DG-600 stalls in a low turn-back after getting high on tow

A pilot was killed when his DG-600 self-launcher stalled in a low turn-back and dived into trees. On an early aerotow for a wave flight, in cold saturated air the canopy likely fogged over and, with a low head-on sun, he probably lost his outside references. Unable to hold station, the glider rose into the high tow position and pushed the tug's nose down, and both released. He then turned back low at about 40° of bank; the speed fell to about 70 km/h, below the stall speed for that bank, and the glider stalled into trees. Investigators tied the loss of control to a probable loss of visual references from misting and sun glare.

1. Early aerotow for a wave flight: The pilot took an early-morning aerotow for a Pyrenees wave flight, in cold, fully saturated air.
2. Canopy misting, low-sun glare: The canopy most likely fogged over and, with a low head-on sun, the pilot probably lost his outside visual references.
3. High tow position; both release: Unable to hold station, the glider rose into the high tow position and pushed the tug's nose down; both pilots released the rope.
4. Low, steep turn-back: The pilot began a 180° turn back at low height and about 40° of bank.
5. Stall, dive into trees: The speed fell below the stall speed for that bank; the glider stalled and struck trees near-vertically. The pilot was killed and the glider destroyed.