What happened
The pilot reported that all four fuel tanks had been topped off prior to the flight. During engine start-up in 15-degree weather, the pilot switched the fuel selectors from the inboard tanks to the outboard tanks and observed that the fuel gauges registered empty. After recycling the fuel control valves, which were difficult to move due to the cold temperature, the gauges showed a full reading.
The takeoff procedure was reported as normal, and all gauges appeared normal prior to rotation. However, within seconds of rotation, the pilot experienced what was believed to be a loss of both engines. As altitude was lost, the pilot initiated a turn to avoid potential damage to life or property near the takeoff path.
The investigation
An inspection of the aircraft revealed that flight control continuity was maintained to all control surfaces. Investigators found that the left wing inboard and outboard fuel tanks had been compromised. No fuel was present in the left wing gascolator.
In the right wing, fuel was observed in the inboard tank, but the outboard tank had been compromised and contained no fuel. The investigation of the right gascolator revealed the presence of fuel and dirty brown water contamination. Both the left and right propeller blades exhibited minor bending. No preexisting anomalies were found in either engine that would have prevented normal operation.