What happened
On January 2, 2010, a Reims Aviation F 150 M, registration F-GAGL, was conducting a local instructional flight departing from Lognes aerodrome. The flight, involving an instructor and a student pilot, was intended to last approximately one hour and focus on maneuvers such as turns, climbs, and descents.
During the final approach to runway 26, while the instructor was handling the controls to maintain separation from preceding traffic, the engine power significantly decreased at an altitude of approximately 800 feet. Despite attempts to apply full power and use the carburetor heat, the engine failed to produce power. The instructor declared an emergency and executed a forced landing in a nearby field. The aircraft struck the ground in a nose-down attitude, causing the nose gear to collapse. The aircraft bounced, struck trees, and came to rest on its nose approximately 50 meters from the initial impact point. Both occupants evacuated the heavily damaged aircraft without injury.
The investigation
The investigation focused on the cause of the engine failure and the fuel levels present at the time of departure. Post-accident inspections of the fuel tanks revealed less than 10 liters of fuel remaining, and the carburetor contained only a trace amount. No mechanical anomalies or fuel leaks were found in the carburetor or fuel system.
Prior to the flight, the crew had measured the fuel levels using a graduated dipstick: the instructor measured 35 liters in the right tank, while the student measured 25 liters in the left tank. The instructor did not verify the student's measurement. The crew decided not to refuel, believing the existing quantities were sufficient for the planned one-hour mission.
Investigators also examined the aircraft's logbook, which contained entries such as "+50 L" and "PC" (plein complet/full tank) for the previous flight. However, the pilots of that preceding flight stated they had not refueled and had not made those specific entries. The investigation could not identify who recorded those inaccurate fuel levels.
Findings
- The primary cause of the accident was insufficient verification of the fuel quantity during pre-flight preparations.
- The crew relied on inaccurate information in the aircraft logbook, which suggested a higher fuel level than what was actually available.
- The fuel measurements taken by the crew were likely incorrect due to the difficulty of obtaining precise readings with the provided dipstick.
- The aircraft was not equipped with a low-level fuel warning indicator.