What happened
Prior to departure, the pilot was informed by a San Angelo Flight Service Station briefer that computer systems in southern Texas were unavailable for a 90-minute period, meaning no current weather data could be provided. Although weather information was accessible through the National Weather Service in Midland and various Flight Service Stations in Midland, McAlescent, and De Ridder, the pilot did not contact these sources, and the briefer did not suggest doing so. The pilot also failed to obtain updated weather information during the flight.
Approximately 38 minutes into the flight, while traversing an area with potential icing, the aircraft experienced a significant reduction in ground speed. The speed dropped from 270 knots to 150 knots over a four-minute period, followed by a further deceleration to 100 knots within 12 seconds. Roughly 33 seconds before the speed reached 100 knots, the pilot requested a descent from 15,000 feet to 13,000 feet. At the time of this request, the aircraft was traveling on a ground track of approximately 080° with winds from 213° at 43 knots.
Before air traffic control could approve the descent, the aircraft reached 14,800 feet. Radar contact was subsequently lost after a single return was observed at 9,700 feet, indicating a descent rate of 12,750 feet per minute. While the aircraft was certified for flight in known icing conditions, the operational status of its anti-ice or deice systems could not be verified due to the damage caused by the impact and subsequent fire. All five fatalities occurred during the accident.
Findings
Investigation revealed that instrument meteorological conditions were present above 12,500 feet, with the freezing level forecasted between 10,000 and 12,000 feet. No mechanical malfunctions were identified prior to the impact. Although low levels of ethanol were detected in the toxicology samples of all occupants, the reliability of these samples was questioned due to evidence of unreliability.