Piper PA 23-250 N40285 accident near Knoxville, Tennessee

Probable cause

The flight instructor’s failure to comply with published engine-out procedures and recommended airspeeds, which resulted in a lack of directional control, collision with trees, and impact with the ground; the left engine lost total power due to fuel starvation.

NTSB analysis

During a simulated single-engine instrument approach in a multi-engine airplane, the flight instructor, who was seated in the right seat, told the multi-engine rated pilot receiving instruction, who was seated in the left seat, to go around. The pilot applied full power to the right engine and attempted to fly the pattern with a simulated left engine failure. Shortly after, while the airplane was in a left crosswind turn, the left engine lost total power. The instructor observed that the left propeller was stationary and took control of the airplane.

The instructor chose to fly at minimum controllable speed (Vmc) rather than the recommended best single-engine rate of climb speed (Vyse) and attempted to restart the failed engine rather than perform the airplane manufacturer's approved engine-out procedures. Unable to restart the left engine, he attempted to maneuver the airplane for a landing but was unable and flew toward rising terrain. Approaching a residential area, the instructor maneuvered the airplane to avoid a house, and the airplane subsequently impacted trees, fell to the ground, and came to rest on top of an automobile. The instructor stated that after the accident, he returned to the airplane to shut off the fuel and electrics when he noticed the left fuel selector was between the on and off position.

A postaccident examination revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. However, a lack of fuel was observed in the left engine's fuel system forward of the fuel injection servo.

Based on the observed intermediate position of the left fuel selector after the accident, the lack of fuel in the fuel system forward of the fuel injection servo, and the lack of mechanical malfunctions or failures noted during the wreckage examination, it is likely that the left engine lost total power due to fuel starvation. The manufacturer's approved procedures for an engine failure during takeoff included, among other things, maintaining a best rate of climb airspeed. A review of the manufacturer's pilot's operating manual indicated that even with a total loss of engine power on the left engine, the airplane would have been able to climb about 520 ft per minute had the required pilot inputs been made. The instructor failed to comply with the published engine-out procedures and recommended airspeeds, which led to the lack of directional control, collision with trees, and impact with the ground.

Text from the NTSB. Open the NTSB docket for ANC18LA016 for the full record.