DEN05LA063

While descending, the airplane's engine started "missing" and began to lose power. Unable to maintain altitude, the pilot declared an emergency and executed a forced landing to a field. During the landing, the nose landing gear collapsed and the outboard 4 feet of the left wing was bent upward. Examination of the engine revealed no anomalies that would have precluded normal engine operation. The reason for the reported partial loss of engine power was not determined.

On March 20, 2005, approximately 1200 mountain standard time, a Mooney M20F single-engine airplane, XB-FRU (Mexican Registration), operated by a private pilot, was substantially damaged during a forced landing following a partial loss of engine power while descending near Norwood, Colorado. Visual meteorological conditions prevailed at the time of the accident. The personal cross-country flight was being conducted under the provisions of Title 14 CFR Part 91 without a flight plan. The pilot was not injured. The flight originated at Lubbock, Texas, at 0810, and was destined for Telluride (TEX), Colorado.

According to the pilot, while en route he requested an update of the weather conditions at TEX. Due to deteriorating weather conditions at TEX, the pilot requested an instrument rules flight (IFR) approach to TEX. Denver Air Route Traffic Control Center was vectoring him from the "CONES" VOR (VHF Omnidirectional Radio Range) to Telluride. The pilot stated that there was a snowstorm approaching from the northwest.

During the vectored approach and while maneuvering the airplane to stay "clear of clouds," the airplane's engine started "missing" and began to lose power. The pilot noted no abnormal indications on the engine instruments. Unable to maintain altitude, he declared an emergency, and executed a forced landing in a field. During the landing, the airplane's nose landing gear collapsed, the right main landing gear separated, and the outboard 4 feet of the airplane's left wing was bent upward approximately 10 degrees. After a visual examination, the pilot stated that he had approximately 2 hours of fuel remaining.

At 1229, the reported weather conditions at Telluride Regional Airport (TEX), Telluride, CO, located approximately 20 nautical miles at 110 degrees from the accident site, at an elevation of 9,078 feet msl, was, wind, 000 degrees at 0 knots; visibility, 1 1/4 statute miles; sky condition, scattered at 300 feet; broken at 700 feet; temperature, 1 degree C.; dew point, minus 4 degrees C.; altimeter setting, 29.78. The calculated density altitude was 9,681 feet msl.

On April 26, 2005, at the facilities of Beegles Aircraft, Greeley, Colorado, under the supervision of the NTSB investigator-in-charge, the engine and propeller was examined. The engine remained attached to the airframe. The engine crankshaft was rotated by hand via the propeller and continuity was established throughout the engine and accessories. Thumb compression was noted on all cylinders. The top spark plugs were removed and according to the Champion Spark Check-A-Plug chart AV-27, the spark plug electrodes displayed coloration consistent with normal operation. When the engine crankshaft was rotated, the magnetos produced spark through the ignition harnesses to the sparkplugs. No anomalies were noted with the engine. The reason for the reported partial loss of engine power was not determined.

Examination of the propeller blades revealed the blades bent aft and displayed chordwise scratching and leading edge gouging.