What happened
On Thursday, October 22, 1998, at 12:38 PM, a collision occurred on the parking apron at Pontoise Aerodrome involving two aircraft operated by local flying clubs. The first aircraft, a Cessna F 150 L (registration F-BVXG), was preparing for a training flight. After engine start, the instructor received taxi clearance for departure on runway 23, while the student performed brake tests. During these maneuvers, the aircraft drifted approximately three meters from its original parking position.
Simultaneously, a Cessna F 152 (registration F-GCHG) was taxiing back to its parking spot following a local flight. Air traffic control queried the crew of the F-BVXG regarding whether they could allow the F-GCHG to pass. The instructor agreed to the passage. As the F-GCHG approached from the right, the instructor of the F-BVXG believed the incoming aircraft would not have sufficient clearance. To prevent a collision, the instructor signaled the crew of the second aircraft to stop and simultaneously shut down his own engine. However, the pilot of the F-GCHG misinterpreted the hand signals as a greeting and continued taxiing, leading to the impact.
The investigation
The investigation focused on the sequence of taxiing maneuvers and the communication between the two aircraft. Investigators examined the actions of both crews, the instructions provided by air traffic control, and the environmental conditions at the time of the accident. The investigation established that the instructor of the F-BXVG attempted to use visual signals and engine shutdown to halt the other aircraft, but failed to utilize radio communications to alert the approaching pilot of the impending danger.
Findings
- The collision resulted in a bent propeller on the F-BVXG and the left wing of the F-GCHG being severed approximately 50 cm from the wingtip.
- The primary cause of the accident was an erroneous assessment of the clearance required for the passing aircraft.
- The pilot of the F-GCHG misidentified the instructor's warning signals as a friendly greeting.
- The instructor of the F-BVXG did not issue a radio announcement to warn the other pilot before the collision occurred.