What happened
On Wednesday, November 27, 2002, a Robin DR 400-120, registered F-BVMQ, was conducting a training flight involving an instructor and two students. The flight originated from Lens aerodrome, with a planned route including stops at Arras and Vitry before returning to Lens.
While flying at an altitude of approximately 600 feet, the instructor noticed the low fuel pressure warning light illuminate. In an attempt to maintain engine power, the instructor activated the electric fuel pump; however, this action failed to resolve the issue, and the engine RPM began to decrease. Realizing the aircraft could not reach the intended destination at Vitry, the instructor performed an emergency landing in a cultivated field. The aircraft sustained no damage during the landing.
The investigation
The investigation focused on the fuel state of the aircraft and the pre-flight procedures. Investigators found that the fuel tank was completely empty at the time of the incident. Notably, when the aircraft's electrical system was powered on, the fuel gauge indicated that the tank was nearly full.
Records from the aircraft logbook revealed that the plane had been in flight for four hours and 47 minutes since its last documented refueling. The instructor, who had personally performed the pre-flight checks, noted that the fuel gauge showed a full tank during engine start. Upon reviewing the logbook, the instructor observed that the total flight time since the last refueling entry was significant, but he incorrectly assumed that a supplemental refueling had occurred and simply had not been recorded in the logbook.
Findings
- The primary cause of the fuel exhaustion was a confirmation bias during the cross-check of the aircraft logbook against the fuel gauge readings.
- The instructor relied on a visual assumption regarding recent refueling rather than verifying the actual fuel quantity through physical inspection or logbook accuracy.
- The fuel gauge provided misleading information, indicating a nearly full tank when the reservoir was actually empty.