What happened
On October 8, 2005, a Cessna 185 F « Skywagon », registration F-GCVX, was performing parachute jump operations departing from Valenciennes. During the fifth rotation of the day, shortly after climbing to an altitude of approximately 1,500 feet, the engine lost power. The pilot attempted to restart the engine but was unsuccessful, forcing an emergency landing in a nearby field. Upon impact with the ground, the aircraft's landing gear collapsed, causing the plane to slide roughly thirty meters before coming to rest on its belly. The pilot sustained slight injuries, while the aircraft was heavily damaged.
The investigation
The investigation focused on the cause of the engine power loss and the fuel state of the aircraft. Investigators found that both fuel tanks and the fuel system were empty at the time of the accident. No fuel leaks were identified in the wreckage. The aircraft was not equipped with a low-fuel warning alarm.
Prior to the flight, the pilot had used a manual dipstick to check fuel levels, a method used because the pilot considered the cockpit fuel gauges to be unreliable. Based on this measurement, the pilot estimated there were 150 liters of fuel remaining, which he believed provided three hours of flight time based on a standard consumption rate of 50 liters per hour. However, radio communications indicated the engine had been running for approximately two hours and twenty minutes, exceeding the pilot's calculated remaining endurance.
Findings
- The primary cause of the engine failure was fuel exhaustion.
- There was a significant misunderstanding regarding the interpretation of the manual fuel dipstick readings. The fuel tanks had been recently drained and refilled to calibrate a measurement scale; due to the tank shape, any fuel below 15 liters could not be measured by the dipstick. While the pilot believed he needed to add 15 liters to his reading to find the usable total, the actual volume onboard was only 120 liters.
- The pilot made an erroneous estimation of the aircraft's endurance, failing to account for the actual fuel remaining versus the consumption rate.