Piper PA-32 N4261T accident near Pilot Point, Alaska

Probable cause

The pilot's continued flight into known icing conditions, which resulted in structural icing and a forced landing on icy, snow-covered terrain.

NTSB analysis

The airline transport pilot reported that, at 800 ft during a visual flight rules cross-country flight, the windscreen began accumulating trace ice, so he landed the airplane at an airport that he was flying over on the route. An agent at the destination airport reported to the pilot by telephone that the visibility at the destination was 10 miles, that the clouds were at 3,000 ft, and that no ice was reported. Subsequently, the pilot decided to continue the flight toward the destination to "take a look" at the weather conditions. He stated to the passenger that he would return to the departure airport if the weather was poor.

After departing and within 8 miles of the airport, the windscreen began to accumulate ice again, and the pilot maneuvered the airplane back toward the departure airport. The pilot stated that, shortly after, at 500 ft, the airplane encountered severe icing conditions. He stated that he saw that the windows and wing leading edges were rapidly accumulating ice, that the engine began running roughly, and that the flight controls began feeling "sluggish." The engine surged with corresponding propeller vibrations. Both the pilot and the passenger stated that instrument meteorological conditions were present when the airplane was at 500 ft. The airplane could not maintain altitude and descended through 400 ft, and the pilot conducted a forced landing on snow-covered terrain about 5 miles from the airport. During the landing, the nose and right main landing gears sheared off due to impact with ground ice, and the fuselage then impacted terrain. Both occupants sustained serious injuries, and the left wing, horizontal stabilizer, and fuselage sustained substantial damage.

The pilot stated that there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. Even though a review of weather information for the area where the reported icing encounter occurred revealed no probability of icing at the reported time and altitude of the encounter, the airplane previously encountered icing conditions in the area and the pilot subsequently landed the airplane to evaluate the ice and the weather. The pilot then decided to take off and continue the flight toward the destination. It is likely that the pilot flew the airplane into an area of visible moisture at below freezing temperatures and that the airplane and propeller accumulated ice, which resulted in reduced aerodynamic performance and prevented the airplane from maintaining altitude.

Text from the NTSB. Open the NTSB docket for ANC17TA015 for the full record.