What happened
The pilot was operating a rented multiengine airplane as part of a scheduled 70-hour flight period spanning three weeks. Following a series of previous legs involving refueling with 73 gallons and 6ASS88.9 gallons of fuel, the pilot departed on the accident leg after a brief stop where no refueling occurred.
Approximately 1.5 hours into the flight, while operating under night IMC (instrument meteorological conditions), the right engine lost power, followed shortly by the loss of power in the left engine. The pilot received radar vectors to an airport during the subsequent emergency descent. During this descent, the pilot did not feather either propeller. The aircraft descended through the cloud layer and landed in an open field, located 6 miles short of the destination airport. There were no injuries.
The investigation
Investigators examined the wreckage and found 3 quarts of fuel remaining in the right wing tanks and 1 quart of fuel remaining in the left wing tanks. No fuel stains were observed on the ground, wings, or fuselage. The capacities of the main and auxiliary fuel tanks were measured and verified.
The engines were removed for testing; they ran normally during test runs, and the fuel burn rates were found to be consistent with the manufacturer's manual. Based on the average fuel consumption recorded during previous legs of the flight period, investigators determined that approximately 39 gallons of fuel were unaccounted for at the accident scene.