zanl188
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Skin Change

Sun Jul 29, 2007 10:11 pm

I didn't find this aircraft in the NTSB accident database so I'm curious. Is this skin change due to an AD, corrosion, nonreportable accident, etc? Seems to be too new to need new skin due to corrosion....

Thanks


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erj-145mech
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RE: Skin Change

Sun Jul 29, 2007 10:39 pm

Skin damage. Look at the lower right of the second window opening on the removed panel.
 
zanl188
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RE: Skin Change

Sun Jul 29, 2007 10:45 pm

Quoting Erj-145mech (Reply 1):
Skin damage. Look at the lower right of the second window opening on the removed panel.

Thanks..

That also explains the missing frame at the corresponding location on the aircraft.

BTW Great Photo....
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zanl188
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RE: Skin Change

Sun Jul 29, 2007 10:51 pm

Followup question...

Will the original skin panel go back on the aircraft once repaired? I understand it's hard to tell from a pix.

Looks like ramp rash... I'd hate to be the ramper involved, this looks pricey.. Looking at all the rivets that need to be drilled out and replaced, there has got to be some major labor dollars involved here....
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N231YE
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RE: Skin Change

Sun Jul 29, 2007 11:56 pm

Reminds me of the E-170 nose/forward fuselage replacement going on at CLE. There, the DL E-170 that sustained heavy damage after running off the runway, had its nose and fuselage (up to the wing leading edge) cut off, and is awaiting a replacement. There are some photos of this at opshots.net
 
boeingfixer
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RE: Skin Change

Mon Jul 30, 2007 12:07 am

Quoting ZANL188 (Reply 3):
Followup question...

Will the original skin panel go back on the aircraft once repaired? I understand it's hard to tell from a pix.

No, the skin will probably be replaced. To go through all the effort to remove the skin is an indication that the skin panel is damaged beyond repairable limits. Once the skin is off, it's easier to template it and make a new one instead of repairing the old skin.

Cheers,

John
Cheers, John YYC
 
Dalmd88
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RE: Skin Change

Mon Jul 30, 2007 5:49 am

Wow, a lot of work for a small area of damage. I'm suprised they had to remove the whole skin section instead of just repairing the area. Must have been due to the proximity to the window. Also noticed a couple of frames were out in the damaged area.
 
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HAWK21M
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RE: Skin Change

Mon Jul 30, 2007 3:59 pm

Interesting.
Wasn't a repair scheme with the Skin installed a possibility.Looks like a frame has been removed too.Anyone aware what transpired.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
boeingfixer
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RE: Skin Change

Tue Jul 31, 2007 7:31 am

Quoting HAWK21M (Reply 7):
nteresting.
Wasn't a repair scheme with the Skin installed a possibility.

That would all depend on the limits and repair schemes in the SRM. That damage may have required an external repair that was beyond SRM limits thus requiring a skin replacement.

Cheers,

John
Cheers, John YYC
 
dl757md
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RE: Skin Change

Tue Jul 31, 2007 9:02 am

Quoting DALMD88 (Reply 6):
Wow, a lot of work for a small area of damage. I'm suprised they had to remove the whole skin section instead of just repairing the area. Must have been due to the proximity to the window.

My thoughts exactly. We don't usually have to deal with damage around windows as due to the height of them on our aircraft that area doesn't receive much damage.

Quoting BoeingFixer (Reply 8):
That would all depend on the limits and repair schemes in the SRM. That damage may have required an external repair that was beyond SRM limits thus requiring a skin replacement.

We do repairs all the time that are beyond SRM repair limits. Engineering then issues a preliminary ERA which after Boeing approval becomes a final ERA. Apparently they don't have the same engineering capabilities and/or Embraer wouldn't approve the repairs.

Quoting BoeingFixer (Reply 5):
Once the skin is off, it's easier to template it and make a new one instead of repairing the old skin.

Templating a whole skin panel is rarely successful. It's much easier and more accurate to put up a clean piece of skin and back-drill it in my experience.

DL757Md
757 Most beautiful airliner in the sky!
 
474218
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RE: Skin Change

Tue Jul 31, 2007 10:27 am

Quoting Dl757md (Reply 9):
Apparently they don't have the same engineering capabilities and/or Embraer wouldn't approve the repairs.

