On July 15, 1994, a Cessna 180 (registration N333QB) was involved in an aviation accident near Battle Lake, MN. Investigators recorded the probable cause as: The pilot's miscalculation of usable fuel capacity, based on incorrect placard data rather than actual tank specifications, which resulted in fuel exhaustion. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot experienced a total loss of engine power within three miles of the intended destination. Investigation confirmed no usable fuel remained in either tank due to miscalculated capacity.
What happened
The aircraft was operating under visual flight rules and was approximately three miles from its intended destination when it suffered a complete loss of engine power. The pilot was unable to restart the engine or maintain altitude, resulting in an emergency situation close to the airport.
The investigation
Examination of the wreckage revealed that there was no usable fuel remaining in either wing tank. Further inspection confirmed that the aircraft's fuel tanks were actually 30.0-gallon units with a 27.5 gallon usable capacity. However, the pilot had based his pre-flight fuel planning on the 32.5 gallon capacity listed on the placard inside the cockpit.
Findings
The discrepancy between the placarded capacity and the actual usable fuel volume led to an inaccurate calculation of available endurance. The pilot assumed a higher fuel load than was physically accessible, leading to fuel exhaustion. No mechanical failure of the engine or fuel system was identified as a contributing factor.
Probable cause
The pilot's miscalculation of usable fuel capacity, based on incorrect placard data rather than actual tank specifications, which resulted in fuel exhaustion.