DEN05FA114

Prior to takeoff, the pilot obtained a weather briefing from the flight service station. Witnesses, who were located on the airport, reported that shortly after takeoff, the airplane was 150 feet agl and flying runway heading. The right wing was low, landing gear extended, and the nose in a climb attitude, but the airplane was not climbing. As the airplane approached the end of the runway, the airplane lost altitude and "was still mushing along." The right wing then rolled to an almost vertical attitude, the nose dropped, the airplane rolled to the left and impacted terrain. One witness stated there were no mechanical problems with the airplane and the engine sounded normal. The airplane was destroyed by postimpact fire. Examination of the airframe and engine revealed no anomalies that would have precluded normal operation. The airplane was 126.2 lbs over gross weight at the time of the accident. Witnesses reported gusty wind conditions, thunderstorms in the area, and no precipitation. Weather data revealed environmental conditions that supported dry microburst activity at the time of the accident.

History of flight

On July 24, 2005, approximately 1620 mountain daylight time, a Beech N35 single-engine airplane, N31TE, was destroyed when it impacted terrain following a loss of control during takeoff from Salt Lake City Municipal Airport #2 (U42), near West Jordan, Utah. The private pilot, a pilot-rated passenger, and another passenger sustained fatal injuries. The airplane was registered to and operated by the pilot. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 91 personal flight. The flight was originating at the time of the accident.

According to a local fixed based operator (FBO), the airplane arrived at U42, on July 22, 2005, approximately 1130. According to a credit card receipt, the airplane was filled with $140.11 of 100LL aviation fuel. FBO personnel stated the airplane remained parked until the day of the accident.

FBO personnel stated that on the day of the accident, the pilot and one passenger arrived at the airport approximately 1300. The pilot returned his rental car, waited for another passenger, and spent approximately 2 hours in the "weather room" at the FBO.

A witness, who was located on the airport, reported the airplane departed runway 16. Approximately 2,000 feet down the runway, the airplane was 150 feet agl and flying runway heading. While at 150 feet agl, "the right wing was low, gear down, and nose in a climb attitude, but not climbing." The right wing was down for almost the entire length of the runway. As the airplane approached the end of the runway, the airplane lost altitude, was approximately 50 feet agl, and "was still mushing along." The right wing then rolled to an almost vertical attitude, the nose dropped, the airplane rolled to the left and impacted the terrain. The airplane appeared to impact the ground with the nose and left wing. The witness reported the wind was approximately 35-40 knots from a west-northwest direction at the time of the accident airplane's takeoff.

Another witness, the wife of one of the passengers, reported to local authorities that she typically watched her husband take off. Located near the FBO during the takeoff, the witness observed the airplane remain low and level near the south end of the runway. She thought to herself, "good [pilot] stay level and low because the altitude is different here compared to California." She watched the airplane wobble two times and then strike the ground in the dirt mounds prior to the airport perimeter fence. She stated there were no mechanical problems during the takeoff, and the engine sounded "normal."

According to a pilot who landed at U42 just prior to the accident airplane's takeoff, the airport UNICOM reported 10 knot winds from 220 degrees and gusting to 12-15 knots. During landing to runway 34, the pilot experienced light turbulence. The pilot stated, "at no time did we experience wind shear or change in wind direction." After landing, the pilot reported the winds "continued westerly and appeared steady."

Personnel information

The pilot held a private pilot certificate with airplane single-engine land and instrument ratings. The pilot was issued a second-class medical certificate on April 9, 2004, with the limitation, "Must Wear Corrective Lenses." The pilot's logbook was not located; however, a review of the pilot's insurance records, dated May 1, 2004, revealed the pilot had accumulated 5,000 total flight hours, and 4,000 hours in the accident airplane make and model. According to the pilot's last medical application, the pilot reported 5,000 total flight hours.

Aircraft information

The 1961-model Beech N35, serial number D-6745, was a single-engine, low wing, V-tail, retractable landing gear, semi-monocoque design airplane. The airplane was powered by a six cylinder, air-cooled, horizontally opposed, fuel-injected Teledyne Continental Motors IO-520-BB (2), (serial number 274578-R), engine, rated at 285 horsepower, and equipped with a three-bladed constant speed propeller. The airplane was configured to carry a maximum of four occupants. Maximum gross weight for the airplane was 3,125 pounds (lbs).

The airplane was issued a standard airworthiness certificate on July 27, 1962, and was certificated for normal category operations. The airplane's current registration was issued to the pilot on April 25, 1985. The airframe, engine, and propeller logbooks were not located.

Meteorological information

Approximately 1400, the pilot obtained a weather briefing from Cedar City Flight Service Station.

At 1505, the Salt Lake City Center (KZLC) Center Weather Service Unit issued Center Weather Advisory number 101 which was valid until 1605. The advisory was issued for an area of thunderstorms 30 miles wide from SLC to 50 miles south of SLC. The thunderstorms were identified as having tops to 38,000 feet and were moving from 260 degrees at 10 knots.

At 1537, the National Weather Service (NWS) Salt Lake City Regional Forecast Office issued a short term forecast. According to the forecast, the area of Salt Lake, Tooele Valleys, and southern Wasatch Front was area of potentially strong thunderstorms that had developed over western Salt Lake and northwest Utah counties. The storms could produce locally heavy rain and gusty surface winds through 1615.

At 1555, Convective SIGMET 75W was issued for portions of Colorado, Wyoming, and Utah, which was valid until 1755. The accident site resided on the northern border of the advisory. The advisory was issued for an area of thunderstorms moving from 240 degrees at 15 knots, with tops to 44,000 feet.

At 1556, the Salt Lake City International Airport (SLC) automated surface observation system (ASOS), located approximately 10 miles north of U42, reported wind calm, visibility unrestricted at 10 miles, scattered clouds at 9,000 feet, ceiling broken at 13,000 feet and 20,000 feet, temperature 33 degrees Celsius, dew point 11 degrees Celsius, and altimeter setting of 29.99 inches of Hg. The following remarks were included: lightning distant southeast through southwest, thunderstorm distant southeast through southwest moving east, and towering cumulus clouds distant north through southeast. The calculated density altitude was 7,756 feet.

At 1626, the short term forecast reported that thunderstorms would continue across Salt Lake and northern Utah counties through 1700. The storms could produce locally heavy rain and gusty surface winds.

At 1639, the SLC ASOS reported wind from 210 degrees at 17 knots, visibility unrestricted at 10 miles, scattered clouds at 9,000 feet, ceiling broken at 13,000 feet and 20,000 feet, temperature 33 degrees Celsius, dew point 10 degrees Celsius, and altimeter setting of 29.98 inches of Hg. The following remarks were included: wind shift at 1619, cumulonimbus clouds distant east through southeast moving east, and towering cumulus clouds distant north through east. The calculated density altitude was 7,755 feet.

The Geostationary Operations Environment Satellite number 12 data was obtained from the National Climatic Data Center. Both visible and infrared imagery was obtained surrounding the time of the accident. The satellite imagery surrounding the time of the accident from 1500 to 1645, approximately every 15 minutes, were reviewed. At 1610, the infrared image depicted an enhanced area of clouds associated with cumulonimbus clouds over the accident site with cloud tops in the range of 33,000 feet. The visible image depicted the accident site on the edge of a cumulonimbus cloud. A few overshooting domes are observed in the anvil an indication of an active mature stage storm with strong updrafts.

The area forecast, valid at the time of the accident, for northwestern Utah was for scattered to broken clouds at 12,000 to 14,000 feet, with tops to 25,000 feet, with widely scattered thunderstorms and li