Piper Rudder AD 2025-02-11 !!!

Datum: 18.03.2025

Piper Rudder AD 2025-02-11!

The FAA released the final version of Airworthiness Directive AD 2025-02-11 , efective March 20-th 2025! The AD requires the owners of most Piper high-wing aircraft with rudder posts made of 1025 carbon steel to upgrade to a rudder with a post made of 4130N low alloy steel . The affected model list includes a wide range of aircraft, from J-3 Cubs to PA-22 Tri-Pacers and Colts! https://www.aopa.org/news-and-media/all-news/2025/february/13/faa-rejects-modifications-to-piper-rudder-ad

Category I Airplanes: Airplanes having both a rudder post mounted beacon light and a 150 or greater horsepower (hp) engine installed	Within 2 years after the effective date of this AD.
Category II Airplanes: Airplanes having either a rudder post mounted beacon light or a 150 or greater hp engine installed	Within 3 years after the effective date of this AD.
Category III Airplanes: All airplanes not in Category I or Category II that do not have a rudder post mounted beacon light and have an engine less than 150 hp and greater than 100 hp installed	Within 5 years after the effective date of this AD.
Category IV Airplanes: All airplanes not in Category I, II, or III that do not have a rudder post mounted beacon light and have and engine of 100 hp or below installed	Within 10 years after the effective date of this AD

Performing AD 2025-02-11, our Company has tested a couple of Classic Piper Rudder Posts to determine the material they are made from. Please follow the pictures and description. The results are clearly visible.

From SERVICE BULLETIN NO. 1379B Procedure:
.... Apply one drop of the 70% nitric acid onto the surface of the part. Do not allow nitric acid to drip/run.
Observe the drop for a reaction, which, if it occurs, will be immediate.
• If the drop remains clear , the rudder post is made from 4130N steel . No replacement interval applies.
• If the drop turns a yellowish orange or brown, the rudder post is made from 1025 steel. In this configuration, the rudder is subject to a replacement interval.  
NOTE: Regardless of findings, neutralize the drop of acid using a baking soda paste, followed by a clean
water rinse and drying. Any unused waste nitric acid must be disposed of in accordance with the
national and local regulations.....  

https://piperflyer.com/component/fileman/file/SB_1379B.pdf.html?routed=1&container=fileman-attachments

Why Is It Important for the Aircraft Owner to Determine the Rudder Post Material?

During an aircraft's lifetime, many Piper rudders have historically been replaced without proper logbook entries. As the 3rd, 5th, or even later owner of a classic Piper, you may have no record of what happened 30–45 years ago. This simple test can save you a lot of money!

This AD is not popular within the Piper Community, we know. However our Company is here to assist you to perform this AD, determine the rudder post material, and helping you with rudder replacement, if that needs to be done in the future...

Classic Aircraft Team