Glider stall during ridge soaring flight

Casualties unknown • Woodstock, VA, US

A pilot experienced a stall and subsequent impact with trees while attempting to maneuver a glider near a ridge due to diminishing orographic lift.

What happened

Following release from a tow plane, the pilot flew a glider for approximately 10 miles along a ridge. During the flight, the pilot failed to recognize that the wind speed required to produce sufficient orographic lift had decreased. Additionally, the pilot did not execute a turn toward the valley while maintaining enough altitude to clear the terrain. As the aircraft entered a turn into very weak ridge lift, the glider experienced a stall and struck trees.

Findings

  • The pilot's pre-departure evaluation of weather conditions had predicted good orographic lift in the area.
  • There were no mechanical deficiencies reported with the glider.

Probable cause

The pilot failed to recognize diminishing wind speeds necessary for orographic lift and failed to turn toward the valley while sufficient altitude was available, resulting in a stall and impact with trees.

Frequently asked questions

What happened in the 2002-06-16 Schleicher ASK21 accident near Woodstock, VA?

A pilot experienced a stall and subsequent impact with trees while attempting to maneuver a glider near a ridge due to diminishing orographic lift.

What aircraft was involved and where did it happen?

The accident on 2002-06-16 involved a Schleicher ASK21, registration N341KS, operated by Frederic Winter, at Woodstock, VA.

What was the probable cause of the accident?

The pilot failed to recognize diminishing wind speeds necessary for orographic lift and failed to turn toward the valley while sufficient altitude was available, resulting in a stall and impact with trees.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20020620X00941. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.

Loading the flight search…