Piper PA 32R-300 N4213F accident near Dawsonville, Georgia

Probable cause

The failure of the pilot, who was not a certified mechanic, to tighten the B-nut on a remotely mounted oil filter line, which resulted in oil exhaustion, a total loss of oil pressure, and a subsequent total loss of engine power.

NTSB analysis

The private pilot was conducting a personal flight and reported that, while the airplane was climbing after takeoff, the engine began to run roughly and lose power. The pilot began a descent for an emergency landing and, during the descent, he sensed a "bad" engine vibration, which was followed by a complete loss of engine power. The pilot selected an area on an asphalt-covered automobile racetrack to make a forced landing, which resulted in substantial damage to the airplane's wings and fuselage.

A postaccident engine examination revealed a crack in the accessory case and a large hole in the crankcase near the No. 6 cylinder pad. A subsequent internal examination revealed damage to the engine's internal components, including the main bearings and the No. 6 connecting rod, that was consistent with oil exhaustion.

The airplane was equipped with a remotely mounted oil filter. A B-nut on one of the oil filter lines was found to be loose with about 2 ½ threads showing. The B-nut was tightened by hand and rotated about 1 ¾ turns, which resulted in about ½ thread showing.

The pilot stated that he was not an airframe and powerplant mechanic but that he had replaced the oil line about 1 week before the accident. The accident flight was the first flight after that maintenance.

Text from the NTSB. Open the NTSB docket for ANC18LA006 for the full record.