ANC12TA008

The pilot of the tailwheel-equipped airplane reported that she had taxied for an extended period in loose snow at the departure airport. The subsequent flight and accident landing were in sub-freezing temperatures. On touchdown at the destination airstrip, the tires immediately dug into the shallow snow layer, and the airplane nosed down and skidded for several yards before nosing over. The pilot stated that she thought the brakes had frozen and locked the tires prior to landing, probably precipitated by taxiing in the loose snow at the departure airport. Postaccident examination found one brake still locked by ice and one free. No mechanical deficiencies other than the frozen brake were found.

On November 11, 2011, about 1130 Alaska standard time, a Bellanca 8GCBC airplane, N88417, sustained substantial damage when it nosed over during landing, about 22 miles south of Delta Junction, Alaska. The airplane was operated by the State of Alaska, Department of Fish and Game, Anchorage, Alaska, as a visual flight rules (VFR) public aircraft flight. The solo private pilot was not injured. Visual meteorological conditions prevailed, and a VFR flight plan was active. The flight departed Chena Marina Airport, Fairbanks, Alaska, about 1000. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), the pilot said it was about 22 degrees F., the runway had not been packed down, and there was a 1-2” dusting of snow on the runway. She began aerial game observations about 1040, and about 1120 decided to land to organize data on the ground. She touched down at stall speed in a 3-point configuration, and upon full contact with the ground, the tires immediately dug into the snow. The tail of the airplane came up very suddenly, and the nose hit the ground. The airplane skidded for several yards before it nosed over. Based on the way the airplane reacted on touchdown, in conjunction with photos taken from the air and ground of the accident site, the pilot said she believes that the brakes iced up and locked prior to touch-down, probably the result of taxiing and takeoff in the light, loose snow at Chena Marina. She noted the accident landing wheel tracks were deep and dug into the underlying grass, whereas the tracks left by the two airplanes that landed to provide assistance, did not penetrate the shallow layer of snow. She said she was very familiar with the airplane and the landing airstrip, and that she had not had any mechanical issues with the airplane, or difficulty landing on the airstrip previously. A postaccident inspection of the brake system by the State's aircraft mechanic did not reveal any brake anomalies. During a telephone conversation with the NTSB IIC, an aircraft mechanic who responded to the accident site, said he found the left brake free, and the right brake frozen. He said it is not unusual for brakes to freeze after extended taxiing in deep snow. During taxi the brakes heat, and melt the snow which refreezes after the airplane becomes airborne. He examined the brakes after the airplane was recovered, and did not find any mechanical anomalies.