On July 27, 2004, at 1329 Pacific daylight time, a Cessna 172P, N65615, collided with bushes and terrain during landing at Big Bear City Airport, Big Bear City, California. Cruise Air Aviation, Inc., Ramona, California, was operating the airplane under the provisions of 14 CFR Part 91. Neither the instructor pilot nor student was injured; the airplane was substantially damaged. Visual meteorological conditions prevailed for the cross-country instructional flight, and a visual flight plan had been filed. The flight originated at Ramona at 1235. The airplane was landing on a temporary runway (26), which is normally the south taxiway, during the major repairs to the main runway 08/26. The temporary runway was marked with a displaced threshold and normal striping. The airplane landed prior to the displaced threshold. The instructor reported gusty winds and extreme windshear, which was not reflected during his preflight weather briefing, or by the Unicom advisory service. The Automated Weather Observation System (AWOS) was out of service. The instructor reported that during the base leg turn the student pilot voiced some concerns about his ability to land the airplane due to his lack of familiarity with the airport and the turbulence. The instructor took the controls and lined up with the runway. According to the CFI, he asked the Unicom about the wind conditions and was told "280 degrees at 9-14 knots." Additionally, the Unicom advisory service reported that the winds were "quirky or freaky." The instructor put in an additional 10 degrees of flaps after clearing some trees. Upon encountering a high rate of sink he applied full power for a go-around and retracted the flaps to 10 degrees. He reported that the airplane was moving violently down and left, and ground contact was inevitable. The instructor pilot reported that there were no mechanical issues with the airplane.