lrm material and process spec revie · process specification i recommend section 2.8.2, inspection...

9/17/2003 1LRM Spec Review

LRM Material and Process Spec ReviewLRM Material and Process Spec Review

Cindy ColeCindy Cole

Certification ManagerCertification Manager

The Lancair CompanyThe Lancair Company


GeneralGeneral

We donWe don’’t perform LRM at t perform LRM at LancairLancair, but we have , but we have investigated it. We do perform structural wet investigated it. We do perform structural wet layuplayup..

Most comments are picky detailsMost comments are picky details

Some are based on our Some are based on our ACOACO’’ss requirements for requirements for material database reportsmaterial database reports


TerminologyTerminology

I was very confused on the term I was very confused on the term ‘‘batch acceptance.batch acceptance.’’Spec must differentiate:Spec must differentiate:

Supplier Quality Assurance performed by the fiber Supplier Quality Assurance performed by the fiber manufacturermanufacturerReceiving tests performed by fabric manufacturer Receiving tests performed by fabric manufacturer Quality assurance tests performed by the material Quality assurance tests performed by the material manufacturer (on mixed resin batches and fabrics)manufacturer (on mixed resin batches and fabrics)Receiving tests performed by the endReceiving tests performed by the end--user (user (akaaka part part producer) on resin and fabricproducer) on resin and fabricTests performed by the endTests performed by the end--user as inuser as in--process verificationprocess verification


TerminologyTerminology

To me To me ‘‘acceptanceacceptance’’ should indicate should indicate ‘‘when it comes in the when it comes in the door.door.’’ I believe the term I believe the term ‘‘quality assurancequality assurance’’ should be used in should be used in place of place of ‘‘acceptanceacceptance’’ testing by the base material manufacturers testing by the base material manufacturers after they have made their product. after they have made their product. The term The term ““EquivalenceEquivalence”” is used for different things. Section 4.3 is used for different things. Section 4.3 of Material Spec is of Material Spec is ““Equivalency Baseline Enhancement.Equivalency Baseline Enhancement.”” This This should be should be retitledretitled ““Database EnhancementDatabase Enhancement”” or something or something similar to distinguish it from equivalence testing performed by similar to distinguish it from equivalence testing performed by an endan end--user to show they can use properties developed by the user to show they can use properties developed by the material supplier.material supplier.The Glossary should include terms like Batch, Batch The Glossary should include terms like Batch, Batch Acceptance, Equivalence, etc., that may be defined in the text Acceptance, Equivalence, etc., that may be defined in the text of the document, but should be defined in the glossary as well.of the document, but should be defined in the glossary as well.


Material Specification, LRM Material Specification, LRM Processes and MaterialsProcesses and Materials

Figure 2.1 (1.1 in the process specification) flow chart Figure 2.1 (1.1 in the process specification) flow chart should not have a line between the Fiber should not have a line between the Fiber Reception/Storage and Resin Mixing, nor between the Reception/Storage and Resin Mixing, nor between the Resin Reception/Storage and Resin Reception/Storage and PreformPreform Assembly Assembly (unless you consider (unless you consider TackifiersTackifiers to be Resin).to be Resin).


Material Specification, LRM Material Specification, LRM Processes and MaterialsProcesses and Materials

Section 2.2 lists materials that are typically not Section 2.2 lists materials that are typically not controlled by their own material specification, but controlled by their own material specification, but rather by a qualified products list. We have had to rather by a qualified products list. We have had to put mold release agents into a material specification put mold release agents into a material specification which include receiving inspection testing. Not sure which include receiving inspection testing. Not sure what is meant by what is meant by ‘‘adhesivesadhesives’’ in this section.in this section.

Figure 3 shows Figure 3 shows tackifiedtackified fabric as part of the material fabric as part of the material procurement spec. I would have expected this to be procurement spec. I would have expected this to be part of the material acceptance spec. Materials arenpart of the material acceptance spec. Materials aren’’t t purchased in purchased in preformspreforms, are they?, are they?


