Primary finding
Probable cause
Flight by the pilot into known icing conditions, which resulted in airframe icing and an inability of the aircraft to maintain altitude on the ils glidepath, once the landing gear was lowered. The weather conditions were related factors.
Investigator assessment
Analysis narrative
The pilot received a full weather briefing approximately five and a half hours before departure, which included an airmet for icing conditions in the area. Thirty minutes before takeoff, he received a weather update and was given four pireps about moderate to severe icing conditions along his route of flight. He reported heavy icing conditions during cruise and eventually advised air traffic control that he was unable to maintain altitude. The pilot was then cleared for the ils approach. He reported the airplane had two inches of ice accumulation and was accumulating more. After extending the landing gear at approximately 800 feet agl, the pilot was unable to maintain altitude on the ils glidepath and landed short of the runway.
Source record
Factual narrative
On December 5, 1993, at 1957 central standard time, a Cessna 210B, N9684X, sustained substantial damage when it landed short of runway 31 at Dubuque Municipal Airport, Dubuque, Iowa. The pilot received serious injuries, and his sole passenger received minor injuries. An IFR flight plan was filed, and instrument meteorological conditions prevailed at the time. A weather observation from Dubuque Municipal Airport was taken three minutes after the time of the accident. The observation reported a measured ceiling of 200 overcast, two miles visibility with fog, temperature 37 degrees, and dewpoint 37 degrees. According to the FAA, approximately five and a half hours before departure, the pilot received a full weather briefing and was given an Airmet for icing conditions in the area. Thirty minutes before takeoff, the pilot received an update on the weather conditions. At this time the pilot was given four Pireps for moderate to severe icing conditions which existed in the area of his destination. In a written statement provided to the NTSB, the pilot says he was experiencing heavy icing conditions and eventually advised air traffic control that he was unable to maintain altitude. Air traffic control then cleared the pilot for the ILS approach at Dubuque Municipal Airport. At approximately 3,300 feet, the pilot reported the airplane had two inches of ice accumulation. At 800 feet AGL, he lowered the landing gear and was unable to maintain the glideslope. The airplane landed short of the runway. -