AD proposed for Piper rudder post failures

According to the notice of proposed rulemaking, the FAA explains that the “AD would require replacing any rudder equipped with a rudder post made from a certain carbon steel with a rudder equipped with a rudder post made from a certain low-alloy steel.” The FAA estimates that the potential AD would affect 30,992 airplanes in the United States, costing operators about $3,000 each.

Both incidents occurred in Alaska. One involved a Piper PA–12 on floats, and the other involved a Piper PA–14. Both aircraft sustained substantial damage when the rudder structurally failed. On January 10, 2022, the NTSB published the Structural Failure of Piper Part Number 40622 Rudder Posts Made of 1025 Carbon Steel report that included the NTSB accident investigation reports and recommendations urging the FAA to issue an AD to address the problem.

In the report the NTSB “determined that the rudder posts fractured above the upper hinge and the top portion of the rudder folded over the upper tail brace wires,” and “that the rudder posts were made from 1025 carbon steel and fractured due to fatigue.”

On September 4, 2020, the FAA issued an Airworthiness Concern Sheet that requested information about these failures from the aviation community and found that there were five additional broken rudder incidents dating back to 1979.

The FAA is asking for the public to send any written data, views, or comments about this proposed AD by mail or online. Instructions on how and where to comment as well as a list of Piper aircraft models affected by this potential AD can be found in a copy of the proposal posted for public inspection ahead of the proposal's expected publication in the Federal Register, which will set the timeline. AOPA will also review and comment.