What happened
An air ambulance mission was underway to transport a critically ill patient from Rawlins Municipal Airport/Harvey Field in Wyoming to Casper, Wyoming. The flight originated from Steamboat Springs, Colorado. While maneuvering for a VOR/GPS approach to runway 22, the pilot executed a right turn to establish the final approach course. During the inbound leg toward the airport, the aircraft type impacted mountainous terrain located roughly 2.5 nautical miles east-northeast of the airfield.
At the time of the accident, local weather conditions included light snow, mist, and broken cloud ceilings between 1,100 and 1,800 feet. Prior to departure, the pilot had been briefed on snow activity along the route and expressed intentions to operate under instrument flight rules. However, witnesses near the airport reported weather ranging from freezing rain to heavy snow. The aircraft struck the ground in a 45-degree nose-down attitude, which was consistent with an aerodynamic stall.
Findings
Post-accident investigations revealed that the aircraft had accumulated significant clear ice, measuring up to 1.5 inches thick, on the wings, vertical stabilizer, propeller, and landing gear. This ice contamination degraded the aerodynamic performance of the plane, directly contributing to the stall that led to the impact. While no mechanical failures were found in the aircraft systems, the investigation noted that the operator failed to follow certain industry best practices for EMS flight planning, specifically regarding the avoidance of icing conditions during IFR operations. There was no definitive evidence of corporate pressure on the pilot, though the possibility of self-imposed pressure could not be dismissed.