This June 2007 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Mooney M20J.
Location: Canton, Mass.
Injuries: 1 Fatal.
Aircraft damage: Destroyed.
What reportedly happened: The private pilot had logged 1,670 hours, including 158 hours in actual instrument conditions and 1,342 hours in the accident airplane.
During an approximately 45-day period prior to the accident flight, the pilot reported problems with the manual and electric pitch trim. She said the trim was very stiff and appeared to be sticking, noting the issue manifested when she attempted to move the trim toward the nose up position. The problem was addressed twice by a maintenance repair facility at the pilot’s home airport, and once by an avionics repair facility. Despite these efforts the pilot continued to report problems of trim stiffness. On the day of the accident she successfully flew a localizer approach, and descended through a cloud layer into visual conditions about 500 feet above ground level. According to witnesses, the airplane suddenly pitched up, then down, and descended rapidly into swampy terrain.
An examination of the wreckage, including the pitch trim system, did not reveal any pre-impact mechanical malfunctions. The flaps were found fully extended, and the pitch trim was found in a nose up position, consistent with a normal approach and landing descent.
Probable cause: The pilot’s failure to maintain airspeed, which resulted in an inadvertent stall and subsequent impact with terrain.