2 fatalities

2017-03-04: Beechcraft 60 Duke (N39AG) — David B. Mutchler — Duette, United States of America

Duette, United States of AmericaFlight

On March 4, 2017, a Beechcraft 60 Duke (registration N39AG) operated by David B. Mutchler was involved in an aviation accident near Duette, United States of America in flight. 2 people were killed. Investigators recorded the probable cause as: The pilots' decision to perform flight training maneuvers at low airspeed at an altitude that was insufficient for stall recovery. Contributing to the accident was the flight instructor's inappropriate use of non-standard stall recovery techniques. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781191976Data APIEditorial standards

A multi-engine airplane crashed during an instructional flight after transitioning from slow flight into a stall that developed into a spin. The pilots had practiced non-standard stall recovery techniques the previous day. The airplane was operating at low altitude insufficient for recovery. No preexisting mechanical anomalies were found.

Circumstances

The private pilot and the flight instructor were conducting an instructional flight in a multi-engine airplane to meet insurance requirements. The accident occurred on the second day of two days of training.

Witness Observations

Radar data showed the airplane maneuvering between 1,000 ft and 1,200 ft above ground level (agl) just before the accident. Witness descriptions were consistent with the airplane transitioning from slow flight into a stall that developed into a spin, from which the pilots were unable to recover before impact with terrain.

Wreckage Examination

Examination of the wreckage did not reveal evidence of any preexisting mechanical malfunctions or anomalies that would have precluded normal operation of the airplane.

Training Details

After the first day of training, the pilot told friends and fellow pilots that the instructor provided non-standard training that included stall practice requiring emergency recoveries at low airspeed and low altitude. The instructor used techniques not in keeping with established flight training standards, including increasing power before reducing the angle of attack during stall recovery and introducing asymmetric power while recovering from a stall in a multi-engine airplane. Both techniques are dangerous errors that can lead to a spin. During the first day, the airplane entered a full stall and spun before control was regained at very low altitude. Despite the pilot's experience in multi-engine airplanes and the accident make and model, he chose to continue the second day of training with the instructor instead of seeking a replacement.

Accident Dynamics

The spin encountered on the accident flight likely resulted from the stall recovery errors advocated by the instructor and practiced on the prior day. Unlike the previous flight, the accident flight did not have sufficient altitude for recovery because it was operating below the safe altitude required for stall training (one allowing recovery no lower than 3,000 ft agl).

Probable Cause

The pilots' decision to perform flight training maneuvers at low airspeed at an altitude that was insufficient for stall recovery. Contributing to the accident was the flight instructor's inappropriate use of non-standard stall recovery techniques.