Discus bT hits trees short of outlanding after sustainer fails to start

The pilot of a Discus bT was seriously injured when the glider struck trees short of an outlanding field at Spaichingen; aircraft destroyed. Shortly after a winch release at Klippeneck the pilot extended the sustainer to test it, but it would not start. The glider headed south-west, losing height as further start attempts continued with the engine deployed. From ~170 m AGL the pilot turned toward a field; the approach height was insufficient and the glider, descending steeply with engine extended, struck trees on a 3 m embankment and overturned. The probable cause was misjudgement of the outlanding while attempting to restart the sustainer.

1. Winch launch from Klippeneck: The pilot launched the Discus bT by winch from RWY 23 at the Klippeneck gliding site.
2. Sustainer fails to start after release: Shortly after release the pilot extended the sustainer to test it; the starter cranked but the engine did not run. A return to the airfield was no longer possible from the height available.
3. Height lost during start attempts: The glider tracked south-west, descending continuously while the pilot made further start attempts with the engine deployed. After about three minutes of flight, height had reduced to ~170 m AGL.
4. Turn toward outlanding field: From the descending flight path the pilot turned left at ~170 m AGL toward a selected outlanding field, while still attempting to restart the engine.
5. Engine extended, increased sink rate: With the sustainer still deployed the drag was higher than in clean configuration, steepening the approach and reducing the glide reach.
6. Trees struck on embankment; overturned: On approach from the west, over a motocross site and across a track bounded by a 3 m vegetated embankment, the glider contacted trees on the embankment; the left wing was severed and the glider overturned onto an adjacent field, coming to rest on its left side supported by the deployed sustainer and tail. The pilot was seriously injured and the glider destroyed. No technical defects were identified; fuel and starter-battery state were adequate. The probable cause was misjudgement of the outlanding situation while attempting to restart the sustainer, leading to obstacle contact on approach.