As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PROP OVERSEED DURING DESCENT. FOUND ENGINE INNER CONCENTRIC SHAFT TO BE BINDING ON OUTER CONCENTRIC SHAFT. AS POWER LEVER IS RETARDED, INNER CONCENTRIC SHAFT ROTATES SLIGHTLY CLOCKWISE INCREASING PROP GOVERNOR HIGH SETTING. THERE IS NO PROVISION FOR LUBRICATION IN THIS AREA AND IT ONLY RELIES ON SPRING FORCE TO RETURN THE PROP GOVERNOR TO A LOWER SETTING. INNER SHAFT REMOVED, CLEANED, LUBRICATED AND REINSTALLED