airplane’s canopy was open about 8 to 10 inches. Flight track data showed that, about 10 minutes later, while in cruise flight at an altitude about 2,600 ft mean sea level, the airplane entered a hard right turn immediately followed by a left spiraling descent toward the ground. A witness observed the airplane in a vertical descent but did not see the impact.

The airplane impacted a rural field with minimal forward momentum. The sliding canopy was found separated from the fuselage on the front right side of the wreckage. The canopy screw knob lock was found mostly unscrewed or loosened. Damage to the canopy and witness marks on the rear fuselage were consistent with the canopy position fully open during impact. According to the pilot’s family, he would typically fly with the canopy partially open when increased airflow was necessary to cool the cockpit. A placard in the airplane indicated that the canopy could be opened to halfway in flight and that flight was not allowed with the canopy fully open.

The airplane’s engine monitor data were consistent with normal engine operation before the turning descent; however, during the descent, the manifold pressure was low, which is consistent with a closed throttle plate. The data are consistent with a commanded throttle reduction and not a loss of engine power, which would have indicated a value closer to outside barometric pressure.

The canopy moving to a fully open position in flight would have significantly increased drag and presented a major distraction for the pilot. During the turning descent, it is likely that the pilot pulled the throttle to idle in attempt to slow the airplane and regain control. The airplane ultimately entered an aerodynamic stall and subsequent spin from which the pilot was unable to recover with the altitude available.

Text from the NTSB. Open the NTSB docket for CEN21FA290 for the full record.