History of Flight
On July 8, 2011, about 1721 mountain daylight time, a Schweitzer SGS2-32 glider, registration N591CC, sustained substantial damage when it impacted terrain during takeoff initial climb following a practice low altitude rope release near Ferndale Airport (53U), Bigfork, Montana. The airline transport rated pilot sustained fatal injuries and the airline transport rated pilot examiner sustained serious injuries. The glider was registered to Wave Soaring Adventures Inc., Lake Tapps, Washington, and operated under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight.
According to the pilot examiner, the purpose of the flight was to renew the pilot’s flight instructor certificate. Prior to the accident, they conducted maneuvers including stalls, steep turns, accelerated stalls, slow flight, and thermal climbs, followed by a landing on runway 15. After landing, the examiner briefed the tow plane pilot and the pilot receiving the checkride that the next flight would simulate a rope break during takeoff from runway 16 at about 260 feet above ground, maintaining 75 mph during a right turn back to the runway.
During the second flight, the examiner released the rope at 260 feet and noticed the airspeed slowing. He instructed the pilot to increase speed to 75 mph and maintain bank until aligned with runway 33. The examiner stated that before alignment, the pilot made a quick control stick movement to the right, causing an accelerated stall. Multiple witnesses observed the glider depart normally, release from the tow rope at about 200-300 feet, then enter a steep right bank and descend into terrain. The tow plane pilot reported feeling the release at about 200 feet and landed uneventfully.
Personnel Information
The pilot, aged 61, seated in the rear seat, held an airline transport pilot rating with multi-engine land ratings, a commercial pilot certificate with single-engine land and glider ratings, multiple type ratings, and a flight instructor certificate with glider rating. He held a second-class medical certificate issued May 3, 2011, with a limitation for corrective lenses for near vision. He reported 14,760 total flight hours.
The pilot examiner, aged 68, seated in the front seat, held an airline transport pilot rating with multi-engine and single-engine land ratings, a commercial pilot certificate with single-engine sea and glider ratings, multiple type ratings, and a flight instructor certificate with single-engine land, instrument airplane, and glider ratings. He held a second-class medical certificate issued July 15, 2010, with a limitation for corrective lenses. He reported 36,500 total flight hours, including 475 hours in gliders and 35 hours in the accident make/model.
Aircraft Information
The two-seat tandem mid-wing glider (serial number 34) was manufactured in 1966. It had dual flight controls. Both seats had lap and shoulder seatbelt restraints. The instrument panel was forward of the front seat. The most recent annual inspection was completed April 19, 2011, at 6,450 total airframe hours. No prior records were located.
Meteorological Information
Recorded data from Glacier Park International Airport, about 18 miles northwest, at 1655 showed wind from 250 degrees at 15 knots gusting to 30 knots, broken clouds at 7,500 and 9,000 feet, temperature 19°C, dew point 0°C, altimeter 29.89 inHg. The pilot examiner reported wind at the accident time from about 235 degrees at 5 knots gusting to 8 knots.
Airport Information
Ferndale Airfield is uncontrolled with class G airspace, elevation 3,072 feet msl, and one turf runway (15/33) 3,500 feet long and 95 feet wide.
Wreckage and Impact Information
FAA examination showed the glider impacted terrain about 300 feet beyond the departure end of runway 15, coming to rest upright. Control continuity was established to all primary flight controls. Both wings remained attached; the right wing was partially separated inboard of the inboard aileron attach point, and the right wingtip was separated. The forward fuselage and instrument panel were separated. The wreckage was recovered for further examination.
Medical and Pathological Information
An autopsy by the state medical examiner on July 8, 2011, determined the cause of death as blunt force injuries. Toxicology tests by CAMI found amlodipine, atorvastatin, fexofenadine, ibuprofen, and valsartan in unspecified amounts.
Tests and Research
Post-accident examination revealed the left wing was mostly undamaged; the right wing was impact damaged outboard of the inboard aileron attach point. The right aileron was bent. The vertical stabilizer, rudder, and horizontal stabilator were mostly undamaged. The fuselage was bent and buckled aft of the seating area; forward area showed upward and aft crushing. The instrument panel was separated.
The front seat shoulder restraint was brown webbing with black lap belts. The restraint was looped around a tubular support beam that was bent and partially separated. The shoulder restraint webbing was separated above the chest adjusters. The rear seat shoulder restraint was black, looped around a similar beam, and separated at the stitched webbing. Both front and rear restraints were sent to the NTSB Materials Laboratory.
Examination by a Senior Metallurgist found the front restraints separated through fabric webbing above the chest adjusters with frayed edges, consistent with tensile overstress. The webbing was worn and stained. No identification markings were present. The rear seat restraints consisted of a yoke with buckles and two single straps with loop adjusters, one strap labeled as FAA-PMA component manufactured by Aero Fabricators with model number H702200 and manufacture date likely Feb 19, 2004. The webbing was intact but stitching threads were mostly broken at the folded ends.