FAA NRPM for AD for PA-25

[soa...@yahoo.com]

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all LAVIA ARGENTINA S.A. (LAVIASA) Model PA-25, PA-25-235, and PA-25-260 airplanes. This proposed AD was prompted by reports of corrosion in the front and rear wing spars and cracks in the front wing spar. This proposed AD would require inspecting the front and rear wing spars for corrosion and crack(s); inspecting the upper/lower spar flange of the front wing spar for any crack(s); repairing or replacing front and rear wing spars if crack(s) or corrosion are found, as applicable. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this NPRM by January 2, 2026.

The NRPM  is available here:  Federal Register :: Airworthiness Directives; LAVIA ARGENTINA S.A. Airplanes

[Lynn Alley]

This is really bad.  As I read it,  it requires (by FAA estimates, which are often low) about $2K worth of recurring inspections every 100 hours or annually, including an eddy current inspection of the front spar for airplanes older than 40 years.  The FAA estimates 24 hours do do the inspections.  It could easily be more than that.  My local hourly costs for such work are about 150% of what the FAA estimates.  This could easily turn into $3-4K of work or more every 100 hours.

The only bright spot is that the FAA allows the aircraft to return to service after repair of any detected problem, while the original AD requires full replacement of the spar involved.

[Larry Ruggiero]

By rough count from the FAA aircraft registration database, there are 460 Pawnees registered in the U.S., most of which are assumedly engaged as glider tugs, banner tugs, and agricultural applicator aircraft, and assumedly by small business or non-profit organizations. How then can the Feds argue under Regulatory Findings that this “would not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act,” knowing full well that this could ground most all of them? What legally constitutes a “substantial number?”

Larry Ruggiero, Carolina Soaring Association 

[Bill Tisdale]

The FAA grossly underestimates the cost of this AD. They are using a shop hour labor rate of $85/hr. How many shops are $85/hr. We see for 2024 rates between $125-$135/hr. That alone increases the annual inspection cost to $3240 every 100hrs, or annually, which ever occurs first. Not $2040.

Replacement cost of 40hrs per spar is grossly under estimated in hours, plus at $135/hr its $5400/spar, not $3400.

Cost of replacing the fabric on the wing will more than triple that cost.

Bill

On Tuesday, November 18, 2025 at 12:14:04 PM UTC-5 Lynn Alley wrote:

[Chris Behm]

Larry-

Pardon my ignorance, but are all the 460 Pawnees affected, or just the newer ones that were made in Argentina (What I thought was implied)?

Regards,

Chris Behm

[Lynn Alley]

It is every one.  The Argentinian company bought the type certificate from Piper, and is now using that authority to mandate inspections on the whole fleet.  On the older ones built by Piper (older than 40 years) the AD specifies even more rigorous eddy current inspections.  I believe all of the ones older than 40 years were made by Piper.

[Lynn Alley]

The Argentinian AD (incorporated by reference in the FAA's NPRM) explicitly calls out airplanes built by Piper.  And the FAA's NPRM estimates 467 aircraft will be affected.  That is every Pawnee in the US.

[Michael Fadden]

Ugh. Our club just voted to send the Pawnee motor out for a  re-build over the winter. This may change that plan. Not good, at all. 

Mike  

[Mark Recht]

I’m not sure how effective making comments on the NPRM is, but those of you more familiar with the process might want to make the following points to the FAA:

1) EASA have issued a modified version of The Argentinian AD which reduces the inspection frequency for glider tow planes (limited to 1000kg MTOW, without spray-gear) from 100hr/annual to 1000hr/4 years. We are trying to do the same in the UK as are the Australians.

2) The Eddy current inspection procedure in the Argentinian AD cannot be carried out as published on US built Pawnees outboard of the strut attach, because a doubler is on the opposite side of the spar than in Argentinian built Pawnees. Australia and the UK have an AMOC (approved by Laviasa) which works and actually removes the need for the outboard EC inspection completely on B/C models, only requiring it on D models with wing fuel tanks.

Good luck !

Mark

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[Frank Whiteley]

Please see the attached SSA summary on the NPRM.

On Tuesday, November 18, 2025 at 8:06:21 AM UTC-7 soa...@yahoo.com wrote:

[Roy Bourgeois]

Does anybody have a electronic copy of SB 25-57-11   that they can post or share?

I have SB 25-57-09

Roy

[Mark Recht]

Here you go

https://drive.google.com/file/d/1ka-q_NXNFchiScvgP_peedD-LPWlXyYi/view?usp=sharing

Mark

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[Larry Ruggiero]

I’m not a lawyer, but I literally just spent a night last weekend at a Holiday Inn Express, so… humor mode off. Can anyone voice an educated opinion on how to ensure the FAA followed the required Regulatory Flexibility Act wrt this proposal? Hopefully the SSA has data on how many glider operations (nevermind numerous banner towing, and ag applicators) use Pawnees, so that we can provide a more accurate statement re: economic impact for both commercial and non-profit operations. Worst case scenario is that a substantial number of wings will require new spars, with obvious downstream effects. If ours were to fail either one proposed AMOC visual inspection or the NDT inspection, our small club would be mostly out of operation, and our fixed costs without income from tow fees and commercial rides (hangar rent, insurance, etc) could drive us under.

Also, does anyone have greater info (or a copy of whatever service bulletin applies) re: the aft spar inspection I’ve seen mentioned with this?  Everything I’ve seen so far references the main spar only. Thanks…

Larry

[Mark Mocho]

File for a Freedom Of Information Act (FOIA) request asking for all correspondence, both internal and external, all emails, transcripts of discussions within the FAA and third parties concerning the issuance of this NPRM. Request dates of all procedural decisions involving the NPRM, including date of initiation, date of issuance, dates and duration of the response request, all responses, all information concerning the cost determination and the procedures followed to arrive at the cost of compliance. Also request the names of all FAA personnel involved in the NPRM, including signatures and dates of approval by all department heads who approved the NPRM issuance. Add in whatever else you may think is appropriate. Including the names of their wives, children and any pets.

Expect the FAA to take the maximum amount of time allowed for a response before immediately asking for an extension. Expect a great deal of the information to be redacted. File an appeal about the redacted material. 

A FOIA request is your RIGHT, and one of the most effective means a citizen has to hold the bureaucracy accountable. It cannot be "swept under the rug." It forces the FAA to respond immediately, as opposed to blowing off any other form of request or inquiry.

This method was what FINALLY got the FAA to act in a somewhat favorable manner concerning the 3,000 Life Limit AD on the Centrair Pegase 101A. The information provided under the FOIA request revealed numerous violations of the Administrative Procedures Act (APA), including a greatly shortened response period (38 days rather than the required 90 days), and evidence of six managers and department heads "examining" the NPRM and signing off on it one ONE afternoon immediately prior to a Federal Holiday. Also, several "ex parte" (Communications with Centrair) references were made, even though the conversations with Centrair never happened. These violations of procedure finally made the FAA agree to an "Alternate Method of Compliance" (AMOC) that allowed for an increase of the Life Limit by 1,500 hours, with provision for further extensions.

[Michael Fadden]

Just curious - is/has SSA commented officially?

I don't know if it still can be found anywhere but the journal of events that Mark refers to regarding the Pegasus life-limit issue is a lesson in taking on city hall and winning. That said, it was a monumental task and took incredible perseverance. Bob Carlton was the prime mover. Thanks to his efforts (and those helping him, including Mark),  I made the decision to buy a Peg.  Very nice glider.    

