Piper Rudder AD Comment Period Extended


The FAA has extended the comment period on an AD that would require the replacement of rudders on almost 31,000 Piper aircraft made before 1974.  In a Notice of Proposed Rulemaking in October, the agency ordered every rudder equipped with a rudder post made of 1025 carbon steel be replaced with rudders that have posts made of 4130N low-alloy steel. Piper switched from 1025 to 4130N in 1974. The estimated cost of the rudder replacement is $3,000. The comment period was extended to Feb. 20, 2024.

The AD was issued in response to rudder post failures in a PA-12 and a PA-14 in Alaska in 2020 and 2021, which caused the rudders to fold over parallel to the horizontal stabilizer. In both cases, the pilots were able to land safely and the FAA determined the cause as fatigue failure. Several commenters on the AD, including the Aircraft Owners and Pilots Association and the Short Wing Piper Club, asked for the extension to work on their response, saying “it’s controversial and could drive substantial costs, among other things,” according to the FAA notice.


Russ Niles
Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.


  1. Makes me wonder about all the other vintage tailwheel aircraft like my Champ. Hope this doesn’t turn into the proverbial slippery slope.

    • As the sun doth rise in the east and set in the west, so doth AOPA object to every gdmn A.D. ever issued (as if FAA engineers had never looked at it carefully) seeking cancellation and, failing that, interminable delay, and at the very least a cheaper (and usually less safe/durable) compliance route.
      @JoeP:on your point those wonderful little Luscombes have carried a vertical fin attach point replacement AD for decades (~$350+labor).

  2. If I had a plane with a 1025 post I would easily invest $3000 for a new 4130 post. You spend more than that on an iPad and software. One day the rudder will peel over just right and into the ground you will go.

    • Absolutely. Any restorer of antique/vintage aircraft is familiar with AC23-27 which makes it easier to get approvals for substitution of parts approved on other aircraft. But in the appendix there is a list of things that are basically approved already. Certain modern parts like bearings, belts, etc. But replacing 1020 and 1025 steel parts with 4130 is automatically approved as long as it is a non-heat treated part. Makes perfect sense.

  3. This is the reason ADs are issued. Once a condition is discovered it’s really not a matter of cost but safety. I’m not concerned with the owner/pilot as much as the innocent passenger. If you can’t afford to keep your aircraft safe, it’s time to move on to another form of transportation.

  4. Sad that it appears that AVWeb spent virtually zero time researching the absolute absurdity of this proposed AD. The TWO rudder issues (out of 31,000 aircraft) occurred on highly modified aircraft – both Alaska-based seaplanes (saltwater environment) with aftermarket heavy Grimes rotating beacons top post mounted on the rudder (heavy top-loading), and both with modified STC’d 160 & 180 horsepower engines (higher vibration, p-factor, etc). No accidents, no incidents, no fatalities, no funerals. So have the entire fleet spend more like $10,000 to fix a non-problem that is not an issue with 99.999% of the impacted aircraft. Also…it’s very head-scratching that your video “describing” the problem is produced by a company that stands to make a fortune selling the “solution.” This proposed AD is FAA overreach at its finest.

    • James Wood is correct. Very poor reporting. I realize AVweb published this around the holidays but still…come on. Maybe talk to the Short Wing Piper Club first. Or is this a paid advertisement for the replacement rudder Mfg? The FAA away overreached on this one and I don’t see any mention of that. Did you investigate any of this at all before publishing?

      • I read the FAA Notice because that’s what this story about: extending the comment period. It wasn’t ever intended to be a comprehensive story on the cause and effect of the AD and the extension.

    • All we did was report on an FAA action that affects thousands of readers. Isn’t that what we’re supposed to do? I get that Piper owners are upset but we do these kinds of stories routinely to ensure that those who might be affected know the latest developments. The video seemed to explain the issue to those not familiar with it but I’ll take it down because there are allegations it misrepresents the issue.

    • The AD, is perfectly correct. High time, heavy use aircraft are the canary in the coal mine. Other, lighter use aircraft will, most likely, eventually suffer the same fate. Fatigue is a harsh mistress.
      From a retired Aero Engineer.

