Corrosion pictures - required treatment?

[German guy]

Today, I shoved my new $26.99 borescope camera into some of of our 172's openings.

Please find attached a few pictures, they are from the right wing, the elevator and the horizontal stabilizer. The level of corrosion seemed to be pretty much same throughout these areas. The left wing and the rear of the fuselage looked slightly better.

What do you think? Is a treatment with CorrisionX or ACF-50 sufficient or is there more that needs to be done?

I also remember that I recently saw a document (by Cessna!?) in which pictures of different stages of corrosion and their treatment were discussed, but can't find it anymore. A link to it would be greatly appreciated.

 

[Jay Honeck]

Are these areas that you can access with a wire brush or some sort of abrasive? If so, I would clean up the areas, wipe it down with Ospho (or something similar that neutralizes corrosion), and spray the area with zinc chromate primer.

Wait a few days for it to really dry, and THEN hit it with CorrosionX.

If you can't access those areas, you may be stuck doing just CorrosionX, but I'm not sure that will stop it. That's a fair amount of corrosion, and you want to knock the chunky-loose stuff off before spraying.

 

[Tom-D]

must have been a Florida aircraft.

I'd disassemble, clean, replace, as required, treat and paint.

When it's gone that far there really is no saving it.

 

[German guy]

Are these areas that you can access with a wire brush or some sort of abrasive? [...]

Sadly no.

must have been a Florida aircraft.

I'd disassemble, clean, replace, as required, treat and paint.

When it's gone that far there really is no saving it.

It indeed lived there for the last few years. To disassemble the affected areas would mean a complete rebuild of pretty much everything, what is not really practicable. If such measures would indeed be necessary, trying to return it to the seller or parting it out would be the only two viable options.

What really frustrates me (I would actually like to use much stronger language here) is that Daytona Aircraft Services in Daytona Beach (they are a Cessna partner) did such a lousy job with the pre-buy inspection. And I thought that it is a good idea to have the seller bring the plane to them, because a Cessna service knows what they are doing. Right...

- They did not find the completely worn torque link bushings
- They did not find the broken spring in the pilot's seat adjustment mechanism
- They confirmed that the GPS installation is IFR legal, however no related 337, no compatible CDI and no annunciation panel existed.
- I asked him (in written, my request was also confirmed in written by him) to particularly look for corrosion. No discrepancies in this regards were however mentioned in his report, he even told me on the phone that besides of a little bit of corrosion on some outside screws, the plane is corrosion free.

A local A&P said that it is not bad, because the corrosion is only on the surface, but that we should treat the plane with CorrosionX.

 

[AKBill]

must have been a Florida aircraft.

I'd disassemble, clean, replace, as required, treat and paint.

When it's gone that far there really is no saving it.

Treated corrosion in the wing of my Beechcraft. Had to drill out and remove trailing edge panels to gain excess. Cleaned, treated and painted. So far it still looks good.

Corrosion X will not fix your problem. As Tom says, "disassemble, clean, replace, treat and paint" .

 

[flyingron]

Even if you could get there with a wirebrush or traditional abrasive paper DON'T DO IT. Corrosion on aluminum should be cleaned up with a non-metal abrasive (i.e., scotchbrite).

Corrosion-X won't "fix" things, but it will slow down the progression.

 

[timwinters]

Hmmm...was the guy who did the prebuy blind or was this not on his list of items to check for? If it was me, I'd be having a pretty serious talk with him.

I hate to say it but this is why I have, when airplane shopping in the past, ignored all of those that were, or had been, residing in coastal areas.

 

[frfly172]

Give it a thorough treatment with corrosion X ,it won't fix the problem,but it will slow it down. It will also protect the areas that aren't affected yet. Be prepared to clean up the seepage on a regular basis.

 

[WhiskeyPapa]

Is this a serious case? Looks like it doesn't go very deep, but what do I know. Would be interested in thoughts of A&Ps with experience in treating. There was minor corrosion found on the plane I'm buying, but my engineer is confident it's of minor significance… can be treated.

 

[N801BH]

Sadly no.




It indeed lived there for the last few years. To disassemble the affected areas would mean a complete rebuild of pretty much everything, what is not really practicable. If such measures would indeed be necessary, trying to return it to the seller or parting it out would be the only two viable options.

What really frustrates me (I would actually like to use much stronger language here) is that Daytona Aircraft Services in Daytona Beach (they are a Cessna partner) did such a lousy job with the pre-buy inspection. And I thought that it is a good idea to have the seller bring the plane to them, because a Cessna service knows what they are doing. Right...

