Tri-County Regional Airport
Aircraft Accident/Incident Report

Lone Rock, Wisconsin 53556
Saturday, February 7, 2004 13:20 CST

The airplane was substantially damaged during an in-flight collision with terrain following an inadvertent stall on short final. The pilot reported that the instrument flight rules (IFR) flight had initially been operating above a broken to overcast cloud layer. However, about the mid-point of the trip the flight encountered instrument meteorological conditions (IMC) and light rime ice. The pilot stated that he requested a higher altitude in an attempt to avoid the icing conditions, but air traffic control cleared him to a lower altitude due to the flight's proximity to its intended destination. The flight remained in IMC as it was vectored for an instrument approach. At the missed approach point, the pilot did not have the airport in sight due ground snow cover and his unfamiliarity with the area. He executed a missed approach. While being provided with radar vectors for another approach, the pilot obtained visual contact with the airport. When he entered visual flight rules (VFR) conditions, he cancelled the IFR flight plan and entered a traffic pattern for runway 36. The pilot reported that on short final the airplane drifted left of the runway centerline. He applied a little power in an attempt to get re-aligned. The pilot stated: "The aircraft started rolling left. I applied full power and attempted to abort my landing. The aircraft engine responded but we completely rolled until inverted and subsequently made contact with the ground." In a follow-up interview, the pilot stated that the aircraft had accumulated rime ice along the leading edges of the wings. An AIRMET for occasional moderate rime or mixed icing below 10,000 feet mean sea level was in effect at the time of the flight. A certified re-recording of the weather briefing was provided to the NTSB. During the briefing, the pilot was informed of the AIRMET and of a pilot report of light rime ice along his route of flight. The pilot had received his instrument rating seven weeks prior to the accident. He reported 2.5 hours of actual instrument flight time and minimal experience with in-flight icing conditions. Federal Aviation Administration publications state that ice formation on an aircraft's flight surfaces may adversely affect performance and control. They note that with ice accretion an "aerodynamic stall may occur with little or none of the usual cues in advance of the stall or at the occurrence of stall."

The pilot's continued flight into icing conditions resulting in ice accretion on the wing and his failure to maintain airspeed resulting in a stall.