History of Flight
On January 4, 2016, at about 1615 mountain standard time, an experimental Aerostar SA YAK-52, registration N912EB, collided with terrain while maneuvering near Alpine Airport, Alpine, Wyoming. The private pilot and a pilot-rated passenger sustained fatal injuries; the airplane was destroyed. The aircraft was registered to and operated by Wyoming Wings LLC under 14 CFR Part 91. The local personal flight had departed Alpine Airport around 1530. Visual meteorological conditions prevailed, and no flight plan was filed.
Family members reported that the accident airplane departed for an area northwest of the airport where the pilot planned to perform aerobatics. Two other aircraft, flown by the passenger's father and the pilot's son, then departed for local sightseeing. The passenger's father returned to the airport, landed on runway 13, and taxied to prepare for departure on runway 31, standard practice when winds allowed. He observed the YAK performing aerobatics west of the airport and heard the pilot's son announce a 3-mile straight-in final for runway 13. He departed runway 31 and turned 90° west to clear for landing traffic. At pattern altitude, he saw a debris field forming behind the son's aircraft, which was on a 2-mile final. He flew over the site and broadcast that the YAK was down. He noted slight cloud cover and low light conditions.
The pilot's son stated that he departed after his father and flew along the east side of a reservoir before turning south over his home. He returned north and maneuvered to the west side of the reservoir. As he proceeded north, he descended over the frozen, snow-covered reservoir. He reported that the surface had no cracks, and flat lighting made it difficult to judge height above ground. Farther north, cracks in the ice aided depth perception. About 7 miles north of the airport, he crossed to the east side and headed south. About 5 miles out, he announced his intention to land on runway 13. He saw the passenger's father's airplane take off and turn west. Around 100–200 ft above the ground and 3 miles from the airport, he heard his father in the YAK radio that he was either going to join up or perform a flyby. The son initiated a go-around and flew over the airport. He looked over his shoulder for the join up and listened for a radio call, but none came, and he never saw the YAK. He then heard the passenger's father radio him and realized something was wrong. He proceeded to the area where the other airplane was circling and saw a disturbance in the snow.
An airport resident who heard the radio transmissions looked for the YAK to fly over. After hearing the conversations, he contacted the pilots in the air and notified emergency authorities.
Wreckage and Impact Information
The airport was at the southeast corner of a reservoir that surrounded it on three sides. The accident site was on flat, featureless, snow-covered terrain about 2 miles northwest of the airport, near the extended centerline for the final approach to runway 13. The debris field was 578 ft long on a magnetic heading of 122°. The first point of contact was a crater measuring about 15 ft long, 6 ft wide, and 2 ft deep. On the left side of the crater's beginning were a piece of the left wing-tip and the pitot tube, with about 1 ft buried. A few feet farther was a piece of the left aileron. At the end of the crater lay a separated propeller blade. The left wing fragmented into several pieces, most in the first half of the debris field. The inverted right wing was about 400 ft along the centerline. The main wreckage—fuselage and empennage—lay 500 ft into the field. The last major component, the separated engine, was at the end.
The airplane was highly fragmented. All control surfaces and major components were identified. The aircraft had flight controls for both seats. Disconnects in flight control push-pull tubes were angular and jagged; cable disconnects were splayed.
The propeller had separated from the engine crankshaft along with the crankshaft propeller flange. The spinner was crushed and showed thermal damage. Two of three blades were separated from the hub; the remaining blade was melted outboard of mid-span. The exposed crankshaft exhibited extensive spiral cracking around half of its circumference.
Additional Information
The FAA pamphlet "Flying in Flat Light and White Out Conditions" describes flat light as an optical illusion causing loss of depth-of-field and contrast, often occurring in snow-covered areas with overcast skies. It can obscure terrain features and create illusions of ascending or descending. The FAA's Pilot's Handbook of Aeronautical Knowledge notes that featureless terrain, such as snow-covered ground, can create an illusion of being higher than actual, leading to lower approaches.
Medical and Pathological Information
The Booneville County Coroner's Office performed an autopsy on the pilot, reporting cause of death as blunt force injuries. Examination was limited by injury severity but revealed severe coronary artery disease with up to 80% stenosis and microscopic evidence of prior heart muscle ischemia. Toxicological tests by the FAA were negative for alcohol or performance-enhancing drugs; tests for carbon monoxide or cyanide were not performed. The drug valsartan was detected in liver and kidney. The 61-year-old front-seat pilot had reported high blood pressure, high cholesterol, and recent diabetes to the FAA. At his last medical exam on May 24, 2014, he reported using valsartan, ezetimibe/simvastatin, fenofibrate, and metformin—none with performance warnings. His physician reported excellent diabetes control. The 17-year-old rear-seat passenger had no reported medical conditions or medications; no autopsy or toxicology was performed.