I saw Gamco doing a similar repair, only around the L-1 door, to an A300 about 10 years ago. Again the damage did not look that bad. When I asked why a skin replacement rather than a simpler patch I was told it was outside the SRM limits and Airbus would not approve repairs outside the SRM. There and the only approved fix would be a skin replacement.
 
flight152
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RE: Skin Change

Tue Jul 31, 2007 11:05 am

Quoting N231YE (Reply 4):
There are some photos of this at opshots.net

Link? I couldn't find them on the site.
 
dl757md
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RE: Skin Change

Tue Jul 31, 2007 11:29 am

Quoting 474218 (Reply 10):
I was told it was outside the SRM limits and Airbus would not approve repairs outside the SRM.

I wonder if this is one of the reasons DL doesn't have Airbus. I'll have to ask around work as I was never involved in any sheet-metal repairs on the A-310s we had.

DL757Md
757 Most beautiful airliner in the sky!
 
474218
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RE: Skin Change

Tue Jul 31, 2007 11:37 am

DL757Md,

I think you will find that the Airbus SRM is fairly limited, or at least it was on the A300 and A310's.
 
777wt
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RE: Skin Change

Tue Jul 31, 2007 11:24 pm

Quoting N231YE (Reply 4):
Reminds me of the E-170 nose/forward fuselage replacement going on at CLE. There, the DL E-170 that sustained heavy damage after running off the runway, had its nose and fuselage (up to the wing leading edge) cut off, and is awaiting a replacement. There are some photos of this at opshots.net

That was Shuttle America's.

I dobut if it will get the replacement section at CLE, they took so many parts off, right now it's just the mid section and the wings. I think they are gonna take the wings off and put all the parts on a flatbed truck and haul it to either IND or CMH.
 
boeingfixer
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RE: Skin Change

Wed Aug 01, 2007 2:29 am

Quoting Dl757md (Reply 9):
Quoting BoeingFixer (Reply 8):
That would all depend on the limits and repair schemes in the SRM. That damage may have required an external repair that was beyond SRM limits thus requiring a skin replacement.



Quoting Dl757md (Reply 9):
We do repairs all the time that are beyond SRM repair limits. Engineering then issues a preliminary ERA which after Boeing approval becomes a final ERA. Apparently they don't have the same engineering capabilities and/or Embraer wouldn't approve the repairs.

Your error is assuming that Embraer engineering is as generous as Boeing's when it comes to custom engineered repairs. In my experience as a Sheet Metal tech and QA inspector, I'm well aware of what can be done through Boeing in regards to EA's etc.. But, since I do not know how Embraer approaches this subject, I left all conjecture out of my reply. It's highly possible that they are as stringent as Airbus is for skin repairs.

Quoting Dl757md (Reply 9):
Quoting BoeingFixer (Reply 5):
Once the skin is off, it's easier to template it and make a new one instead of repairing the old skin.



Quoting Dl757md (Reply 9):
Templating a whole skin panel is rarely successful. It's much easier and more accurate to put up a clean piece of skin and back-drill it in my experience.

In my experience, back drilling causes more damage to the attaching structure. A properly planned and layed out template is better than back drilling in my opinion. Also, the Embrear skin may have bonded window doublers etc.. that can't be seen in the photo which also might contribute to a complete skin replacement.

Cheers,

John
Cheers, John YYC
 
777wt
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RE: Skin Change

Wed Aug 01, 2007 3:37 am

Quoting BoeingFixer (Reply 15):
Your error is assuming that Embraer engineering is as generous as Boeing's when it comes to custom engineered repairs. In my experience as a Sheet Metal tech and QA inspector, I'm well aware of what can be done through Boeing in regards to EA's etc.. But, since I do not know how Embraer approaches this subject, I left all conjecture out of my reply. It's highly possible that they are as stringent as Airbus is for skin repairs.

I work on the ERJ-145 & the ERJ-170....as for skin damage in the SRM, dents have limits, creases or scratches have limits to a certain depth. The area where it's critical is the RVSM static ports.

From my experience, Embraer approves most flyby's in which the aircraft can continue revenue service for a # of hours or cycles before heavy repairs is due.
Dings under or around the door, even the bottom of the main cabin door can have damage no taller than 1/2" and must be blended out.
Dings in the back of the aircraft near the belt loader area is allowed up to about 1/8" deep or less. Got to look up the AMM to refresh my memory.

This is done to minimize the impact of operations due to the aircraft being out of service and the time needed to get the materials, engineering reviews of the perment repair, and the planning along with man power.


One time a truck was left in netural and went under the aircraft at my station! Embraer approved the ferry permit provided that the outflow valve is locked open and ferried in that way.

2 weeks later it came back with a perment repair of a big plate over the area where the damage occured and 2 new stringers were installed.
 
dl757md
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RE: Skin Change

Wed Aug 01, 2007 4:10 am

Quoting BoeingFixer (Reply 15):
Your error is assuming that Embraer engineering is as generous as Boeing's when it comes to custom engineered repairs

See below.

