What happened
On July 25, 2000, an Air France Concorde, registration F-BTSC, was performing a takeoff from Paris-Charles de Gaulle Airport. During the takeoff roll, a significant failure occurred involving the aircraft's landing gear. The sequence of events led to a catastrophic release of fuel and a subsequent intense fire, causing the aircraft to crash near Gonesse, France.
The investigation
Investigators examined the wreckage, the runway debris, and flight data recorders to reconstruct the accident. The investigation focused on the destruction of fuel tank number 5 and the origin of the fire. Key elements analyzed included the condition of the tires, the presence of metallic debris on the runway, and the structural integrity of the wing's lower surface. Extensive computer simulations and impact tests were conducted to model how a piece of tire debris might have interacted with the aircraft structure. The investigation also scrutinized the electrical systems within the main landing gear bay to determine if they could have served as an ignition source.
Findings
- A piece of metallic debris, identified as a strip from a worn tire, was found on the runway.
- A large fragment of tire rubber, weighing approximately 4.5 kg, struck the underside of the wing.
- The impact of the tire debris caused the rupture of fuel tank 5, leading to a significant fuel leak.
- The investigation established that the fuel leak ignited within approximately one second of the tank's failure.
- While several ignition sources were considered, including engine surges and hot engine components, the high energy of the initial flame suggested a rapid ignition event.
- It was noted that electrical cables for the brake fans in the left main landing gear bay were potentially damaged by debris from a tire failure, making an electrical arc a highly probable cause of the initial ignition.