Accident Description
A glider pilot experienced an accident during the landing approach when the aircraft's left wing contacted trees. The flight had been uneventful until the pilot began his descent. While on downwind leg, the altimeter indicated an altitude of approximately 1,000 feet. Believing he had another 1,000 feet of clearance above the ground, the pilot intentionally lost altitude to prepare for landing. Shortly thereafter, he realized the glider was much closer to the ground than expected and initiated a left turn toward the runway. During this turn, the left wing struck trees.
Pilot Actions
The pilot reported that his standard procedure before any flight was to set the glider's altimeter to read zero feet above mean sea level (MSL). On the day of the accident, he entered the glider immediately after another person had exited. The pilot thought he had set the altimeter to read MSL, but post-accident examination revealed that the altimeter was actually set to that day's barometric pressure setting. This mis-set resulted in the altimeter displaying a higher altitude than the glider's true height above ground.
Post-accident Examination
Examination of the aircraft after the accident confirmed that the altimeter was adjusted to the local barometric pressure for the day, not to the zero MSL setting the pilot intended. The investigation found no other anomalies with the aircraft or its systems.