On October 23, 2004, at 1105 mountain daylight time, a Cessna T210H, N2240R, was substantially damaged during a forced landing attempt following a loss of engine power near Missoula, Montana. The commercial pilot and his passenger were not injured. The airplane was being operated under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the cross-country personal flight that originated from Philipsburg, Montana, 21 minutes before the accident. A flight plan had not been filed. The pilot said that he was flying to Missoula International Airport, Missoula, Montana, for some avionics maintenance. He was on final for runway 29, and he had been cleared to land. The pilot said that he put the "low" auxiliary fuel pump on, to move the fuel selector to the fullest tank, and then he turned it off. He then noticed that he was below the glide path, and he advanced the throttle for more power. The power did not increase. He attempted an engine restart to no avail. The pilot said that he was "very close to the ground," so he abandoned the restart attempt and performed a forced landing. During the landing roll, the airplane traversed a drainage ditch and struck a transmission pole with its left wing. The nose wheel landing gear and right main landing gear were separated from the aircraft. The outer three feet of the left wing was crushed aft and the entire left wing was bent aft at the wing root. The fuselage was wrinkled and twisted. The owner of the airplane stated that the airplane had been topped-off with fuel approximately 1.0 hour, of engine operation, before the accident. On October 29, 2004, under the auspices of a Federal Aviation Administration Inspector, the engine was test run; it started and ran "without a problem." The airplane manufacturer's Pilot's Operating Handbook gave the following guidance for DESCENT and BEFORE LANDING checklist procedures: DESCENT [checklist] 1. Power-- AS DESIRED. 2. Mixture-- ADJUST for smooth operation (full rich for idle power). BEFORE LANDING [checklist] 1. Fuel Selector-- FULLER TANK. 2. Landing Gear-- EXTEND 3. Landing Gear-- CHECK 4. Mixture-- Rich etc. The airplane manufacturer's Pilot Safety and Warning Supplements manual states: "The auxiliary fuel pump should not be operated during takeoff and landing, since gravity and the engine driven fuel pump will supply adequate fuel flow to the fuel injector unit." "Each time the auxiliary fuel pump switch is turned on or off, the mixture should be readjusted."