Accident Summary
The airplane impacted a tree and terrain after experiencing a total nonmechanical loss of engine power.
Pilot's Fuel Calculation
The pilot reported that with the fuel tanks half full, there would be 20 gallons of fuel. He calculated that after a 2-hour flight at a fuel burn of 8 gallons per hour, there would be 4 gallons of reserve fuel remaining.
Fuel System Specifications
The airplane was equipped with two main fuel tanks with a total capacity of 42 gallons, of which 38 gallons were unusable.
Advisory Publications
According to Federal Aviation Administration publication FAA-P-8740-03, a "safe flight time" is based on multiplying the usable fuel on board by 75% and dividing that result by the previously confirmed consumption rate. The publication also notes that fuel gauges must be calibrated to accurately indicate an empty tank but do not have to be accurate at any other fuel level. Additionally, the performance and fuel information in the pilot operating handbook is based on testing new aircraft with experienced test pilots.
Forced Landing Considerations
During the approach to the airport, the pilot changed his planned landing runway to land with a more favorable wind. The engine quit on the base leg of the newly selected runway. The wind at the time of the accident was 360 degrees at 7 knots. Advisory Circular 61-21A states, "When a forced landing is imminent, wind direction and speed should always be considered, but the main object is to complete a safe landing in the largest and best field available."
No evidence of fuel was found aboard the airplane.