ASK 21 hits trees short of airfield on gusty approach

The rear-seat occupant of an ASK 21 was seriously injured when the glider struck trees on final at Kamp-Lintfort; aircraft substantially damaged. After a winch launch and ~12 min of local soaring in gusty 22-33 km/h easterlies, the two-seater turned in to land. The pilot reported increased sink on final and the glider approached low from the west. About 100 m short of the boundary the right wing contacted trees; the glider yawed through 180 degrees and fell onto a swimming-pool cover, where a roof beam penetrated the rear cockpit. No technical defects were found. The probable cause was misjudgement of approach height in the gusty wind.

1. Winch launch and local soaring: An ASK 21 launched by winch from the 600 m grass strip at Kamp-Lintfort with two occupants, taking off in direction 070 degrees. After release the two-seater flew several circles in the southern pattern area for about 12 minutes. The pilot in command held ~500 h total with 10 h and 60 landings on type, and 9 flights in the previous 90 days.
2. Gusty 22-33 km/h easterly wind: Visual flight conditions prevailed with light cloud, but witnesses reported very gusty wind from 070-100 degrees at 22-33 km/h. The mean wind values were high and the gust spread demanding for a glider approach.
3. Increased sink on final approach: Returning to land, the pilot reported encountering greater than expected sink during the final approach and was unable to hold the planned glide path to the airfield.
4. Low approach from the west: The glider continued at low altitude from the west toward RWY 07. Height above the obstacles between the approach line and the airfield boundary was misjudged in the prevailing wind.
5. Right wing strikes trees short of field: About 100 m west of the airfield boundary the right wing contacted trees. The contact occurred at low height with no margin to recover the flight path.
6. 180-degree yaw onto pool cover: The glider rotated approximately 180 degrees about the vertical axis and fell forward fuselage-first onto the cover of a swimming pool. The cockpit canopy was destroyed and a beam of the cover structure penetrated the rear cockpit area.
7. Rear-seat occupant seriously injured: The rear-seat occupant was seriously injured; the front-seat pilot was not reported injured. The glider was substantially damaged. No technical defects were found on the aircraft. The probable cause was identified as misjudgement of approach height in the gusty wind conditions, leading to the tree contact short of the airfield.