Proposed Piper rudder AD
Posted: Sat Dec 30, 2023 12:03 pm
The FAA is currently drafting an AD that will mandate the replacement of nearly all rudders on fabric covered Piper aircraft.
This is as a result of the failure of the rudder posts on two (note TWO aircraft ONLY) Alaska-based aircraft which were float-planes and equipped with non-STC’d anti-collision beacons of circular cross-section which were mounted atop the rudder posts.
On the failed rudder posts there was evidence of fatigue cracking at the points of failure - immediately above the upper rudder hinges.
The view of many owners in the USA is that those anti-collision beacons, given their circular cross-sections, would have always produced lateral oscillatory forces within the rudder posts during flight - that’s just fundamental aerodynamics - and these forces being concentrated at the point of maximum bending i.e. just above the upper rudder hinges.
It is, therefore, no small wonder that fatigue cracking and, ultimately, failure of those rudder posts occurred. Therefore, many consider that for the FAA to possibly mandate imposing such a blanket AD, which would affect nearly ALL fabric-covered Piper aircraft, is inappropriate; it should be aimed at those machines with the non-standard and non-STC’d anti-collision beacons.
If you are the owner of a fabric covered Piper aircraft you can submit your own comments regarding the proposed AD.
However, you only have approximately 50 days left to submit comments…
FAA website:
https://www.regulations.gov/document/FAA-2023-1893-0001
US Government Comments website:
https://www.regulations.gov/commenton/F ... -1893-0001
I think it will greatly benefit owners of LAA administered Piper aircraft to make comments regarding the current wording of the proposed AD.
Tony
This is as a result of the failure of the rudder posts on two (note TWO aircraft ONLY) Alaska-based aircraft which were float-planes and equipped with non-STC’d anti-collision beacons of circular cross-section which were mounted atop the rudder posts.
On the failed rudder posts there was evidence of fatigue cracking at the points of failure - immediately above the upper rudder hinges.
The view of many owners in the USA is that those anti-collision beacons, given their circular cross-sections, would have always produced lateral oscillatory forces within the rudder posts during flight - that’s just fundamental aerodynamics - and these forces being concentrated at the point of maximum bending i.e. just above the upper rudder hinges.
It is, therefore, no small wonder that fatigue cracking and, ultimately, failure of those rudder posts occurred. Therefore, many consider that for the FAA to possibly mandate imposing such a blanket AD, which would affect nearly ALL fabric-covered Piper aircraft, is inappropriate; it should be aimed at those machines with the non-standard and non-STC’d anti-collision beacons.
If you are the owner of a fabric covered Piper aircraft you can submit your own comments regarding the proposed AD.
However, you only have approximately 50 days left to submit comments…
FAA website:
https://www.regulations.gov/document/FAA-2023-1893-0001
US Government Comments website:
https://www.regulations.gov/commenton/F ... -1893-0001
I think it will greatly benefit owners of LAA administered Piper aircraft to make comments regarding the current wording of the proposed AD.
Tony