What happened
On October 24, 2021, a private glider, registration OY-TBX, was performing local visual flight rules (VFR) maneuvers at Klelund Aerodrome near Holsted. The pilot had successfully completed two landings on runway 1s and was proceeding with a third approach.
During the long final approach, the aircraft was traveling at 120 km/h, which was 10 km/h above the recommended approach speed, with the air brakes fully extended. As the pilot transitioned to the short final, a strong headwind prompted a decision to partially retract the air brakes to a quarter-extended position. Immediately following this adjustment, a stall warning horn activated. In response, the pilot fully retracted the air brakes. This maneuver caused the HB Brditschka HB 23/2400 Scanliner to stall and drop from an altitude of approximately 2 meters. The aircraft struck the ground heavily on the left main landing gear and the nose gear, subsequently veering left off the runway.
The investigation
The Danish Accident Investigation Board examined the flight sequence, meteorological conditions, and the resulting damage to the aircraft. The investigation noted that while no METAR or TAF was issued specifically for Klelund, nearby weather reports from Esbjerg indicated winds of approximately 13 knots. The investigators also noted the presence of a cornfield with 3-meter-high crops adjacent to runway 19, which the pilot believed could influence local wind direction and velocity.
Findings
- The aircraft sustained significant damage, including the separation of the left main landing gear leg from the fuselage and the deformation of the nose gear.
- The primary cause of the accident was a stall occurring at a very low altitude during the landing flare.
- The stall was triggered by the pilot's decision to retract the air brakes following an approach speed that was already 10 km/h above recommended levels.