DEN06FA065

Radar data depicted the airplane reverse course from a southerly track to a northerly track. The pilot reported to air route traffic control center (ARTCC) that he had just lost manifold pressure in the left engine and that he needed to go lower. The controller cleared the pilot to descend from 16,000 feet mean sea level (msl) to 14,000 feet msl. The center controller asked the pilot if he had reversed course due to his engine problem and the pilot acknowledged in the affirmative. The controller assigned the pilot another frequency and the pilot acknowledged the frequency change. No further transmissions were made from the pilot on either frequency and radar contact was lost at an encoded altitude of 11,400 feet msl. The wreckage was located in mountainous, down sloping, snow covered, forested terrain. The airplane was destroyed. An examination of the airframe, engines, and airplane systems revealed no anomalies. Radar echoes and satellite data indicated that the accident airplane most likely entered clouds approximately 1010. Based upon the current icing potential algorithm, there was a high likelihood of icing and supercooled large water droplets at 14,000 to 16,000 feet msl in the accident area. Based on area forecasts, PIREPS, and weather advisories, the accident airplane most likely encountered moderate to severe turbulence and moderate to severe mixed icing during the final few minutes before the accident.

History of flight

On April 17, 2006, at 1026 mountain daylight time, a Cessna T310R, N289WB, owned and piloted by a private pilot, was destroyed when it impacted mountainous terrain 15 nautical miles (nm) east of Heber City, Utah. A post impact fire ensued. Instrument meteorological conditions prevailed at the time of the accident. The personal business flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 and an instrument flight rules (IFR) flight plan had been filed. The pilot was fatally injured. The cross-country flight departed Billings, Montana, approximately 0730, and was en route to Cedar City, Utah.

The pilot was traveling to Palm Springs, California, for a medical conference. At 0955:22, a Salt Lake City (SLC) Air Route Traffic Control Center (ARTCC) controller rerouted the flight to MEGIE intersection then direct to Cedar City, due to poor weather in the Salt Lake area. National Track Analysis Program (NTAP) radar data depicted the airplane reverse course from a southerly track to a northerly track at 1023:54. At 1024:04, the pilot reported to SLC ARTCC that he "just lost manifold pressure in [his] left engine" and that he needed to "go lower." The controller cleared the pilot to descend from 16,000 feet mean sea level (msl) to 14,000 feet msl. At 1025:07, the center controller asked the pilot if he had reversed course due to his engine problem and the pilot acknowledged in the affirmative. The controller assigned the pilot another frequency and the pilot acknowledged the frequency change. No further transmissions were made from the pilot on either frequency and radar contact was lost at 1026:05, at an encoded altitude of 11,400 feet msl.

An alert notification (ALNOT) was issued by the Federal Aviation Administration (FAA) at 1057 on April 17. The airplane was located approximately 1630 by the Wasatch County Search and Rescue Team, Heber City, Utah, on April 18 in the Uinta National Forest.

Personnel information

The pilot, age 60, held a private pilot certificate with airplane single and multi-engine land, and instrument ratings, initially issued in June of 1986. The instrument rating was added to the certificate in February 1988, and the airplane multi-engine privileges were added in February 2005. The pilot held a third class airman medical certificate issued on September 21, 2005. The certificate contained the limitations "must wear corrective lenses [and] possess glass for near [and] [intermediate] vision."

According to the pilot's FAA Airman Certificate and/or Rating Application (Form 8710-1) for the multi-engine certificate check ride, he reported a total time of 677 hours; 52.3 hours of which were logged in multi-engine airplanes and 104 of which were solely by reference to the instruments. The pilot's flight logbook was located within the wreckage. A review of the logbook by the National Transportation Safety Board (Safety Board) Investigator-in-Charge (IIC) indicated that the pilot had logged no less than 737 hours total time: 154 of which was logged in multi-engine airplanes. The pilot had logged no less than 107 hours in the accident airplane and no less than 23 hours in instrument meteorological conditions.

