Mechanical & Engine Failure · NTSB MIA08FA122

Yates Lancair IV-P — Springfield, KY

1 fatal High-time pilot
DateJune 18, 2008
LocationSpringfield, KY
AircraftYates Lancair IV-P (amateur-built)
Purpose of flightPersonal
ConditionsDay · Visual Meteorological Cond
Phase / occurrencePrior to flight Aircraft maintenance event
Pilot age54
Pilot total time6,209 hrs · High time
Time in type196 hrs
Fatalities1

Probable cause

A total loss of engine power due to a loss of engine oil as a result of the installation of the wrong oil adapter O-ring seal.

NTSB findings

  • Aircraft-Aircraft power plant-Eng oil sys (airframe furnish)-Eng oil dist (airframe furn)-Inadequate inspection
  • Aircraft-Aircraft power plant-Eng oil sys (airframe furnish)-Eng oil dist (airframe furn)-Failure - C
  • Aircraft-Aircraft power plant-Eng oil sys (airframe furnish)-Eng oil dist (airframe furn)-Incorrect service/maintenance - C
  • Aircraft-Fluids/misc hardware-Fluids-Oil-Fluid level
  • Personnel issues-Task performance-Maintenance-Installation-Other/unknown

What happened

Shortly after takeoff, the pilot radioed air traffic control to report that he was losing engine oil pressure and that his windscreen was covered with oil. He was advised that he was 4 miles from the nearest suitable airport. Air traffic control lost radar and communications with the pilot and the airplane crashed at the approach end of a runway at the airport. Visual examination of the engine revealed that the No. 2 connecting rod penetrated through the top of the aft section of the engine case. Examination of the accessory case revealed that a Supplemental Type Certificate (STC) SE5743NM Aviation Development Corporation oil filter adapter was attached to the accessory oil filter adapter fitting. A visual inspection of the oil filter adapter revealed that the O-ring between the mating surfaces was extruding 3/4 inch. Visual inspection of the O-ring revealed that it was leaking oil for an undetermined amount of time and was dry rotted and brittle. Review of the STC revealed that the O-ring was the incorrect part that was installed on the engine. A review of the engine and airframe logbooks did not reveal when the installation of the improper O-ring was performed. The engine had accumulated about 351 hours of operation since manufacture.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.

View the official NTSB docket →