Mike

[Christopher Kimble]

Would you please post or share SB 25-57-09?  (Thanks!)

Chris

[Joe Gieseke]

Here you go.

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[Roy Bourgeois]

Here you go Chris

[soa...@yahoo.com]

> Just curious - is/has SSA commented officially?

The SSA plans to respond, as stated in their summary.  While it is common for individuals to post comments early in the process, organizations such as EAA, AOPA, and the SSA will post their official comment closer to the deadline.  AOPA usually posts their response in the final 72 hours for example.  The reason for waiting is to collect as much information as possible concerning the impact of the regulatory action on the public, issues with the proposal, and potential mitigation activities.  

While the SSA can anticipate that an AD is forthcoming, because of the FAA's ex parte rules we are not able to discuss (we tried) the specifics until the NPRM is released.  

SN

[Christopher Kimble]

Thank you, Roy and Joe, for sharing the PDF of Laviasa SB 25-27-09.  However, the NPRM specifies a different service bulletin, SB 25-57-09, for the initial borescope inspection of the wing spars.  SB 25-27-09 is actually available at a Laviasa website, so I have had it for some time.  A helpful person just sent me a copy of SB 25-57-09.  (It is watermarked to restrict its use to a specific organization, so I don't feel free to share it.)   The two service bulletins, SB 25-27-09 and SB 25-57-09, are identical, word-for-word and picture-for-picture.  Why, I wonder, would Laviasa issue identical service bulletins?   

Adding to the confusion is that my copy of SB 25-27-09 has the same revision level (Rev 0) and publication date (11/27/2023) as the NPRM specifies for SB 25-57-09.   But my copy of SB 25-57-09 is Rev 0, dated 7/16/2024.  

Another wrinkle is that the ANAC AD (2024-05-01 R1) requires compliance with SB 25-57-09, but in a later paragraph refers to it as 25-27-09.   

Chris

[Mark Recht]

Apparently ANAC (the Argentinian FAA) issued the AD with a typo referring to SB25-57-09, so rather than change the AD, Laviasa agreed to re-issue the same SB25-27-09 under a new number so it would match - you couldn’t make it up !

Mark

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[Larry Ruggiero]

This is getting ridiculous. Between the fabric openings in this bulletin, plus the standard inspection openings, along with the rectangular openings in every rib bay behind the spar for the onerous spar inspection, there will be a lot of potential for vibration negatively affecting the fabric, especially in the area behind the prop wash. Pawnees were flying fine for decades, fully loaded in ag operations,  and as glider and banner tugs, until some idiot pulled way harder than designed for. You can't regulate against stupidity. 

Larry Ruggiero 

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[Joe Gieseke]

Hi Larry 

Referencing this... " 

until some idiot pulled way harder than designed for. You can't regulate against stupidity. "

Its appears that you don't have a good understanding of the issue.

Its a maintenance issue, not a design or pilot issue.

Joe G

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[Larry Ruggiero]

Joe, you don't know me and I don't know you, but as a 40+ year pilot rated in power and glider, plus having been a career Air Force maintenance/logistics officer, and currently an A&P/IA who's been flying and maintaining our Pawnee for almost 10 years, I stand by what I said. Watch the video. The Sinaloa pilot over G'd the airplane, most likely pulling hard beyond maneuvering speed while simultaneously dumping a large load, which further decreases maneuvering speed, thus more readily exceeding design limits. I'm pretty certain issues with maintenance came up not necessarily as a direct result of investigating this particular accident, but instead after the manufacturer started looking at its own Pawnees and legacy Pawnees in order to cover its potential liability. Have they found issues of valid concern? Yes. But how many more openings in the wing are practical or feasible? They could mandate replacing the bottom skin with a completely removeable panel, and it still would not guarantee mechanics would do their due diligence nor would it prevent pilots from flying the airplane beyond its design limits. Mandating more unnecessary holes in the aircraft is a knee jerk reaction. That the proposed FAA AD could end up mandating annual or more frequent eddy current inspections is a completely unnecessary and overburdensome response that fixes nothing.

There have already been service bulletins and AD's for examining wing root attachment points, as well as increased inspection of non-sealed struts. I'd venture to say most US based Pawnees now used as tugs have been recovered at some point since manufacture, which further implies they had their inner structure carefully looked at when opened up, and examined for poor prior repairs or faults such as corrosion. If you look at the accident video, the wing itself didn't appear to fail anywhere mid-span, which would justify closely looking at the spars. Pawnees are robust aircraft, even those that are decades old, IF properly maintained and flown within their limits. The Sinaloa crash occurred not because of poor maintenance but because of reckless flying.

Larry

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[Joe Gieseke]

Ok, thanks.

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[Hank Nixon]

I re covered our Pawnee wings last winter. During that time I inspected the spars , knowing what might be coming. 

No cracks, no extra holes, no corrosion.

Now I get to do it all again while replacing spars so we don't have to spend a couple thousand a year, or more, for funky inspections.

Lesson?

I re covered it one year too soon.

And the best part? Our airplane was never an ag machine.

Sigh

UH

[william feiges]

The problem with waiting for the AD to be finalized is your tow plane will be down next summer during prime soaring season.  I don’t think I have ever heard of an AD being changed due to cost.   So buckle up and it get them fixed during the off season.  

[Roy Bourgeois]

Here is some food for realistic thought on this issue.  The PA-18 (Super Cub) wing is, except for the fuselage attachment fittings, pretty much the same design as the PA-25 (Pawnee) wing.  The wing spars are identical as is the leading edge construction. Improper leading edge repair and corrosion impact both wings exactly the same way.  However, the planes have very different maximum gross weights  (1750 lbs for the Super Cub vs  2900 lbs for the Pawnee). Most of that extra weight capacity in the Pawnee is in the fuselage hopper load. It appears that there are no reported instances of an empty  Pawnee having wing failure, and no reported problems with any Super Cub wing failures at all. It seems likely that the Pawnee's extra working weight aggravates crack propagation. 

For Pawnees not flying with a full fuselage load there is no good case for requiring repeated inspections.  Once a Pawnee is initially inspected for improper repairs and for corrosion (which are two different problems) there should be no reason for repeated inspections if the hopper is removed and the weight  restricted to 1750 lbs or something close to that.  If the plane is weight restricted it can be used for towing and there is no reason  to expect future maintenance issues any different from the Super Cub.

We own a Pawnee and we plan to bring this approach to the attention of the FAA in connection with the NPRM. We suggest that the SSA should look into this as well.

ROY  

[Mark Mocho]

This is a nice, common-sense argument for reducing the impact of the NPRM. Since we are dealing with the FAA, it is therefore useless. The Service Bulletin came from the Type Certificate holder, Laviasa, and there is no way that the FAA can consider backing off from the TC owner's recommendation. Indeed, I am actually surprised they aren't just grounding the entire fleet, as that covers their butt completely. And they would then argue that the "cost of compliance" is zero.

For the Pegase 3,000-hour life limit AD, we tried to use the argument that there has never been a "fatigue" failure of a composite aircraft in the history of fiber reinforced plastic (FRP) construction. And an OSTIV study published in "Technical Soaring" stated that testing could not reach an actual answer about fatigue life because the testing equipment wore out or broke before fatigue failure occurred. Their best estimate of fatigue life for an FRP wing and spar was 1.6 x 10(6) hours, or 1,600,000 hours. The FAA and the AD author were completely unmoved.

