What happened
On April 5, 2008, at approximately 13:53 UTC, a Shempp-Hirth Janus B glider, registration I-BRAE, was performing a takeoff tow from the Corrado Gex Regional Airport in Saint Christophe, Italy. The glider was being towed by a Robin DR400/180 R, registration I-ITAZ.
During the climb, while the aircraft was at an altitude of approximately 1,000 meters, the glider's canopy suddenly opened. The sudden movement caused the plexiglass canopy to shatter. The pilot managed to intervene by manually securing the canopy frame, which remained attached to the aircraft and successfully resealed. Following the incident, both the glider and the tow plane disconnected the tow cable and proceeded to land at Aosta Airport without further complications. There were no injuries to the pilot.
The investigation
The investigation examined the cockpit procedures and the mechanical integrity of the locking mechanism. Prior to takeoff, the pilot had performed standard checks, which included pushing the locking knob fully into place and verifying that the locking hook was seated. The pilot also performed a physical check by pushing upward on the canopy and confirming via radio that the canopy was "closed and locked."
Investigators found no evidence of a mechanical failure within the canopy's closing system. The investigation noted that in most instances of glider canopy openings, the cause is an improper closure during pre-flight preparations. The shattering of the plexiglass was attributed to the mechanical stress placed on the material during the sudden opening event.
Findings
- The primary cause of the incident was likely an improperly secured canopy by the pilot prior to takeoff, although the possibility of an accidental activation of the release mechanism during flight was considered a less likely secondary factor.
- Atmospheric conditions at the time included turbulence and winds from 290 degrees at 25 knots.
- The incident resulted in damage to the glider's plexiglass and minor scratches to the wing roots, as well as the loss of the tow cable, which fell into an industrial area near the airport.