Possible new AD for Piper PA28's

Your typical AP/IA isn’t going to have the equipment nor certification to perform this AD so in that regard it’s a bit unusual although it looks that by the convoluted bizarre formula they have devised to calculate “factored service hours’ you’re going to have a very high time Cherokee before you ever have to worry about it. Just don’t ever lose your logbooks.
 
Silvaire said:
Your typical AP/IA isn’t going to have the equipment nor certification to perform this AD so in that regard it’s a bit unusual although it looks that by the convoluted bizarre formula they have devised to calculate “factored service hours’ you’re going to have a very high time Cherokee before you ever have to worry about it. Just don’t ever lose your logbooks.
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Really? They just found a Warrior with this issue and sent a wing out for a repair at my flight school. No special equipment was required.
 
Glad cooler heads prevailed. Good on the FAA for assigning a higher weight to aircraft in training fleets. 100 hours inspection as a metric isn't the end all be all,but I'll take it. Oh and Eff Embry Riddle and their socializing losses shtick.

Eddy current inspections are currently done for the prob hub on non-suffix Hartzells. It's pretty simple and portable equipment. Eddy current inspections are not onerous at all. Really the cheapest and simplest of NDIs beyond the good ol' shade tree "TLAR" pencil whip check :D

At any rate, for my never-a-trainer "high time" Arrow, this is another AD C/W by N/A in the books. #winning.

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Clip4 said:
Really? They just found a Warrior with this issue and sent a wing out for a repair at my flight school. No special equipment was required.
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I suppose if you see a crack with your naked eye well that’s that but to sign it off as having no cracks you’d have to use an eddy current tester and have a level 2 NAS 410 certification. At least that’s what the AD says.
 
Silvaire said:
I suppose if you see a crack with your naked eye well that’s that but to sign it off as having no cracks you’d have to use an eddy current tester and have a level 2 NAS 410 certification. At least that’s what the AD says.
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There are mobile people with that equipment.
 
Obviously it's going to be a wide range, but can anyone (maybe our A&P's/IA's out there) put a ballpark price on this? Just trying to budget for buying one.
 
Silvaire said:
Your typical AP/IA isn’t going to have the equipment nor certification to perform this AD
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Show me where the AD says it must be accomplished by a certified person?

OK I see it,
C. Personnel Qualifications

Personnel doing the eddy current inspection must have NAS 410 Level II or Level III certifica t io n.

I see the costs rising
 
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kgruber said:
The VAST majority will not have to be tested.
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Right on,, most of the non-training fleet don't have 5000 hours. But the way this is written says that we must re-compute at each annual or 100 hours.
so the way I read it, this is a reoccurring AD at each 100 hours or annual.
 
It might end up being that way, but the AD as currently written in that document is merely an interim action looking for data. What people care about is the inspection side of the thing. That's what costs money and labor. A "recurring EC inspection" evolution of this AD is facts not in evidence right now, however natural it may be to assume that would be what the superseding version of this AD will look like in the end.

If such a recurring EC inspection requirement is made, it will definitively favor the non-100hr in their history (with complete logbook) PA28s for sure, on a resale basis. Good news for me. Guess I'll be able to add another carrot to the stick in order to facilitate getting rid of this thing after all. People with high "factor time" spars are screwed on this exchange, again on a resale basis.

Now, having to do a recurring EC inspection would give me pause on two fronts:

(1)it's a logistics PITA, if the prop hub EC inspection on my Arrow is any indication. It's not the cost, but having to schlep the airplane around or pay a premium to have the guy drive to your prop to run the probe every 100 hours gets annoying. The inspection itself is not expensive. Neither would be this one on the spar, except....

..(2) and most importantly, this inspection is destructive in my book, because it requires people to physically mess with that spar bolt area. That's a no-go for me. Just like the comanche tail horn torque tube AD, this will lead to maintenance-induced cracking, which defeats the purpose the inspection was supposed to guard against in the first place. NO way I own an airplane where the FAA tells me Joe bag o donuts AP is supposed to unbolt my spar joints every 100 hours or every annual, and I get to eat a whole spar when they hamfist that spar bolt holes for the 5th or 6th time. Just like we let the roofer insurance ambulance chaser walk up to your roof with cleats and pinball hammer on and he never finds damage right? :rolleyes:

If you could EC or dye inspect the thing without touching the bolts, cool. Examples that come to mind are the wide body 210s I'm looking at with the improved, no-replacement-required-every-1000hr saddles, which merely get dyed in place every annual but don't get touched otherwise. The Beech 33/35 spar web dye inspection is another one. But unbolting and re-assembling bolt on spar joints every annual just to EC it? Hell no, I won't own a plane like that. It's a spar replacement being created by proxy, and I don't do manufactured demand, never mind is not in the interest of mine and my family's safety of flight.
 
