What happened
On August 22, 2020, an Alexander Schleicher Ka 2b glider, registration OY-XEO, was participating in a passenger flight event at Arnborg (EKAB). During the winch launch on runway 27, the glider's airbrakes inadvertently deployed. Although ground personnel observed the deployment and attempted to notify the pilot via radio, the aircraft was not equipped with a radio, preventing communication.
Following release from the winch, the pilot noticed the aircraft was sinking more than expected but did not realize the airb_rakes were extended. While attempting to maneuver toward the runway for a landing on runway 27, the pilot's focus on reaching the landing point led to a collision with a pole and chain used for runway delimitation. The impact caused the tail and rear fuselage of the glider to break off, resulting in a heavy impact with the ground. The passenger sustained minor injuries.
The investigation
The Danish Accident Investigation Board examined the aircraft, the pilot's training records, and meteorological conditions. The investigation included a review of video footage of the landing sequence. Technical examination of the OY-XEO revealed no mechanical defects in the aircraft itself. Investigators also looked into the organizational structure of the flight event, which was operated as a cost-sharing arrangement under the Danish Glider Union (DSvU).
Findings
- The airbrake handle was likely not in the fully retracted and locked position prior to takeoff.
- The unintended deployment of the airbrakes significantly reduced the glider's climb performance and altitude maintenance capabilities.
- Increased workload and mental tunnel vision prevented the pilot from identifying and correcting the abnormal aircraft configuration.
- The lack of onboard radio equipment prevented ground personnel from warning the pilot of the deployment.
- The organizational structure for cost-sharing flights lacked standardized safety barriers for pilot selection and operational oversight.