Primary finding
Probable cause
The pilot’s inadequate preflight fuel planning which resulted in a total loss of engine power due to fuel exhaustion and subsequent forced landing.
Investigator assessment
Analysis narrative
The pilot and the pilot-rated passenger were flying the multi-engine airplane on a long cross-country trip. At an intermediate stop, the pilot had the airplane serviced to a total fuel quantity of 60 gallons and estimated that the fuel consumption for the planned 3-hour return flight would be slightly more than 9 gallons per hour, per engine. What he did not realize was that the total fuel consumption displayed to him by his flight planning application was only accounting for 9 gallons per hour total, or about half of what it should have been. About 3 hours after departure, the right engine began to sputter and subsequently lost total power. After declaring a fuel emergency to air traffic control, the left engine also lost power. The pilot and pilot-rated passenger determined that they would not be able to glide the airplane to a nearby airport and they began to scan for an alternate landing location. They attempted to land in a large parking lot, but the airplane struck power lines before contacting the ground. The airplane came to rest upright on the main landing gear. The left wing was separated outboard of the left engine, and the fuselage, right wing, and empennage sustained substantial damage. A small postimpact fire ignited near the portion of the left wing that separated from the fuselage and was quickly extinguished after the accident. Postaccident examination of the airplane revealed that less than 1 gallon of fuel remained in the right wing fuel tank and no fuel was present in what remained of the left wing fuel tank. There was no odor of fuel at the accident site. Given this information, it is likely that the loss of engine power to both engines was due to the pilot exhausting the airplane’s usable fuel supply.