On February 29, 2004, about 1000 eastern standard time, a Bellanca 7ECA, N86715, was substantially damaged while landing at Hornell Municipal Airport (4G6), Hornell, New York. The certificated private pilot was not injured. Visual meteorological conditions prevailed for the flight that originated from a private airstrip near Avoca, New York. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The accident airplane was equipped with skis, and the runway at the private airstrip was 2,000 feet long, 100 feet wide, consisting of 12 to 15 inches of crusted snow. About 0910, during the takeoff run, the left ski encountered soft snow. The left ski imbedded into the snow and separated from the spring gear. The increased friction caused the right ski to drag and bend vertically. The airplane was near takeoff speed, and the pilot believed his only choice was to continue the flight. The pilot continued the takeoff, declared an emergency, and flew to Hornell. The pilot subsequently performed a "dead stick" precautionary landing on runway 18 at Hornell. During the landing on the asphalt runway, the left wing struts bent and the spring gear was further damaged. The pilot added that he had used his private airstrip one day prior the accident takeoff, and did not experience any problems. Between the prior use and the accident takeoff, the weather had warmed and cooled, but there was no precipitation. Prior to the takeoff, the pilot taxied along the airstrip for 15 minutes while letting the airplane engine warm up. During the taxi, the pilot did not note any problems with the runway.