Morgan, UT, USA
N5642L
AMERICAN AA-1
A witness reported that the airplane took off just before sunrise and that the engine sounded normal. During climbout, the airplane impacted rising terrain about 3 miles from the airport and about 776 feet above field elevation. A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A review of the recorded meteorological data showed that the weather conditions were conducive to frost formation. Further, a witness at the airport reported observing frost on the surfaces of parked airplanes on the day of the accident. Therefore, it is likely that the airplane had frost on its surfaces before takeoff and that the pilot failed to adequately clear the frost off the airplane during the preflight inspection, which increased drag and reduced the production of lift; therefore, the airplane was unable to gain sufficient altitude to clear the rising terrain.
HISTORY OF FLIGHT On November 15, 2012, about 0700 mountain standard time, an American AA1, N5642L, sustained substantial damage when it impacted terrain near the Morgan County Airport (42U) Morgan, Utah. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The commercial pilot, who was the sole occupant of the airplane, was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight, which was originating at the time of the accident with a planned destination of Logan-Cache Airport, Logan, Utah. One witness located near the airport, reported watching the airplane take off from runway 03. The witness stated that the sound of the engine appeared to be normal. A witness, located at 42U, reported that he noticed frost formed on the parked airplanes' exposed surfaces during the morning hours of the day prior and the day of the accident. The witness stated the weather conditions the day of the accident were similar to the previous day. The witness further reported that the accident airplane had a canopy cover and was parked outside on the ramp. Another witness, near the airport, reported frost covering his grass on the morning of the accident. A family member of the pilot reported the airplane overdue to local law enforcement the afternoon of November 15, 2012, after becoming concerned when the pilot had not arrived at his planned destination. The Federal Aviation Administration (FAA) issued an Alert Notification (ALNOT) for the missing airplane. The wreckage was located by law enforcement personnel about 1715 on Nov 15, 2012, in mountainous terrain near 42U. Examination of the accident site by the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) revealed that the wreckage of the airplane was located about 2.8 miles north of 42U. All major structural components of the airplane were located within the 50-foot long debris path. The fuselage and inboard portions of both wings were mostly consumed by a post-accident fire. PERSONNEL INFORMATION The pilot, age 50, held a commercial pilot certificate with an airplane multi engine land (limited to center thrust) single-engine land, glider and instrument ratings. The pilot was issued a third-class airman medical certificate on April 27, 2007, with no limitations stated. The pilot reported on his most recent medical certificate application that he had accumulated 200 total flight hours. A review of the pilot's logbook revealed that he had accumulated a total of 217.1 flight hours, 21.5 hours within the preceding 90 days, 12 hours within the preceding 30 days, and no logged flight hours within the previous 24 hours. The total time logged in the accident make/model airplane was 23.4 hours. The pilot also logged 242 glider hours and was a former military pilot. AIRCRAFT INFORMATION The two-seat, low-wing, fixed-gear airplane, serial number (S/N) AA1-0042, was manufactured in 1968. It was powered by a Lycoming IO-320 engine, serial number L5481-27, rated at 150 horsepower. The airplane was also equipped with a Sensenich model 74DH-53, serial number 28707, variable pitch propeller. Reviews of copies of the maintenance logbook show an annual/100 hour inspection was completed on August 18, 2012, at a recorded tachometer reading of 1,824.46 hours and airframe total time of 4,098.96 hours. METEOROLOGICAL INFORMATION A review of recorded data from the Hill Air Force Base, Ogden, Utah, automated weather observation station, located about 9 miles west of the accident site, revealed at 0655 conditions were wind from 120 degrees at 16 knots, visibility 10 statute miles, clear sky, temperature 1 degree Celsius, dew point -3 degrees Celsius, and an altimeter setting of 30.29 inches of mercury. Using the reported weather conditions and field elevation, the calculated density altitude was about 4,133 feet. The United States Naval Observatory Sun data for Morgan, Utah, for the day of the accident, indicated sunrise at 0715 and the beginning of civil twilight at 0645. AIRPORT INFORMATION Morgan County Airport (42U) is a non-towered airport with a reported field elevation of 5,020 feet. The airport was equipped with an asphalt runway, runway 03/21 (3,904 feet long by 50 feet wide). Investigative personnel noted that rising terrain was present in all quadrants of the airport, including the departure end of runway 03. The FAA Airport Master Records describing 42U, does not mention takeoff obstacles for runway 03 departures. The airport manager reported that due to terrain in the close proximity off the departure end of runway 03, that runway 21 was routinely used for the takeoff runway unless the airplane was capable of a high climb rate. An estimate of the high terrain off the departure end of runway 03, which was at about 3 miles past the departure end, was about 6,450 feet mean sea level. WRECKAGE AND IMPACT INFORMATION Examination of the accident site revealed that the airplane impacted terrain about 2.8 miles northwest of runway 03 at coordinates 41:10.55N and 111:43.27W, and an elevation of 5,796 feet. Wreckage debris of mostly broken canopy pieces and the left wing was located within about 50 feet of the main wreckage. The first identified point of contact (FIPC) was a small area of disturbed dirt. Within the disturbed dirt, portions of a red lens were observed, consistent with the left wing's navigational lens. The pitot tube was also found in the area of the FIPC. Extending from the FIPC was a larger area of disturbed dirt. This larger disturbance area was about 4 feet wide, 6 feet in length and 4 inches deep (in the deepest portion). The fuselage came to rest inverted on a heading of about 120 degrees magnetic approximately 42 feet from the FIPC. The right wing, empennage and engine remained partially attached to