What happened
A Piper Malibu PA-46-310P, operating under instrument flight rules, was traveling from Salem, Oregon, toward Springbank, Alberta, when the aircraft experienced a loss of power. While descending through 17,000 feet approximately 55 nautical miles southwest of Calgary, the pilot notified the Edmonton Area Control Centre of an engine emergency.
In an attempt to reach Fairmont Hot Springs airport in British Columbia, the pilot attempted an emergency descent. However, at roughly 19:12 mountain daylight time, the aircraft crashed into a wooded area located about 11 nm east of Invermere, British and Columbia. The accident occurred during nighttime operations. There were three fatalities resulting from the impact.
Findings
Investigation into the crash identified that an unapproved component had been installed within the alternator coupling. This part generated debris that partially obstructed oil flow to the number two connecting rod bearing. The resulting lack of lubrication led to overheating and the subsequent failure of the bearings, as well as the connecting rod cap bolts and nuts, which caused the engine failure.
Several contributing factors were noted during the investigation:
- Low visibility due to the accident occurring after sunset made identifying a safe landing site difficult.
- A lack of reported engine knocking prevented maintenance crews from detecting the deteriorating engine state.
- The aircraft was operating without an oil filler cap, which may have contributed to oil loss.
- The crew did not have current instrument flight rules charts or approach plates available for the flight.
- A specific service bulletin regarding gear-driven alternator engines had not been applied to this particular engine model.