- They did not find the completely worn torque link bushings
- They did not find the broken spring in the pilot's seat adjustment mechanism
- They confirmed that the GPS installation is IFR legal, however no related 337, no compatible CDI and no annunciation panel existed.
- I asked him (in written, my request was also confirmed in written by him) to particularly look for corrosion. No discrepancies in this regards were however mentioned in his report, he even told me on the phone that besides of a little bit of corrosion on some outside screws, the plane is corrosion free.

A local A&P said that it is not bad, because the corrosion is only on the surface, but that we should treat the plane with CorrosionX.

I would get the previous owner and Daytona Aircraft Services together demand a "come to Jesus" moment.... DAS needs to buy the plane from you, or the previous owner needs to buy it back..

Ps. Don't be afraid to get the FAA involved... Sellers and FAA approved mechanics and shops need to be held accountable... IMHO..

 

[RotorAndWing]

Ps. Don't be afraid to get the FAA involved... Sellers and FAA approved mechanics and shops need to be held accountable... IMHO..

The FAA will not involve themselves in personal disputes. IIRC, there was no inspection done (100 hour/annual) and a prebuy is meaningless in the eyes of the FAA (regulation wise).

The only question I have is "Why did you wait until after buying the airplane to purchase a boroscope and look inside?"

Seems to me this would (should) have been done before exchanging money.

 

[N801BH]

The FAA will not involve themselves in personal disputes. IIRC, there was no inspection done (100 hour/annual) and a prebuy is meaningless in the eyes of the FAA (regulation wise).

The only question I have is "Why did you wait until after buying the airplane to purchase a boroscope and look inside?"

Seems to me this would (should) have been done before exchanging money.

Hmmm..

I didn't know that...

Seems to me a person holding an invoice from a FAA approved repair station stating "no corrosion" is a pretty damning document.....

And that is not including the "other" problems the buyer found..

If a prebuy is NOT an inspection, what is it?

 

[Geico266]

The FAA will not involve themselves in personal disputes. IIRC, there was no inspection done (100 hour/annual) and a prebuy is meaningless in the eyes of the FAA (regulation wise).

The only question I have is "Why did you wait until after buying the airplane to purchase a boroscope and look inside?"

Seems to me this would (should) have been done before exchanging money.

I have seen the FAA VERY interested in talking to the A&P that signed off the annual on planes like this. Corrosion like this doesn't happen in one year. One guy in particular lost his "license" permenetly for signing off a 120 that had corrosion in the wings. I believe the owner was able to collect from his insurance, but I'm not sure about that.

 

[Skip Miller]

If a prebuy is NOT an inspection, what is it?

A pre-buy is an inspection but there are no rules or guidelines as to what is looked at and what is acceptable. You need to have one done by someone you know and trust. -Skip

 

[RotorAndWing]

I have seen the FAA VERY interested in talking to the A&P that signed off the annual on planes like this. Corrosion like this doesn't happen in one year. One guy in particular lost his "license" permenetly for signing off a 120 that had corrosion in the wings. I believe the owner was able to collect from his insurance, but I'm not sure about that.

Pay attention. Did the shop doing the prebuy sign it off as an annual or a 100 hour?

I believe the answer is "no". While the mechanic that did sign off the previous annual "may" be culpable, now we are getting into an area of what is "acceptable" in regards to the degree of corrosion.

I believe this thread is centered on the shop that did the prebuy.

 

[RotorAndWing]

Hmmm..

I didn't know that...

Seems to me a person holding an invoice from a FAA approved repair station stating "no corrosion" is a pretty damning document.....

And that is not including the "other" problems the buyer found..

If a prebuy is NOT an inspection, what is it?

No where in regulations does the FAA define a prebuy or requirements thereof. A prebuy can be a simple "walk around" or a detailed full disassemble.

A CRS (certified repair station) follows regulations, maintenance manuals and a GMM (General Maintenance Manual). As far as I've ever seen, there is no mention in any of these about prebuy inspections.

Basically, a prebuy is whatever the parties involved have agreed upon.

 

[Geico266]

Pay attention. Did the shop doing the prebuy sign it off as an annual or a 100 hour?

I believe the answer is "no". While the mechanic that did sign off the previous annual "may" be culpable, now we are getting into an area of what is "acceptable" in regards to the degree of corrosion.

