On July 13, 1995, a Cessna 310D (registration N6976T) was involved in an aviation accident near Alamosa, CO. Investigators recorded the probable cause as: TOTAL LOSS OF POWER IN BOTH ENGINES DUE TO FLOODING AFTER THE PILOT HAD PLACED BOTH FUEL PUMP SWITCHES IN THE HIGH BOOST POSITION AND MOVED THE MIXTURE CONTROLS TO THE FULL RICH POSITION. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During landing preparation, the pilot advanced mixture controls, causing both engines to lose power simultaneously at low altitude and airspeed. The aircraft collided with rough terrain during forced landing. Electric fuel pumps were found in high boost position.
Event Sequence
During the approach for landing, the pilot advanced the mixture controls. Both engines then lost power at the same time. The airplane was flying at a low altitude and had a low airspeed. The pilot attempted to execute a forced landing, but the aircraft struck rough terrain.
Post-Accident Inspection
After the event, the electric fuel pumps were found in the high boost setting. The supplemental flight manual for the airplane indicates that when the engine-driven fuel pumps are functioning normally, a total loss of engine power can occur if the electric fuel pumps are set to high boost.
Relevant Conditions
The density altitude at the destination airport was approximately 9,700 feet.