Quoting Dl757md (Reply 9):
Apparently they don't have the same engineering capabilities and/or Embraer wouldn't approve the repairs.

I actually assumed that it was a possibility that Embraer wasn't as generous as Boeing when approving repairs beyond the scope of the SRM.

Quoting BoeingFixer (Reply 15):
In my experience, back drilling causes more damage to the attaching structure.

Using drill bushings and step reamers it is actually quite easy yet somewhat time consuming to back drill with no chance for damage to existing structure.

Quoting BoeingFixer (Reply 15):
A properly planned and layed out template is better than back drilling in my opinion.

We have different experiences and have been exposed to different tricks. There's always more than one way to skin a cat.

Cheers
DL757Md
757 Most beautiful airliner in the sky!
 
N231YE
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RE: Skin Change

Wed Aug 01, 2007 6:36 am

Quoting 777WT (Reply 14):
That was Shuttle America's.

I dobut if it will get the replacement section at CLE, they took so many parts off, right now it's just the mid section and the wings. I think they are gonna take the wings off and put all the parts on a flatbed truck and haul it to either IND or CMH.

Yes it was Shuttle America's...actually I am hearing the aircraft may now be scrapped. Supposedly, Embraer does not want to take a completed nose section out of the production line (for this aircraft) due to the high number of orders they are receiving. CLE ARFF tried to purchase the what's left of it for training, I am told.

Quoting Flight152 (Reply 11):
Link? I couldn't find them on the site.

http://www.opshots.net/gallery/displ...?album=lastupby&cat=0&pos=86&uid=1

http://www.opshots.net/gallery/displ...?album=lastupby&cat=0&pos=85&uid=1
 
EMBQA
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RE: Skin Change

Wed Aug 01, 2007 6:49 am

Quoting 777WT (Reply 14):
I dobut if it will get the replacement section at CLE,

Nope... they are just awaiting the new nose section to arrive. It will be done in CLE.

Quoting N231YE (Reply 18):
.actually I am hearing the aircraft may now be scrapped

Nope... there is no talk of it being scrapped. It is still on space to be repaired and flying by years end.

I have been involved in several full skin replacements. Most cases it is driven by the SRM. In the picture above I'd say it had to do with the size of the damage in proximity to the window. Most time only small repairs are allowed within a fixed area around windows.

[Edited 2007-07-31 23:54:03]
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N231YE
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RE: Skin Change

Wed Aug 01, 2007 6:58 am

Quoting EMBQA (Reply 19):
Nope... there is no talk of it being scrapped.

Not exactly...that is the talk around CLE (that is aircraft may never fly again.) As stated, the ARFF was in/currently in talks to purchase the airframe for training.
 
777wt
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RE: Skin Change

Wed Aug 01, 2007 9:27 am

I saw the photos of the recovery process and the damage the aircraft has once it's in the hanger.

It's bad enough the skin and stringers from the nose section to near the front of the wings are damaged beyond repair. The floor in the cockpit twisted and pushed upwards. Same goes for the throttle quadart.

The city of CLE gave the recovery team a hard time because they won't let them cut the fence post which they needed to remove otherwise it would cause further damage. After the firefighters insisted on defueling the plane, the recovery went underway.
 
N231YE
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RE: Skin Change

Wed Aug 01, 2007 10:03 am

 
EMBQA
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RE: Skin Change

Wed Aug 01, 2007 12:36 pm

Quoting N231YE (Reply 20):
Not exactly...that is the talk around CLE (that is aircraft may never fly again.)

Trust me on this one.... my information source is A LOT better then yours
"It's not the size of the dog in the fight, but the size of the fight in the dog"
 
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HAWK21M
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RE: Skin Change

Wed Aug 01, 2007 6:46 pm

Quoting 474218 (Reply 10):
When I asked why a skin replacement rather than a simpler patch I was told it was outside the SRM limits and Airbus would not approve repairs outside the SRM.

Wouldn't Airbus approve a Repair Scheme if sent to them prior.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
tdscanuck
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RE: Skin Change

Wed Aug 01, 2007 8:01 pm

Quoting HAWK21M (Reply 24):
Quoting 474218 (Reply 10):
When I asked why a skin replacement rather than a simpler patch I was told it was outside the SRM limits and Airbus would not approve repairs outside the SRM.

Wouldn't Airbus approve a Repair Scheme if sent to them prior.

They would if 1) the repair scheme works, 2) they have the resources to prove it works, and 3) the customer has the appropriate relationship with Airbus to ensure that 2) happens.

