What happened
On July 27, 2015, at approximately 17:04 LMT, a SZD-9 bis 1E Bocian glider, registration SP-3799, was engaged in a training flight at the Rybnik Gotartowice aerodrome. The flight, operated by Ośrodek Szkolenia Lotniczego BB-Aero, was intended to practice procedures for emergency situations.
As part of the training, the instructor and the winch operator had agreed that the winch tension would be released at an altitude of approximately 20 meters to simulate a tow-rope failure. During the climb, the winch operator terminated the pull as planned. However, the student pilot failed to react to the sudden loss of tension. The instructor, attempting to maintain control, moved the control stick toward himself to transition into a gentle level flight and manually released the tow rope.
Following the release, the instructor noted to the student that the maneuver had been missed. In response, the student deployed the full aerodynamic air brakes. This action caused the glider to enter a descent, striking the ground with its right wingtip and main landing gear. The aircraft slid approximately 120 degrees to the right before coming to a halt. The impact caused significant damage to the landing gear, the forward fuselage, the right wingtip, the right air brake plate, and the seating of both the instructor and the student.
The investigation
The PKBWL investigation examined the flight sequence, the aircraft's technical condition, and the crew's actions. The investigation confirmed that the aircraft was properly documented and maintained. The inquiry focused on the sequence of events following the winch release and the specific inputs made by the student pilot during the low-altitude flight phase.
Findings
- The instructor failed to secure the glider's airspeed following the winch release, failing to transition the aircraft into a proper glide.
- The student pilot deployed the full aerodynamic air brakes, which directly caused the glider to stall and impact the ground.
- The instructor's actions were performed at a critically low altitude, leaving a deficit of time to correct the flight path.
- The investigation noted that training exercises involving emergency procedures should be conducted in a manner that does not compromise flight safety.