A review of air traffic control recordings indicated that, after the Glasair Sportsman GS-2 crossed over the mountains, the pilot checked in with the Denver terminal radar approach controller and expressed concern about the weather at her destination airport.
After receiving weather for a closer airport, which included visibility 1.5 miles in mist with a 400-foot overcast ceiling, she changed her destination to that airport. About three minutes later, she asked the controller if other pilots had reported icing during descent, and the controller responded that other pilots had reported icing in cloud tops about 9,000 feet mean sea level (msl).
The pilot advised that she wanted to change back to her original destination, and the controller cleared the approach.
About 20 minutes later, the pilot advised the controller that the airplane was “picking up rime ice,” and, about three minutes later, she again asked for clearance to the intermediate airport in Castle Rock, Colo. The controller cleared that approach.
During the approach, the controller issued three low altitude alerts because the plane was not maintaining the assigned altitudes, and he provided the pilot with the weather information for the destination airport, which included visibility 2 miles in mist, 400 feet overcast, and temperature and dew point below freezing at -1° C.
The pilot reported being established on the approach about three miles from the final approach fix shortly before the controller issued the third low altitude alert. After this alert, she responded that the plane was climbing and maintaining altitude and was established on the approach.
Shortly thereafter the controller asked the pilot to indicate the airplane’s altitude, but she did not respond. Radar track data indicated that the airplane was about 6,800 feet msl before radar and radio contact were lost. The airplane subsequently descended and hit terrain, seriously injuring the pilot.
The National Transportation Safety Board determined the probable cause as the pilot’s improper decision to continue flight into known icing conditions, which adversely affected the airplane’s performance and resulted in a loss of airplane control. Investigators added that the ATC services were adequate and no deficiencies were noted.
NTSB Identification: CEN14FA032
This October 2013 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.