The cost of compliance with the Pegase life limit AD was stated as $85. This was one hour at $85/hour to "make a pen and ink change to the Operating Handbook and Maintenance Manual." Or, more accurately, "Delete the 3,000-hour Inspection Procedure and throw your aircraft away once it hits 3,000 hours." It was a completely absurd decision, and the FAA STILL refuses to rescind or modify the ridiculous AD. The best they would do was to approve an Alternate Means of Compliance (AMOC) to allow for an additional 1,500 hours for US registered Pegase gliders, or 4,500 hours total. This is in spite of the fact that EASA certified Pegase gliders have NO life limit, as long as they continue to pass a 3,000-hour, 6,000-hour, and 9,000-hour inspection.

The entire experience with the FAA over the nine-year battle inspired me to print commemorative T-shirts. I still have some if you are interested.

[Lynn Alley]

Is it certain that replacing the spar or even the whole wing terminates this AD and so removes the need for future inspections?  I didn't see any words to that effect in the NPRM, but I might have missed something.

[Charles Mampe]

I like your thinking, thus as already mentioned, it's too obvious and smart thus will fail with the FAA.

Maybe contacting the cert holder with that idea to try and get concurrence?

[Mark Mocho]

SSA has received several large bequests in recent years, which have been used to fund several projects to help ensure the future of soaring in the US. These include funding for clubs to acquire and implement simulator-based training, youth programs, and the like. I believe this NPRM and AD, if adopted, present a great threat to soaring, so much that I suggest that the SSA:

-Adopt and issue a response to the NPRM defining the impact to soaring, argue that the FAA's assertion about cost of compliance is incorrect and unreasonable. Request a delay in implementation of the AD.

-Contact and work with the Argentinian, Australian, British and other international gliding organizations, as well as EASA to define a modified AD (as has been done by EASA) to reduce the onerous inspection/test/repair protocol to something more reasonable than requiring an expensive inspection every 100 hours, especially since the loads imparted in gliding operations are much lower than Agricultural spraying operations.

-Suspend funding of simulator purchases and some youth programs and redirect the funds toward a bulk purchase of appropriate wing spars from Laviasa and/or other qualified aviation parts manufacturers. Offer replacements at reduced cost to affected soaring clubs with Pawnees.

-Identify and contract with aviation maintenance centers across the US to agree on a price for inspection/test/repair work at a package price. Include clubs who have the expertise and ability to perform these services in-house.

-Make available low or zero interest loans to soaring clubs to pay for parts and inspection/test/repair services.

-Urge SSA members to respond during the NPRM response period. Provide a template for SSA members to include the SSA's major points in a personalized response. Email this template to all SSA members with links to the FAA website specifically addressing the NPRM response.

-Contact the FAA Small Aircraft Directorate to inquire about the possibility of an Alternate Method of Compliance (AMOC) that may be easier financially and practically than the proposed AD.

-Contact FAA Designated Engineering Representatives (DER), Authorized Inspectors (IA) with Piper Pawnees and other similarly constructed aircraft for input and suggestions on alternate means of compliance.

-Contact AOPA and EAA to inform them of this NPRM and AD and ask for advice/assistance.

I can't expect the FAA to exactly roll over and let this issue slide, as that is not in their nature, but a coordinated response and offer of assistance in finding a solution probably won't hurt. Also, if it can be proven that the cost of compliance is greatly underestimated, contacting our elected representatives in Washington, D.C. to inform them of the economic impact will be helpful. Assuming the Congresspersons and Senators can take time out from their busy schedule of peeing on each other's shoes. All correspondence with elected representative should include the FAA Administrator and head of Small Aircraft Directorate.

I believe the SSA, as a 501(c) tax exempt organization may not be permitted to petition the US Government directly. I also think this is spelled out in the SSA Bylaws. However, it certainly does not forbid the SSA from encouraging and directing its membership to join forces with like-minded organizations to fight against and possibly modify the FAA's rather heavy-handed NPRM and AD. It would also be useful for a qualified aviation attorney to compare the Laviasa Service Bulletin to determine whether the FAA has overstated the requirements for this AD.

(One Service Bulletin from Centrair requiring replacement of aileron hinge pins on a series of 13 gliders due to faulty materials was expanded by the FAA to an AD requiring replacement on ALL US registered gliders, regardless of serial number. It was successfully rescinded. Especially since the dummy that wrote it listed the cost of compliance at $1 per pin and two hours of labor. In actuality, it was more like $14 per pin and 35 hours of labor.)

[Ronald Gleason]

Bravo Mark, great thoughts and proposals.  I agree with the fact that this issue will severly impact the soaring population. 

[Davis Chappins]

Does the FAA actually read the comments submitted? Do they actually care?

Or are they going to proceed regardless of 10 vs 10,000 comments?

[George Underhill]

I'd bet someone reads them since they publish the comments.  I'd also bet with Laviasa issuing an AD that a serious case of CYA would prohibit not doing the same here.  I think our best hope is to get the Australia AMOC.  

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[Peter N. Steinmetz]

Yes, they must document that they red and consider them. And if truly 10,000 vs 10 they will have some serious justifying to do.

I don’t care for Federal regulatory agencies one bit but do think the FAA tends to be one of the more rational ones. 

Peter

[Davis Chappins]

You say serious justifying but they are justifying to themselves? They are making the rule, letting the public comment, then deciding whether or not they want to listen to any of the comments?

There are 21 comments so far. There's 8,000 SSA members. This affects every single glider pilot in the US. Why isn't there a nationally organized push to create and submit thousands of comments?

Do 7,979 people not care?

It would be quite simple, for example look at the two anonymous comments. Those were submitted by me after ingesting the other comments, this thread, the FAA guidelines on submitting comments, and the EASA AD. They were produced by different AI models, about 4,000 characters, submitted from different IPs.

If we really wanted to, we could submit 50 comments a day that all say more or less the same thing, but written differently.

Would the FAA pay attention if this AD received 1,000 comments?

[Ryszard Krolikowski]

Good point Davis!

Also

I didn't read any comments, but same like we lost 200+ Blanik's  L13 because some club in Europe abused their L13 with winch and aerobatics for 12000 hrs, we going to have way more expensive tows because some crops duster overloaded chemical tanks.

Ryszard Krolikowski

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[Rex Mayes]

As an owner operator of 6 PA25s, this could be considered an “existential threat” to a well established Northern California soaring center in reality, we will survive this largely because we will do this work in house.  

I fear that the FAA will consider their hands tied due to the fact that the precedent has been set by other countries.  I do not have faith that the bureaucrats who likely have no skin in the game, will consider any comments.  They will likely  publish the AD by copy and paste.  

 There is no motivation for them to investigate this with the soaring society in mind. 

The AD should be published based on the risks of spar failure and not by how much this will affect our activity.  

I believe the risk of spar failure for a PA-25 used in aero tow operations after  airframe restoration since ag operation, is extremely low.  I have seen some pretty ratted Pawnees used in tow operations, that seem like they have never been cleaned, let a lone inspected for cracks in the spar cap.  Most however, are in good shape and may have a few extra, or over size holes in the spar caps.  These ought likely to be inspected and evaluated.

I will be disappointed but not super surprised if any of my spars have less than perfect holes in the spar caps. I believe this inspection and judgement/ risk assessment would be left to IAs instead of an onerous blanket policy of NDT.

I do support encouraging thousands of comments to the FAA addressing this NPRM but limit the comments to risk assessment  and not how the soaring pilots are going to be put out or victimized by it.

Rex

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[Mark Mocho]

I urge everybody to comment on the FAA NPRM. Deadline for comments is 02 January 2026. My comment follows. Feel free to use it as a template or write your own. Further suggestions to my comment are welcome. Also, please point out any misstatements or errors.

