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Is this corrosion or a gasket?


DustinNwind

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31 minutes ago, Freemasm said:

Hadn’t given this a two sided thought until now. The quote from a few comments back;

Remember we as pilots are the final say if the plane is airworthy.“

In reality is only half true (to me). A pilot “over ruling” an A&P or IA only makes sense to me in one direction. Can anyone think of an instance where it would be prudent for a pilot to fly an aircraft an inspector found unairworthy? 

 

I think it goes the other way more often; the pilot feeling it's unsafe when the owner/IA says it's good to go.

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Just now, INA201 said:

What is the best way to prevent this type of corrosion?

Better aluminum from the aluminum factory, don't stress the less than spec aluminum.    Based on my readings, Intergranular corrosion is when the particles that make up the alloy that is Aluminum decide to release their bonds to the other particles.    Generally it is caused by stress to the aluminum.  Not sure if is a slightly harder than normal landing or just sitting on the ground.   What would be interesting is if there was some traceability of the planes that have had the spar go south and see if they were all from the same batch of Aluminum.  

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8 minutes ago, INA201 said:

What is the best way to prevent this type of corrosion?

-Good paint to seal out moisture and contaminants 

-CorrosionX or ACF-50 on bare aluminum interior structure

-prayer (oftentimes intergranular corrosion is begun with the extrusion process itself, or over stress like Yetti said, above.)

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6 minutes ago, Freemasm said:

Going to respectfully disagree with you here, Sir. Lots of different designs but this cap design is a single piece angle where it takes up both the lift (compressive) load and the drag load (also compressive). This IG appears to be on the main cap, not the doubler.  In a very simplified way looking at this application, the spar caps take the load.  The web transmits load between the caps.  Similar condition on the bottom cap would have probably already had some tragic consequences.  Let me know where I"m wrong. MSer's always do.

I could very well be wrong... but as I was told when mine had to be repaired do to corrosion, the spar cap can be spliced, doubled, etc whereas the spar itself would have to be replaced which is effectively a new wing. I was quoted between $60K and $120K (used or new wing) to repair spar corrosion but only paid $2600 to repair the spar cap with a doubler.

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• Could this happen without someone seeing it? This obviously went unnoticed and I've had a number of people say - good find, but to me it was an obvious find glaring at you like a full moon at 35,000' .

• Is this type of corrosion from nature or from a bad batch of metal?

I'm not going to give out the N number or the name of the seller, as he's a great guy and I'm fully under the impression he was/ is not aware of the situation fully. Again, to reiterate, it's not on the open market and hopefully he takes care of it or scraps it before it does. The plane is a 1966 M20E that sits outdoors on the west coast on the coast. 

 

Again, thank you everyone for your question, input and discussion. This is a fitting conversation to have considering what happened to Piper - most Mooney owners assume their plane is robust and impervious to structural failure due to nothing happening in the past.. the past is a good talking till the present stops you dead in your tracks. It would be nice get a better picture of what the aging metals are looking like in various situations and how that would effect all aircraft. Could this be a good Mooney Corporate candidate for structural test under corrosive state?

 

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There have been 1 or 2 pilots that have tested the Mooney Spar in a thunderstorm.  Out of the entire fleet of Mooney's those planes have been the example of what not to do.   There is one plane that played with a thunderstorm and survived.

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12 minutes ago, Freemasm said:

 

Obviously misunderstood you, Sir. My apologies.  It sounded like you were saying "it's only the cap." The caps account for basically all of the spar's structural integrity.  The spar proper is an assembly or caps, doublers, webs, stiffeners, extensions, etc. It's also an integral part of the fuel tanks. (Why? Because they hate us).  Replacing a Mooney spar would be nightmarish and incredibly cost prohibitive. Splicing (or more accurately, reinforcing in your example) the area is way more manageable which I assume is your point. Again, my apologies   

No worries. :) It's often difficult, try as I might to wordsmith my posts carefully, to convey the thoughts in my head.

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6 hours ago, gsxrpilot said:

Remember, this is the Spar CAP, not the Spar. That is a huge difference.

The spar cap is corroded to the point that failure is not far away.  In flight the lower spar cap in under a tension load and the upper is under a compression load.  The spar web merely keeps the caps from collapsing.

