On July 8, 2000, approximately 0905 mountain daylight time, a Cessna 150M, N4723, owned and operated by the pilot, was substantially damaged when it collided with terrain shortly after taking off from Montrose Regional Airport, Montrose, Colorado. The private pilot and his passenger were seriously injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal flight being conducted under Title 14 CFR Part 91. The flight was originating at the time of the accident. According to the pilot's accident report, the airplane had just undergone an annual inspection and the engine had been completely rebuilt. He was preparing to ferry the airplane back to its home base. Prior to takeoff, the pilot made a full power check of the engine and adjusted the mixture. Not wanting to overheat the cylinders in the climbout, the pilot enriched the mixture "a little." The airplane lifted off from runway 13 at 70 knots. "It became apparent at around 250 feet that the power was deteriorating and I leaned the mixture a little and made a shallow rudder turn to the right, hoping to pick up speed and get a gradual climb, when the engine quit and the plane mushed to the ground, stalled, and crashed," he wrote. The on-scene examination disclosed the flaps were up, the elevator trim tab was in the takeoff range, and the altimeter had been set to 29.92 inches of mercury (standard atmospheric pressure). Engine examination disclosed no evidence of preimpact failure or malfunction. When questioned by an FAA inspector at the hospital, the pilot said there was "nothing wrong with the engine," and that all engine instruments appeared to be normal during the takeoff and climb. He admitted he had not performed weight and balance calculations, nor had he consulted the Cessna 150 PILOT'S OPERATING HANDBOOK for high altitude performance data. Witness statements corroborated the pilot's statement. Asked how this accident might have been prevented, the pilot wrote: "By landing straight ahead when power loss noted (regardless of terrain)." In the narrative portion of the accident report, the pilot wrote: "If I had landed straight ahead, we would have been okay. Perhaps a sleepless night clouded my judgment. The loss was mine and a passenger was injured in the crash --- something I'll always regret and blame my stupidity." Weight and balance calculations were performed based on known data (see docket exhibits). It was determined that the airplane was 32.8 pounds over maximum gross weight (1,600 pounds). Near the time of the accident, the altimeter setting was 30.20 inches of mercury, and the temperature was 25 degrees C. (77 degrees). Under these conditions, it was computed that the airport's (elevation 5,759 feet msl) pressure altitude was 5,479 feet msl (0.28 inches of mercury, or 280 feet correction factor), and the density altitude was 7,844 feet msl.