"Many PA-25 Pawnee aircraft are utilized for towing gliders. The loads imparted during glider tow are far less than those experienced during agricultural operations. There is no extra weight carried, as the chemical hoppers are not loaded and there is no spray equipment or pump installed. Maneuvering is much gentler than the typical spray operation which involves hard pull-ups and steep turns. This type of flight loading with a higher airframe weight imparts much more stress than a glider tow. The inspection at 100 hours may be justified for hard-working agricultural airframes, but not for glider operations. I recommend a MUCH less rigorous inspection procedure and interval for Pawnees used exclusively for glider towing. Also, the FAA's estimate for cost of compliance is seriously in error. The stated number of hours required for inspection and cost per hour are less than half of what can be realistically expected. These costs, even at the estimated rate, will seriously cripple the small businesses and soaring clubs who operate PA-25 Pawnee airplanes. I urge the FAA to reconsider the onerous effect the NPRM as written and explore Alternate Means Of Compliance (AMOC) procedures for glider operations. Argentinian, Australian and European National aircraft safety organizations have adopted alternate methods of compliance for glider operations. Under the Bilateral Aviation Safety Act, the FAA is obliged to write regulations that mirror other National and International agencies such as EASA, if they are signatories to the BASA. I am completely opposed to the NPRM as written, as it will cause an excessive financial hardship on organizations who use the PA-25 Pawnee for glider towing."

[Bill Hill]

👍

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[Mark Mocho]

I agree with what Rex says, but I think the financial impact of this NPRM Must be stated. It is not uncommon (rather the opposite) for the FAA to seriously understate cost of compliance, as they are supposedly required to consider the financial impact on owners of affected aircraft. This is to "ensure" that "no significant financial burden" will ensue as the result of the rule. Obviously, even the underestimated costs by the FAA will have significant effects on operators of the PA-25 Pawnee.

[Brian LaBorde]

The FAA will not be swayed by an argument that "this costs too much". That won't work. 
IF Roy's argument that tow planes are not under the load that AG planes are, and are not at the same risk, then that argument CAN sway the FAA. Put boundaries around this... if you are using it as an AG and carrying MTOW then yes, regular inspections make sense. If used as a tow plane then NO they don't (or at least can be spread out much farther than they are suggesting.)

If we are going to respond (along with the SSA) then we should be logical about the argument. 

my two cents. 

BL

On Saturday, November 22, 2025 at 1:30:00 PM UTC-7 Roy Bourgeois wrote:

[Mark Mocho]

The FAA may not be "swayed" by the financial burden, but they are "swayed" by Congressional investigation. Write your Congressperson. On the Pegase Life Limit AD, we received substantial help from a staffer at NM Senator Tom Udall's office, as well as his predecessor NM Senator Jeff Bingaman. The staffer lodged a request on behalf of Senator Udall and the FAA rather blithely blew her off and refused to respond. They came around when word of a possible official Congressional Investigation on our behalf was leaked to them. The AMOC on the Pegase was issued within two months. Also, Representative Sam Graves (R-MO), Chairman of the House Transportation and Infrastructure Committee offered his assistance. Rep. Graves is an active pilot and even flies in airshows with a Curtiss P-40 Warhawk.

[Lynn Alley]

Is anyone else flying metalized Hutchinson wings as per STC  SA501SW?

We have a Pawnee with these at Elk Mountain Soaring in Utah.  Our initial assessment is that we can't comply with the AD as currently formulated in the NPRM using the verbatim procedures documented in the materials incorporated by reference.  One simple example is that our metalized wings don't have a removable cover over the wing-walk area that can be removed for inspection.  Instead, it has stressed skin there that is integral to the rest of the wing, and that is riveted to the adjacent ribs.  There are several other examples where the documented procedures won't work.

Don't think the STC holder will be of any help.  That business is long since gone.

We would like to establish contact with anyone else using these wings, with a view toward making coordinated responses during the comment period.

Lynn

On Friday, December 5, 2025 at 3:22:20 PM UTC-7 Brian LaBorde wrote:

[Tom Seim]

Here is a link to the Argentina AD:

bing.com/ck/a?!&&p=2d4a86ef1727178821737360a0f6f9c2541cc4f1fd5d6dd9fdc4f9b54237a093JmltdHM9MTc2NDg5MjgwMA&ptn=3&ver=2&hsh=4&fclid=11eee4be-e758-6546-03fc-f2bae6e264c3&psq=ANAC+Argentina+AD+2024-05-01+R1&u=a1aHR0cHM6Ly9hZC5lYXNhLmV1cm9wYS5ldS9ibG9iL1JBLTIwMjQtMDUtMDFfUjEucGRmL0FEX1JBLTIwMjQtMDUtMDFSMV8x&ntb=1

What certainly can be argued are:

1. Hourly tech costs

2. Unworkable instructions

3. Necessity of recurrent inspections

On the third point, if an aircraft has been in service for thousands of hours and tens of years, and no corrosion is found, then it should be a one-time inspection only.

Tom 2G

To view this discussion visit https://groups.google.com/d/msgid/rasprime/a47bc078-49bc-458c-841c-082a39e6c0e5n%40googlegroups.com.

[John Godfrey]

Whatever the outcome, the SSA could provide actual value to the sport by offering interest free loans for compliance (in addition to proactive lobbying).

Details will no doubt be on the website...

[Warwick Patterson]

Keep in mind that the rest of the world has had to deal with this AD for more than a year already...so operators in USA don't have to dive into this blindly. EASA, Oz/NZ and others have issued alternate method of compliance, or different inspection timelines for the spars for towing aircraft. GLiding Australia especially has some very intelligent people leading the effort, and they have some load data from a previous issue that has proven helpful. We are hopeful something will happen here in Canada too, based on precedent set in other ICAO countries. 

That said, a lot of inspections HAVE found some seriously corroded wing elements and other issues...so it was probably a good thing to have all the wings inspected. The 100 hour inspection cycle is onerous and not based on reality for glider ops, so I hope that gets changed everywhere.

[Larry Ruggiero]

Can someone post links to the foreign AMOCs referenced throughout our discussions? Would be handy to use for developing our own AMOC proposals. Thanks…

Larry

[Lynn Alley]

I think we could really use some direction on how to respond from the SSA.  The SSA document posted by Frank Whiteley on this forum on November 18th suggests we coordinate our responses through Rick Hoffman.  Wouldn't it make sense for the SSA to issue some more explicit guidelines on what we should be putting in those responses, so that Rick doesn't have to respond to each on a one-by-one basis?

And time is becoming of the essence.  There are only a few more weeks left in the comment period.

Lynn

[Tom]

I am waiting to make a comment until SSA comes out with some guidance, based on facts, like Rex and others they have weighed in with great advice.  That collective guidance would be helpful as a consistent, thoughtful and hopefully large group of operators/owners voices.

Tom

To view this discussion visit https://groups.google.com/d/msgid/rasprime/4826CD6B-E25D-458E-B485-4D04A76F4A3E%40williamssoaring.com.