Material Specification, Development Material Specification, Development of Material Controlsof Material Controls

Section 3.3, titled Part Producer Responsibilities for Section 3.3, titled Part Producer Responsibilities for Material use in Structural Design, should include Material use in Structural Design, should include more information on other tests for qualification of a more information on other tests for qualification of a material (lightning protection, compatibility with material (lightning protection, compatibility with secondary adhesives, etc.)secondary adhesives, etc.)Our ACO has requested that the material database Our ACO has requested that the material database reports have specific wording regarding the reports have specific wording regarding the limitations of the data. If we want to work that into limitations of the data. If we want to work that into the specification, this may be the place to do it.the specification, this may be the place to do it.

This report provides material data that may be used in Part This report provides material data that may be used in Part 23 aircraft design, including B23 aircraft design, including B--Basis values that meet the Basis values that meet the requirements of 23.613 taking into account environmental requirements of 23.613 taking into account environmental factors per 23.603. factors per 23.603.


Material Specification, Development Material Specification, Development of Material Controlsof Material Controls

Section 3.3 recommends Section 3.3 recommends ““that the endthat the end--user perform user perform the purchaser batch acceptance tests on panels cured the purchaser batch acceptance tests on panels cured using the material supplierusing the material supplier’’s baseline cure process.s baseline cure process.”” I I disagree. Receiving Inspection should be performed disagree. Receiving Inspection should be performed using the same cure cycle that the parts will be made using the same cure cycle that the parts will be made with. In practice it wonwith. In practice it won’’t work at our facility to have t work at our facility to have a separate cure cycle just for receiving inspection.a separate cure cycle just for receiving inspection.


Material Specification, Qualification Material Specification, Qualification RequirementsRequirements

Section 4.2 recommends a check for maximum Tg. Is Section 4.2 recommends a check for maximum Tg. Is this really something to check?this really something to check?

Section 4.3 Item 1 says the material equivalency and Section 4.3 Item 1 says the material equivalency and batch acceptance requirements should be recalculated batch acceptance requirements should be recalculated and the specification updated. I think it should and the specification updated. I think it should specifically say in this step that the Bspecifically say in this step that the B--Basis design Basis design values are NOT changed.values are NOT changed.


Material Specification, Qualification Material Specification, Qualification RequirementsRequirements

Section 4.6.3 says Level 2 changes can be approved with Section 4.6.3 says Level 2 changes can be approved with less than the full equivalency test plan required for a less than the full equivalency test plan required for a Level 3 change. So what is required?Level 3 change. So what is required?Section 4.6.4 says that a full equivalency test program is Section 4.6.4 says that a full equivalency test program is required per ARrequired per AR--03/19 for a Level 3 change. I haven03/19 for a Level 3 change. I haven’’t t seen this document, but if it is the same as ARseen this document, but if it is the same as AR--00/47, it 00/47, it requires one batch with 8 replicates for strength and 4 requires one batch with 8 replicates for strength and 4 for modulus. Section 4.6.4 further states that for modulus. Section 4.6.4 further states that ““Testing Testing to validate Level 3 changes should involve a minimum to validate Level 3 changes should involve a minimum of three batchesof three batches…”…” Appears to be in conflict.Appears to be in conflict.


Material Specification, Resin Material Specification, Resin ProcurementProcurement

Section 6.3.2 says Section 6.3.2 says ““None of the tests in Table 1 are None of the tests in Table 1 are recommended for batch acceptance testingrecommended for batch acceptance testing”” yet the yet the footnote on Table 1 identifies some tasks as footnote on Table 1 identifies some tasks as ‘‘acceptance tests.acceptance tests.’’

Table 2 recommends cured resin tension test. Table 2 recommends cured resin tension test. WouldnWouldn’’t compression be more relevant?t compression be more relevant?

Section 6.3.5 is the PCD for resins, yet it includes Section 6.3.5 is the PCD for resins, yet it includes references to fabric.references to fabric.



Section 6.4.2.4 ( typo, listed as 6.4.3.4) says that Section 6.4.2.4 ( typo, listed as 6.4.3.4) says that replacement data is only allowed if (1) test replacement data is only allowed if (1) test abnormality, (2) statistical outlier, abnormality, (2) statistical outlier, andand (3) bad (3) bad specimen prep or conditioning. I believe that should specimen prep or conditioning. I believe that should be be oror..

