N104TH Schempp Hirth DISCUS CS accident

NTSB WPR18TA192 · 2018-07-11 · Goldfield, NV

Docket — crew, injuries and powerplant

Summary

The commercial pilot reported that, during the personal glider flight, the weather conditions deteriorated, so he chose to land the glider at an alternate airport. While attempting to reach the alternate airport, the glider encountered continuous sinking air. When he realized the glider would not reach the alternate airport, the pilot chose to land on a nearby road. Just before touchdown, the right wing impacted a berm that paralleled the road, and the glider subsequently cartwheeled and then came to rest inverted.   The pilot reported no preimpact mechanical malfunctions or failures with the airframe that would have precluded normal operation. The glider encountered atmospheric lift conditions that were not sufficient to maintain flight, which necessitated a forced landing on uneven terrain.

Full narrative

On July 10, 2018, about 1832 Pacific daylight time, a Schempp Hirth DISCUS CS glider, N104TH, collided with terrain during a forced off airport landing, following a loss of lift, near Goldfield, Nevada. The commercial pilot sustained serious injuries. The glider sustained substantial damage to the fuselage and both wings. The glider was registered to Sparrowhawk21 LLC. and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal local flight. Visual meteorological conditions existed about the time of the accident, and no flight plan had been filed. The flight originated from Tonopah Airport (TPH), Tonopah, Nevada about 1330.

The pilot reported that during the long cross country flight, he had to deviate to an alternate airport, due to deteriorating weather. While attempting to reach his selected off airport landing site, he encountered continuous sinking air. He realized that he would not make it and made the choice to land on a nearby road. Just prior to the landing touchdown the right wing impacted a dirt berm that paralleled the road, which caused a ground loop. The glider cartwheeled and came to rest inverted.

The pilot reported no mechanical malfunctions with the airframe that would have precluded normal operation.

Probable cause

The glider’s encounter with atmospheric lift conditions that were not sufficient to maintain flight, which necessitated a forced landing on uneven terrain. The National Transportation Safety Board determined the probable cause of this accident.

Circumstances

Event type
Accident
Highest injury
Serious
Weather conditions
Visual Meteorological Cond
Light condition
Day
Sky condition
OVC
Ceiling (ft)
9000
Visibility (sm)
10
Wind direction
80
Wind speed (kt)
18
Temperature (F)
82
Distance from field
0.0

Aircraft

RegistrationMakeModelDamageFAR part
N104TH Schempp Hirth DISCUS CS SUBS 091

Sequence of events

#OccurrencePhase
1 Enroute-cruise Windshear or thunderstorm Climb
2 Enroute-cruise Loss of lift defining Climb
3 Landing-landing roll Collision with terr/obj (non-CFIT) Cruise
4 Landing Off-field or emergency landing Cruise
5 Landing Loss of control on ground Cruise
6 Landing Roll over Cruise

Findings

Finding
Environmental issues-Conditions/weather/phenomena-Temp/humidity/pressure-Thermal lifting-Effect on operation cause
Environmental issues-Physical environment-Terrain-Rough terrain-Contributed to outcome factor