[Mark Mocho]

Update on the SSA’s Response to the Pawnee Wing Spar Problem

December 5, 2025

• The FAA issued an NPRM soliciting public comment on an AD that is being proposed for corrosion and a wing spar inspection
• This is based on three accidents- two in SA and one in Mexico and involved Agricultural use Pawnees that are flown at a max gross weight and carry very corrosive phosphates for aerial application to crops.  The airplanes were operated beyond normal flight parameters that are not found in our glider towing operations and resulted in wing failures.  Mostly due to corrosion. poor maintenance practices, and exceeding the operational limitations of the Pawnee.
• The AD would require an initial inspection for corrosion and an inspection of the wing leading-edge attachment to the spar.  Additionally, an eddy current (non-destructive testing for corrosion and cracking) is required both for the initial inspection and following inspections on either a calendar basis, flight hours basis, or a combination of both.
• It is possible (approximately 30-40%) that of the aircraft flown for towing, some additional holes in the leading-edge attachment were made that may not have structural implications but are in excess of the allowable original holes for leading-edge attachment.  If this is the case, the spar will need to be replaced.
• This AD requires an inspection, possible spar replacement, which may result in a repair cost of $40-$50,000.  Annual reoccurring inspections may add additional costs of $2,000 to $3,000 in excess of normal annual inspection costs.
• The SSA is responding to this NPRM disagreeing with the proposed AD and offering alternative inspection procedures and following reinspection procedures that would be less invasive and expensive while offering the same level of safety to operators.
• Many Clubs' annual budgets may run between $75,000 and $125,000.  Some of the larger club's budgets may exceed those numbers.  However, it's easy to see the potential negative impact to the club both from additional maintenance expense and operational downtime for the repair resulting in a revenue interruption.
• The SSA is in discussion with a number of aircraft financial institutions and exploring possible loans to help clubs finance Pawnee repairs
• Time frame on this is unknown at this time.  The NPRM response is due Jan 2, 2026 although the SSA is requesting an extension to respond as the topic is a complicated one that requires both stress and fatigue analysis to support our positions.

[Tom Seim]

For what it's worth, here is my comment:

I believe it is too soon to issue an AD based on this action by Argentina. Pawnees are simply not falling out of the sky due to broken spars. A search showed only one such accident, and it involved aerial application. Most PA-25s in use today are for aerial towing, a much lower stress situation than aerial application. Furthermore, the procedure in the Argentina AD cannot be used for many PA-25s in the US. We need to know more about how the accidents in Argentina occurred and the environment they were exposed to. Aerial application involves carrying corrosive chemicals that contributed to the accidents. This is not the case in aerial towing. Also, were these aircraft stored outdoors in a very wet environment? Would it make a difference if the aircraft were stored in a hangar or a dry environment? Why are annual inspections mandated if the use is for aerial towing and not aerial application? More research should be done before any AD is issued. Also, the FAA's use of $85 shop rate is totally unrealistic and should be double that.

[Tom Seim]

I will add that numbers matter in these situations, so the more comments the better - just don't depend upon the SSA or someone else to do it for you. Copy and paste if you have to.

Tom 2G

[Tom Watson]

I think Tom is correct about numbers. I think the FAA is in their usual cover cheeks mode. The more maintenance arguments backed by data or exposing the lack technical competence and data by Lavisia, the better. The FAA could care less about soaring or clubs. They can’t manage what is on their plate now. Witness the drone airspace debacle or the unwillingness to accept portable, affordable  ADSB for safety.

 I also wonder why the SSA has not gone all in on Congressional pressure? It has worked before. Maybe the clubs in every state should do this. What is there to lose? The recent AD on Piper rudders is instructive as to FAA rationality. Two partial rudder failures(corrosion at the top hinge) on PA seaplanes with beacons kept outside in Alaska, resulting in controllable landings caused an AD requiring rudder replacement in 30,000 aircraft in one to five years. No universal AMOC acceptable. 

My thought is to use all data backed defenses and political pressure available as soon as possible. 

Good luck, 

Tom Watson TSS

Sent from my iPhone

On Dec 10, 2025, at 4:30 PM, Tom Seim <toms...@gmail.com> wrote:

I will add that numbers matter in these situations, so the more comments the better - just don't depend upon the SSA or someone else to do it for you. Copy and paste if you have to.

To view this discussion visit https://groups.google.com/d/msgid/rasprime/77d4bcfd-5ef8-4b8d-bc77-fd9a9cf061c9n%40googlegroups.com.

[Tom]

Hi all,

Below is the draft I would submit at this time. It is based on the thoughtful input of many in this group, and I welcome and would greatly value guidance from this group and SSA to help refine it further.  I need to coordinate getting this draft to our group so a number of comments from the Sugarbush Soaring Association members can be filed.

Thanks, Tom

I respectfully submit this comment in opposition to the NPRM as currently written. My objection is not to the goal of ensuring continued airworthiness of the PA-25 fleet, but to the application of a one-size-fits-all inspection regime that does not distinguish between fundamentally different operational uses of the aircraft. The proposed requirements fail to account for the markedly lower structural loads, benign operating profiles, and corrosion-free service histories of PA-25 aircraft used exclusively for glider towing, and therefore impose an unnecessary and disproportionate burden on this segment of operators.

Given the absence of a documented pattern of wing separation accidents involving PA-25 aircraft in glider towing service, this matter warrants additional study rather than an immediate, broad regulatory response. A clear distinction must be made between PA-25 aircraft engaged in aerial application and those that have operated for many years solely as glider towplanes.

A substantial number of PA-25 aircraft in the United States are dedicated exclusively to glider towing, and their operating environment is fundamentally different from agricultural service. Glider towing imposes significantly lower structural loads. These aircraft do not carry chemical hopper weight, spray equipment, or pumping systems, and flight profiles are routine and conservative. This stands in sharp contrast to agricultural operations, which involve repeated high-gross-weight pull-ups, steep turns, and aggressive maneuvering. It is these spray missions and associated load spectra that historically drove the structural concerns underlying the proposed inspection requirements.

There is also an important distinction with respect to long-term environmental exposure. PA-25 aircraft that have not been used for agricultural application for decades have not been subjected to corrosive chemicals, residues, or operating environments commonly associated with aerial application. The absence of such exposure materially reduces corrosion risk and should be explicitly considered when evaluating both the necessity and frequency of structural inspections for aircraft used exclusively in glider towing service.

Given these fundamental differences, a 100-hour inspection interval may be appropriate for aircraft engaged in high-cycle agricultural operations, but it is unnecessary and disproportionate for glider towplanes. A reduced inspection requirement for PA-25 aircraft used solely for glider towing would be reasonable, technically defensible, and consistent with both actual operational loading and long-term exposure history.

The FAA’s economic analysis further underestimates the true compliance burden. The labor hours and hourly rates cited in the NPRM are substantially below what operators can reasonably expect to incur. Even using the FAA’s own assumptions, the projected costs would have a serious adverse impact on the small businesses and non-profit soaring organizations that rely on PA-25 aircraft. Using realistic labor and cost figures, the impact becomes unsustainable.

Additionally, other national aviation authorities, including regulators in Argentina, Australia, and Europe, have already recognized the unique operational characteristics of PA-25 aircraft in glider towing service and have established alternate means of compliance. Under the Bilateral Aviation Safety Agreement framework, the FAA is expected to consider regulatory harmonization with partner authorities where appropriate. This proposal presents a clear opportunity to do so.

In light of the issues outlined above, I respectfully request that the FAA withdraw the NPRM in its current form and reissue it after conducting additional analysis that clearly differentiates between PA-25 aircraft used in agricultural operations and those used exclusively for glider towing. A reissued NPRM should incorporate operational load spectra, corrosion exposure history, and realistic cost assumptions specific to glider towing service, and should solicit targeted input from affected soaring organizations and operators before proposing inspection intervals or compliance requirements.

