What happened
On July 5, 2015, a Piper PA25 Pawnee, registration F-GIGX, was performing glider towing operations at the Fayence aerodrome. Following the completion of a tow, the pilot was on final approach to the unpaved runway 10. Approximately 800 meters from the runway threshold, the engine stopped.
In an attempt to maintain glide distance, the pilot retracted the flaps to reduce drag. Realizing the runway could not be reached, the pilot executed a forced landing in a nearby vineyard. During the landing sequence, the aircraft maintained a speed near the stall threshold. As the aircraft neared the ground, the pilot extended the flaps into the landing configuration. Upon impact, the landing gear collapsed after striking a vineyard post, causing the aircraft to slide approximately ten meters and pivot to the left before coming to a halt. The aircraft sustained heavy damage.
The investigation
The investigation focused on the fuel management practices of the flying club and the mechanical indicators used to monitor fuel levels. The club operates two Piper PA2 and PA25 aircraft with different fuel capacities and different mechanical gauge systems. On the aircraft involved, F-GIGX, the gauge consists of a float and a vent. When fuel levels are low, the float is no longer visible, leaving only the vent visible.
The pilot had performed five towing sorties. While the pilot recorded flight times in the towing log, the investigation found that the pilot relied on visual inspections of the external mechanical gauge rather than calculating remaining endurance. The investigation established that the pilot had misidentified the vent on F-GIGX as the mobile fuel gauge used on the club's other aircraft, F-GFPD, leading to an erroneous belief that sufficient fuel remained.
Findings
- The engine failure was caused by fuel exhaustion resulting from insufficient monitoring of remaining fuel levels.
- The pilot failed to adhere to the club's established fuel management procedures, which require rigorous monitoring of consumption.
- The presence of two similar aircraft with different fuel capacities and different visual gauge configurations contributed to pilot confusion regarding remaining endurance.