History of Flight
On April 5, 2015, at approximately 1424 Pacific daylight time, a Schleicher ASW-27 glider, registration N27QV, experienced an inflight breakup after encountering clouds near Reno, Nevada. The glider had departed from Minden-Tahoe Airport (MEV) earlier that morning at about 0715. The pilot, who was the sole occupant, reported flying for approximately 6.5 hours. While passing near Reno at an altitude of about 14,000 feet, the pilot attempted to navigate through a gap in the clouds. The clouds quickly closed in, enveloping the glider. The pilot stated that the glider suddenly accelerated beyond its design limits, causing the wings to separate from the fuselage. The pilot then bailed out using a personal parachute. Radar data indicated the glider approached Reno from the north along ridgelines, made a left turn followed by an elongated 360-degree turn, then proceeded south. Just south of Interstate 80, the glider's path made a sharp turn northward and ended.
Personnel Information
The 77-year-old pilot held an airline transport pilot certificate for multiengine airplanes and commercial privileges for single-engine land, sea, and glider operations. He also held a third-class medical certificate issued on April 18, 2014, with the limitation that corrective lenses and a hearing aid must be available. The pilot reported a total flight time of about 20,000 hours, with 190 hours in the accident glider make and model.
Aircraft Information
The glider was a high-performance, single-seat, low-wing Schleicher ASW-27, serial number 27098, manufactured in 1998. Its most recent annual inspection occurred on May 26, 2014, at an airframe total time of 1,551 hours. The wings each contained a single spar that did not directly connect to the fuselage; instead, the spars joined together in the fuselage just aft of the cockpit via a two-pin tapered lug and clevis fitting. The left wing carried the lug portion, and the right wing carried the clevis. Two fittings on each wing root rib engaged two metallic pins on each side of the fuselage to transmit lift forces into the airframe.
Meteorological Information
The nearest weather reporting station was Reno/Tahoe International Airport (RNO), about 3 miles southeast of the accident site. Surface observations around the time of the accident recorded sustained winds from the south at 25–30 knots, with gusts to 30–35 knots. Weather observers noted altocumulus standing lenticular clouds, which can indicate mountain wave activity. A weather balloon launched a few hours after the accident showed southeasterly winds of 20–50 knots up to about 15,000 feet, where winds increased to 50 knots. Geostationary satellite imagery confirmed standing clouds over the regional terrain in the hour or two before the event, and polar-orbiting satellite data depicted clouds along the final portion of the glider's flight path about 40 minutes prior to the accident.
Wreckage and Impact Information
Due to the nature of the accident, the NTSB investigator-in-charge did not conduct an on-scene investigation. Local law enforcement reported that glider components came to rest at various locations in the Reno area. The pilot landed on top of a parking garage, and the fuselage came to rest about 50 yards south. The right wing landed in a park about 1 mile northeast of the fuselage, and the left wing was found inside a vacant warehouse about 0.4 miles east of the main wreckage. No ground injuries occurred, and only minor damage was reported to one vehicle.
Tests and Research
Postaccident examination revealed that the right wing failed in positive overload and the left wing slid out of the fuselage. The right wing attachment point was mostly intact, with a fracture in the fuselage above it; the wing pins transmitting lift loads showed no obvious deformation. The main spar fracture occurred near the fuselage: the upper spar cap fractured about 12 inches outboard of the centerline, and the lower spar cap fractured about 24 inches outboard. About 5.5 feet of the upper spar cap and web and about 3 inches of the lower spar cap were missing, as was most of the inboard 5.5 feet of skin and leading edge. The outboard right wing was largely intact but fractured about 64 inches inboard of the tip; the wing tip and winglet were missing. Portions of the aileron and flap were present. The left wing attachment point sustained damage: the forward wing pin had slight aftward tip deformation and an elongated hole; the aft wing pin showed significant aftward deformation. The fuselage structure above the left wing attachment was fractured, and the forward wing pin carry-through was fractured. All left wing wreckage was inside the warehouse. Its main spar fractured about 75 inches outboard of the centerline, and a secondary fracture occurred about 64 inches inboard of the tip; the wing tip and winglet were missing. Portions of the aileron and flap were present. The main spar was intact from about 74 inches left of centerline through the center fitting to about 1–2 feet right of centerline. The two spar pins were intact and installed in the tapered lug and clevis; the left-wing lug and right-wing clevis forks were intact. The glider was equipped with a flight data recorder, but it sustained major impact damage and no usable data could be recovered.