Becoming an Approved Boeing Bonding Facility for all Aircraft

[johnpowers]

We have completed all the required test on our Autoclave per the Boeing requirements. We have manufactured contless test panels for metal peel test, honeycomb peel test, lap sheer test, ect. We are required to perform what is call an Embedment test in accordance with BMS8-30. This is an obsolete spec. BMS8-30 was replaced by BMS5-90. Both the BMS8-30 and the new BMS5-90 were the specs. on application and tests for applying and using Foam Adhesives. However, the new BMS5-90 does not state anything about an Embdement test. We are unable to obtain the old spec BMS8-30 becuase it has been cancelled and Boeing is not very helpful nor do we want to ask them to many questions, they might think we don't know what we are doing. But after 20 years in airframe structural repairs/overhauls and manufactuing composite type panels we have never heard of this type of test. Does any one have any information regarding an Embedment test or the old Boeing spec BMS8-30??? Here is what we are required to do:

Accomplish the embedment strength test at 80° F +/- 10° F called out in BMS 8-30 (it is known that this is an obsolete specification) , except use BMS 5-90, type IV per BAC 5514-590 cured at 250° F in lieu of BMS 8-30, type I adhesive and the minimum embedment strength is 1312 pounds for the BMS 5-90 adhesive. After the test the samples are to be cut in half and checked for voids to ensure they meet the requirements in BMS 5-90.

 

[bf109g]

I have to admit I'm stumped. Why are they having you perform a material qualification test and not a bonded assembly test?

I'd think that you'd be showing how your processes meet the BAC5514-590 requirements for core splicing.

 

[johnpowers]

we are required to produce 5 250F cure panels and 5 350F cure panels, for a total of 60 test samples which require peel test. I do agree with you, we are not qualifing the adhesive. the adhesive has already been qualified through the companies on the QPL list. However, this test must require us to mfg a test panel and some type of jig in order to perform such a test. Is it possible it could me some type of shear test???

 

[SWComposites]

Who is requiring you to do this? Why cannot they supply the spec you are being asked to qualify to?

 

[monkeydog]

It sounds like you are trying to perform a requirements trace "audit" to your process. If you have it in a "flow-diagram" format, or easy to follow format (so a non-technical person could understand), you might go back to you boeing contracts point-of-contact and explain you need specs xyz to satisfy the requiements called out in the mother spec.

 

[materialsliz]

Doing a search on Boeing's supplier site, there is a Machine and Process Tools doc # D33080-1.926 that details a mold, a parting tool, and a saw fixture for making the Embedment test specimens. It calls out BAC5452 as a reference, but looking at that spec it appears to have been superseded by BAC5514 which doesn't appear to reference the Embedment test. This tooling doc was all that came up in a search for "Embedment test".

My company deals with Boeing a lot. They have so many specs sometimes obsolete references aren't deleted when they should be. You should point out to them or whoever is contracting you this test is not referenced or detailed in any superseding spec you can find and see what they say. Since it is only listed in obsolete docs it sounds like the test is also obsolete.

 

[johnpowers]

materialsliz, BAC5514 is the spec we are trying to get approved to by Boeing. Once we are certifed to BAC5514 it allows us to mfg honeycomb composite and metal-to-metal parts. I.E. Skins, Panels, Trailing Edges, Leading Edges, ect. In order to adhere to BAC5514 we must write a quality procedure(QP) showing our knowledge and understanding of the spec. We have already done this, part of the process involves certifing our Autoclave curing oven I/A/W Boeing's Autoclave operating paremeters. We have completed all the required QP's, Autoclave test to make sure our autoclave operates within the required heat up rates and pressure requirements. We also mfg test panels for 250F adhesive's and 350F adhesives which we had honeycomb peel tested. The last required operating test is to conduct an Embedment Test I/A/W BMS 8-30. Boeing finally sent us the BMS 8-30 spec. To our surprise it requires us to mfg a testing fixture/jig. This fixture/jig is the tool that we would use to actually conduct the test. It requires us to mfg a test panel using BMS 5-90 foaming adhesive with honeycomb core. Then we cut the test panel in 6 sections and put one of the cut samples in the fixture/jig. The problem now is how to Mfg the fixture/jig per the specifications in BMS 8-30. Without this fixture/jig we can't perform the Embedment Test. I have reviewed the mfg specs, material, and process and there is not enough data on how to assemble the tool fixture. Does anyone know who can mfg the testing apperatus for us or who we can contact that might have previously mfg the testing apperatus so we can purchase the testing tool/fixture/jig????

 

[materialsliz]

Does the BMS show a sketch or dwg of the test fixture it wants you to use? There are several companies that make test fixtures for ASTM specs, a search online can give you their names. Perhaps one of those might be able to make your test fixture if they have a sketch to go by.

