Schempp Hirth Flugzeugbau Gmbh ARCUS M N16DN accident near Richfield, Utah

Probable cause

An inflight loss of control and subsequent inflight breakup for reasons that could not be determined based on the available information.

NTSB analysis

The pilot of the glider reported that he was circling in thermal lift, approaching an altitude of 17,000 feet mean sea level, when one of the rudder pedals "slammed back" and threw his foot off the pedal, accompanied by a "thud" sound. The pilot reported that there was no change in the glider's yaw, pitch, or bank angle, but that he was unable to move the rudder pedals. Shortly thereafter, the glider's bank angle and speed began to increase, and the pilot applied corrective actions; however, he was unable to recover. The pilot instructed the passenger to bail out, and as he jettisoned the canopy, the glider began to break up. The pilot and passenger egressed and landed under parachute, incurring minor injuries.

Postaccident examination of the recovered wreckage, including the flight control system, revealed no evidence of any preexisting mechanical malfunction or anomalies. Based on the available information, the reason for the inflight loss of control could not be determined.

Text from the NTSB. Open the NTSB docket for WPR18LA177 for the full record.