I believe this thread is centered on the shop that did the prebuy.

Reading comprehension a little low this morning? I said the FAA would be interested in talking to the mechanics that signed off the previous annuals. Corrosion like this doesn't happen in one year, and should have been noted in the annual write up in the log books.

 

[RotorAndWing]

Reading compression a little low this morning? I said the mechanic that signed off the previous annuals.

Not as bad as your writing skills, obviously.

 

[Geico266]

Not as bad as your writing skills, obviously.

Hey, at least my spell check works.

But the facts are, the last A&P IA to sign off the annual could and should be held accountable. That corrosion is well past borderline acceptable, IMHO. It needs to be repaired.

 

[tmyers]

So sorry to see this Oliver, yes call the service center in FL that did your prebuy. As all have said there are no standards in prebuy other than what you specifically ask for. In this case if you specifically asked for some confirmation on the presense or lack of corrosion and they told you there was none there may be some recourse via an aviation attorney.

Same with the GPS installation, if it is something you specifically requested it may be time to get in their faces.

Also consult with your local A&P for their thoughts.

Again, I am so sorry for what you are experiencing and keep me posted.

 

[RotorAndWing]

But the facts are, the last A&P IA to sign off the annual could and should be held accountable..

The maintenance requirements for a Part 91 GA aircraft are very low. How are you going to hold him "accountable"? You could complain to the FAA, in which they will investigate, and the A&P will simply cite regulations, the Cessna MM and AC43.13, and then the FAA will probably drop it unless there is some really bad corrosion in critical areas.

Or, you could hire a lawyer, $pend lots of money, make allegations and hope to recover some expenses. In the end the only winner here is the lawyer.

The purchaser bought a almost 50 year old airplane and didn't perform due diligence until after the purchase. A "prebuy" is not a regulation backed inspection, and in reality is only an opinion (unless the buyer has an annual or 100 hour done in conjunction).

Sorry, that's just reality.

That corrosion is well past borderline acceptable, IMHO. It needs to be repaired.

You've seen a few photos. In your own admission it's "borderline". Now the question is who will pay to do the work?

All I can say is "good luck" as there is no easy way out, and no cheap way.

"Buyer beware".

 

[Fearless Tower]

The only question I have is "Why did you wait until after buying the airplane to purchase a boroscope and look inside?"

That was my first thought too, but he does mention several other items that the pre-buy shop missed, so maybe he was suspicious and wanted to take a look himself?

 

[RotorAndWing]

That was my first thought too, but he does mention several other items that the pre-buy shop missed, so maybe he was suspicious and wanted to take a look himself?

Yea. But still, $26.99 for the boroscope before the purchase would have saved a lot of grief.

 

[Fearless Tower]

Yea. But still, $26.99 for the boroscope before the purchase would have saved a lot of grief.

True. Very expensive lesson.

 

[Tom-D]

This is simply a case of the buyer being dependent upon some one else, and being let down.

As far as the corrosion, There really isn't any thing you can do about it, except treat it, and leave it alone. If you try to remove it you are simply removing metal that may weaken the structure. You are not going to get all of it, so leave it alone.

Education is expensive.

Your only real legal recourse is with your agent, who did the pre-buy. they did not do their job. The seller is not required to tell you that their aircraft is anything, it is up to YOU the see what it is.

 

[flyingron]

Give it a thorough treatment with corrosion X ,it won't fix the problem,but it will slow it down. It will also protect the areas that aren't affected yet. Be prepared to clean up the seepage on a regular basis.

There are definite advantages to having a dark colored paint job.

 

[gitmo234]

Take it some place and get it treated. What year is it? At some point the older ones are going to get some corrosion. Not the end of the world.

 

[Checkout_my_Six]

so...what amount of corrosion is allowable?....was there any serious pitting?....was more than 10% of material removed?

If not....treat and roll on. Southern A&Ps are use to this.

Next question.....what does alclad look like after 40 years?

 

[Tom-D]

A pre-buy is an inspection but there are no rules or guidelines as to what is looked at and what is acceptable. You need to have one done by someone you know and trust. -Skip

A buyer hires an agent to do certain things, when the buyer can prove his agent did not do those things, does he have a case?

I'm not a lawyer, but that seems to be the case here. the buyer did ask for the corrosion to be looked for.

 

[German guy]

Thank you for all your replies, too many to answer all of them separately.