Just a warning: I'm not sure how much you've dealt with Boeing, but don't be surprised when the BAC5514 qual doesn't cover you for making all honeycomb or metal bonding parts for Boeing. Boeing Commercial and Boeing Military like to have their own separate qual docs and they rarely cross each other. So far we've done 4 separate quals just for making laminate and honeycomb parts for 1 model aircraft, and 2 other quals for 2 other aircraft's parts. It would be nice if they had just 1 qual doc.

 

[Compositepro]

Contact Wyoming Test Fixtures, or Orange County Material Testing Lab, or Delsen Test Lab.

 

[bf109g]

Now I'm confused. Where does the requirement for testing to the obsolete spec show up? Is there a facility/process qualification outside of BAC5514 that you're working to in order to get certified?

I ask because this may be a hurdle which I may have to eventually overcome.

 

[johnpowers]

bf109g - Boeing will send you a list of all the requirements you must adhered to and you must write work order instructions, quality procedures, perform test on curing ovens, define you procedures in you CCA- Clean Room and so on.

materialsliz - YES, BMS does show a sketch or dwg of the test fixture, however it is crude and does not have full detials. if it did, we would produce it ourselves. Do you know any companies that you have sent test panels to that could help us??

 

[materialsliz]

Sorry, I don't. We do all our mechanical qual testing in house, and we haven't yet run up against a spec that makes us make our own test fixtures. All the tests we've had to do are per ASTMs, SACMAs or other Boeing specs that use ASTM fixtures, and none have been as weird as this one you are describing.

The only thing I can tell you is to ask Boeing for their design of the fixture, stating you want to make sure you fab it the same way they did so the test results can be compared correctly. They must have some design otherwise how would they be able to compare different company's qual data?

 

[bf109g]

Unless, of course, the BMS8-30 test should have been removed from the vendor approval doc when BMS8-30 was made obsolete.

I'd innocently ask Boeing why you need to accomplish a test to an obsolete spec...

 

[johnpowers]

As well, we have always mfg our own tools, fixtures, and jigs, however , this is not something that can be easily interperated.
I have the design of the fixture: Please review the attachment.

 

[materialsliz]

Huh, maybe it's just me, but it looks pretty straightforward. An approx. 3" cubed welded box open on the front and back face, with a 2" x .12" wide slit in the bottom center for the tab of the test specimen, and a welded tab device on the box top. Looks like the tensile machine grips the tab on the specimen and the tab on the box and the box gets pulled up, separating the tab specimen from the core.

What problems are you having with this sketch?

 

[johnpowers]

materialsliz, your thoughts are intelligent, but this is a 3" welded box and pulling the box apart is not going to test the strength of our bonding capability with this core and adhesive type. But you seem to be on the right track. From looking at it in more depth, I think that the tab on the top and bottom are mfg along with the honeycomb core asy when it's cured/cooked. If you notice the core is 1" and the skin can't be more than .020 or .040 thick. This means there will be over 1 inch room on the inside of the box allowing the device to seperate the core from the skin with adequet room. Again, the spec does not state what tpye of device to us or must be used to pull the core and present us with a PSI strength.
On the other hand the top of the box shows a ball Dia. which means that there could be some type of force applied at the top and naturally applying force at the bottom. The reason I point this out is becuase after the test is complete, we are required to cut the sample in half and check for any voids I/A/W BMS5-90, the Faoming Adhesive Application.

 

[SWComposites]

1) while I have worked with lots of BMS specs, I have never seen or heard of this test.

2) is the core material specified? because the result will be a function of the core as much as the adhesive. If the core material is not specified, then you need to ask Boeing what to use.

3) my interpretation is this: the lower vertical tab is bonded to the core block; this is what is tested. The rest of the items in the figure are the fixture. The upper tab is attached to the ball, and it appears the top plate should have a concave hemispherical "cup". This allows the upper tab to rotate relative to the box, providing alignment during loading. The upper and lower tabs are gripped in standard test machine grips, and loaded in tension. The test specimen (bonded tab and core) is slid into the fixture.

4) I don't see any "skin" in the figure

5) my guess is that the lower tab that is bonded to the core is aluminum, as the thickness is 0.064", as common aluminum sheet thickness. This should be specified in the BMS spec.

6) I would weld a back plate to the fixture box to stiffen it.

I'm not in the office for the next couple of weeks, so am not reachable by phone. Post any questions here and I'll try to reply when I'm at a computer.

Regards,

Steve W.

 

[johnpowers]

Thank you for all of your help.

 

[materialsliz]

Good luck John, hope it goes well.

BF109g-to answer your question more thoroughly, what I've seen is this: Boeing's part dwg will call out "make per BAC####". BAC#### states "supplier facilities must be qualified to D6-#####". In the D6 doc it says what your autoclave/oven has to meet (another D6 doc), what your layup room reqs have to be, if your laser ply locators or CNC cutting machines have to be qualified (another D6 doc), etc. along with what types of qual panels and tests to perform, and what materials to use. So far all of our quals have followed this path.

 

[bf109g]

liz -

Yep, layer on layer of reference specs. I've been down that road on metal parts.