If any of 1), 2), or 3) are missing, you don't get approval.

Tom.
 
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HAWK21M
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RE: Skin Change

Wed Aug 01, 2007 10:57 pm

Quoting Tdscanuck (Reply 25):
They would if 1) the repair scheme works, 2) they have the resources to prove it works, and 3) the customer has the appropriate relationship with Airbus to ensure that 2) happens.

If any of 1), 2), or 3) are missing, you don't get approval.

No Approval means No repair or is it allowed but Airbus is not responsible for the repair.It should be the latter,Thats how Boeing functions.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
N231YE
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RE: Skin Change

Wed Aug 01, 2007 11:02 pm

Quoting EMBQA (Reply 23):
Trust me on this one.... my information source is A LOT better then yours

You may be right, after all, this is a rumor...

The best way to find out is to go up to the hangar myself and ask one of the mechanics when I have a chance (I've been up there before...there pretty friendly guys).
 
tdscanuck
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RE: Skin Change

Wed Aug 01, 2007 11:25 pm

Quoting HAWK21M (Reply 26):
If any of 1), 2), or 3) are missing, you don't get approval.

No Approval means No repair or is it allowed but Airbus is not responsible for the repair.It should be the latter,Thats how Boeing functions.

Strictly by the regulations, it means Airbus/Boeing isn't responsible and isn't certifying the repair so you need to get certification from another source (a DER or the local regulatory rep).

From a practical standpoint, no ethical DER would sign off on a repair that the manufacture wouldn't sign off and you'd have a very tough time convincing most local regulators that the repair was OK if Airbus/Boeing didn't say it was OK.

Tom.
 
swiftski
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RE: Skin Change

Thu Aug 02, 2007 7:46 am

There is no photo in our database with that ID number. Back.

:S?
 
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HAWK21M
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RE: Skin Change

Thu Aug 02, 2007 6:50 pm

Quoting Tdscanuck (Reply 28):
From a practical standpoint, no ethical DER would sign off on a repair that the manufacture wouldn't sign off and you'd have a very tough time convincing most local regulators that the repair was OK if Airbus/Boeing didn't say it was OK.

Exactly What I was thinking.If the Manufacturer is not confident,who will be.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
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TZTriStar500
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RE: Skin Change

Thu Aug 02, 2007 11:27 pm

Quoting HAWK21M (Reply 30):
Exactly What I was thinking.If the Manufacturer is not confident,who will be.
regds
MEL

But what are you guys saying here? Obviously if one goes to the manufacturer, you are asking for their "buy-in" and regulatory approval of that repair. However, one would not approach the manufacturer for their "buy-in" and then solicit an outside DER for repair approval. This woud defeat the purpose of the outside DER altogether unless that said DER is cheaper. With Boeing, for example, if an airline is not a first-tier operator or does not have a service agreement, then the base charge for a manufacturer DER approved repair is quite expensive...many thousands $$. There are many DER approved structural repairs that happen in this industry with NO manufacturer involvement whatsoever except for following respective SRM and drawing guidance which are significantly cheaper than what the manufacturer would charge.
35 years of American Trans Air/ATA Airlines, 1973-2008. A great little airline that will not be soon forgotten.
 
tdscanuck
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RE: Skin Change

Fri Aug 03, 2007 12:04 am

Quoting TZTriStar500 (Reply 31):
Obviously if one goes to the manufacturer, you are asking for their "buy-in" and regulatory approval of that repair. However, one would not approach the manufacturer for their "buy-in" and then solicit an outside DER for repair approval.

You could, there just usually isn't much point. There are two parts to any repair: technical substantiation and regulatory approval. You usually get both in the same place but there's no regulation that says you have to.

Quoting TZTriStar500 (Reply 31):
There are many DER approved structural repairs that happen in this industry with NO manufacturer involvement whatsoever except for following respective SRM and drawing guidance which are significantly cheaper than what the manufacturer would charge.

If the repair is per SRM, there's no need for a DER approval. SRM repairs are pre-approved by the regulator.

For a repair outside SRM, whoever is certifying the repair needs to have enough data to show that the proposed repair meets the regulations. Since the regulations specify the load capacity that the structure must have, certifying the repair may require knowing the loads. This data is typically only available to the manufacturer.

If someone can show that the proposed repair is stronger than the original structure (relatively easy) and that it won't cause problems for any other structure (harder, but still doable) then the DER should be able to certify it. That's a different case than going to the manufacturer for a repair approval, not getting it, then trying to get it approved elsewhere. In that case, the DER or regulator is going to want to know why the manufacturer didn't approve the repair, which is going to significantly impact your ability to get anyone else to approve it.

