What happened
On August 1, 2018, a Jantar Std 3 glider was participating in a regional Club A class competition. The flight, which began with a winch launch and release at 600 m AGL, was part of a 282 km course involving four turning points. During the competition, the pilot encountered steadily worsening weather conditions. After passing the second turning point, the pilot began maneuvering to avoid rain, eventually flying through precipitation while approaching the third turning point.
At approximately 700 m AGL, the pilot attempted to return to the destination aerodrome. However, the presence of rain and a large forested area necessitated flying along the edge of the woods to locate a suitable landing site. While searching for a field, the pilot encountered increased sink rates caused by rain and dynamic vertical currents within a stormy atmosphere, forcing a return to a previously identified location.
As the pilot approached the site at approximately 250 m AGL, the landing field was obscured by a hill. An attempt to maneuver around the hill using a sideslip with slightly deployed airbrakes resulted in encountering turbulence and sudden increased sink on the leeward side. This forced the pilot to turn back toward the field, but the maneuver resulted in approaching the landing area with excessive altitude and airspeed. In an attempt to dissipate energy, the pilot executed a slip, but the glider struck the ground mid-field with significant excess energy. The pilot attempted to use wheel braking to stop before the end of the field, but the braking was insufficient. To avoid impacting a road, the pilot applied left rudder, causing the aircraft to veer and scrape the fuselage along the ground until hitting uneven terrain, which caused the aircraft to spin and come to a halt beyond an unpaved road.
The investigation
The investigation, conducted by the operator's commission, examined the flight path, meteorological conditions, and the mechanical state of the aircraft following the impact. The investigation focused on the pilot's decision-making process during the encounter with heavy precipitation and turbulent air, as well as the aerodynamic performance of the glider during the descent.
Findings
- The primary cause of the accident was the late decision to perform an emergency landing in unfavorable weather conditions, which resulted in a landing maneuver executed with insufficient time and in unplanned terrain.
- The pilot's flight through a zone of precipitation contributed to the accident by reducing the glider's aerodynamic efficiency.
- The aircraft sustained severe structural damage, including a broken tail boom, a broken right side of the elevator, a canopy canopy torn from its locks, and a dislodged instrument panel.
- The pilot sustained no injuries.