Cracks in Wing Skins

Ted

Ted

The pilot formerly known as Twin Engine Ted
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The Aztec is going through annual now. In the process, on the left wing they have found one line of rivets forward of the wing spar has several small cracks. You can see the line where the stresses have been placed going from the spar forward.

Every other line of rivets on the left wing also shows these stress lines. The right wing forward of the wing spar shows these stress lines, although not as severely, and aft of the wing spar looks just fine. The plane has been flown through severe turbulence on multiple occasions, at least under my ownership. A DER has been enlisted to get his opinion on the cracks and a repair for them.

From the experience of the A&Ps on the board, do you consider cracks of this sort on wing skins to be big problems or easily fixable? I am concerned with the structural integrity of the wings at this point. My A&Ps have been quick to point out that Aztecs are not known for wings falling off. I also have no desire to be the first, and also don't want to sell someone else a deathtrap. I'd rather scrap it if that's the case. What I am additionally concerned about is the condition of the wing spar and other structural components.

Thoughts appreciated.
 
actual cracks in the aluminum or paint? I'd be concerned (as you are) if actually looking at a problem with the skin. Piper will probably be concerned too.
 
tonycondon said:
actual cracks in the aluminum or paint? I'd be concerned (as you are) if actually looking at a problem with the skin. Piper will probably be concerned too.
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The aluminum. There are cracks in the paint in other locations. As I said, you can see stress areas where I expect more cracks in the aluminum to surface.

The airframe has about 10,000 hours on it.
 
Ted DuPuis said:
The Aztec is going through annual now. In the process, on the left wing they have found one line of rivets forward of the wing spar has several small cracks. You can see the line where the stresses have been placed going from the spar forward.
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Not to borrow trouble but it were discernable did you fly an unairworthy aircraft?

I am not qualified to answer your question.

IOW, while there is valuable and substantiated opinion gotten from this board, shut about about it and go with your source.
 
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Ted DuPuis said:
The Aztec is going through annual now. In the process, on the left wing they have found one line of rivets forward of the wing spar has several small cracks. You can see the line where the stresses have been placed going from the spar forward.

Every other line of rivets on the left wing also shows these stress lines. The right wing forward of the wing spar shows these stress lines, although not as severely, and aft of the wing spar looks just fine. The plane has been flown through severe turbulence on multiple occasions, at least under my ownership. A DER has been enlisted to get his opinion on the cracks and a repair for them.

From the experience of the A&Ps on the board, do you consider cracks of this sort on wing skins to be big problems or easily fixable? I am concerned with the structural integrity of the wings at this point. My A&Ps have been quick to point out that Aztecs are not known for wings falling off. I also have no desire to be the first, and also don't want to sell someone else a deathtrap. I'd rather scrap it if that's the case. What I am additionally concerned about is the condition of the wing spar and other structural components.

Thoughts appreciated.
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With the price of twins these days that's probably an option.

Does Piper even have a structural repair manual for the Aztec?
 
Rotor&Wing said:
Get the DER involved. He will have much more expertise in this than the run of the mill A&P.
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Well, the good ol run of the mill A&P can replace the skins and call it a replacement, and log it as such. The DER will design a repair, and devalue the aircraft with a major structural repair, and 337 to prove it.
 
Tom-D said:
With the price of twins these days that's probably an option.

Does Piper even have a structural repair manual for the Aztec?
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If I had to bet the MM refers you to the 43-13. Worst case I'd price a Williams wing repair, probably spendy but you might still come out ahead of scrapping.

FWIW harbor freight and Costco both have good inexpensive video scopes that can be most helpful with inspecting the inside of the wing.
 
Skylane81E said:
If I had to bet the MM refers you to the 43-13. Worst case I'd price a Williams wing repair, probably spendy but you might still come out ahead of scrapping.