This wing is toast and should not fly anywhere.  I hope no one dies in it.

Clarence

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The corrosion does seem extensive. I'm betting on the L angle to be attacked as well as the rivets. 

As an IA, I recommend that it be inspected by a mechanic that SPECIALIZES in such damage repair. I've worked on many helicopters and transport category aircraft, and you'd be surprised at how much spar material and other structural material gets grinded on, and cut on, and patched up. I get really sad, followed by mad, when I hear about planes being destroyed for something that could have been (economically) repairable. Not saying it will be cheap, but I believe that anything is repairable with enough time and money. I'm now in the world of cubs, champs, taylorcrafts, beavers, C170/180/185's, the list goes on. Non of these planes are made new, and most haven't been manufactured in over half a century. We go to great lengths to keep such a fleet going, many spending far more then the plane is worth on the market, because they are just not being made anymore.

They Mooney Flyer is quite fortunate to have such a high number produced fleet that, in airplane years, is still quite young. (one of the main reasons I bought one, shall I say) But it will not be forever. 

My point is, to those that are quick to judge, and hang to death a flying airplane, further inspection is warranted, by someone that is knowledgeable, and skilled in such disciplines.  

Now, let us be clear, I have not personally inspected this plane (I know not of this plane), I'm not stating this plane is safe for flight, I'm not saying that it isn't safe. I'm not saying that the cabin tubes are or are not rotted out. I'm not saying that the engine is or is not falling off........ all I'm saying is that further inspection should be done before we condemn this plane to the gallows. 

You would not take your parent, SO, or child out back and put them down for having cancer. You would seek a specialist for a cure. And then a second opinion, and a third, until you found the right one.

I'm sorry if I have offended anyone, I truly mean not to. All I'm trying to do is keep a flying plane flying if its prudent. 

 

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6 minutes ago, tangogawd said:

My point is, to those that are quick to judge, and hang to death a flying airplane, further inspection is warranted, by someone that is knowledgeable, and skilled in such disciplines.  

Now, let us be clear, I have not personally inspected this plane (I know not of this plane), I'm not stating this plane is safe for flight, I'm not saying that it isn't safe. I'm not saying that the cabin tubes are or are not rotted out. I'm not saying that the engine is or is not falling off........ all I'm saying is that further inspection should be done before we condemn this plane to the gallows. 

You would not take your parent, SO, or child out back and put them down for having cancer. You would seek a specialist for a cure. And then a second opinion, and a third, until you found the right one.

I'm sorry if I have offended anyone, I truly mean not to. All I'm trying to do is keep a flying plane flying if its prudent. 

 

I agree. My 252 was condemned as well. And the more pictures I took of the damage, the worse it got. At the end of the day it was $2600 to repair. And another Mooney escapes the Reaper AKA @Alan Fox.

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Guest tommy123

Take any advice offered on this site with a grain of salt, although many speak with the authority of a mechanic, IA or engineer many are not.

The only way to properly assess the condition of this aircraft is by a experienced, qualified person that  inspects actual airplane.

Internet expert’s advice is worth what you paid for it.

Edited by tommy123
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12 hours ago, tangogawd said:

 I get really sad, followed by mad, when I hear about planes being destroyed for something that could have been (economically) repairable. Not saying it will be cheap, but I believe that anything is repairable with enough time and money. 

My point is, to those that are quick to judge, and hang to death a flying airplane, further inspection is warranted, by someone that is knowledgeable, and skilled in such disciplines.  

You would not take your parent, SO, or child out back and put them down for having cancer. You would seek a specialist for a cure. And then a second opinion, and a third, until you found the right one.

I'm sorry if I have offended anyone, I truly mean not to. All I'm trying to do is keep a flying plane flying if its prudent.

The economic feasibility and keeping a plane flying.   First of all this is not an airworthy plane nor should it fly.  Since flying is a hobby for most of us we would like to fly the plane we bought so buying something and having it be worked on for a year eliminates the goal of flying.  You have a true love for working on the planes, which is good. This plane would meet your goals of working on a plane. GSRPilot had a pitting type corrosion which is different than what is going on here with a structural corrosion.  The unknown is how much structure is left and how much is required to keep the wings from falling off. A new wing could fix this problem or disassemble of the spar and replace with new material. But again that would be working on the plane and not flying it. What is wrong with the overall process is the whole reason for certification and traceability in the FAA world has been lost.   Being able to trace all the planes that have this batch of aluminum would be the best course of action and see if other planes with that batch of alum are impacted or going to be impacted. 