Aircraft information

The accident airplane, a Cessna T310R (serial number 310R0817), was manufactured in 1977. It was registered with the FAA on a standard airworthiness certificate for normal operations. The airplane was equipped with two Teledyne Continental Motors (TCM) TSIO-520-B engines rated for 285 horsepower at 2,700 rpm. Each engine was equipped with a McCauley 3-blade, controllable pitch propeller.

The airplane was registered to and operated by the accident pilot, and was maintained under an annual inspection program. A review of the maintenance records indicated that an annual inspection had been completed on January 12, 2006, at an airframe total time of 8,834.6 hours. In September of 2005, the pilot experienced low oil pressure and subsequent engine failure, on the left engine, while flying in Reno, Nevada. The engine was removed and inspected, at which time the bearings, gaskets, seals, and o-rings were replaced. The engine was returned to service in November of 2005. On April 14, 2006, the left wing fuel transfer pump was replaced at an airframe total time of 8,845.0.

According to the aircraft maintenance log, on April 14, 2006, maintenance had been completed on the avionics system in the airplane. The Bendix IN 152A radar indicator and GA 56 GPS antenna were removed. An Avidyne EX 500 multi function display (MFD) was installed, as per Supplemental Type Certificate (STC) SA0016BO, interfaced to the Garmin GNS 530/430, NSD 360A bootstrap heading output, and the XM076 XM weather uplink. In addition, a heads-up technology XMD076 XM weather uplink receiver with a Comant Combination CI 401-420 XM/GPS antenna with a Comant CI 511 GPS attenuator was installed.

Meteorological information

On April 16, 2006, at 1200, the pilot logged into the Direct User Access Terminal System (DUATS) and obtained a low altitude weather briefing for his proposed route of flight. On April 17, 2006, at 0645, the pilot logged into DUATS and obtained a low altitude weather briefing for the same route of flight. The pilot also filed two IFR flight plans; one from Billings to Cedar City and the other from Cedar City to Palm Springs.

On April 17, at 0900, a Surface Analysis chart, prepared by the National Weather Service, National Center for Environmental Prediction, depicted a cold front extending through northwestern Utah. Doppler weather radar (approximately 76 nautical miles northwest of the accident location) scanned the accident area at 1017:33, 1023:04, and 1027:28. The nominal beam center ranged between 14,600 feet and 15,800 feet msl. Data indicated reflectivity values of 21 to 22 dBz in the accident area around the accident time.

Aviation area forecasts were issued for Utah by the Aviation Weather Center (AWC) in Kansas City, Missouri, the day of the accident, starting at 0515. The forecast for the north third of Utah was as follows: sky conditions, broken at 12,000 feet msl with tops at flight level 240; occasional, overcast at 8,000 feet msl with scattered light rain showers. Starting at 0700, AWC forecasted the sky condition overcast at 6,000 feet, visibility 4 statute miles with light rain and snow. Starting at 1000, AWC forecasted visibility 3 statute miles with light rain and snow showers, isolated snow, rain, and thunderstorms with cumulonimbus tops at flight level 300.

Airman's Meteorological Information (AIRMET) for instrument flight rules (IFR) and mountain obscuration (SIERRA), turbulence (TANGO), and icing (ZULU) were all issued by AWC for areas in Utah, including the accident airplane's route of flight. AIRMET SIERRA for IFR stated to expect occasional ceilings below 1,000 feet above ground level (agl), visibility below 3 statute miles due to clouds, precipitation, fog, and mist. AIRMET SIERRA for mountain obscuration stated to expect mountains occasionally obscured by clouds, precipitation, and mist. AIRMET TANGO stated to expect occasional moderate turbulence below flight level 180 due to strong low and middle level winds. AIRMET ZULU stated to expect occasional moderate rime and mixed icing between 8,000 feet msl and flight level 200. No significant meteorological information (SIGMET) or center weather advisories were issued by the Salt Lake City Center Weather Service unit for the time of the accident.

Multiple pilot reports (PIREPS) had been issued for the Salt Lake City area regarding icing and turbulence. Reports given for icing included light to moderate mixed icing, and light to moderate rime icing, from 9,000 feet msl to 19,000 feet msl. Reports given for turbulence included light to moderate turbulence and continuous light to severe turbulence from 4,000 feet msl to 19,500 feet msl.

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