  5. Who is going to cover and paint 31,000 rudders?

    How about an inspection panel to determine with a borescope if any corrosion is present?

    How about some common sense?

    Another FAA solution in search of a problem to justify their existence.

  6. In our day and age, no FAA bureaucratic or political appointee will ever make a risk decision.

    .001% chance of injury and wind-up in front of Congress or lawsuit? Shift responsibility to the aircraft owner and claim its not that expensive to fix with a fake labor rate of $85 an hour for a shop A&P.

  7. Even with a 5 year compliance date on a lot of thats a lot of rudders. I don’t know that Univair and the Alaska guys ramping up selling their version of it would still take many years to produce over 31,000 rudders, and that assumes the hinges all line up perfectly. Massive over reaction of 2 incidents (not acccidents) where nobody was injured, no fatalities, no property damage to others. Needs a lot more data and engineering and testing to try to find if this is in factual and serious enough to warrant such a massive undertaking.

  8. James Woods nailed it.

    Two failures on two highly legally modified aircraft, both of which had top mounted beacons and much larger engines on PA series. There appear to have no noted failures on J series (with a different part number, yet FAA wants to apply across the board.

    This initial proposal is a huge over reach by the FAA.

  9. This should be an “on condition” requirement. An inspection, and then a replacement if warranted.
    But if I was the plane owner I would want to spend the money anyway. The steel is prone to corrosion and if the life of the aircraft is to be extended then a tail replacement is the way to go, regardless of the state where the plane is stored.

    • Thinking further, any inspection requirement by the FAA will be repetitive, so how can this inspection be done without removing the fabric every time? From a practical approach, the repetitive cost will persuade an owner to accept that the tail replacement is a terminating action and a one time event and beneficial to perform it now.

  10. The two failures were above the top rudder hinge. All you have to do grab the the top of the rudder and shake it hard. If it is going to fail you will know it.
    Additionally we have been successful at removing the rudder and opening the bottom of the rudder post with the appropriate sized drill and inserting a 4130 inner tube inside the existing rudder post all the way to the top.

    $300 won’t even cover the cost of covering and painting a new rudder. How many of you FAA supporters above this even know an A&P that does fabric work?
    I do fabric work and I wouldn’t remove the rudder, cover and paint the new one, Install the Nav light wiring and rig the controls for less than $1500.

    Cover tape and stitch the rudder 4 hours. 3 Coats of Polybrush, 3 coats of Poly spray, sand, 2 coats polyurethane color, 8 hours including cleaning spray equipment between coatings. Materials will cost at least $ 300 to $400 including hazmat shipping.
    Depending on color a quart of paint can cost $100.

    I doubt anyone in FAA today has ever done fabric work.

  11. Interesting that both sides immediately question the motives and/or regular behavior of either the FAA or AOPA.
    We’d likely be better off sending both complete organizations out to look for new careers despite all the talent and experience lost. That’s not saying we should do that, it’s just saying it should be obvious that total overhauls are necessary. A good start would be greatly reducing the size and scope of both institutions.

  12. Yes, the FAA updated the NPRM docket to grant a 90 day extension, but there is no mention of why. It is because the docket is incomplete per the law, is it because there isn’t sufficient data in the FAA investigation to properly evaluate any of the aircraft, is it because at least one of the two aircraft for which there is any data and possibly both were in an unairworthy configuration. The FAA has no clue what the root cause is. These rudders have lasted over 70 years. How is it that they suddenly become unsafe. Those folks that are unwilling to fight to protect their right to fly from this type of bureaucratic overreach may not deserve to fly. Avweb needs to tell the whole story and not just grab the headlines. It’s interesting how they used a video published by a rudder manufacturer before the NPRM was issued that claimed an AD would be issued.

  13. I believe the extension request from the AOPA and SWPC was requested to allow more time to get comments NOT supporting the AD.
    I know Richard McSpadden, AOPA SAFETY was working to gather data opposing the AD.

  14. I cannot all these folks who are fighting this. Yes the FAA is overreacting, but to be fair it’s what Americans do these days. Just look at the whole lead thing with the EPA.

