History of Flight
On July 2, 2011, at 1219 Pacific daylight time, a Schleicher ASW-20 experimental category glider, registration N838KS, impacted mountainous terrain 7.6 miles south-southwest of Lone Pine Airport, Lone Pine, California. The private pilot, the sole occupant, was fatally injured, and the glider sustained substantial damage. Visual meteorological conditions prevailed; no flight plan was filed. The flight originated at Inyokern Airport, Inyokern, California, at 1109.
The glider was towed airborne from Inyokern Airport at 1109. According to colleagues, the pilot intended to fly along the mountains on the eastern side of Sequoia National Forest. The wreckage was found along Horseshoe Meadows Road at an elevation of 7,478 feet mean sea level on the eastern slope of the mountain range. The entire glider was concentrated at the crash site.
Personnel Information
The pilot, aged 56, held a private pilot certificate with airplane single-engine land and glider ratings, issued April 4, 2004, and a third-class medical certificate issued February 10, 2010, with a limitation requiring corrective lenses for distant and near vision. His logbook showed 339 total flight hours, including 224 hours in gliders and 144 hours in the accident glider make and model. The most recent flight review was conducted on February 6, 2011, in a Grob 103 glider.
Aircraft Information
The single-seat, high-performance glider, serial number 20599, was manufactured in 1982. An annual inspection was performed on March 13, 2011, at a total airframe time of 1,045.54 hours. The glider had a wingspan of 50 feet and a length of 22.3 feet, and was equipped with a supplemental oxygen system.
Meteorological Information
Surface observations from nearby automated stations indicated clear skies and increasing surface temperatures. At China Lake Naval Air Weapons Station (KNID), 52 miles south-southeast of the accident site, winds were variable at 3 knots at 1156, with 10 miles visibility and clear skies below 12,000 feet. At Eastern Sierra Regional Airport (KBIH), 55 miles north-northwest, winds were from 160 degrees at 15 knots gusting to 21 knots at 1156, with clear skies. Upper air data from Las Vegas, Nevada, showed a dry environment from the surface to 25,000 feet, with no clouds or icing conditions. The sounding indicated conditional instability from the surface through 17,000 feet, which could support strong winds near mountainous terrain.
Flight Recorder Data
The glider was equipped with a Cambridge Aero Instruments Model 25 Secure Flight Recorder. Data recorded every 6 seconds showed that the glider departed Inyokern via tow at 1109:40, released at approximately 1114 at about 5,000 feet GPS altitude, then proceeded north along the Sierra Nevada ridge. From 1120 to 1145, altitudes ranged between 8,500 and 10,000 feet mean sea level. After 1147, the glider flew at altitudes between 9,000 and 7,000 feet, below the ridge along the eastern slope. At 1218:04, the glider reversed course, and ground speed decreased from about 90 knots to 60 knots. The last recorded data at 1219:04 placed the glider 720 feet north of the accident site at a GPS altitude of 7,536 feet. Terrain elevation at that point was 7,427 feet, giving an above-ground-level altitude of 109 feet over 65-degree sloping terrain, with the wing tip approximately 25 feet from the ground.
Wreckage and Impact
The wreckage was located on a 65-degree slope below Horseshoe Meadows Road, characterized by loose rocks, sand, boulders, scrub, and pine trees. The glider was oriented on a bearing of 090 degrees. Wings and tail remained attached; the cockpit was crushed from below. The pilot was strapped in and wearing an oxygen cannula. Flight control continuity was established from the cockpit to the ailerons, elevator, and rudder. The flight recorder was recovered.
Medical and Pathological Information
An autopsy performed on July 11, 2011, determined the cause of death as multiple traumatic injuries with exsanguination from laceration of the aorta and lungs, and intracranial hemorrhages with multiple fractures. Forensic toxicology detected Diazepam (0.076 ug/ml in urine), Nordiazepam (0.029 ug/ml in urine), Oxazepam (0.921 ug/ml in urine and 0.009 ug/ml in blood), and Temazepam (5.465 ug/ml in urine and 0.041 ug/ml in blood). The pilot's wife reported he was taking diazepam and temazepam, which had not been reported to the FAA. Both are benzodiazepines: diazepam as an anti-anxiety medication and temazepam as a sleep aid. Neither is approved for use by airmen, and both may impair mental or physical abilities required for hazardous tasks.