What happened
On the evening of October 9, 2003, a Pilatus PC-6 B2-H2 Turbo-Porter, registered F-GEBS, was performing a skydiving flight out of AD Mimizan. Shortly after departing from runway 26, the aircraft experienced an engine failure at an altitude of approximately 350 feet during the initial climb.
Following the loss of power, the pilot was forced to perform an emergency landing in an unpaved field. To facilitate the landing, the pilot feathered the propeller and executed a left-hand turn to avoid obstacles. The pilot noted that the airfield's location within the Landes forest, combined with the presence of several three-meter-high irrigation ramps across available landing areas, necessitated this specific maneuver. During this turn, the aircraft reached the edge of an aerodynamic stall. The aircraft eventually landed in a fallow field near the threshold of runway 08. There were no injuries among the pilot or the nine skydivers on board, and the aircraft sustained no damage.
The investigation
The investigation focused on the mechanical failure of the Pratt & Whitney PT6A-27 engine. Investigators examined the fuel system to determine why the engine ceased operation immediately after the pilot deactivated the auxiliary fuel pump.
Findings
Technical analysis revealed that the engine failure was caused by the loss of drive to the high-pressure fuel pump. This failure was the result of significant corrosion and wear found on the splines of the rotor drive sleeve. The fuel pump in question had operated for 561 hours since its last overhaul in November 2000.