FTW98FA088

The single-engine airplane was established at a cruising altitude of 12,000 feet MSL. The instrument rated commercial pilot requested a descent to a lower altitude and was given clearance to descend to 10,000 feet by ATC. After the pilot acknowledged the clearance, radar contact and voice communications from the aircraft were lost. No distress calls were received from the aircraft. The wreckage of the airplane, which had impacted the ground in a near vertical attitude, was found by a search and rescue helicopter in an open field. Several aural witnesses, located near the accident site, reported hearing a very loud engine noise followed by silence. Several residents in the vicinity reported the local weather to be foggy, with freezing rain, and low clouds. The aircraft, which was not equipped for flight in icing conditions, was operating within the boundaries of a current weather advisory, which called for rime icing in the clouds below 8,000 feet. No mechanical anomalies were found during examination of the wreckage. Pilots flying various types of aircraft in the vicinity of the accident site had reported light to moderate icing in the clouds from 16,000 feet to 4,000 feet. According to the NTSB meteorologist, it was likely that the pilot could have encountered IMC conditions with light to moderate icing.

On January 7, 1998, approximately 1150 central standard time, a Mooney M20K airplane, N231DS, registered to and operated by the pilot, impacted the ground following an uncontrolled descent approximately 8 miles northwest of Vernon, Texas. The aircraft was destroyed by impact forces and both occupants, the commercial rated pilot and 1 passenger, were fatally injured. An Instrument Flight Rules (IFR) flight plan was filed and instrument meteorological conditions prevailed in the vicinity of the accident. The Title 14 CFR Part 91 personal cross country flight had originated from San Marcos Municipal Airport, San Marcos, Texas, approximately 1000 and was en route to Garden City, Kansas, for a scheduled refueling stop. The aircraft's intended final destination was Andover, Minnesota.

The aircraft's cruising altitude en route from San Marcos was 12,000 feet MSL as identified by positive radar returns from Fort Worth Center. Approximately 1145 the pilot requested a descent to 10,000 feet and was given the clearance to descend by Center. After the pilot acknowledged the clearance, both radar returns, and voice communications from the aircraft were lost. The last reported radar position of the aircraft was near the Hobart 193 degree radial at 40 nautical miles. Immediately after the lost contact, Fort Worth center issued an ALNOT (missing aircraft) message. The ALNOT remained in effect until aircraft wreckage, identified as N231DS, was found by a search and rescue helicopter.

Several aural witnesses, located about 1 1/2 miles from the fog obscured accident site, reported hearing a very loud engine noise followed by silence at about 1150. Several people living in the vicinity of the accident reported the weather to be foggy, with freezing rain, ice pellets, and low clouds. The aircraft was within the boundaries of a current AIRMET which cited rime icing in clouds below 8,000 feet.

No distress calls were heard from the aircraft.