CEN17LA226

The airplane was in cruise flight when the engine's forward main seal (crankshaft seal) began to leak engine oil. Shortly thereafter, the engine lost power, and the pilot subsequently performed a forced landing to a field about 5 miles west of the departure airport. Postaccident examination of the engine revealed that the bottom half of the crankshaft seal had slipped forward from its placement, which allowed engine oil to leak from the engine. The seal had an approximate time in service of 21 hours since its replacement. It is likely that maintenance personne installed an improperly sized crankshaft seal, which led to it slipping, allowing the engine oil to leak.

On June 9, 2017, about 1505 central daylight time, a Piper PA-32R-301T, N782SW, experienced a loss of engine power during cruise flight. The airplane impacted terrain during a forced landing to a field near Dalhart, Texas. The airplane received substantial damage. The pilot was uninjured, and the passenger sustained minor injuries. The airplane was operated by the pilot under 14 Code of Federal Regulations as a personal flight that was operating on a visual flight rules flight plan. The flight originated from Dalhart Municipal Airport (DHT), about 1456, and was destined to Angel Fire Airport (AXX), Angel Fire, New Mexico. A National Transportation Safety Board Pilot/Operator Accident/Incident Report was not received from the pilot. A Federal Aviation Administration inspector reported that the airplane was in cruise flight when the engine's forward main seal (crankshaft seal) began to leak engine oil. The engine lost power shortly afterward, and the pilot performed a forced landing to a field about five miles west of DHT. A post-accident photo of the seal shows that the bottom half of the seal slipped forward from its placement. The airplane exterior was covered with engine oil. The airplane was powered by a Lycoming TIO-540-S1AD, serial number L-7309-61A, engine. An engine logbook entry dated November 14, 2016, with a tachometer time/total time of 5,995.01 hours, showed an "oversized" front crankshaft seal, part number LW-15628P50, was installed. The next logbook entry was dated March 6, 2017, with a tachometer/total time of 5,998.0 hours, for an annual inspection performed by the same mechanic that installed the crankshaft seal. The airplane accumulated about 22 hours since the replacement of the seal, with a total time of 6,016.8 hours at the time of the accident.