What happened
On August 1, 2013, at approximately 10:00 local time, a mid-air collision occurred at the Argenton-sur-Creuse aerodrome. The accident involved two aerobatic aircraft operated by the Marcel Dassault Voltige aero club: a Mudry Cap 21, registration F-GLOT, and a Mud．ry Cap 10, registration F-GUMI.
The instructor and student pilot in the F-GUMI had departed earlier for an elementary aerobatic instruction session in a designated nearby zone. Upon completing their maneuvers, the crew of the F-GUMI announced their intention to integrate into the aerodrome traffic pattern on the 123.5 MHz frequency, targeting a left-hand downwind for the unpaved runway 22. Simultaneously, the pilot of the F-GLOT departed for an aerobatic session performed vertically over the aerodrome.
Video analysis from the F-GLOT shows the F-GUMI on a high-speed short final approach for runway 22, while the F-GLOT was flying on a parallel trajectory slightly higher and behind. As the F-GUMI initiated a climbing left turn just before the runway threshold, the two aircraft collided at an altitude of approximately 130 meters (420 ft AAL). The impact caused the destruction of the F-GLOT and the death of its pilot. The F-GUMI sustained damage to its left wing, left elevator, and vertical stabilizer, but the instructor and student were able to land the aircraft safely.
The investigation
The BEA investigation utilized several advanced techniques to reconstruct the flight paths. Investigators analyzed onboard video footage from the F-GLOT to track the movement of the F-GUMI. To understand the pilot's perspective, the BEA used a replica of the F-GLOT cockpit and a specialized camera rig to simulate the pilot's field of view.
By extracting frames from the video, investigators calculated the horizontal speed and trajectory of the F-GUMI. The analysis confirmed that the F-GUMI was not following the standard aerodrome circuit at the time of the collision, but was instead on a trajectory that deviated from the established pattern.
Findings
- The collision was caused by the failure to maintain the 'see and avoid' principle.
- The F-GUMI was flying at a high speed on a trajectory that was not aligned with the standard aerodrome traffic pattern.
- The pilot of the F-GLOT was performing maneuvers that placed the aircraft in the path of the approaching F-GUMI.
- Solar positioning at the time of the accident placed the sun behind and to the left of the F-GLOT, which may have caused glare and hindered the crew of the F-GUMI from detecting the other aircraft during their climbing turn.