the main fuselage. The left wing was located about 10 feet from the FIPC. Thermal damage consumed a majority of the airplane including the cabin area and inner portion of the wings. Flight control continuity was established from the individual flight control bellcranks to the center portion of the cabin, and to the pilot controls for the rudder and elevators. The control torque tube was separated at the fuselage and found several feet from the main wreckage. The left wing was crushed aft and was thermally damaged. Both the left flap (outer attach point only) and left aileron remained attached to the wing with thermal damage observed to each. The left fuel tank was breached and observed to have sustained thermal damage. The right wing remained partially attached to the fuselage and sustained thermal damage. Both the right flap and right aileron were attached at all the respective mounts and sustained thermal damage. The right fuel tank was intact and contained a liquid that smelled consistent with automotive fuel. The fuel tested negative for water contamination. The wing tank fuel cap was intact and functional. The empennage was mostly intact and sustained thermal damage. The rudder remained attached to its respective attach points and the bottom half was consumed by thermal damage. The elevators were intact and remained attached to the all attach points. The instrument control panel and cabin area was consumed by the post impact fire and prevented the observation of instrument indication. The fuel selector valve sustained extreme thermal damage and its position was unable to be determined. Molted metal was present in all valve openings. The postaccident examination of the airframe revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Examination of the Lycoming O-320 engine, serial number L5481-27 revealed that the engine sustained thermal damage to the left and bottom sides, including the accessory case. All of the engine accessories remained attached to the engine via their respective mounts. The left and right magnetos were removed from the engine. Both magneto drive shafts remained intact and could be rotated by hand. A spark was produced at all the respective leads on the right magneto. No spark was produced by the left magneto. The left magneto was disassembled and the internal components were thermally damaged. The vacuum pump was removed and examined. The drive shaft was rotated by hand and appeared functional. The vacuum pump was disassembled and the rotor and vanes were intact. The starter ring gear was displaced aft and bent. All cylinders remained attached to the crankcase and exhibited thermal damage. The top sparkplugs were removed. The top sparkplugs exhibited black color deposits within the electrode area. All sparkplug electrodes exhibited normal wear signatures when compared to the Champion Check-A-Plug comparison chart, with the exception of the number #4 spark plug, which was coated with oil and light gray in color. All rocker covers were removed and the cylinder overhead areas were unremarkable. The carburetor was disassembled and the needle valve and floats were intact. The float assembly did not display proper movement and sustained thermal damage The neoprene needle valve was melted from the thermal damage. The fuel screen was free of debris. The propeller was removed in order to facilitate rotating of the engine crankshaft. The engine was rotated by hand by using a hand tool attached to the accessory drive gear. Rotational continuity was established throughout the engine and valve train. The rocker arms moved during crankshaft rotation and thumb compression and suction was obtained on all cylinders. The oil sump and oil pump exhibited thermal damage and were intact. The engine exhaust system and intake tubes remained attached to all cylinders, with the exception of #3 cylinder intake tube which was separated and found at the accident site. The two-bladed variable speed propeller remained attached to the crankshaft flange. One propeller blade exhibited an aft bend at mid span and twisting. The tip was bent aft and exhibited gouging. Leading edge gouging and chord wise scratches were observed on the bent portion. The other propeller blade exhibited a bend towards the non-cambered side that began about 10 inches from the end. The blade exhibited slight twisting and the blade tip exhibited gouging. The postaccident examination of the engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATION The Utah Department of Health, Office of the Medical Examiner conducted an autopsy on the pilot on November 16, 2012. The medical examiner determined that the cause of death was "multiple blunt force injuries." The FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, performed toxicology tests on the pilot. According to CAMI's report, cyanide, volatiles, and drugs were tested, and had negative findings. TESTS AND RESEARCH The National Transportation Safety Board, Senior Meteorologist, observed that on November 15, 2013, dew point temperatures were below freezing and dew point depressions were as small as 1 degree Celsius. ADDITIONAL INFORMATION The Federal Aviation Administration Handbook of Aeronautical Knowledge, Chapter 11, page 11-13, explains the temperature/dew point relationship. "When the temperature of the air is reduced to the dew point, the air is completely saturated and moisture begins to condense out of the air in the form of fog, dew, frost, clouds, rain, hail or snow." On page 11-15, the handbook notes that "On cool calm nights, the temperature of the ground and objects on the surface can cause temperatures of the surrounding air to drop below the dew point. When this occurs, the moisture in the air deposits itself on the ground, buildings, and other objects like cars and aircraft…If the temperature is below freezing, the moisture is deposited in the form of frost." The handbook points out that, frost is a definite flight safety hazard. "Frost disrupts the flow of air over the wing and can drastically reduce the production of lift. It also increases drag, which combined with lowered lift production, can adversely affect the ability to take off." The handbook then states on page 11-18, "aircraft that have ice, snow, or frost on their surfaces must be carefully cleaned prior to beginning a flight because of the possible airflow disruption and loss of lift."
The pilot's inadequate preflight inspection, which resulted in frost remaining on the airplane's surfaces and led to its inability to produce enough lift to clear rising terrain.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
