The passenger reported that he could not remember if the pilot of the Maule M5 checked the fuel before the flight, which originated from Woodinville, Wash. The passenger told investigators that it took several tries to get the engine to start. About 30 minutes into the flight, the engine started to sputter, then stopped.
The pilot was unable to restart the engine, and the airplane began to lose altitude. The passenger recalled seeing the stall warning light illuminate as the airplane was in a turn, but he did not recall the impact.
The airplane hit a home about 16 nautical miles northeast of the airport. The pilot was killed in the crash.
GPS data revealed that the airplane made several course heading changes at varying altitudes and airspeeds during the flight. During the last 16 seconds of the flight track, the airplane turned left, which was likely indicative of the pilot attempting to make a forced landing to a nearby pond. The last GPS data showed the airplane at an altitude of 650 feet MSL and a groundspeed of 40 knots.
Investigators learned the airplane’s previous flight occurred 102 days before the accident. During this period of inactivity, the airplane remained parked outside on an airport ramp exposed to inclement weather conditions conducive to the formation of condensation in the partially filled fuel tanks. No records were found indicating that the airplane had been refueled before the accident flight.
Fuel was recovered from the airplane at the accident site. Analysis of a fuel sample revealed the presence of water. Investigators determined that fuel contamination likely resulted in the loss of engine power and the pilot’s inability to restart the engine after the power loss. The pilot likely failed to maintain adequate airspeed following the loss of engine power.
The NTSB determined the probable causes of this accident as the pilot’s failure to maintain adequate airspeed following a total loss of engine power due to fuel contamination, which resulted in a stall/spin and subsequent impact with terrain.
NTSB Identification: WPR13FA141
This March 2013 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.