Casualties unknown

Glider Damaged During Off-Airport Landing After Loss of Thermal Lift (N86661)

Adelanto, CA, US

On September 29, 1991, a Let L-13 (registration N86661) operated by Big Wing Flyers Inc. was involved in an aviation accident near Adelanto, CA. Investigators recorded the probable cause as: IMPROPER PLANNING/DECISION BY THE PILOT. LOSS OF THERMAL LIFT WAS A RELATED FACTOR. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

A glider pilot and passenger conducted an off-airport landing on a dirt road after failing to maintain thermal lift. During the landing roll, the right wingtip struck vegetation, causing the glider to pivot into uneven terrain and sustain damage to the right wing and empennage.

Accident Description

A certificated private pilot and a passenger were on a local area glider flight after being launched by an aerial tow airplane. While returning to the private airstrip, the pilot was unable to maintain thermal lift and decided to make a landing on a dirt road.

During the landing roll, the right wingtip struck high vegetation, causing the glider to pivot to the right into uneven terrain. The right wing and empennage were damaged as a result of the impact with the terrain and vegetation.

No further details were provided regarding the aircraft, operator, location, or injuries.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X18140. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.