From the Federal Register: https://www.federalregister.gov/d/2018-27577/p-53

"(3) An example of determining factored service hours for an airplane with no 100-hour inspections is as follows: The airplane maintenance records show that the airplane has a total of 12,100 hours TIS, and only annual inspections have been done. Both main wing spars are original factory installed. In this case, N = 0 and T = 12,100. Use those values in the formula as follows: (0 × 100) + [12,100−(0 × 100)]/17 = 711 factored service hours on each main wing spar."

Therefore, since my '69 Arrow has never had 100 hour inspections and is now showing 3670 hours TIS, I calculate the "factored service hours" to be (0 x 100) + [3670-(0 x 100)]/17 = 216. Since I fly about 70-80 hours/year and I am just over 75 years old now I could fly for another 64 years!!!
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FAT CHANCE!!!
 
Arrow76R said:
From the Federal Register: https://www.federalregister.gov/d/2018-27577/p-53

"(3) An example of determining factored service hours for an airplane with no 100-hour inspections is as follows: The airplane maintenance records show that the airplane has a total of 12,100 hours TIS, and only annual inspections have been done. Both main wing spars are original factory installed. In this case, N = 0 and T = 12,100. Use those values in the formula as follows: (0 × 100) + [12,100−(0 × 100)]/17 = 711 factored service hours on each main wing spar."

Therefore, since my '69 Arrow has never had 100 hour inspections and is now showing 3670 hours TIS, I calculate the "factored service hours" to be (0 x 100) + [3670-(0 x 100)]/17 = 216. Since I fly about 70-80 hours/year and I am just over 75 years old now I could fly for another 64 years!!!
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FAT CHANCE!!!
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Only an airplane with a main wing spar that has a factored service life of 5,000 hours,
 
It's ironic, because if they do settle on a final rulemaking that requires recurring unbolting and inspection of the boltholes in question, at whatever interval they decide in the end, this will further pick on aging structures that otherwise would have been fine if not for the constant damage done by the disassembly. Whereas samples not affected by the AD due to low "factor" time will soldier on without accelerated damage, in effect making the aged structures perform even worse by comparison. Talk about confirmation bias.

But I'm gonna give the FAA some elbow room here. There's a chance they get all the data and realize it's not a problem, and end up not requiring recurring inspection beyond the already ridiculously high amount that part 23 allowed for as part of certification in the first place. I believe in the case of the PA-28 it was something like 40,000 hours for non-trainer use. Hell the PA-44 wing spar is limited at like 14,663, which seems lowly by comparison.

The second irony is that this all started because of greedy Embry Riddle beating up an Arrow without oversight until they killed two people, and now the make and model in question is no longer a relevant piece to the flight training market by virtue of the changes in ACS. So it's literally a moot point now. You can't make this stuff up.
 
hindsight2020 said:
... this all started because of greedy Embry Riddle beating up an Arrow without oversight until they killed two people, and now the make and model in question is no longer a relevant piece to the flight training market by virtue of the changes in ACS. So it's literally a moot point now. You can't make this stuff up.
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What oversight was required that wasn't given? And why are they greedy? I charge for my services.
 
kgruber said:
I think that is brilliant, and have not seen it before.
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+1. I think they're trying to put a "cycle" value to the spars similar to landing cycles, pressurization cycles, and start/run cycles on other aircraft. If this becomes a future trend will definitely make complete aircraft history an important commodity. Will be interesting to read the comments in the NPRM docket as this plays out.
 
What just happened to the value of the PA-28s that do not have complete records?
 
Tom-D said:
What just happened to the value of the PA-28s that do not have complete records?
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I think that will totally depend on what the superceding version of this AD ends up looking like, wrt to what kind of interval they'll mandate the EC inspection to be conducted going forward.
 
