Incident Overview
On June 7, 1997, at 17:51 local time, a LAK-12 "Lietuva" glider, registration LY-GFO, operated by the Biržai Aero Club, collided with a power line support in the vicinity of Pociūnai aerodrome, Lithuania. No injuries occurred among the occupants. The glider sustained damage requiring factory-level repair. Additionally, a farmer's crops and the power line support were damaged.
Sequence of Events
The glider was participating in the Lithuanian Open Class gliding championship. The task was a 530 km route: Pociūnai - Gelgaudiškis - Merkinė - Pociūnai, to be flown twice. The glider departed at 11:48 local time. The first lap was completed without incident. During the second lap, after passing Merkinė, the glider encountered a rain area near Daugai and experienced a strong downdraft. After passing Birštonas, the glider encountered another strong downdraft exceeding 5 m/s from the slope of the Nemunas River. At that point, returning to Birštonas fields for a successful landing was no longer possible. The pilot intended to land on the other side of the Nemunas, but during the approach the glider collided with a power line support.
Aircraft Information
The glider was a LAK-12 "Lietuva", manufactured in Lithuania in 1988, with factory number 6126 and registration LY-GFO. It had accumulated 343 hours and 43 minutes since new. Its maintenance and operation met established requirements.
Pilot Information
The pilot, born in 1962, was a Lithuanian citizen holding a glider pilot instructor license valid until June 5, 1999. He had a total of 633 flight hours, with 46 hours in the preceding 90 days.
Meteorological Conditions
The weather was described as simple, with changing cloud cover at 6/8, cloud base above 2000 m, visibility exceeding 10 km, and wind from 60° at 5 m/s.
Damage and Safety
The collision caused the left wing spar to break, the wing joining pin to bend, the upper and lower skins to detach from the side rib, the airbrake control lever to break and its rod to deform, the canopy glass to shatter, the elevator to break, the stabilizer skin to fracture, and the fuselage skin dent at the canopy frame. Both wings separated from the fuselage, and the fuselage rotated 360° about its longitudinal axis and 180° about its vertical axis. The pilot was wearing lap and shoulder belts, and the seat and belts were undamaged. There was no fire.
Probable Cause
The investigation stated that possible pilot fatigue could have had an influence on the accident.