Standard Libelle falls short of the runway with airbrakes open throughout the flight

The pilot was seriously injured and the glider destroyed when it struck trees on a riverbank about 314 metres short of the runway threshold. The flight was a practice circuit, released from aerotow at about 455 metres above ground. From the release the glider sank steadily at 2.8 to 4.1 metres per second, although the controls, noise and vibration felt normal. The pilot extended the approach to let another glider clear the runway, and the height left was not enough to reach it. Both airbrakes were found about 4 centimetres extended and their lever unlocked; the lever and its lock were serviceable, and the cause could not be established.

1. Practice circuit at Kapfenberg: The pilot launched by aerotow from runway 07 at about 09:48 UTC for the first of three practice circuits planned that morning in a club Standard Libelle.
2. Airbrakes part-open from the start: Both airbrakes stood about 4 centimetres out. On tow the glider hung persistently below the towplane, an early sign of the added drag that went unread.
3. Steady high sink after release: The pilot released at about 455 metres above ground at 95 km/h. The glider then sank continuously at 2.8 to 4.1 metres per second while handling and noise stayed normal.
4. Brake position hard to verify in flight: On this type the airbrakes are barely visible from the strapped-in seat, and the position was never confirmed at the cockpit lever during the flight.
5. Approach extended for traffic: A glider ahead was still on runway 07, so the pilot lengthened the downwind leg to give it time to clear. The remaining height fell further.
6. Impact with trees short of the runway: The glider struck willows on the bank of the river Mürz 314 metres before the threshold at about 94 km/h. The pilot was seriously injured and the glider was destroyed.