What happened
On July 4, 2008, at Lisie Kąty aerodrome, an SZD 9 bis 1E Bocian glider, registration SP-2823, was conducting a training flight with a student pilot and a trainee instructor. During the initial tow phase at approximately 600 m AGL, the tow rope loosened. An attempt by the student pilot to tension the line failed, resulting in the rope breaking as the tow aircraft began its descent.
Following the break, the crew continued the flight, eventually beginning a landing pattern. To lose excess altitude, the instructor directed the student to fly the fourth circuit with airbrakes open. Upon reaching the straight-in approach, the student re-opened the airbrakes. At approximately 150 m AGL, the trainee instructor took control and initiated a left-hand turn with a 30-degree bank. During this maneuver, the glider lost airspeed and entered a left-hand spin. The recovery from the spin was delayed, occurring only at an altitude of approximately 10 m AGL.
Following the recovery, the instructor decided to land by executing a 180-degree turn to land in the opposite direction of the flight path. During this high-bank turn, the left wingtip struck the ground, causing the glider to skid. The fuselage subsequently struck the ground, and the right wing impacted protruding concrete posts, resulting in the total destruction of the aircraft. The crew sustained minor injuries and escaped the wreckage unassisted.
The investigation
The PKBWL investigation examined the flight history, the technical condition of the SZD 9 bis 1E Bocian, and the qualifications of the crew. The investigation established that the aircraft was technically sound and the weather conditions were suitable for flight. The investigators also reviewed the trainee instructor's training records, noting a lack of recent flight experience and a history of difficulty maintaining required parameters during previous examinations. Furthermore, it was determined that the trainee instructor was operating without the required authorization from the Civil Aviation Authority.
Findings
- Improper landing approach planning, specifically the decision to use open airbrakes during the circuit to lose altitude.
- Pilot technique errors, characterized by a failure to react to the loss of airspeed, which led to the spin and a delayed recovery.
- Poor decision-making by the trainee instructor, who chose to land from a 180-degree turn rather than continuing straight-in after the spin recovery.
- Inadequate instructor proficiency, driven by insufficient theoretical knowledge and low practical flying skills.
- Lack of regulatory oversight, as the trainee instructor lacked the necessary official authorization to conduct instructional practice.