    But in this case, if I had one of those aircraft I’d be replacing that daggum part so quick it wouldn’t be funny. The FAA shouldn’t have time to issue a new AD before every owner has replaced this.

    Yes the 1020 and 1025 has held up for years, but everything has a life. And with steel tubing you can’t tell what it was exposed to during its life. Perhaps it was stored out side before use and rusted from the inside out. No practical inspection is going to catch that. Fatigue stresses can be minute. MagnaFlux or other testing to detect those things is in this case impractical. The only reasonable answer is to fix it and be done with it. Even at 5000 to 6000 it’s still cheap in the aviation frame of reference. Just because its only happened twice so far and both folks survived doesn’t guarantee you’re not next – or your survival.

    And I think the reporting is perfecting fine. I have seen less than admirable reporting by this publication in the past and don’t hesitate to note it, but in this case it was a straight forward unbiased report of what’s out there. I will note that no mention was made that no contact was attempted to any of the Super Cub authorities – and it was Super Cubs this happened to. But that would have been asking more than basic reporting – and honestly I prefer just the facts. Good job

  15. Additional Examinations
    Concerned that the structural failure of these rudder posts was indicative of a
    wider safety issue, the NTSB examined three additional similarly fractured rudders.

    The NTSB obtained two rudders from a repair facility, and the third was provided in
    response to an airworthiness concern sheet the FAA issued in September 2020 (the
    rudder had been found and reported during an inspection).
    The NTSB found that the
    three additional rudders were also consistent with Piper part number 40622, and they too had
    posts made of AISI 1025 steel and had fractured above the upper hinge.
    Our evaluation showed that the peak stresses on the nominal rudder post
    approached the endurance limit of AISI 1025 steel.

    All five of the rudders the NTSB
    evaluated had an aftermarket beacon or strobe installed on the top of the rudder
    post. The additional surface area and mass of a beacon or strobe would likely
    increase the stresses even further (see the following table for more information about
    each rudder examined and its associated airplane).

    Table. Five Piper rudders examined and associated airplane information appears below:

    Year Built*
    ANC20LA059 Rudder PA-12 160 Horsepower Float 1947
    ANC21LA064 Rudder PA-14 160 Horsepower Float 1948
    Repair Facility Rudder PA-12 150 Horsepower Wheel/Ski 1946–1948
    Repair Facility Rudder PA-12 180 Horsepower Wheel 1946–1948
    Airworthiness Concern
    Sheet Rudder PA-18 160 Horsepower Wheel 1969

    scratches, or surface roughness features were found on all five of the rudder posts.
    The fracture origin areas were damaged, but corrosion pits or scratches on the
    exterior surface were associated with fatigue origin areas on two of the examined
    rudder posts.

  16. Waldo M stated:
    I wonder if new rudders for J-3s and PA-11s made by Univair and others use 4130 steel? My guess is that to comply with manufacturer specs for a PMA approved part, they are made from 1025 steel, but I emphasize that is a guess.

    My guess was wrong. I just spoke with Jason at Univair. He stated that all Cub rudders made by Univair have used 4130 chrome moly steel since the mid 1970s.

  17. “The NTSB found 5 occurrences, 3 PA12, 1 PA14 and 1 PA18. In addition, The FAA has found 12 more corroded occurrences. Not sure what all models they were on. Bottom line is all the rudders are the same part number and seems they all are the 1025 mild steel ones built by Piper prior to June 3, 1974.” ( Supercub.org )

  18. Butch Gilbert

    Fatigue failures can involve corrosion, but in some cases, there is no corrosion present. Thus, your simple borescope inspection will not cut it.

  19. The reality is almost all certified GA airplanes are over 40 years old. If the airplane has not been hangared then that is 40 + years of rain and sun and weathering. This will be much worse if the airplane is based on either coast.

    Corrosion is insidious and relentless so I think this AD is going to be the start of a steady drip drip of age aircraft related AD’s as more and more of these issues come up. Sadly many are likely to be the end of the line for airframes which will be beyond economic repair due to the AD compliance requirements.

    The AD for Cantilever Cessna wing carry through castings is a good example. It is a 40K repair by replacement and is going to ground a lot of airframes especially the older C177’s