Engine Failure and Crash
During cruise flight at 14,000 feet mean sea level, the engine failed. Air traffic control vectored the flight to a nearby airport, but the pilot instead flew toward another airport and subsequently crashed in a residential area.
Engine Examination Findings
Post-accident examination of the engine revealed that 1.8 quarts of oil were drained. Three of the six connecting rods had failed due to lack of lubrication. Detonation damage to the No. 6 cylinder piston was noted, and scoring of piston sidewalls was observed on five of the six cylinders. Evidence of heat discoloration was found on the connecting rod journals for three of the six cylinders.
Instrument and System Issues
The aircraft's TIT (Turbine Inlet Temperature) gauge, which had been miscalibrated by 30 to 40 degrees when the airplane was manufactured, was found to indicate 110 degrees Fahrenheit low near the maximum continuous point of 1,750 degrees. The air/oil separator hose to the scavenge pump was plugged about 10 inches along its length with a substance containing a high lead content. This plugging resulted in recurring pilot reports of excessive oil consumption.
Previous Maintenance Actions
Due to the pilot's complaint of excessive oil consumption, four of the six cylinders had been removed and replaced within the previous six months. Approximately one month before the accident, one of the cylinder pistons was removed and replaced after examination revealed piston sidewall damage consistent with detonation.