FWIW harbor freight and Costco both have good inexpensive video scopes that can be most helpful with inspecting the inside of the wing.
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It does have a MM that may have a structures section in it. Plus the illustrated parts break down has the skin part number, you can order them from the factory, that makes it a simple skin replacement. and no DER or 337 required.
 
Take it apart and look around inside first before buying anything. Get required info, then make decision.
 
Replacing wing skins is no big deal, just time consuming. You can use the old skin as a pattern. A good A&P can set you up, or have him do the work.
 
Geico266 said:
Replacing wing skins is no big deal, just time consuming. You can use the old skin as a pattern. A good A&P can set you up, or have him do the work.
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why would you want to use the old stressed wrinkled skin as a pattern when you can buy new skins from Piper?

First thing I would do is get an eddy current tester and find all the cracks and mark them. then call Piper tech center and see if it's airworthy as is.

""Technical Product Support
The Technical Product Support Specialists at the factory are directly responsible for field technical support of our products. On behalf of the field service facilities, they interface with Engineering, Manufacturing, Quality Assurance, Purchasing, the FAA, our suppliers and other departments on individual technical matters. While their hours of operation at the factory are 7:30 AM to 4:30 PM EST, they are on call after hours for emergency AOG support and can be reached by calling Piper’s Worldwide Customer Care line 1-877-879-0275, Option #3 then 2273 (CARE)."""
 
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Tom-D said:
Well, the good ol run of the mill A&P can replace the skins and call it a replacement, and log it as such. The DER will design a repair, and devalue the aircraft with a major structural repair, and 337 to prove it.
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Tom-D said:
It does have a MM that may have a structures section in it. Plus the illustrated parts break down has the skin part number, you can order them from the factory, that makes it a simple skin replacement. and no DER or 337 required.
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When one is talking about skin cracks in a wing area it could be something else within the structure working. Using your (half-a$$) method you advocate just riveting a new skin on and calling it good. :nonod:


Tom-D said:
why would you want to use the old stressed wrinkled skin as a pattern when you can buy new skins from Piper?

First thing I would do is get an eddy current tester and find all the cracks and mark them. then call Piper tech center and see if it's airworthy as is.

""Technical Product Support
The Technical Product Support Specialists at the factory are directly responsible for field technical support of our products. On behalf of the field service facilities, they interface with Engineering, Manufacturing, Quality Assurance, Purchasing, the FAA, our suppliers and other departments on individual technical matters. While their hours of operation at the factory are 7:30 AM to 4:30 PM EST, they are on call after hours for emergency AOG support and can be reached by calling Piper’s Worldwide Customer Care line 1-877-879-0275, Option #3 then 2273 (CARE)."""
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So do you think Piper is going to make a determination over the telephone??

Ted's smart enough to realize that something else might be at play here and getting an expert opinion before proceeding is the smart way to go in both potential repairs and liability. It could be something minor such as loose skin rivets allowing the skin to fret and crack or it could be something much greater.
 
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The obvious issue in this case is that the aircraft is old, and the cost of doing any sort of major investigation and repairs is likely going to result in a significant portion of its value. Were it still the only aircraft at my disposal and I was intending on keeping it forever, it would be logical to investigate this further and potentially commit to some expensive repairs. In my case, this will probably not make sense. Especially since I can easily pull off the engines, props, avionics, boots, and Janitrol to sell myself, and then sell or give the remaining hull to the A&P school in the building next to where it currently is sitting.

We are waiting to hear back from the DER, and will proceed from there.
 
Rotor&Wing said:
When one is talking about skin cracks in a wing area it could be something else within the structure working. Using your (half-a$$) method you advocate just riveting a new skin on and calling it good. :nonod:

My Half A$$ed method allows you to inspect the interior of the wing.

So do you think Piper is going to make a determination over the telephone??

