What happened
On August 22, 2020, a Rolladen-Schneider LS4 glider, registration OY-XMD, was performing a private landing at True Gliding Field (EKAS). During the second flight of the day, the pilot was on final approach for runway 26 with the airbrakes partially extended. As the aircraft approached the threshold, it encountered turbulence caused by nearby trees. The pilot perceived a significant drop in airspeed and attempted to correct the situation by pushing the control stick forward and extending the airbrakes further.
These corrective actions caused the aircraft's sink rate to increase sharply at a low altitude. Consequently, the pilot was unable to sufficiently flare the glider before impact. The Rolladen-Schmidt LS4 struck the runway in a nearly level position with significant force, though the pilot was able to stabilize the aircraft and complete the landing further down the runway.
The investigation
The investigation examined flight data from the aircraft's Flarm unit, which provided ground speed and altitude profiles. Analysis of the meteorological conditions revealed challenging weather, including a southwest wind of approximately 10–18 knots with gusts up to 30 knots, and the presence of nearby rain showers. The investigation also reviewed the pilot's training status and the airfield's operational procedures.
Investigators determined that while the pilot experienced a perceived loss of airspeed, the Flarm data showed the ground speed did not drop below 76 km/h, meaning the aircraft was not near a stall. However, the pilot's decision to push the stick forward and extend airbrakes directly contributed to the increased descent rate.
Findings
- An increase in the sink rate at a low altitude prevented the pilot from executing an optimal flare and landing.
- The pilot's recent training status, which was categorized as "rusty" according to the training barometer, combined with the challenging weather conditions, likely influenced the pilot's decision-making in a negative direction.
- The aircraft sustained structural damage to the landing gear bushings, the wheel well, and the wing-to-fuselage attachment points.
Safety action
Following the incident, the gliding club implemented a new procedure: during difficult weather conditions, the flight instructor responsible for the day's operations must assess whether an individual pilot's training proficiency is sufficient for solo flight.