Accident Sequence
On November 15, 2012, about 0700 mountain standard time, an American AA1, registration N5642L, sustained substantial damage when it impacted terrain near the Morgan County Airport (42U) in Morgan, Utah. The commercial pilot, the sole occupant, sustained fatal injuries. The flight was originating at the time with a planned destination of Logan-Cache Airport, Logan, Utah. Visual meteorological conditions prevailed, and no flight plan was filed.
A witness near the airport reported watching the airplane take off from runway 03 and noted the engine sound appeared normal. Another witness at 42U observed frost on parked airplanes' exposed surfaces on the morning of the accident and the previous day, noting similar weather conditions. A third witness reported frost covering his grass that morning.
The pilot was reported overdue by a family member that afternoon, prompting an FAA Alert Notification. Law enforcement located the wreckage about 1715 on November 15 in mountainous terrain near 42U.
Aircraft and Pilot Information
The two-seat, low-wing, fixed-gear airplane, serial number AA1-0042, was manufactured in 1968. It was powered by a Lycoming IO-320 engine (150 hp) and equipped with a Sensenich variable-pitch propeller. The last annual/100-hour inspection was completed on August 18, 2012, at a tachometer reading of 1,824.46 hours and airframe total time of 4,098.96 hours.
The pilot, age 50, held a commercial pilot certificate with multi-engine (limited center thrust), single-engine land, glider, and instrument ratings. He had a third-class medical issued April 27, 2007. His logbook showed 217.1 total flight hours, with 23.4 hours in the accident make/model, and 242 glider hours.
Meteorological Conditions
Recorded data from Hill Air Force Base (about 9 miles west) at 0655: wind 120° at 16 knots, visibility 10 statute miles, clear sky, temperature 1°C, dew point -3°C, altimeter 30.29 inHg. Calculated density altitude was about 4,133 feet. Sunrise was at 0715 with civil twilight beginning at 0645.
Airport Information
Morgan County Airport (42U) has a field elevation of 5,020 feet. Runway 03/21 is 3,904 feet long and 50 feet wide, with rising terrain in all quadrants. The airport manager reported that runway 21 was routinely used for takeoff unless the airplane had a high climb rate, due to terrain off the departure end of runway 03. High terrain about 3 miles past runway 03 was estimated at 6,450 feet msl.
Wreckage and Impact
The accident site was about 2.8 miles north of 42U at an elevation of 5,796 feet. The debris path was about 50 feet long. The first identified point of contact (FIPC) showed disturbed dirt with red lens fragments consistent with the left wing's navigation light and the pitot tube. The fuselage came to rest inverted on a heading of about 120° magnetic, 42 feet from the FIPC. A post-impact fire consumed most of the fuselage and inboard wings.
Flight control continuity was established for rudder and elevators. The left wing was crushed aft and thermally damaged; the right wing remained partially attached. The right fuel tank contained a liquid smelling like automotive fuel, testing negative for water. No evidence of mechanical malfunctions or failures precluding normal operation was found in the airframe or engine.
Engine and Propeller
The Lycoming O-320 engine sustained thermal damage. Both magnetos were removed; the right produced sparks, the left had thermal damage and no spark. The vacuum pump was functional. The engine rotated by hand with continuity and compression on all cylinders. The propeller remained attached; one blade showed aft bending and gouging, the other showed bending and scratches.
Medical and Pathological
An autopsy determined the cause of death as multiple blunt force injuries. Toxicology tests for cyanide, volatiles, and drugs were negative.
Additional Information
National Transportation Safety Board meteorologists noted that dew point temperatures were below freezing with depressions as small as 1°C on the accident morning. The FAA Handbook of Aeronautical Knowledge states that frost on aircraft surfaces can disrupt airflow and reduce lift, advising thorough cleaning before flight.