Probably would get a dialog started, if nothing else

Ted's smart enough to realize that something else might be at play here and getting an expert opinion before proceeding is the smart way to go in both potential repairs and liability. It could be something minor such as loose skin rivets allowing the skin to fret and crack or it could be something much greater.
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either way, that skins is coming off and being replaced, Why would you recommend a patch and all the approval process when it is much better as a replacement.

Typical FAA thinking (we must be involved)
 
Ted DuPuis said:
The obvious issue in this case is that the aircraft is old, and the cost of doing any sort of major investigation and repairs is likely going to result in a significant portion of its value. Were it still the only aircraft at my disposal and I was intending on keeping it forever, it would be logical to investigate this further and potentially commit to some expensive repairs. In my case, this will probably not make sense. Especially since I can easily pull off the engines, props, avionics, boots, and Janitrol to sell myself, and then sell or give the remaining hull to the A&P school in the building next to where it currently is sitting.

We are waiting to hear back from the DER, and will proceed from there.
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I'd like to see pictures.

there is a Aztec 250 D setting in the big hangar at OKH that is in pretty good condition, it has a good airframe, but has not been flown in a few years.

It could be the replacement parts you need. It belongs to Pete Morgan, the airport manager see airnav.com to get his info.
I have not seen the aircraft in a while, but I'll bet it could be ferried with little work.
 
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Tom-D said:
either way, that skins is coming off and being replaced, Why would you recommend a patch and all the approval process when it is much better as a replacement.

Typical FAA thinking (we must be involved)
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Please show in my post where I recommend doing a patch.
 
Let'sgoflying! said:
how much would a used, serviceable wing cost after install and painting?
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That's a very good Idea. I'd think that Wentworth has one right there in Minn.

That would be cheaper than any repair, even with a proper strip and paint.

I wonder if both wings are involved?
 
Rotor&Wing said:
Please show in my post where I recommend doing a patch.
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That is what a repair is. Other wise known as a alteration to design. requiring all the approval process.

that is what DER's do, design modifications.
 
Tom-D said:
That is what a repair is. Other wise known as a alteration to design. requiring all the approval process.

that is what DER's do, design modifications.
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Tom, not sure why you are all worked up about this, but what ever. Wing skins cracking at rivet lines is not uncommon. Replacing wing skins is not uncommon. This is why I prefer experimental aircraft. Vans wing skins are 1/4 of the cost of certified and they are prepunched and a perfect fit every time. I've replaced damaged wing skins using the old ones are a pattern with no problems at all except the normal fabrication process.

Cracked skins is not necessarily an indication of a structural problem in the wing, it is more than likely an indication of the skin reaching it's " flexing life" limit. To condem the wing to beer cans before pulling the skin off is premature and wastefull IMHO.

Replacing the wings? :eek: Way too early to be discussing that.
 
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And having a DER look at it to say "look further" or "scrap it" is a good idea. At this point the DER is really just acting as a subject matter expert and giving advice about whether it makes sense for Ted to go further or start salvaging it.
 
Tom-D said:
That is what a repair is. Other wise known as a alteration to design. requiring all the approval process.

that is what DER's do, design modifications.
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Difference between a repair and a patch. You're twisting words (which is becoming very typical in your postings)
 
Geico266 said:
Tom, not sure why you are all worked up about this, but what ever. Wing skins cracking at rivet lines is not uncommon. Replacing wing skins is not uncommon. This is why I prefer experimental aircraft. Vans wing skins are 1/4 of the cost of certified and they are prepunched and a perfect fit every time. I've replaced damaged wing skins using the old ones are a pattern with no problems at all except the normal fabrication process.

Cracked skins is not necessarily an indication of a structural problem in the wing, it is more than likely an indication of the skin reaching it's " flexing life" limit. To condem the wing to beer cans before pulling the skin off is premature and wastefull IMHO.

Replacing the wings? :eek: Way too early to be discussing that.
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Worked up?? not really, simply giving my opinion as always.
 