Tom-D said:
What just happened to the value of the PA-28s that do not have complete records?
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I don't know about the value at this point, but I'd say the resale market for a PA-28 with 5000hrs just evaporated until at least March.
 
This is how I read it also. I think the FAA took those high cycle flight school planes and are attempting to factor in the added training abuse. The average owner that goes and flies does not pile on take off and landings. I think at times when training I landed upwards of 8 times in an hour. What owner does that?

I do wonder where they came up with the equation. That plane that failed I believe had around 7200 tt. If it was always subject to 100 hr inspections that would in theory mean it had at 72 of them. So the equation for that plane is (72 × 100) + [7200 - (72 × 100)]/17 = 7619 slightly rounded.

So the equation basically means always flight school planes that have always had 100 hr inspections will be subject to this inspection starting at around 5000 hrs tt and 50 x 100 hr inspections. The equation clearly weight commercial use as the largest risk factor. All private planes are basically excluded.

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drotto said:
This is how I read it also. I think the FAA took those high cycle flight school planes and are attempting to factor in the added training abuse. The average owner that goes and flies does not pile on take off and landings. I think at times when training I landed upwards of 8 times in an hour. What owner does that?

I do wonder where they came up with the equation. That plane that failed I believe had around 7200 tt. If it was always subject to 100 hr inspections that would in theory mean it had at 72 of them. So the equation for that plane is (72 × 100) + [7200 - (72 × 100)]/17 = 7619 slightly rounded.

So the equation basically means always flight school planes that have always had 100 hr inspections will be subject to this inspection starting at around 5000 hrs tt and 50 x 100 hr inspections. The equation clearly weight commercial use as the largest risk factor. All private planes are basically excluded.

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Not quite. Don't forget airplanes with incomplete logs, or airplanes with wing spar replacement. There's plenty o' PA-28 variants that resemble that remark in non-flight school hands. Ditto for prior trainer airplanes with applicable factor service life, now on private hands.

As I mentioned before and on the Piper board, the real interesting thing will be what the final AD, after this data-gathering AD gets done sending data to the FAA, will look like. Removing and replacing those bolts every time the FAA says you have to EC inspect the spars, is gonna be a big deal for those affected airplanes. That's too destructive for my taste, especially in the context of checking for cracking in the first place. Talk about manufactured demand. I wouldn't own one. Too destructive, in too an important component, and too expensive to replace once maintenance is done inducing the crack in the first place by unnecessarily fiddling with that joint, then looking at the owner and telling me "it was like that when we got to it". You mean after the umpteenth time you fiddled with it? Yeah, copy that :rolleyes:. I ain't playing that game, not with components as economic non-starter and labor intensive as a fregging wing spar, and not with my family cruiser.

I think, if the FAA retains the same level of nuance as they did with this proposed interim data gathering action, they'll end up setting up a much less invasive recurring inspection schedule for the affected airplanes. Otherwise they've just killed the PA-28 trainer market, and imo create a more hazardous environment by proxy for the very airplanes they think are the most vulnerable for spar failure in the first place. Talk about "the road to hell is paved with good intentions".

But none of that has happened yet. So we will wait and see. Sure, as an owner of an original spars, full log Arrow with zero 100hr inspections, I'm glad to be excluded from the melee. That's a surprising display of nuance on the part of the FAA. Credit where credit is due. I'll reserve final judgement until the superseding AD is released; they still have an opportunity to pry buffoonish FAA outcomes from the jaws of nuanced victory. :D
 
Out of curiosity, I own a PA32R- 301. I noticed the AD applies to PA32's with the 300 designation but not the 301's. What changed?

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drotto said:
Out of curiosity, I own a PA32R- 301. I noticed the AD applies to PA32's with the 300 designation but not the 301's. What changed?

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There actually are no PA32R on the list.
 
Heftiger said:
There actually are no PA32R on the list.
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I noticed that. Was something changed or the use of the 32R's was deemed different enough ( not used for training) that it is not seen as an issue?

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drotto said:
I noticed that. Was something changed or the use of the 32R's was deemed different enough ( not used for training) that it is not seen as an issue?

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Odd since the 28R is on there (of course, since its one of the aircraft that spurred the AD), but I don’t know enough about the attach structures to know if there’s a difference. Somebody suggested it was accidentally left out and would be added before it was finalized. *shrug*
 
drotto said:
Out of curiosity, I own a PA32R- 301. I noticed the AD applies to PA32's with the 300 designation but not the 301's. What changed?
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My bet is that it is an oversight. But who knows?
 