I mainly purchased the borescope as a toy of which I though might come in handy every once in a while. Even if I would have had it before we bought the plane, I wouldn't have known how to interpret what I see. I still don't, otherwise I would have started this thread... :wink2: My lack of experience in this regards was btw. the reason why we ordered the pre-buy inspection in the first place.
My aircraft ownership learning curve is currently going up a lot more steeply than I like.

The previous owner was an A&P who did the last annual this March.

We selected the Cessna service in Daytona Beach because I did my homework and because I therefore knew that an independent A&P should do the pre-buy inspection and that planes from coastal areas are particularly prone to corrosion.

This was their response by e-mail to my request to particularly pay attention to corrosion issues:

We are used to seeing aircraft that spend a lot of time outside in the FL environment, and the unavoidable corrosion issues that they experience. We are experienced in this area and will do everything we can to assure this aircraft is inspected and any corrosion that can be detected is documented. Once we know the condition of the areas we can see, a determination of the areas we can’t see can be assumed.

I don't see much room for interpretation in this statement.

All the pictures I posted above were from the area directly next to (max. 15" away) the inspection covers under the wings and already existing openings in the elevator and horizontal stabilizer. If I found the corrosion without any issue and an el-cheapo borescope, the Cessna Center as well as the previous owner / A&P should have found it too, I guess?

We bought the plane 'as is', what eliminates by my understand any right of the buyer to demand repairs or a return of the purchased good. That the previous owner just signed off the annual might however 'motivate' him to agree to a return. I also don't know how far the Cessna Center's liability goes, as they specifically confirm that they will conduct a corrosion inspection, but come up empty handed.

Pretty much all the articles I read, like this one from AVWEB, state that a corrosion inspection is one of the core elements of a pre-buy inspection. This also seems to be the consensus in personal discussion and internet forums.

I think it is time to get legal consultation...

 

[Tom-D]

so...what amount of corrosion is allowable?....was there any serious pitting?....was more than 10% of material removed?

If not....treat and roll on. Southern A&Ps are use to this.

When you see that "White" powder, the corrosion is already into the base metal.

Remember, I buy this junk and repair it, But I don't pay fair market for it.

 

[Checkout_my_Six]

One thing is for sure....if you get the FAA involved, your airplane will be grounded, regardless what anyone thinks.


IMHO....this is a subjective thing. Ask 10 A&Ps and you will get 10 answers.

 

[Checkout_my_Six]

When you see that "White" powder, the corrosion is already into the base metal.

Remember, I buy this junk and repair it, But I don't pay fair market for it.

Yup....been there dun it too.

 

[Tom-D]

One thing is for sure....if you get the FAA involved, your airplane will be grounded, regardless what anyone thinks.


IMHO....this is a subjective thing. Ask 10 A&Ps and you will get 10 answers.

One must remember that much of these old Cessnas are .016" alclad 2024-T3, how much can be rotted away and still meet structure requirements?

 

[Checkout_my_Six]

One must remember that much of these old Cessnas are .016" alclad 2024-T3, how much can be rotted away and still meet structure requirements?

the alclad is non-structural....and once the meat is corroded, below the alclad layer, it's only a short time till the material is done.

the allowance is 10% thickness....

Savy has a good article on this topic.... http://www.avweb.com/news/savvyaviator/189857-1.html

 

[AKBill]

I just bought a Beech Musketeer solely for parts. Wings, flight controls, tail and gear will fit my Sport 150. I intend to refurbish the parts and keep them just in case corrosion or some other damage requires these parts need replaced. Sell them with plane if and when I give it a new home. I know its a little extreme but I got a deal on the Musketeer, $400.00.

Sorry to hear about you dilemma, Hope you get the issue resolved without to much of a hassle. Good luck.....

 

[Tom-D]

the alclad is non-structural....and once the meat is corroded, below the alclad layer, it's only a short time till the material is done.

the allowance is 10% thickness....

Now the question becomes, How would any A&P in the field, determine the depth of the corrosion to determine airworthiness?

And where did you see the 10% requirements?

 

[Checkout_my_Six]

There is an AC for corrosion....and it might also be in AC 43.13

any thickness measuring device would work.....to determine material thickness.

 

[Tom-D]

There is an AC for corrosion....and it might also be in AC 43.13

any thickness measuring device would work.....to determine material thickness.

how would you get it in there? remember we are in the field with no disassembly allowed.

Cessna has a real structural repair manual to go by. That supersedes the ACs

 

[Checkout_my_Six]

yup....