Accident Overview
The pilot of a single-engine airplane reported that during cruise flight, the engine "quit" while the aircraft was at an altitude of 1,500 ft above ground level. The pilot subsequently executed a forced landing in a large, flat pasture. During the landing roll, the airplane nosed over. There was no report of fuel tank breach from the landing.
Fuel Examination
A telephone conversation with the aircraft recovery specialist revealed that the fuel tanks remained intact. Recovery efforts yielded 1.5 gallons of fuel from the right tank and 2.5 gallons from the left tank, totaling 4 gallons of usable fuel.
Engine Data Analysis
The airplane was equipped with a J. P. Instruments (JPI) engine monitoring unit. Data downloaded from the unit covered approximately 1 hour and 13 minutes of the accident flight. Analysis of the data indicated a sudden decrease in exhaust gas temperatures (EGT) and cylinder head temperatures (CHT) for all cylinders simultaneously around the time of the engine failure. The complete data plot is available in the public docket for the accident.
Manufacturer Information
The 1967 Cessna 180 Owner's Manual specifies that 2.5 gallons per fuel tank is considered unusable in normal flight maneuvers. This information is relevant to understanding the amount of fuel that would be available for engine operation.