What happened
During a daytime cross-country flight conducted in instrument meteorological conditions (IMC), the pilot reported that the left engine had lost power. Following this report, the pilot stated he was unable to maintain the airplane's altitude. Air traffic control provided the pilot with vectors toward the nearest airport.
As the aircraft descended, the pilot reported transitioning into visual meteorological conditions and indicated that the airport was in sight. However, no further communications were received from the pilot following that transmission.
The investigation
Initial measurements of the ground scar at the accident site were consistent with the dimensions of the nose, the right engine cowling, and the length of the right wing. The impact resulted in the nose and the leading edge of the right wing being crushed upward, to the right, and aft.
Investigators examined the fuel system and found that the main fuel tank capacity was 72 gallons. A maintenance entry indicated that auxiliary fuel cells had been disconnected, with lines capped and plugged, and placards were placed stating "DO NOT FILL AUX TANKS" and "AUX FUEL NOT AVAILABLE." An examination of the aircraft confirmed these auxiliary tanks were unusable.
The integrity of the fuel system was found to be intact, with confirmed continuity from the main tanks to both engines. Investigators found approximately 2 ounces of blue-colored fuel in the left main fuel sump, while five and one-half quarts of blue-colored fuel were drained from the right main fuel tank.
Mechanical inspections of the engines included manually rotating the crankshaft, which confirmed continuity from the crankshaft flange to the rear accessory case gears; thumb compression was present on all cylinders for both engines. The left propeller blades were found in the non-feather position against the stop locks and showed no evidence of rotation. A test run of the left engine revealed no discrepancies that would have prevented the engine from producing power prior to the accident.