Covering form of preliminary or final report
| Date of event : | 2019-08-24 |
| Incident number : | CZ-19-0782 |
| Report : | Final report |
| Place of event : | Vrchlabí Airport |
| Registration mark : | Accident |
| Weight category MTOM: : | <2250 kg |
| Type of operation : | Recreational and sport aviation |
| Plane / SFM : | Airplanes |
| Type of plane / SFM : | L-13A BLANÍK |
| Health effects of event : | Without injury |
| PDF document : | 
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Description:
Synopsis:
On 24 August 2019, the AAII was notified of an incident of the L-13A BLANÍK glider at LKVR. When practising correction of incorrect landing technique – simulated glider floating, the student pilot with an instructor on board initially responded to the emerged situation correctly. Having slightly forwarded the control stick, he stopped glider’s ascent and closed airbrakes. However, he then opened the airbrakes again. The instructor did not respond to the arisen situation and the glider fell roughly on the grass RWY 11 at LKVR. The rough landing resulted in undulation of the fuselage skin, damage to the undercarriage and its fuselage fixture. Following expert investigation of the glider, the incident was reclassified as air accident.
The glider crew were not injured.
Analysis:
The event analysis is based namely on the instructor’s explanation, road user’s testimony, and expert investigation of the damaged glider.
The student pilot was practising defective landing correction in compliance with the Training Plan for Theoretical and Flight Training of the SPL DTO Krkonošský aeroklub Vrchlabí. The instructor performed a practical demonstration of a real life scenario of glider’s behaviour during the floating stage by pulling the control stick up in the landing flare phase. The student pilot responded correctly to the occurred situation by a gentle push of the control stick and at the same time closed the airbrakes. By performing those two steps, he avoided the glider’s deceleration and a fall from a higher altitude. Subsequently, however, he deemed the glider’s acceleration to be sufficient and opened the airbrakes fully again. The glider “pancaked” and the main undercarriage wheel made a rough ground impact.
The instructor did not manage to respond to the pilot’s incorrect action as after the floating simulation during the landing manoeuvre he had not taken such measures that would make elimination of potential errors or unexpected response of the student pilot to the arisen situation possible.
All the damage to the glider was caused by a rough impact onto the ground. The glider could be released into further operation only after the repairs performed by the approved maintenance organisation.
Causes:
The cause of the air accident was inappropriate manipulation of the airbrakes control lever handle during the correction of a simulated error during incorrect landing training session, wherein the repeated airbrake flaps extension caused “pancaking” and subsequent impact of the glider to the ground.
Attached final report in PDF file is in original Czech language.