On May 6, 2002, about 1525 mountain standard time, a Cessna T210N, N888GB, collided with trees following a loss of engine power while on final approach to the Flagstaff Pulliam Airport, Flagstaff, Arizona. Forest Aire L.L.C., was operating the airplane under the provisions of 14 CFR Part 91. The private pilot, the sole occupant, sustained serious injuries; the airplane sustained substantial damage. The personal cross-country flight departed Scottsdale, Arizona, about 1440, with a planned destination of Flagstaff. Visual meteorological conditions prevailed, and a flight plan had not been filed. In a written statement, the pilot reported that, while executing a left traffic pattern for runway 21, he configured the airplane with wing flaps fully extended and the landing gear in the down and locked position. As he made a left turn from base leg onto final approach, about 300 feet above ground level (agl), the pilot noted that the airplane was getting low. He manipulated the throttle control to the full forward position, in an effort to obtain maximum power. The engine did not respond to the throttle input, and the propeller slowed down. In a matter of seconds the engine became quiet and the propeller stopped. About 3,000 feet from the runway, the airplane impacted trees. The pilot further noted that while on the approach, the left fuel tank was selected. During impact, the left fuel tank remained intact, while the right fuel tank was destroyed. The left tank had about 18 gallons of fuel remaining, and he estimated that the right tank had about the same amount, prior to the impact. Under the auspice of the Federal Aviation Administration, a Teledyne Continental Motors (TCM) engine representative examined the airplane and engine. In a written statement, the TCM representative reported that after replacing the propeller and adding oil, the engine started and operated normally, exhibiting normal pressures and acceleration. An aviation routine weather report (METAR) for Flagstaff at 1545 reported that the temperature was 21 degrees Celsius, and the dew point was negative 9 degrees Celsius. The reporting station is located at an elevation of 7,000 feet mean sea level. According to the Cessna Pilot's Association Tech Note 011, in an effort to prevent vapor lock in the 1980 and later models years of the 210/T210-P210, Cessna modified the fuel system by increasing the rear doorpost fuel feed line in diameter from 3/8 inch to 1/2 inch. The objective was for the fuel vapor to return to the main fuel tank from the reservoir tank with less resistance via the forward doorpost fuel line. Due to this modification, Cessna Aircraft deemed those models of airplanes not applicable to Service Bulletin SE81-33, which called out for a modification of the fuel system where the forward fuel feed line is tied into the rear fuel feed line prior to the reservoir tank. The complete Tech Note is appended to this report in the public docket. During a telephone conversation, the president of the Cessna Pilot's Association stated that several years back he tested the vapor lock issues in the 210 aircraft by replacing the fuel feed lines with clear fuel feed lines to observe vapor formation and its corresponding behavior. He recalled that although the rear doorpost fuel feed line was larger in diameter, the vapor continued to impede the line and disrupt fuel flow. He further stated that in effort to recover from vapor lock a pilot merely has to switch the fuel tank and activate the fuel boost pump, which will restart the engine in several seconds.