On April 3, 2001, at 0930 mountain standard time, a Cessna 180 single-engine airplane, N21394, sustained substantial damage when it collided with bushes and trees on departure from the Palo Verde Ranch private airport, Tucson, Arizona. The airplane was registered to and operated by the pilot under the provisions of 14 CFR Part 91 as a personal flight. The private pilot and two passengers were not injured. Visual metrological conditions prevailed and no flight plan had been filed for the local flight, which was originating at the time of the accident. According to the pilot's written statement, he was departing to the west on the 850-foot-long private airstrip. The pilot reported he applied and obtained full engine power at the start of the takeoff roll. Shortly thereafter, he noticed "a momentary uncommanded decrease of thrust." The engine power returned for the remainder of the takeoff roll; however, since the aircraft lost some acceleration at the beginning of the takeoff, the "remainder of the field was required to obtain flying speed." The airplane started to climb, but the airplane's tail impacted a bush at the end of the airstrip and "slowed the aircraft to stall speed." The pilot attempted not to stall the airplane and flew the airplane in level flight for 200 - 300 feet. The airplane then impacted two trees. The airplane impacted the first tree with the landing gear and fuselage. The airplane's left wing contacted the second tree, and the airplane spun around 180 degrees. The airplane impacted the ground tail first before coming to rest. The engine was test run at the salvage facility following the accident. The engine ran through various power settings, including maximum power, with no anomalies noted.