Flight Details
An IFR flight was conducted to a destination airport without available weather reporting. As the aircraft neared the airport, the pilot received the most current weather for the closest airport and the altimeter setting required for the approach. Air traffic control cleared the flight for a non-precision approach.
Weather and Witness Observations
Two pilot-rated witnesses, who were relatives of the pilot and waiting at the airport, reported that the weather conditions at the airport consisted of a ceiling at 500–600 feet and visibility of 3 statute miles. The witnesses observed the aircraft on the downwind leg, flying beneath the clouds at an altitude of 644 feet abeam the runway with the landing gear extended and what appeared to be approach flaps.
One witness reported hearing a sound he associated with the propellers being placed in the low pitch position. He also heard the engines increase RPM, which he thought was full power for a missed approach. The aircraft then began turning base leg after passing 10–20 degrees past the runway numbers. The bank angle increased to approximately 70–75 degrees, and the nose pitched down, leading to ground impact. The witness stated that the engine sound did not change from the moment power was applied to the point of impact.
Post-Accident Examination
Examination of the engines, propellers, and flight controls revealed no evidence of preimpact failure or malfunction. The flap selector switch was found in the down position, and the left flap actuator was in the full down position; no determination could be made regarding the position of the right flap actuator. The stall speed increases by 73 percent at a 70-degree angle of bank and approximately 100 percent at a 75-degree angle of bank.