The Piper PA-32R-301T was in cruise flight when the engine’s forward main seal — the crankshaft seal — began to leak engine oil.
Shortly thereafter, the engine lost power, and the pilot subsequently performed a forced landing to a field near Dalhart, Texas, about five miles west of the departure airport.
Post-accident 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 personnel installed an improperly sized crankshaft seal, which led to it slipping, allowing the engine oil to leak.
Probable cause: The failure of the engine’s front bearing seal due to maintenance personnel’s installation of an improperly sized crankshaft seal, which resulted in oil starvation and a forced landing.
NTSB Identification: CEN17LA226
This June 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.