Beech A45 N3434G accident near Climax, Georgia

Probable cause

The failure of maintenance personnel to ensure that the throttle and fuel metering unit AN "B" nut was secured, which resulted in a total loss of engine power in flight and a subsequent collision with trees while attempting to land after sunset.

NTSB analysis

The pilot was flying a local, personal flight from his personal airstrip after sundown. A witness who heard the airplane before the crash reported that the engine made a "sputtering" sound. The airplane collided with two tall trees and came to rest inverted on the approach end of the runway. The propeller did not exhibit indications of rotational damage. Although the right fuel tank was breached from impact and no fuel was found inside, the left tank contained 11 gallons of fuel.

An annual inspection was completed on the airframe and engine about 2.2 hours before the accident. An examination of the engine fuel lines found the throttle and metering unit outlet AN "B" nut was less than finger-tight. When the fuel manifold valve cap was opened, fuel leaked from the loose throttle and metering unit outlet AN "B" nut. Compressed air was passed through the throttle and metering unit inlet fuel line; bubbles and fuel could be seen coming out of the fuel outlet AN fitting. The condition of the fuel lines was an inspection item specifically noted as completed during the annual inspection. The throttle and metering unit outlet "B" nut most likely was not adequately secured during the inspection and backed off during the 2.2-hour previous flight and the 12-minute accident flight, which subsequently resulted in a total loss of engine power. The pilot was likely attempting to return to the runway, as the landing gear were extended and the flaps were up at the time of the accident. However, since the accident occurred concurrently with the end of civil twilight, it is possible that he did not see the trees on final approach due to the darkening conditions.

Text from the NTSB. Open the NTSB docket for ERA17FA107 for the full record.