History of Flight
On April 11, 2015, at about 1525 mountain standard time, a Schempp-Hirth Standard Cirrus glider (serial number 126) sustained substantial damage after impacting terrain following a winch-tow launch at the A.C. Goodwin Memorial Field Gliderport (AZ86) in Prescott Valley, Arizona. The private pilot, the sole occupant, sustained fatal injuries. The glider was registered to and operated by the Prescott Soaring Society, Prescott, Arizona. Visual meteorological conditions prevailed; no flight plan was filed. The local flight was originating under 14 CFR Part 91.
Several witnesses provided statements. One witness, also a glider club pilot, stated that the accident glider had been flown twice earlier that day. He advised the pilot about the glider's "touchy elevator" and that things happened fast in a fiberglass glider. The pilot launched normally, called a speed of 65 mph, and requested a speed of 65. The witness observed the glider appear slower with increasing angle of attack, then heard a call of "more power." When the glider reached about 800 feet agl, the witness turned to radio the pilot about being too slow, heard "Oh no," and saw the glider in a stall spin to the left before impact.
Another witness reported a slightly bumpy launch, wings started to flutter, then stalled. The left wing dropped, the glider spun two full times at about a 75-degree angle before impact.
A third witness saw the glider climb to about 800 feet agl, slow below stall speed, then spin two and a half to three times before impact.
A fourth witness observed a smooth transition into climb; at about 800 feet agl, the glider appeared to fly through a thermal, wings wobbled right then left. The pilot called 65 mph, shallowed the climb, then called "more power." At about 1,200 to 1,300 feet agl, the glider stalled and spun two and a half times to the left at 70 to 80 degrees before impact.
The tow winch operator reported that the winch was about a mile down the runway. The pilot made a standard radio call requesting 65 mph. The operator added power, saw a normal takeoff, heard the pilot call 65, then heard what sounded like "more power." The operator began adding power but saw the nose drop and the glider enter a spin. He cut power and put the transmission in neutral to release tension. He did not see impact due to a hill.
Personnel Information
The pilot, age 74, held a private pilot glider rating. His initial glider dual instruction was on November 10, 2005; he soloed on March 6, 2006, after 15.4 hours of instruction. He received his private pilot glider rating on March 21, 2015, with a total time of 132 hours, all in gliders. At the time of the accident, his logbook showed 134.8 hours total, 87.7 hours as pilot-in-command, and 9.4 hours in make and model, with no record of instruction in that model. He had 222 ground tow launches total, 168 as pilot-in-command, and 13 ground tow launches in the accident glider, all as pilot-in-command. The most recent ground tow launch in that glider was on March 23, 2014.
Aircraft Information
The glider, serial number 126, received its standard airworthiness certificate in September 1971. The last annual inspection was on March 26, 2015, at an airframe total time of 1,144.6 hours.
Meteorological Information
At 1545, the weather reporting facility at Ernest A. Love Field (PRC), Prescott, Arizona, about 7 nautical miles west-southwest of the accident site, reported wind variable at 6 knots, visibility 10 miles, sky clear, temperature 21°C, dew point -9°C, altimeter 29.94 inches of mercury.
Wreckage and Impact Information
The glider impacted flat, desert terrain in a steep nose-down attitude about 215 feet west of runway 21 and about 2,490 feet from the takeoff start. It came to rest on its left side on a magnetic heading of about 170 degrees. The first impact point was a shallow depression about 6 inches deep, 30 feet east of the main wreckage.
The carry-through wing remained intact, upright, laying on the cockpit area, with the leading edge facing aft, rotated about 180 degrees. The forward fuselage and cockpit area were crushed rearward. The aft fuselage was intact to the empennage, with a circumferential fracture in fiberglass. The vertical stabilizer and rudder were intact. The left stabilator remained attached; the right stabilator separated and was found about 20 feet north.
The outboard one-third of the left wing was intact with moderate damage; the inboard two-thirds were undamaged. The left aileron and spoiler (deployed) remained attached. The right wing's inboard half was substantially damaged; the outboard half had minor damage. The right aileron and spoiler (deployed) were intact. Flight control continuity was verified to rudder and ailerons; stabilator control was verified through pushrods to the vertical stabilizer. The tow rope attachment showed no anomalies. The winch operator reported no anomalies with the winch system.
Medical and Pathological Information
An autopsy on April 12, 2015, by the Yavapai County Office of the Medical Examiner determined the pilot's fatal injuries were due to multiple blunt force trauma. Toxicological testing by the FAA Bioaeronautical Science Research Laboratory detected no carbon monoxide in blood, no ethanol in vitreous, and cyanide testing was not performed. Flecainide and Tamsulosin were detected in liver and blood. Flecainide is used to treat irregular heartbeat; Tamsulosin is an alpha-blocker used to relax muscles in the prostate and bladder neck.