What happened
On July 3, 2015, a Robin DR400-180R, registration F-GAHH, was preparing for a ferry flight to Montluçon-Guéret following maintenance work. After completing engine tests, the pilot taxied from taxiway B to the threshold of runway 06. Approximately 30 seconds after announcing the intention to depart, the pilot aborted the takeoff. During the deceleration, the AFIS officer alerted the pilot to the start of a fire involving the left main landing gear.
The pilot immediately prepared for emergency egress by reclining the seat, unbuckling the harness, and opening the canopy. Once the aircraft came to a complete stop, the pilot successfully evacuated. However, the fire spread rapidly, destroying the vertical stabilizer within three minutes and resulting in the total destruction of the aircraft.
The investigation
The investigation focused on the mechanical state of the braking system and the circumstances leading to the ignition. The aircraft, built in 1976, utilized a central brake handle system that applied pressure to both main wheels simultaneously. The investigation noted that the pilot had used the parking brake during engine tests and released it for the taxi, but used the handbrake to align with the runway without engaging the parking brake.
Due to the intensity of the fire, the wreckage behind the firewall was heavily damaged, making a direct physical examination of the landing gear and braking circuit impossible. Investigators also considered the environmental conditions, noting a high ambient temperature of 35 °C and a significant taxi distance of 1,550 meters from taxiway B to the runway threshold.
Findings
- The pilot noticed that the aircraft was not accelerating normally during the takeoff roll, which prompted the decision to abort.
- It is possible that when the central brake handle was released, it failed to fully relieve pressure within the braking circuit.
- This likely resulted in residual symmetric braking pressure that was too subtle for the pilot to detect during taxi.
- The combination of this residual drag and the high ambient temperature (35 °C) during the long taxi distance likely caused the left main gear to overheat, leading to the fire.
- The prompt alert from the AFIS officer was critical in allowing the pilot to recognize the fire and execute a rapid evacuation.