On August 21, 2000, about 1830 Alaska daylight time, a wheel equipped Cessna 172 airplane, N12188, sustained substantial damage while on approach to Roy's airstrip, Alexander Creek, Alaska. The private pilot/airplane owner and the one passenger aboard were not injured. The 14 CFR Part 91 personal flight departed the Lake Hood airstrip, Anchorage, Alaska, about 1800, and the destination was Alexander Creek. Visual meteorological conditions prevailed, and no flight plan was filed. During a telephone conversation with an NTSB investigator on August 23, the pilot related he and a friend were flying to his cabin located near the Alexander Creek airstrip. He said he thought the winds were fairly calm as he approached to land to the south. While on final approach, about 50 feet above the ground, he said the wind increased and a strong downdraft pushed the airplane onto the approach end of the airstrip, about 15 yards short of the airstrip surface. He said that the nose wheel struck the ground first, and bounced the airplane back into the air. He added that when the airplane settled back onto the airstrip, a nose wheel fork broke, and the airplane nosed over. The airplane sustained substantial damage to the wings, fuselage, and vertical stabilizer. The pilot reported that wind conditions at the time of the accident were from the southwest, at 4 knots, with gusts to 15 knots, and added that there were storms in the vicinity of the accident airstrip. The pilot indicated that there was no preaccident mechanical anomalies with the airplane.