What happened
On March 15, 2005, a Socata TB 20, registration F-GEVA, was conducting a training flight from Melun to Chambéry Aix-les-Bains. The crew, consisting of a pilot and one passenger, planned to perform a touch-and-go maneuver at Bourg aerodrome. Upon arrival, the crew noted that the aerodrome information service was inactive and, seeing no other traffic, decided to enter the circuit on the downwind leg for runway 18.
The pilot performed a landing that was slightly long and fast, with the flaps set to the landing position. During the subsequent ground roll, the pilot moved the flap lever to the takeoff position and applied full power to initiate the takeoff. During the acceleration, the pilot realized that the flaps had remained in the landing configuration. The pilot attempted to abort the takeoff, but the braking was insufficient to stop the aircraft, resulting in a longitudinal excursion from the runway for several dozen meters. There were no injuries and no damage to the aircraft.
The investigation
The investigation focused on the electrical systems and the crew's operational procedures. Investigators discovered that the circuit breaker for the flap control electrical circuit had tripped, though the underlying cause of the electrical failure could not be determined. Following the incident, the operator issued notices to pilots regarding restrictions on using certain equipment on this aircraft model that are powered by the 14-volt electrical circuit.
Findings
Several contributing factors were identified in the sequence of events:
- The crew failed to verify the aircraft configuration before increasing engine power during the touch-and-go maneuver.
- The decision to abort the takeoff was delayed, occurring only when the aircraft had already achieved significant speed and lift, rendering the brakes ineffective.
- The pilot's vigilance may have decreased due to the presence of a highly experienced passenger in the right seat.
- While the operator's manual allows a passenger to handle radio communications, the pilot remains responsible for aircraft management and navigation.