Rotor&Wing said:
Difference between a repair and a patch. You're twisting words (which is becoming very typical in your postings)
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A Patch is a repair, a repair can be a patch. do you believe a DER will design a skin replacement? what do they get paid for ?

A little common sense goes a long way, I'd like to know what the A&P-IA said about the cracks? what will they sign off? After all, they are the ones that will be required to sign block 7 on the 337. and the log book for the annual.

Yes I know a DER can sign the 337, but many don't because they are not there when the work is done.
 
PICs!

I'm not a rated mechanic but I stayed at a holiday inn express last night and I reckon that the wing internal structure can flex farther without damage than the skin.

Of course I would not just slap new skin on it without further inspection.
 
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Tom-D said:
I'd like to see pictures.

there is a Aztec 250 D setting in the big hangar at OKH that is in pretty good condition, it has a good airframe, but has not been flown in a few years.

It could be the replacement parts you need. It belongs to Pete Morgan, the airport manager see airnav.com to get his info.
I have not seen the aircraft in a while, but I'll bet it could be ferried with little work.
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...at which point I've spent more money than I would gain at sellable value vs. scrap value.

No, that isn't worth doing. At least not for me.

No word from the DER yet.
 
Rotor&Wing said:
Not with you apparently.......
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Calling the folks who made the aircraft seems to be the common sense lost on you.

Which would you think would be the most likely to say "yes we've seen that before here is how we fixed it" the Factory or a DER ?
 
Tom-D said:
Which would you think would be the most likely to say "yes we've seen that before here is how we fixed it" the Factory or a DER ?
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Well, let's see. Cessna is going around trying to AD all the Twin Cessnas out of existence. I can see Piper saying "We'll fix your problem! We'll just AD your plane out of legality, and you can buy a new Seneca V."
 
Ted DuPuis said:
Well, let's see. Cessna is going around trying to AD all the Twin Cessnas out of existence. I can see Piper saying "We'll fix your problem! We'll just AD your plane out of legality, and you can buy a new Seneca V."
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well a call would tell. they do know there product best. and I've never heard that tech support being in the sales before.
They do still sell parts and manuals why would they want the bad press?

I really don't do Piper much, but your A&P-IA doing the annual should have the MM and structural repair section that should tell how the skins are replaced, If it is any thing like Cessna, it will say place the wing in a fixture and preload before removal.. If ,, IF that is the case you are in deep Doo Doo. because they are not easy to find.

I'd be reading the manual really well, that is the clue as to how you fix the wing.
 
Last time I called piper they told me that new piper never made a Seneca II.

Muncie aviation might be a good call as might Williams airmotive.
 
Heard back from the DER yesterday. The fix will be simple and inexpensive. We are going to repair the plane and return it to airworthy status, at which point I will finish prepping it for sale and the official sales work will begin. There are no major structural issues, this is just the result of fatigue on the skins.

I'm rather relieved at the results. I didn't want to scrap the plane, but also wasn't going to spend a bunch of money on a major repair to a plane that's over 40 years old and not worth a tremendous amount.
 
Ted DuPuis said:
Heard back from the DER yesterday. The fix will be simple and inexpensive. We are going to repair the plane and return it to airworthy status, at which point I will finish prepping it for sale and the official sales work will begin. There are no major structural issues, this is just the result of fatigue on the skins.

I'm rather relieved at the results. I didn't want to scrap the plane, but also wasn't going to spend a bunch of money on a major repair to a plane that's over 40 years old and not worth a tremendous amount.
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Now that we all know the Aztruck has some "issues" I would like to help you out by buying the plane that has fatigue cracks in it... My offer is 2,465.28.. delievered to Jackson Hole and it must have the tanks topped off before I pay you.:yesnod::yesnod::yikes::D...


Jus kiddin......:rofl::rofl::rofl::rofl:

I would be willing pay 2,466.00 even.:)

Ben ( :stirpot: ) Haas.
 
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