On March 16, 1992, a North American NAVION (registration N4021K) operated by Smith, Scott W. Iii & Chris A. was involved in an aviation accident near Elbe, WA. Investigators recorded the probable cause as: FUEL STARVATION, IMPROPER FUEL, IMPROPER AIRCRAFT SERVICING (FUELING), AND CLEARANCE NOT POSSIBLE. FACTORS CONTRIBUTING TO THE ACCIDENT WERE: NO SUITABLE TERRAIN, LOW CEILINGS, DUSK AND TREES. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During descent after switching from auxiliary to main fuel tanks, engine lost power. Pilot forced landing, broke out of overcast at dusk, avoided road but hit trees. Post-crash inspection found no fuel system malfunction.
Accident Sequence
Shortly after beginning a descent and several minutes after switching from the auxiliary fuel tank to the main fuel tank, the fuel pressure dropped to zero and the engine stopped running. The pilot was unable to restart the engine and conducted a forced landing. While descending through a 500-foot overcast layer during dusk conditions, the pilot emerged above an occupied road and wooded terrain. The pilot maneuvered the aircraft away from the road toward the only suitable landing area available. During this maneuver, the aircraft collided with trees.
Fuel System Examination
A post-crash examination by the Federal Aviation Administration (FAA) revealed no mechanical malfunction within the fuel system.
Pilot Report
The pilot reported departing Moses Lake, Washington, with 20 gallons of 80/87 octane fuel in the auxiliary fuel tank and a 50/50 mixture of 100 low lead and automotive gasoline in the main fuel tank. Research into the issuance of a Supplemental Type Certificate (STC) for automotive gasoline in the Navion was not pursued due to a finding of severe vapor lock during its use.