Let L 23 Super Blanik
Moose, Wyoming/Injuries: 2 Fatal
The pilot and one passenger departed on a sightseeing tour flight in the glider. After being released from the tow airplane about 13,800 ft mean sea level (msl), the glider pilot proceeded to fly over a national park near mountainous terrain. A video recording of the flight from the passenger’s cell phone recorded the pilot state, “this is not good” twice and “I’m in trouble” as the glider neared the terrain. The glider impacted terrain between two mountain peaks (elevations about 12,800 ft msl and 12,500 ft msl) at an elevation about 11,000 ft msl.
A review of weather data found upper level winds were from the south-southwest, which likely provided no significant orographic lift in the area of the accident site on the western side of the mountains and likely provided some downdraft activity due to the range immediately south.
It is likely that the pilot maneuvered the glider close to terrain in an attempt to attain lift, but encountered atmospheric conditions that resulted in a loss of lift, a loss of control, and a subsequent impact with terrain.
According to the operator’s tour flight procedures, aircraft were not permitted to fly within the boundaries of the national park and were to maintain a minimum altitude of 2,000 ft above terrain. It is likely that compliance with the company’s published procedures would have ensured terrain separation during the flight even in the event of an encounter with adverse wind conditions.
Probable cause(s): The pilot’s encounter with atmospheric conditions that resulted in a loss of lift and a subsequent loss of control near terrain that precluded
Note: The report republished here is from the NTSB and is printed verbatim and in its complete form.
