What happened
On May 12, 2020, a glider tow operation commenced at Milewo aerodrome (EPMX) under light rain. The flight involved a Jantar 2B glider, registration SP-3278, being towed by a Job-15 aircraft, registration D-EJHO.
During the takeoff roll, the glider's air brakes unexpectedly opened and fully extended. This deployment created significant aerodynamic drag, preventing the aircraft combination from achieving a sufficient climb rate. As the tow passed the airfield perimeter fence at a low altitude of approximately 2 to 3 meters, the tow pilot determined that the team could not clear the obstacles ahead. The tow pilot ordered an emergency release.
Following the release, the glider pilot attempted an emergency landing in an adjacent field. During the landing roll, the pilot was unable to reach the main wheel brake due to their seating position. The glider veered toward a tree line, striking a tree with the right wingtip before coming to a halt in a drainage ditch. The pilot escaped the cockpit without injuries, but the glider sustained significant damage.
The investigation
The PKBWL investigation examined the cockpit configuration, meteorological conditions, and the takeoff sequence. Investigators reviewed airfield surveillance footage, which confirmed the deployment of the air brakes during the roll. The investigation also looked into the pilot's seating position and the aircraft's maintenance and registration status. It was noted that the tow aircraft, a foreign-registered Job-15, had not been properly reported to the Polish Civil Aviation Authority (ULC) as a permanent resident aircraft at the time of the event.
Findings
- The primary cause of the accident was the improper locking of the air brakes prior to takeoff.
- The takeoff was conducted during light rain, which reduced visibility, increased drag on the wet wing surfaces, and likely contributed to a rushed pre-flight check.
- The pilot's seating position in the cockpit was too far back, which prevented them from reaching the main wheel brake to shorten the landing roll.
- The pilot failed to notice the air brake lever had moved to the 'open' position during the takeoff roll and did not hear a radio warning from ground personnel regarding the brakes.