CEN12LA261

The partial loss of engine power due to an intake valve that was stuck in the open position.

On initial climb, the airplane’s engine lost partial power. The pilot was unable to maintain altitude and airspeed and performed an off-field landing. An examination of the engine revealed that the intake valve on the No. 1 cylinder was stuck in the open position. No other anomalies with the airframe or engine were noted.

On April 26, 2012, about 0805 mountain daylight time, a Beech A36 airplane, N4830M, conducted a forced landing, following a loss of engine power, near Albuquerque, New Mexico. The private pilot and the passenger were not injured and the airplane sustained substantial damage. The airplane was registered to and operated by Gordon Enterprises, Albuquerque, New Mexico, under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The local flight was originating from the Double Eagle II Airport (KAEG), Albuquerque, New Mexico, at the time of the accident. According statements provided by the pilot, the accident flight was the airplane’s first flight in several months. The pilot reported that on initial climb, the airplane's acceleration and climb stopped. The engine lost partial power. Unable to maintain flight, the pilot initially attempted to return to the airport, but was unable to make the airport, so he elected to conduct a forced landing approach to a field. An examination of the engine conducted by inspectors from the Federal Aviation Administration revealed that the number one cylinder intake valve was partially stuck. No other defects were noted with the engine. No deficiencies were noted with the airframe. A bench test conducted on the airplane’s propeller governor did not detect any defects. A photo of the airplane’s propeller, provided by the FAA, show curling of all three of the propeller blades as well as leading edge polishing on at least two blades.