In summary, the NPRM as written does not adequately reflect real-world operational loading, fails to account for the corrosion-free service histories of glider-only aircraft, significantly underestimates compliance costs, and would impose an unnecessary and disproportionate burden on the organizations that rely on these airplanes. I strongly urge the FAA to pursue a risk-based, differentiated approach—either through a scaled Airworthiness Directive or an Alternate Means of Compliance—specifically tailored to PA-25 aircraft used exclusively in glider towing operations.

To view this discussion visit https://groups.google.com/d/msgid/rasprime/CAAE3M4vc8oM76WNzw6sHTijyPAt6nLJ-E%3DvkvY%2B9Vqvg-oQDAA%40mail.gmail.com.

[Peter N. Steinmetz]

Hi Tom,

Very nicely done with lots of good information. My only suggestion would be that you can likely remove the "I respectfully..." parts. While that is certainly very polite when writing to an individual, I don't believe comments to NPRMs are normally addressed like that (though you could check existing ones to be sure). 

Thanks for putting together such a well reasoned set of comments. 

cheers,

Peter

[Charles Coyne]

Well done. Including the "to" address information would also be helpful for folks who will be sending their own version of the letter.

Cheers,

Chuck Coyne

[Tom]

The system for commenting can be complex - here is the ways one can submit comments:

ADDRESSES:

You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any of the following methods:

• Federal eRulemaking Portal: Go to regulations.gov . Follow the instructions for submitting comments.

• Fax: (202) 493-2251.

• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.

• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

The first comment option is not easy to track down so here is the direct link to the digital submission portal for this AD - https://www.regulations.gov/commenton/FAA-2025-3990-0001

Based on some valued input I have revised my submission a bit, more formal and in more of a regulatory format.  I will wait a few days until Ken or SSA provides any input but if I do not get any I will submit before the deadline of Jan 2. 

Here is my latest thoughts, I have two versions/options I am seeking input from folks on:

Commenter Identification:
Tom Anderson
Director of Operations, Sugarbush Soaring Association
Airline Transport Pilot (ATP), Certified Flight Instructor (CFI-I/II-MEI, CFI-II-G)
Tow pilot and glider pilot with over 40 years of professional experience
Operator and maintainer of two PA-25 towplanes for many years, consistently exceeding minimum regulatory and maintenance standards

Subject: NPRM [Insert NPRM Number] – Proposed Airworthiness Directive for PA-25 Aircraft

Comment:

I respectfully submit this comment in opposition to the NPRM as currently written. My objection is not to the goal of ensuring the continued airworthiness of the PA-25 fleet, but to the application of a one-size-fits-all inspection regime that does not distinguish between fundamentally different operational uses of the aircraft. The proposed requirements do not adequately account for the markedly lower structural loads, benign operating profiles, and corrosion-free service histories of PA-25 aircraft used exclusively for glider towing, and therefore impose an unnecessary and disproportionate burden on this segment of operators.

Experience and Basis for Comment:
I am Director of Operations at Sugarbush Soaring Association and a professional pilot with over 40 years of experience. I hold an Airline Transport Pilot certificate, am a Certified Flight Instructor for airplanes (CFI-I/II-MEI) and gliders (CFI-II-G), and have extensive experience as a tow pilot. We have operated and maintained our two PA-25 towplanes for many years, always keeping safety at the forefront and often exceeding minimum regulatory and maintenance requirements. I have also managed maintenance for diverse aircraft types over many years and have overseen operations involving youth and adult flight programs. This experience provides direct familiarity with PA-25 aircraft in glider towing service, including operational loads, maintenance practices, and long-term structural performance.

Discussion:

• Operational Differences: Many PA-25 aircraft in the United States serve exclusively as glider towplanes, and their operating environment is fundamentally different from agricultural service. Glider towing imposes significantly lower structural loads. These aircraft carry no chemical hopper weight, spray equipment, or pumping systems, and flight profiles are routine and conservative. This contrasts sharply with agricultural operations, which involve repeated high-gross-weight pull-ups, steep turns, and aggressive maneuvering—the very activities that drove historical structural concerns and the proposed inspection regime.

• Corrosion and Exposure: PA-25 aircraft not used for agricultural operations for decades have not been exposed to corrosive chemicals, residues, or operating environments associated with aerial application. The absence of such exposure materially reduces corrosion risk and should be explicitly considered when evaluating the necessity and frequency of structural inspections.

• Inspection Intervals: A 100-hour inspection cycle may be appropriate for high-cycle agricultural aircraft, but it is unnecessary and disproportionate for glider towplanes. A reduced inspection requirement for PA-25 aircraft used solely for glider towing is reasonable, technically defensible, and consistent with both operational loads and exposure history.

• Economic Impact: The FAA’s economic analysis underestimates the true compliance burden. The labor hours and hourly rates cited are substantially below realistic operator costs. Even using FAA assumptions, the projected costs would seriously impact small businesses and non-profit soaring organizations that rely on PA-25 aircraft. Using realistic figures, the impact becomes unsustainable.

• International Harmonization: Regulators in Argentina, Australia, and Europe have recognized the unique operational characteristics of PA-25 aircraft in glider towing service and have established alternate means of compliance. Under the Bilateral Aviation Safety Agreement, the FAA is expected to harmonize with partner authorities when appropriate. This NPRM presents a clear opportunity to do so.

Request for Action:
In light of the issues outlined above, I respectfully request that the FAA:

1. Withdraw the NPRM in its current form.

2. Conduct additional analysis differentiating PA-25 aircraft used in agricultural operations from those used exclusively for glider towing.

3. Reissue a revised NPRM incorporating operational load spectra, corrosion exposure history, realistic cost assumptions, and targeted input from affected soaring organizations before proposing inspection intervals or compliance requirements.

Summary:
The NPRM as written does not reflect real-world operational loading, fails to account for the corrosion-free service histories of glider-only aircraft, significantly underestimates compliance costs, and imposes an unnecessary and disproportionate burden on the organizations that rely on these airplanes. I strongly urge the FAA to adopt a risk-based, differentiated approach—either through a scaled Airworthiness Directive or an Alternate Means of Compliance—specifically tailored to PA-25 aircraft used exclusively in glider towing operations.

Option 2 

I respectfully submit this comment in opposition to the NPRM as currently written. I am Tom Anderson, Director of Operations at Sugarbush Soaring Association, an Airline Transport Pilot, Certified Flight Instructor (CFI-I/II-MEI, CFI-II-G) for both airplanes and gliders, and an experienced tow pilot. I have operated and maintained our two PA-25 towplanes for many years, always prioritizing safety and frequently exceeding regulatory maintenance requirements. I have also managed maintenance for diverse aircraft types and overseen flight operations involving youth and adult programs. My experience provides direct familiarity with PA-25 aircraft in glider towing service, including operational loads, structural performance, and long-term maintenance considerations.

My objection is not to the goal of ensuring the continued airworthiness of the PA-25 fleet, but to the application of a one-size-fits-all inspection regime that does not distinguish between fundamentally different operational uses. The proposed requirements fail to account for the lower structural loads, conservative flight profiles, and corrosion-free service histories of PA-25 aircraft used exclusively for glider towing, thereby imposing an unnecessary and disproportionate burden on this segment of operators.

Given the absence of documented wing separation accidents involving PA-25 aircraft in glider towing service, this issue warrants further study rather than an immediate, broad regulatory response. A clear distinction must be made between aircraft used in aerial application and those used exclusively as glider towplanes.

