What happened
On Saturday, August 2, 1997, at 13:25, a mid-air collision occurred during the final approach at the Château-Arnoux airfield. The incident involved two gliders: a Centrair C 101 A (registration F-CHFJ) and a Grob G103 (registration F-CADP).
The F-CHFJ had completed a local flight in the northeast sector of the airfield and was integrating into the standard right-hand traffic pattern for a landing on runway 210. During the approach, a tow pilot notified the crew of the presence of another glider flying a left-hand pattern at a low altitude for the same runway. Despite this warning, the pilot of the F-CHFJ continued the approach, reaching a height of approximately 60 meters on final approach. The pilot did not visually identify the second aircraft until it was only a few meters away. An instinctive evasive maneuver, involving a sharp right bank, was attempted but failed to prevent the collision.
Simultaneously, the F-CADP, carrying an instructor and a student, was returning to the airfield due to a lack of lift. Believing the aircraft was too low to pass west and join the standard traffic pattern, the instructor announced on the radio that they would be performing a left-hand circuit. The collision occurred without the crew of the F-CA DP perceiving the other aircraft. Following the impact, both gliders became entangled and fell into a nearby grove of trees.
The investigation
The investigation focused on the flight paths of both aircraft and the communication between the crews. Investigators examined the sequence of maneuvers leading to the final approach and the visibility of the aircraft within the traffic pattern. The investigation established that the two aircraft were operating in opposing traffic patterns—one right-hand and one left-hand—at low altitudes during the approach phase.
Findings
- The primary cause of the accident was the use of simultaneous right-hand and left-hand traffic patterns for the final approach.
- There was insufficient environmental perception by the crews, specifically a failure to maintain adequate visual separation and awareness of other aircraft in the vicinity.
- The collision resulted in two injuries and the total destruction of both aircraft.