What happened
On August 30, 2005, at 18:20, a Diamond Aircraft DA 42 Twin Star, registered F-GYYJ, was involved in a ground collision at Touss and Toussus-le-Noble aerodrome. The aircraft was being operated for a demonstration flight for an instructor representing a company that had recently purchased the aircraft.
Following a landing, the pilot taxied to a paved parking area. After shutting down the engines, the pilot and instructor exited the aircraft. Shortly thereafter, a Cessna 206G arrived and parked approximately fifteen meters directly across from the Diamond aircraft.
The pilot then began the pre-flight inspection and prepared for a solo flight to Chambéry. During the engine start sequence, the pilot turned toward the rear seat to retrieve aeronautical charts and subsequently focused on programming navigation points into the onboard GPS. During this period of distraction, the aircraft began to move forward without the pilot's awareness. The propeller of the right engine struck the stationary propeller of the Cessna 206G, at a moment when one individual was still inside the Cessna and another had just disembarked.
The investigation
The investigation focused on the movement of the aircraft and the state of the braking system. The pilot stated he could not recall whether the parking brake had been applied prior to engine start. Technical examination of the Diamond Aircraft DA 42 revealed no mechanical anomalies or failures within the braking circuit.
Investigators noted that on level ground, the aircraft is capable of moving under single-engine idle power if the parking brake is not properly engaged. The flight manual specifies that the parking brake must be applied during the pre-flight inspection and before engine start. Furthermore, the manual outlines a specific procedure to ensure the brake is effective: the lever must be moved to the locked position, followed by repeated applications of the rudder pedals to establish sufficient pressure within the braking system.
Findings
- The primary cause of the collision was the incomplete application of the pre-start checklist.
- The pilot was distracted by retrieving charts and programming the GPS during the engine start sequence.
- The parking brake pressure was insufficient because the pilot failed to pump the rudder pedals to establish pressure in the circuit after setting the lever to the locked position.
- The collision resulted in damage to the propeller, propeller cone, reduction gear, and torque damper of the F-GYYJ.