Aircraft Accident/Incident Report

Norden, California 95724
Sunday, February 6, 2005 18:20 PST

The airplane, while operating under an instrument flight rules (IFR) flight plan, departed from controlled flight after encountering icing conditions, entered an uncontrolled descent, and collided with the ground. The airplane was equipped with an Ice Protection System that when activated supplied deicing fluid to the wings, tail, and propeller. The aircraft was not certified for flight into known icing and the Pilot Operating Handbook reads that, "Flight into known icing conditions is prohibited." The pilot received a preflight weather briefing, which advised that there were no pilot weather reports (PIREP) for the intended route of flight, and that the freezing level in the Reno area was 6,000 feet with no precipitation. There were no valid SIGMET's or AIRMET's for icing conditions along the pilot's route. The pilot filed his IFR flight plan for 12,000 feet, but indicated he might request 14,000 feet once airborne. After takeoff, at 1807:46, the pilot contacted Oakland Air Route Traffic Control Center (ARTCC) and requested to climb to 16,000 feet to try to get above the clouds. At 1813:40, the pilot reported that he was still in the clouds and asked about going lower. At 1815:00, the pilot advised ARTCC that if he could go up another 200 to 300 feet, he could get above the clouds. ARTCC requested clarification if the pilot wanted to go up or down. The pilot responded that he would like to go up first to build up some airspeed. The pilot was cleared for a block altitude between 16,000 to 17,000 feet. About 2 minutes later, the pilot transmitted that he was "coming down" and that he was "icing up." The last transmission from the pilot was at 1817:42, again indicating that he was icing up and coming down. According to investigators from Ballistic Recovery Systems (BRS), following the examination of the ballistic parachute system, they determined the system was deployed outside of the operating envelope of the system, which is 133 knots indicated airspeed. An examination of the airplane wreckage did not reveal any evidence of preimpact mechanical failures or malfunctions. Analysis of the actual weather conditions encountered revealed the likelihood that the pilot encountered severe icing related to super-cooled large water droplets as the aircraft achieved 16,000 feet and above. Review of the weather forecast products available at the time of the pilot's briefing disclosed that the AFSS briefing fully conformed to Federal Aviation Administration standards and adequately covered the observed and forecast weather conditions. Although post accident analysis of the weather conditions showed the clear likelihood of severe icing conditions, the algorithms used by the NWS Aviation Weather Center to predict icing conditions showed only a low probability of icing in the area, and, in the absence of PIREPs to the contrary, an icing forecast was not triggered.

the pilot's in-flight loss of control following an inadvertent encounter with unforecast severe icing conditions. A factor in the accident was the inaccurate icing forecast developed by the NWS Aviation Weather Center.