Many PA-25 aircraft in the United States operate solely as glider towplanes, with an environment fundamentally different from agricultural service. These aircraft carry no chemical hopper weight, spray equipment, or pumping systems, and flight profiles are routine and conservative. By contrast, agricultural operations involve repeated high-gross-weight pull-ups, steep turns, and aggressive maneuvering—the very conditions that drove the historical structural concerns underlying the proposed inspection requirements.

PA-25 aircraft not used for agricultural operations for decades have not been exposed to corrosive chemicals or residues common in aerial application. The absence of such exposure materially reduces corrosion risk and should be considered when evaluating both the necessity and frequency of inspections.

A 100-hour inspection cycle may be appropriate for high-cycle agricultural aircraft but is unnecessary and disproportionate for glider towplanes. A reduced inspection requirement for PA-25 aircraft used exclusively for glider towing would be reasonable, technically defensible, and consistent with operational loading and exposure history.

The FAA’s economic analysis underestimates the true compliance burden. Labor hours and hourly rates cited in the NPRM are substantially below realistic operator costs. Even using FAA assumptions, projected compliance costs would significantly impact small businesses and non-profit soaring organizations that rely on PA-25 aircraft. Using realistic figures, the impact becomes unsustainable.

Other national aviation authorities, including regulators in Argentina, Australia, and Europe, recognize the unique operational characteristics of PA-25 aircraft in glider towing service and have established alternate means of compliance. Under the Bilateral Aviation Safety Agreement, the FAA is expected to harmonize with partner authorities when appropriate. This NPRM presents a clear opportunity to do so.

In light of these issues, I respectfully request that the FAA withdraw the NPRM in its current form and reissue it after conducting further analysis that differentiates between PA-25 aircraft used in agricultural operations and those used exclusively for glider towing. A reissued NPRM should incorporate operational load spectra, corrosion exposure history, and realistic cost assumptions specific to glider towing, and should solicit targeted input from affected soaring organizations before proposing inspection intervals or compliance requirements.

In summary, the NPRM as written does not reflect real-world operational loading, fails to account for corrosion-free service histories of glider-only aircraft, significantly underestimates compliance costs, and imposes an unnecessary and disproportionate burden on the organizations that rely on these airplanes. I strongly urge the FAA to pursue a risk-based, differentiated approach—either through a scaled Airworthiness Directive or an Alternate Means of Compliance—specifically tailored to PA-25 aircraft used exclusively in glider towing operations.

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[David S]

Tom,

Very nicely done.  Thank you.  

One small correction:  The "A" in AMOC is "alternative", not "alternate".

Cheers,

   ...david

To view this discussion visit https://groups.google.com/d/msgid/rasprime/CAOx2GjWFTXji5M%3DA_fvGyXqvMhWa3RZPhG_QoYB9oMHKFz0ojQ%40mail.gmail.com.

[Chip Bearden]

Good work. One thought: is it worth including some numbers regarding the economic impact? Words such as "substantially" and "seriously" and "unsustainable" beg questions of "just how much?" and "compared to what"? I realize that opens the door to the FAA dismissing our objections as just so much noise over a relatively (to them) small expense, but they've gone on record with their projections/estimates so should we be more specific with our objections?

Chip Bearden

"JB"

[William Mileski]

For what it's worth, I feel exactly the same as Chip.  The costs associated with compliance are completely unrealistic.

Bill Mileski

Secretary, CT Soaring Association

To view this discussion visit https://groups.google.com/d/msgid/rasprime/3a64da7d-1910-4c12-b4bb-ed230da3b346n%40googlegroups.com.

[John Godfrey (QT)]

I am left largely unpersuaded by the arguments made. The main thrust of the arguments seems to be  “it costs too much and no accidents have happened.” Although the cost is draconian, without proposing a clear (reasonable cost) AMOC that you can show that:

1. Detects any existing problems in the fleet
2. Proposes an alternate inspection method/schedule that can be argued on a engineering/technical basis is equivalent from a safety perspective

I fear the argument made will fall on deaf ears.

 

John Godfrey (QT), CFI-G, SSAI

International Gliding Commission (IGC), Alternate USA Delegate

+1 412 759 5145 Mobile

mailto:quebec...@gmail.com

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[Hank Nixon]

These are well addressed in the coming SSA comment that circulated today within the work group.

I'm sure it will go public quite soon.

UH

[Tom]

Thank you all for your input and especially thank you to Ken and the team from SSA that spent a lot of time researching and developing the best case argument we can hope for.  I incorporated their information and letter into mine and am sharing it below.  I have realistic expectations but feel we have to advocate for a reasonable approach to this rule.  We are also drafting a letter that members can send.

Thanks, Tom

Comment Letter – Sugarbush Soaring Association

To:
U.S. Department of Transportation
Docket Operations, M-30

West Building Ground Floor, Room W12-140

1200 New Jersey Avenue SE
Washington, DC 20590

Docket No.: FAA–2025–3990
Project Identifier: MCAI–2025–00097–A

Subject: Comments on NPRM Docket FAA-2025-3990 – Support for Soaring Society of America Recommendations and Operational Impacts on Sugarbush Soaring Association

Dear Sir or Madam,

I am submitting these comments as Director of Operations for Sugarbush Soaring Association, a soaring club based at Warren-Sugarbush Airport in Vermont, and a member organization of the Soaring Society of America. Our club operates two Piper Pawnee aircraft used exclusively for glider towing. We maintain rigorous inspection, maintenance, and training standards for our members, including both youth and adult pilots.

We fully support the Soaring Society of America’s December 22, 2025, comment letter regarding NPRM Docket FAA-2025-3990. That letter provides detailed technical analysis of Piper Pawnee wing spars, including fatigue and stress studies, inspection methodologies, and operational recommendations (Exhibits A–I). The Soaring Society of America letter clearly demonstrates that Pawnees used solely for glider towing experience significantly lower stress and fatigue loads than Pawnees used in agricultural operations, and that non-destructive borescope inspections with revised intervals maintain safety while avoiding unnecessary destruction of aircraft components.

1. Technical Alignment with Soaring Society of America Recommendations

As documented in the Soaring Society of America letter, Piper Pawnees used for glider towing:

• Operate approximately 1,000 pounds below the typical maximum takeoff weight for agricultural use, significantly reducing wing spar stress (Exhibit B, Smith Front Spar Stress Analysis).

• Are flown at moderate airspeeds with low-G maneuvering profiles, further reducing cumulative fatigue loads.

• Operate seasonally, typically from March through October, and generally accrue between 50 and 150 flight hours per year, with inspections already conducted in accordance with FAA annual and 100-hour inspection requirements (Exhibit G, Statement of Kenneth Sorenson).

The Soaring Society of America’s recommendation to utilize visual inspection aided by a 3 mm borescope for critical areas of the spar flange, and to extend inspection intervals for glider-tow Pawnees to 1,000 hours or more, is well supported by both expert engineering analysis and long-term operational experience. This approach preserves a high level of safety while avoiding unnecessary destructive inspection requirements.

2. Operational Impacts at Sugarbush Soaring Association

The proposed AD, as currently written, would impose significant burdens on our club operations:

Aircraft downtime: The requirement to remove and reinstall 48 sheet metal screws per wing, combined with the need to bring in outside personnel to perform eddy current inspections, would result in extended aircraft downtime. This would significantly limit glider launches, instructional flights, and towing availability during peak operational periods.

Youth and community flight programs: Sugarbush Soaring Association conducts intensive summer and seasonal programs, including youth instruction, line crew operations, and solo flight training. Unnecessary destructive inspections and prolonged aircraft grounding would delay or cancel flights, directly reducing training opportunities for student pilots and diminishing the effectiveness of these programs.

