What happened
On September 6, 2000, a Lockheed C-130A Hercules, registration N116TG, was conducting a forest fire suppression mission near Burzet, France. After refueling at Aubenas, the crew was instructed by the ground operations commander to perform a retardant drop along a specific axis. During the maneuver, the aircraft was observed by ground personnel performing steep turns at a low altitude over the town of Burually.
As the aircraft approached the fire zone, it flew into a heavily wooded ridge, resulting in the total destruction of the aircraft. The accident resulted in two fatalities (the co-pilot and flight engineer) and two injuries (the commander and flight engineer).
The investigation
The investigation focused on the flight path and environmental conditions at the time of the impact. Examination of the wreckage revealed no mechanical failures; the aircraft was within weight and balance limits, and the release doors were closed.
Investigators determined that the crew was flying at the edge of the aircraft's performance envelope. A flight reconstruction using a helicopter under similar lighting conditions confirmed that the crew likely experienced significant solar glare and was obscured by smoke. Furthermore, shadows cast by nearby terrain likely made it difficult for the crew to accurately judge their distance from the ground. The investigation also noted that the co-pilot was acting as the pilot flying during this phase of the mission to facilitate better communication with ground controllers.
Findings
- The primary cause was an inappropriate decision regarding the flight path chosen for the retardant drop.
- The aircraft was operating at the limits of its flight envelope, likely in a low-speed/high-drag regime, which prevented the crew from recovering altitude before impacting the ridge.
- Environmental factors, including intense sunlight and smoke, led to a loss of visual reference and an erroneous assessment of the terrain.
- The high workload on the co-pilot, who was acting as the pilot flying, prevented the execution of an emergency release of retardant to lighten the aircraft.
- The psychological effect of performing the final mission of the season may have acted as a contributing factor.