First flight after maintenance goes awry

The pilot, who was conducting a personal flight in the Piper PA-32R, reported that, while the airplane was climbing after takeoff, the engine began to run roughly and lose power.

He 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.

He selected an area on an asphalt-covered automobile racetrack in Dawsonville, Georgia, to make a forced landing, which resulted in substantial damage to the airplane’s wings and fuselage.

A post-accident 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 was not an airframe and powerplant mechanic, but had replaced the oil line about a week before the accident. The accident flight was the first flight after that maintenance.

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 Identification: ANC18LA006

This October 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.