Incident Details
While on final approach, low and configured to land, the engine lost all power. The pilot attempted to land in a field and collided with power lines. The flight had returned from Mexico, reentered the United States at a port of entry, and proceeded to the destination airport. Upon arrival, the tower advised the pilot to hold for landing sequence; clearance was given after about 5 minutes of holding. Controllers observed the airplane turn left and descend steeply out of sight.
Flight History and Fuel Analysis
Fuel was not available at the Mexico location and was not purchased at the port of entry. A recovered trip log of seven previous trips showed an average similar trip duration of 3.5 hours, as recorded by the mechanical recording tachometer. The average fuel quantity used per round trip was 68.5 gallons, with the highest recorded at 72.6 gallons and the lowest at 65.1 gallons. The longest round trip time was 3.7 hours. The average fuel burn rate was 19.57 gallons per hour. The average number of gallons remaining at Deer Valley airport was 20.5 ±5 gallons. The actual fuel quantity at the time of the incident could not be determined.
Fuel System Findings
The airplane has a two-tank system with 44.5 gallons of usable fuel in each tank when properly serviced. The fuel selector was found in the off position, possibly a reaction to the emergency. The selector provides fuel from either the left or right fuel tank, but not both simultaneously. The postaccident fire destroyed the left wing and part of the right wing root; no fuel was found in the tank system.
Recovered Cessna pilot safety and warning supplements stated that if the fuel tank outlet is uncovered by fuel, fuel flow to the engine may be interrupted and a temporary loss of power might result. A note in the pilot information manual for the fuel system indicates that unusable fuel is minimal due to the design, but when the fuel tanks are 1/4 full or less, prolonged uncoordinated flight such as slips or skids can uncover the fuel tank outlets, causing fuel starvation and engine stoppage. With low fuel reserves, the manual advises against allowing the airplane to remain in uncoordinated flight for periods in excess of one minute.