What happened
On February 27, 2011, a Robin 2160, registration F-GILR, departed Toulouse-Lasbordes for Aix-les-Milles carrying a pilot and one passenger. During the flight, the aircraft encountered continuous, severe turbulence while cruising at approximately 3,500 feet. After 45 minutes of flight, the pilot experienced a sudden impact against the canopy, which began to deform inward toward the cockpit.
In an attempt to stabilize the structure, the pilot used his arm to push the canopy back. This action caused a portion of the canopy to fracture and break away from the aircraft, resulting in the loss of the broken piece along with the pilot's cap and headset. Following the structural failure, the pilot utilized the passenger's headset to contact Montpellier air traffic control. After being directed to the nearest airfield, the pilot successfully performed an emergency landing at Bédarieux la Tour sur Orb. The aircraft sustained slight damage.
The investigation
The investigation focused on the structural integrity of the canopy and the environmental conditions at the time of the incident. Investigators noted that a northwest wind of approximately 45 knots was present at altitude. Upon inspection of the aircraft, no visible evidence of a bird strike was found on the remaining structure. However, the investigation identified several pre-existing cracks in the canopy, many of which had been previously repaired with stop-drilling.
Additionally, the investigation noted that both the pilot and passenger were wearing aerobatic harnesses, which they had tightened due to the intensity of the turbulence.
Findings
- The canopy was structurally compromised by pre-existing cracks that had been previously treated with stop-drilling.
- The structural failure may have been caused by a collision with a bird, though any impact evidence may have been lost when the canopy fragment detached.
- The severe turbulence encountered during the flight may have caused sufficient airframe deformation to rupture the already weakened canopy.