What happened
During the cruise phase of flight, the pilot experienced a loss of power in both engines. The pilot reported that one engine began to sputter, prompting him to switch fuel tanks and verify that the mixture was set to full rich. Shortly after these actions, the second engine also sputtered.
In response to the dual engine failure, the pilot prepared for a forced landing into a small field. During the maneuver, the pilot overshot the intended touchdown point and struck trees adjacent to the field. The Cessna (type not specified in source, but aircraft was substantially damaged) sustained substantial damage during the impact.
Prior to departure, the pilot had requested that FBO line service personnel top off the inboard main fuel tanks. While the pilot verified that the fuel tank caps were present and secure, he did not remove any caps to visually check the actual fuel quantity. The FBO personnel stated the pilot specifically requested that the outboard fuel tanks be topped off.
The investigation
The investigation examined the aircraft's three fuel tanks on each wing: the production inboard and outboard main tanks, and the auxiliary wing tip tanks. The inboard and outboard main tanks utilized sub-flush fuel caps covered by a small, hinged panel, while the auxiliary tank used a standard, twist-off cap that protruded above the wing contour.
During the on-scene investigation, the inboard main fuel tanks were found to be empty. While the outboard main tanks contained an undetermined amount of fuel, both wing tip tanks were found to be separated and ruptured.
Engine examinations were conducted on both powerplants. The fuel flow divider units for both engines were disassembled and found to contain no fluid, though the diaphragms remained intact. No other anomalies were identified during the mechanical examination.