Tom.
 
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HAWK21M
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RE: Skin Change

Fri Aug 03, 2007 6:02 pm

Quoting TZTriStar500 (Reply 31):
There are many DER approved structural repairs that happen in this industry with NO manufacturer involvement whatsoever except for following respective SRM and drawing guidance which are significantly cheaper than what the manufacturer would charge.

If the Manufacturer cannot come up with a repair scheme & an organisation does.What are the chances that the regulatory body will approve it.
Im not talking about costs.Im talking the manufacturer refuses the repair stating not possible.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
tdscanuck
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RE: Skin Change

Fri Aug 03, 2007 6:48 pm

Quoting HAWK21M (Reply 33):
If the Manufacturer cannot come up with a repair scheme & an organisation does.What are the chances that the regulatory body will approve it.
Im not talking about costs.Im talking the manufacturer refuses the repair stating not possible.

Close to nil for the big regulators. They'd want you to prove not only that your repair is OK but show why the manufacturer is wrong...that's technically possible but the onus of proof would be very heavily against the independant organization.

Tom.
 
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HAWK21M
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RE: Skin Change

Sat Aug 04, 2007 1:28 am

Quoting Tdscanuck (Reply 34):
Close to nil for the big regulators.

Thats exactly why I think the Regulatory Authorities would not approve a repair that has not god the nod of the Manufacturer.
regds
MEL
I may not win often, but I damn well never lose!!! ;)
 
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TZTriStar500
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RE: Skin Change

Sat Aug 04, 2007 8:24 am

Quoting Tdscanuck (Reply 32):
If the repair is per SRM, there's no need for a DER approval. SRM repairs are pre-approved by the regulator.

For a repair outside SRM, whoever is certifying the repair needs to have enough data to show that the proposed repair meets the regulations. Since the regulations specify the load capacity that the structure must have, certifying the repair may require knowing the loads. This data is typically only available to the manufacturer.

If someone can show that the proposed repair is stronger than the original structure (relatively easy) and that it won't cause problems for any other structure (harder, but still doable) then the DER should be able to certify it. That's a different case than going to the manufacturer for a repair approval, not getting it, then trying to get it approved elsewhere. In that case, the DER or regulator is going to want to know why the manufacturer didn't approve the repair, which is going to significantly impact your ability to get anyone else to approve it.


I understand this, but I meant when it is obviously beyond the SRM, one would still use its guidelines for the repair design and then substantiate it based on the ultimate strength of the material. Yes its not optimal because you don't have the loads the manufacturer does, but it works.

Quoting Tdscanuck (Reply 34):
Close to nil for the big regulators. They'd want you to prove not only that your repair is OK but show why the manufacturer is wrong...that's technically possible but the onus of proof would be very heavily against the independant organization.

Tom.

This is true, but you wouldn't reach this scenario. One would either go the manufacturer in the beginning or go the independent route. If an operator can, the independent DER route is usually quicker and cheaper, but both should have the same conclusion.

Quoting HAWK21M (Reply 35):
Thats exactly why I think the Regulatory Authorities would not approve a repair that has not god the nod of the Manufacturer.

Yes, they will if you leave the manufacturer out of it altogether and get direct DER approval.
35 years of American Trans Air/ATA Airlines, 1973-2008. A great little airline that will not be soon forgotten.
 
tdscanuck
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RE: Skin Change

Sat Aug 04, 2007 6:08 pm

Quoting TZTriStar500 (Reply 36):
I meant when it is obviously beyond the SRM, one would still use its guidelines for the repair design and then substantiate it based on the ultimate strength of the material. Yes its not optimal because you don't have the loads the manufacturer does, but it works.

That works to certify the repair for static strength but most modern aircraft are also certified as damage tolerant. It's impossible to do a damage tolerance analysis without knowing the loads. You can get around that by assuming worse case for the surrounding structure and backing out the loads but that would probably result in overly conservative inspection requirements.

Tom.
 
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TZTriStar500
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RE: Skin Change

Sun Aug 05, 2007 1:28 am

Quoting Tdscanuck (Reply 37):
That works to certify the repair for static strength but most modern aircraft are also certified as damage tolerant. It's impossible to do a damage tolerance analysis without knowing the loads. You can get around that by assuming worse case for the surrounding structure and backing out the loads but that would probably result in overly conservative inspection requirements.

True and its at that point you send your already approved repair to the manufacturer for the DTA since you generally have 12 months to receive that approval.
35 years of American Trans Air/ATA Airlines, 1973-2008. A great little airline that will not be soon forgotten.

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