This September 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 M20TN.
Location: Kerrville, Texas.
Aircraft damage: Substantial.
What reportedly happened: The airplane was a model that had a provision for the installation of an aftermarket electric trim option. This meant the plane was delivered to the customer without an operating electric trim system so it could be retrofitted at a later date. Prior to departure from the airport, the manual electric trim was enabled in accordance with the manufacturer’s service bulletin.
The pilot reported that during the approach and landing, the nose of the airplane “was very heavy,” and he was unable to keep the nose landing gear from striking the runway before the main wheels touched down.
An inspection of the airplane revealed that the elevator trim control was reversed. A subsequent inspection by the manufacturer revealed that the wires connecting the yoke’s trim control switch were incorrectly labeled so incorporating the trim system service bulletin would reverse the direction of the pitch trim control from the pilot’s input.
Probable cause: The incorrect wire labeling, resulting in the trim controls operating in the opposite direction of the pilot’s input.
For more information: NTSB.gov