I've always loved Piper for various reasons. They have a great product offering, have stayed true to their focus on the GA market (their tent at OSH was excellent) and their planes fly great. For a "slow" trainer they're very comfortable cross county machines and would make a great plane to own privately (and they actually aren't that slow, I could usually coax a few more knots out of a Piper than a Skyhawk). Back when I was renting I would always take the PA28-181 over the 172 or 182 if I had the choice.. BUT, this whole nonsense with the wingspar has really shaken me

5,000 hours is not a lot. Take your typical rental fleet 1972 PA28.. that is 14,600 days old, or a little less than 3 hrs of flight per day to get to 5,000.. I bet most busy club fleets put a lot more than an average of 3 hrs per day on their planes. Heck, even a privately owned plane flying a modest 100 hrs per year is going to be getting near that 5,000 mark... The popular Pipers in our club fly 50-100 hrs per month.. so I bet this does actually effect a large number of airframes, at least for schools and rental fleets

I was always under the impression that airframe fatigue lifespans are designed to operate within their envelope, but at the worst possible end of the envelope.. IE, at max gross, getting jostled at maneuvering speed. I wouldn't consider an aircraft operating in its design envelope to be experiencing lots of "abuse" .. plus, aren't most flight school planes typically flown with an instructor on board? Landings, steep turns, etc., should be flown per the ACS standards.. a plane taking off and landing, even if doing that a few dozen times a day, shouldn't be considered "abusive" - most student landings aren't great, but are they abusively damaging?

And, if training planes really do get all this abuse, then why no systemic wing fatigue issues with the Cessna and SR20 fleets. I believe there are more 172 flying than PA28 and those 172 get just as much abuse from their clubs.. A Skyhawk technically has many more failure points for a wing... the upper and lower attachment points of the struts, the wing section by the struts, and the wing attachment point at the fuselage.. that's 8 points of potential failure for the airframe's wings

I'm disappointed
 
Tantalum said:
5,000 hours is not a lot. Take your typical rental fleet 1972 PA28.. that is 14,600 days old, or a little less than 3 hrs of flight per day to get to 5,000.. I bet most busy club fleets put a lot more than an average of 3 hrs per day on their planes.
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I used to be good at math but you lost me. Do you mean 3 hrs per week?
 
drotto said:
I do wonder where they came up with the equation.
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The docket references an AC and several SBs as the basis for developing the new AD calculations. The 5000hr limit appears to come from previous wing separation data via SB886/SB978A which also includes an attempt to classify aircraft ops types. Both SBs discuss the same incident yet are 7 to 11 years apart. There are a few other items they address in the docket but these seem the most relevant.

AC23-13A
http://rgl.faa.gov/Regulatory_and_G...5127d66408625708c00710ba4/$FILE/AC 23-13A.pdf
SB886
https://bsd-box.net/~mikeg/N8031W/SB_SL/SB_0886.pdf
SB978A
https://bsd-box.net/~mikeg/N8031W/SB_SL/SB_0978.pdf
 
Tantalum said:
I've always loved Piper for various reasons. They have a great product offering, have stayed true to their focus on the GA market (their tent at OSH was excellent) and their planes fly great. For a "slow" trainer they're very comfortable cross county machines and would make a great plane to own privately (and they actually aren't that slow, I could usually coax a few more knots out of a Piper than a Skyhawk). Back when I was renting I would always take the PA28-181 over the 172 or 182 if I had the choice.. BUT, this whole nonsense with the wingspar has really shaken me

5,000 hours is not a lot. Take your typical rental fleet 1972 PA28.. that is 14,600 days old, or a little less than 3 hrs of flight per day to get to 5,000.. I bet most busy club fleets put a lot more than an average of 3 hrs per day on their planes. Heck, even a privately owned plane flying a modest 100 hrs per year is going to be getting near that 5,000 mark... The popular Pipers in our club fly 50-100 hrs per month.. so I bet this does actually effect a large number of airframes, at least for schools and rental fleets

I was always under the impression that airframe fatigue lifespans are designed to operate within their envelope, but at the worst possible end of the envelope.. IE, at max gross, getting jostled at maneuvering speed. I wouldn't consider an aircraft operating in its design envelope to be experiencing lots of "abuse" .. plus, aren't most flight school planes typically flown with an instructor on board? Landings, steep turns, etc., should be flown per the ACS standards.. a plane taking off and landing, even if doing that a few dozen times a day, shouldn't be considered "abusive" - most student landings aren't great, but are they abusively damaging?

