Occurrence
On 18 July 2017 at 12:44 local time, a pilot with a glider pilot license (SPL) departed from Piła (EPPI) airfield in a SZD-30C Pirat glider for a thermal flight. At approximately 17:15 local time, while turning in strong turbulence at an altitude of about 500 meters and an indicated airspeed of 110 km/h, the canopy opened. The pilot returned the glider to level flight, partially closed the canopy, and held it while landing at the departure airfield. The landing was completed without further incident. The frame of the canopy was deformed to an extent that prevented proper closure.
Investigation
Post-flight inspection revealed a fatigue fracture in the material of the canopy lock handle, specifically the tip had broken off. The investigation determined the cause to be the fatigue fracture of the canopy lock handle tip.
Preventive Actions
The user conducted a discussion of the event with glider pilots present at the airfield. Additionally, glider pilots were informed of the need to inspect the canopy lock handle for signs of material fatigue, such as cracks, scratches, fractures, or bends. No safety recommendations were issued.