On January 25, 2001, at 1630 eastern standard time, Cessna 120, N3070N, was substantially damaged during takeoff from the Hancock County-Bar Harbor Airport (BHB), Trenton, Maine. The certificated private pilot/owner was not injured. Visual meteorological conditions prevailed for the local personal flight that originated at the Bar Harbor Airport, at 1630. No flight plan was filed for the flight conducted under 14 CFR Part 91. In a telephone interview, the pilot said the airplane was a "taildragger" and was equipped with skis. He said the purpose of the flight was to practice takeoffs and landings on the snow. The pilot/owner said that he had departed Bar Harbor earlier in the day and successfully performed a landing and subsequent takeoff from a nearby frozen lake. He said he returned to Bar Harbor and performed several takeoffs and landings in the snow-covered infield adjacent to runway 35. According to the pilot: "I had been up practicing touch-and-goes and full stops. On the takeoff, near as I can tell, what happened was that at takeoff speed, I was pulling back on the yoke when I hit a bump. I went up a little and when I came back down the left ski hit a soft spot in the snow. The right ski stayed on top of the snow, but the left ski came down like there was a soft spot and sunk about 12 to 14 inches into the snow. The ski sunk in and caught. The ski submarined under the snow and the plane nosed up and over. I was in a takeoff attitude, the toes were up, and I hit this very little bump in the terrain, a little berm. The only reason I would take off on something so small was because of the speed and attitude. But when that ski sunk in, I hit the left wing tip, the nose prop, and pole-vaulted right over and landed completely upside down facing up [runway] 35." The pilot reported he had approximately 130 hours of total flight experience. He said he had 30 hours of experience in the Cessna 120, 12 hours of which was on skis. The pilot said other pilots with ski-equipped airplanes had shared with him their knowledge and experience about flight with skis, but that he had no formal instruction flying airplanes equipped with skis. He said, "My insurance company required 10 hours for the tailwheel, but actual instruction on skis, I didn't get that." The pilot/owner was asked to describe the performance and handling of his airplane. He said: "Excellent. There was no problem. There wasn't a breath of wind, everything was working good, and it was just one of those things." The weather reported at Bar Harbor was scattered clouds at 4,300 feet with winds from 320 degrees at 4 knots.