What happened
The pilot was conducting a cross-country flight in a glider when the aircraft encountered a sudden loss of thermal lift. With no further altitude or forward momentum available to reach an airport, the pilot initiated a forced landing procedure. The selected site was a vacant, unattended rest stop located along an interstate highway. The surrounding terrain at the rest stop was level, providing a relatively flat surface for the emergency touchdown.
During the final approach to the rest area, the glider's left wing made contact with a light pole situated near the landing zone. This impact resulted in significant structural damage, shearing off the outboard six feet of the left wing. The aircraft came to rest after the wing failure, having sustained critical damage to its lifting surface.
The investigation
Examination of the accident site and the aircraft revealed that the primary cause of the structural failure was the collision with the light pole during the forced landing approach. The outboard section of the left wing was detached from the main spar due to the impact force. No other mechanical failures or pre-existing conditions were identified as contributing factors to the incident.
Findings
The loss of thermal lift was the initiating event that necessitated the emergency landing. The presence of infrastructure, specifically the light pole at the highway rest stop, presented a hazard during the forced landing maneuver. The level terrain allowed for a controlled approach until the obstruction was encountered. structural failure of the wing due to ground contact was the direct result of the collision.