Maintenance and staffing challenges: Our operation relies on a small team of instructors, mechanics, and volunteers. Eddy current inspections require specialized technicians and equipment that are not locally available, increasing cost, logistical complexity, and operational disruption. In contrast, visual inspections using borescopes are non-destructive, practical, and readily implementable by our existing qualified personnel (Exhibits E–F, Ridenour and Kroesch Statements).

Economic impact: Outsourcing eddy current inspections can cost approximately $1,500 to $4,500 per aircraft, exclusive of travel costs and lost operational time. This represents an undue financial burden for non-profit soaring clubs operating with limited margins (Soaring Society of America letter, Section 4).

3. Alignment of Soaring Society of America Technical Findings with Sugarbush Soaring Association Operations

Our operational experience directly confirms the Soaring Society of America’s conclusions:

• Pawnees in our fleet exhibit minimal corrosion or structural wear consistent with their low-stress, glider-tow-only usage, even after decades of service (Exhibit F, Kroesch Statement, Figures 4–5).

• Repetitive removal and replacement of sheet metal screws is inherently destructive and unnecessary, whereas borescope inspection provides effective access to the spar and spar-sheet interface and is sufficient to detect cracks well below sizes that could compromise spar integrity (Exhibits F and G, Figures 7–9).

• Extending inspection intervals and limiting AD applicability for aircraft operating at or below 2,205 pounds MTOW aligns the rule with actual operational stress profiles. This approach maintains an appropriate margin of safety while avoiding unnecessary expense, aircraft damage, and operational disruption for glider-tow operators.

Conclusion

For the reasons stated above, Sugarbush Soaring Association strongly supports the recommendations set forth by the Soaring Society of America. We respectfully urge the FAA to incorporate those findings into the final AD by recognizing the fundamentally different operational profile of Piper Pawnee aircraft used exclusively for glider towing, adopting non-destructive borescope inspection methods, and establishing inspection intervals and applicability criteria that are commensurate with demonstrated stress and fatigue exposure.

Thank you for the opportunity to comment on this NPRM and for considering the operational realities of glider-tow operators while maintaining aviation safety.

Respectfully submitted,

Tom Anderson

To view this discussion visit https://groups.google.com/d/msgid/rasprime/224c9b16-535d-453f-8e2a-7b787780c6efn%40googlegroups.com.

[Brian Nightingale]

Hi Guys ,

                   A little more information on this .SSA is not the only one working on this . A DER has been hired by a club to address this issue . A prominent aviation attorney has also been retained in this matter. Also , several professional Aeronautical Engineers from a major Aircraft manufacturer are also actively working the issue and addressing these with the FAA . We're not alone , and there is more going on with this than most realize . If I receive any more information , I'll pass it along . Don't panic yet!!

[John Godfrey (QT)]

Are the identities of these folks some type of state secret?

Imagine if there was actual collaboration.

 

 

John Godfrey (QT), CFI-G, SSAI

International Gliding Commission (IGC), Alternate USA Delegate

+1 412 759 5145 Mobile

mailto:quebec...@gmail.com

 

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[Brian Nightingale]

I don’t post peoples names without permission. I’ll ask if they mind if you contact them

Sent from my iPhone

On Dec 23, 2025, at 11:58 AM, John Godfrey (QT) <quebec...@gmail.com> wrote:



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[Tom Higgins]

A little Christmas gift from Argentina: well at least a stocking stuffer,

Everyone needs to read this proposed revision from LAVIASA to SB 25-57-11. It has some good changes to it, like removing the recurring eddy current inspection and making it just required just for the initial. It also revises the intervals, but not quite like what we feel should be adequate, but better than every 100 hours.

The other thing is that it gives allowances for a country’s regulatory authority to consider AMOCs.

LAVIASA submitted this as a comment to the NPRM so the FAA will have no choice but to consider this and will most likely rewrite the AD, which, in turn, should delay the release.

Not the perfect answer to the problem, but it definitely will help SSA and the individual operator looking for an AMOC.

Merry Christmas everyone

[Bill Tisdale]

Tom, thanks for that notice on the revised SB. It would be nice if that went final publicly before the Comment Period for the FAA NPRM expires. I'm sure Ken Sorenson and Team have a copy?

Bill

[Larry Ruggiero]

It’s getting better, however l don’t agree with the repetitive removal and replacement of the leading edge screws. The boroscopy itself should be able to show whether there are extra holes or misdrilled holes, if you’re expected to see cracks and other faults in the flanges to begin with. Maybe in conjunction with the initial one-time eddy current inspection, but not after that. When I made an initial exam of our wing through 6” inspection holes already installed, I could see the flanges well enough to tell. Repetitively replacing those screws is inviting more problems and could ultimately slop out the holes. I still think $1500 per set of those inspection plates is ridiculous, however, and they’re more difficult to retrofit than the already PMA’d Piper spec’d rectangular covers Univair sells much cheaper.

Larry Ruggiero

[Tom Higgins]

Agreed Larry. It’s not perfect.

On page 11, Acceptance and Rejection Criteria, it does read as if the LAVIASA has opened the door for the approval of AMOCs, in-spite

of their official stance.

So maybe SSA can make that part of their AMOC

Tom

[John Godfrey]

The complete SSA response is now available at 
https://www.ssa.org/proposed-nprm-the-ssa-responds/?_kx=_zBvJhT4UGZW3HRFswT41yGsK-c2Vwj05-vgwgTGwlY.WFNpes

A very credible effort. Thanks to all involved.

[Brian Nightingale]

Gentleman , 

                     As I mentioned in an earlier post , other efforts to address the NRPM for PA-25 aircraft have been undertaken. I’m attaching a letter from Treasure Coast Soaring member Doug Eastman . Doug’s credentials speak for themselves, and this is the best response I’ve seen to this issue . Other efforts are still underway to address this issue

[Bud Shaw]

Perhaps the use of “significantly” and substantial” and even “greater” and “lower” or other words of comparison could be supported by actual data subjected to statistical analysis.  Do we know the actual g-forces involved and how much they differ between towing gliders and crop dusting such that we could include an analysis?  One’s intuition suggests it’s much different, but numbers beat best guesses.   

Bud Shaw

13232 N River Dr

Omaha NE 68112-3618

+1 (402) 455-1581

https://bit.ly/35CqCke

On Dec 30, 2025, at 18:06, Brian Nightingale <aaaseptic...@gmail.com> wrote:



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<PA25 NPRM REPLY.pdf>

[Ronald Gleason]

If you have read the response by the SSA you should as it includes the numbers you are asking about.  The numbers are in Exhibit B

https://www.ssa.org/proposed-nprm-the-ssa-responds/ 

[Brian Nightingale]

As I mentioned, Doug’s qualifications speak for themselves. He is a structural specialist with many years of experience at a major manufacturer. Further information will be forthcoming when the DER working on this releases his report. It doesn’t take 22 pages to point out that this is a knee jerk reaction by a company trying to limit future liability claims . This letter does exactly what it needs to do . Point out the erroneous conclusions in the proposed AD , and addresses the real issue , which is shoddy maintenance and pilot error . 

To view this discussion visit https://groups.google.com/d/msgid/rasprime/1AD667E3-BDC4-4451-9AFF-DF77A6601348%40gmail.com.

[David S]

If this has not yet gone to the FAA, Doug Eastman might want to make one minor correction:  his name is misspelled at the bottom of his document (the "s" is missing in "Eastman").

   ...david