And, if training planes really do get all this abuse, then why no systemic wing fatigue issues with the Cessna and SR20 fleets. I believe there are more 172 flying than PA28 and those 172 get just as much abuse from their clubs.. A Skyhawk technically has many more failure points for a wing... the upper and lower attachment points of the struts, the wing section by the struts, and the wing attachment point at the fuselage.. that's 8 points of potential failure for the airframe's wings

I'm disappointed
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But you have to look at how heavily that equation is tilted to the 100 hr inspections. A personal plane never getting 100 hr inspections is 85,000 hrs. What plane is ever going to hit that? I know that many PA28's have some 100 hr checks. I would be curious what the average is? If you say the average PA28 has say 25 of those and 5000 tt. But now with a private owner. (25 × 100) + [5000 + (25 × 100)]/17 = 2647 hrs. I know these are a total guess but likely realistic. So yes, it will hit rental fleets and flight schools hard potentially. Most mixed owner type planes will likely be exempt.

How many 100 hr inspections per year does the average flight school get per year? The local private one near me I would say 2 to 3. I big high intensity school likely higher. Let's say the accident plane was completely owner from 0. I think it was an 11 year old plane so 72 ÷11 = 6.5. And that is a very high use school. So a new plane at a local small school would be at least 15 years till it was subject to testing. 50 ÷ 3 = 16.6. So I am not sure how big an issue it is. A small flight school is looking at 15 to 20 years. Big school 7 to 10. Do school routinely keep planes 20 years?

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drotto said:
But you have to look at how heavily that equation is tilted to the 100 hr inspections. A personal plane never getting 100 hr inspections is 85,000 hrs. What plane is ever going to hit that? I know that many PA28's have some 100 hr checks. I would be curious what the average is? If you say the average PA28 has say 25 of those and 5000 tt. But now with a private owner. (25 × 100) + [5000 + (25 × 100)]/17 = 2647 hrs. I know these are a total guess but likely realistic. So yes, it will hit rental fleets and flight schools hard potentially. Most mixed owner type planes will likely be exempt.

How many 100 hr inspections per year does the average flight school get per year? The local private one near me I would say 2 to 3. I big high intensity school likely higher. Let's say the accident plane was completely owner from 0. I think it was an 11 year old plane so 72 ÷11 = 6.5. And that is a very high use school. So a new plane at a local small school would be at least 15 years till it was subject to testing. 50 ÷ 3 = 16.6. So I am not sure how big an issue it is. A small flight school is looking at 15 to 20 years. Big school 7 to 10. Do school routinely keep planes 20 years?

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Exactly, but don't let facts get in the way of those who can't read the difference between airframe hours and "factor" hours get all wound up in a frenzy and call for the grounding of all Cherokees lol.....
 
hindsight2020 said:
Exactly, but don't let facts get in the way of those who can't read the difference between airframe hours and "factor" hours get all wound up in a frenzy and call for the grounding of all Cherokees lol.....
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Can read. And not letting facts get in the way. But ultimately, here is a plane that clearly has issues tolerating the kind of "abuse" it was allegedly designed for. Mind you, flying a plane within its envelope, even if at the edges of it, shouldn't be considered abusive. And I wouldn't call the training at least I received to have been particularly hard on the plane either. I love the Pipers and am dramatically partial to low wings, I have plenty of anti-high-wing rants on this site.. but the fact is that there is obviously some concern out there that the PA28 has some potentially life threatening fatigue issues. Something the abused C172 fleet doesn't apparently face.. and how many heavily used bush and other 182 are out there? Maybe Embry is partly to blame for this through culture, missing the fatigue signs in their wings, etc., but the airframe itself should not be held completely free of blame for this either

Will I continue to rent and fly the PA28 when needed, sure. But am I also a little disappointed in the plane I did all my training in and have formed a bond with. Yes.
 
I know mine has had some 100 hr inspections but I don’t remember them being prolific. I will have to get my flying partner to go through the books for me. I should be ok.
 
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