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I am going to jump to @tangogawd defense just a bit, I agree with not being quick to judge the fate of a plane on a couple of pictures. it is not uncommon for pictures to look worse then the situation actually is. the truth in this matter is that until that area is cleaned up and the damage is measured we can not make an accurate assessment of what should be done.

while in the Navy we had a situation where a technician bore-scoped an area under an engine trough during an inspection, he found what looked to be an area filled with corrosion just waiting to fail. this area was inaccessible without removing the engine trough that was riveted in place with steel rivets. a couple of days later when they had removed the trough we looked in there only to discover what he had seen was some minor surface corrosion that was enhanced by the bore-scope. because the operator, who was new to using a bore-scope, had no other details within the picture to give him a better perspective he assumed the worse. if he had moved the camera back he may have realized what he was looking at was not as bad as he thought. that was an expensive lesson to learn and the pictures even fooled some of the experts that looked at them and they made a decision solely based on a picture not double checking the original findings.

so in short what I am saying is i agree the airplane should be properly evaluated before sending in Alan with his saw.   

Brian    

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On 8/28/2018 at 3:25 PM, M20Doc said:

You’d be doing the owner and any of his passengers a big favour by telling him to take a bus home before his plane kills someone.

Clarence

Piss on that, be doing the pilot, his passengers, and the aviation community as a whole a favor by tipping off the local FSDO.  If he's flying it with the spar cap rotting off, he's probably flying it out of annual.  Last thing we need is another Embry Riddle in-flight breakup making headlines.

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21 hours ago, Yetti said:

There have been 1 or 2 pilots that have tested the Mooney Spar in a thunderstorm.  Out of the entire fleet of Mooney's those planes have been the example of what not to do.   There is one plane that played with a thunderstorm and survived.

I recall reading about two: one where the pilot was uninjured, but his buddy pointed out some popped rivets and wrinked wing skins the next day, and another where the pilot had to go to the ER for internal bleeding after he landed.  The story I recall from the second case is that the plane was sent off to Kerville, and Mooney determined that it had experienced around 13 Gs...

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6 hours ago, ShuRugal said:

Piss on that, be doing the pilot, his passengers, and the aviation community as a whole a favor by tipping off the local FSDO.  If he's flying it with the spar cap rotting off, he's probably flying it out of annual.  Last thing we need is another Embry Riddle in-flight breakup making headlines.

I'd thought the same, I hope the FAA read forums like this.

Clarence

 

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On 8/30/2018 at 3:37 AM, Yetti said:

The economic feasibility and keeping a plane flying.   First of all this is not an airworthy plane nor should it fly.  Since flying is a hobby for most of us we would like to fly the plane we bought so buying something and having it be worked on for a year eliminates the goal of flying.  You have a true love for working on the planes, which is good. This plane would meet your goals of working on a plane. GSRPilot had a pitting type corrosion which is different than what is going on here with a structural corrosion.  The unknown is how much structure is left and how much is required to keep the wings from falling off. A new wing could fix this problem or disassemble of the spar and replace with new material. But again that would be working on the plane and not flying it. What is wrong with the overall process is the whole reason for certification and traceability in the FAA world has been lost.   Being able to trace all the planes that have this batch of aluminum would be the best course of action and see if other planes with that batch of alum are impacted or going to be impacted. 

I was not placing any determination on the airworthiness of this aircraft. All I can do, after viewing the one picture provided, is advise the owner/pilot to have it inspected before further flight. But as you, I can guess with good odds what the determination will be. 

I was simply trying to convey, to those who are quick to scrap an entire airplane over one picture, is that someone who is properly skilled and experienced, needs to evaluate the extent of the damage. 

I wouldn't call this a hobby for most. People are quite passionate, and want to learn and be apart of every aspect of all things that fly. There are lots of owners out there, who have bought projects (sometimes unknowingly) and brought them back from the brink. I by no means was implying that the OP go out and buy this plane, then spent the next year rebuilding the wing, but he is free to do so if he so choices.

 

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