Piper PA-11 N4707M accident near Indianola, Iowa

Probable cause

The pilot's inadequate preflight planning, which resulted in the airplane being operated above its maximum gross weight, degraded its climb performance, and led to an aerodynamic stall during the initial climb.

NTSB analysis

The commercial pilot was using a company airplane to accumulate flight time and experience. Two witnesses reported seeing the airplane climbing after takeoff and noted that the airplane was flying slowly and that it had a "hard time getting any lift." The airplane finally started to climb; however, the wings started rocking and the airplane subsequently descended into terrain. The witness statements were consistent with the prestall motions of the airplane.

The pilot and passenger were employed as company ground personnel. According to company policy, the pilot was not allowed to fly with passengers, and the passenger was only allowed to fly with a company flight instructor. The pilot was not a flight instructor. Examination of the airplane revealed no mechanical anomalies that would have precluded normal operation. A postaccident estimation of the airplane's weight and balance showed that the airplane exceeded its maximum gross weight at the time of the takeoff. It is likely that the pilot's inadequate preflight planning led to the airplane being operated above its maximum gross weight and degraded its climb performance and led to an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for CEN16LA310 for the full record.