Retest section should be specifically identified as Retest section should be specifically identified as pertaining to both supplier and part producer testing.pertaining to both supplier and part producer testing.

Paragraph three references Paragraph three references prepregprepreg



Section 6.4.3 requires two copies of Section 6.4.3 requires two copies of certscerts. Why?. Why?

Section 6.4.5 says the specification should define the Section 6.4.5 says the specification should define the requirements for certifying a test lab. I donrequirements for certifying a test lab. I don’’t think t think that should go in each material specification. Belongs that should go in each material specification. Belongs in a separate guidance document, or nowhere. Test in a separate guidance document, or nowhere. Test lab certification is left to the Quality Department at lab certification is left to the Quality Department at LancairLancair, just like any other vender approval (no type , just like any other vender approval (no type design requirements).design requirements).



Section 6.7 says that batches rejected by a purchaser Section 6.7 says that batches rejected by a purchaser should not be rerouted to other purchasers. We should should not be rerouted to other purchasers. We should allow a way for the material supplier to sell to a allow a way for the material supplier to sell to a different customer with different requirements (e.g. different customer with different requirements (e.g. sports industry). Can this be reworded?sports industry). Can this be reworded?


Material Specification, Fabric Material Specification, Fabric ProcurementProcurement

Section 7.1 discusses Section 7.1 discusses ‘‘cure conditions.cure conditions.’’ Is this Is this applicable to fabrics?applicable to fabrics?

Section 7.3.3 is the PCD for fabric, but discusses Section 7.3.3 is the PCD for fabric, but discusses resin.resin.

Section 7.4.2.2 references cured and uncured materialsSection 7.4.2.2 references cured and uncured materials


Material Specification, Cured Material Specification, Cured Material AcceptanceMaterial Acceptance

Table 6 may be easier to understand if it were broken Table 6 may be easier to understand if it were broken into three tables that corresponded to text into three tables that corresponded to text descriptions of (1) IMQ testing (2) Receiving descriptions of (1) IMQ testing (2) Receiving Inspection testing and (3) Database Enhancement Inspection testing and (3) Database Enhancement testing, with frequencies given for each.testing, with frequencies given for each.

Section 8.3.4.4 should perhaps reference foam instead Section 8.3.4.4 should perhaps reference foam instead of honeycomb core. Mentions of honeycomb core. Mentions prepregprepreg. (recommend . (recommend search and replace)search and replace)



Should the laminate tests include planned variations Should the laminate tests include planned variations in cure cycle, resin content, and hardener content?in cure cycle, resin content, and hardener content?

As shown in Figure 4, was it considered to forego As shown in Figure 4, was it considered to forego performing the Batch Acceptance (receiving) tests and performing the Batch Acceptance (receiving) tests and instead perform only the Batch Release Tests?instead perform only the Batch Release Tests?

Goal should be for it to be the responsibility of the Goal should be for it to be the responsibility of the supplier to provide a good product and prove it. (i.e. not supplier to provide a good product and prove it. (i.e. not the responsibility of the endthe responsibility of the end--user to ensure they received user to ensure they received good material) Responsibility of the endgood material) Responsibility of the end--user to provide a user to provide a good part and prove it.good part and prove it.



Section 8.4.2.2, Constituent Receiving Inspection Section 8.4.2.2, Constituent Receiving Inspection Tests, copies the material procurement spec. Does it Tests, copies the material procurement spec. Does it belong here?belong here?Section 8.4.2.4, Part Acceptance Tests, recommends Section 8.4.2.4, Part Acceptance Tests, recommends only performing a test on excess resin to validate only performing a test on excess resin to validate proper cure, when the materials have batch release proper cure, when the materials have batch release testing prior to use. What kind of test should that testing prior to use. What kind of test should that be?be?8.4.2.5, Retest, says to inform end8.4.2.5, Retest, says to inform end--users of a material users of a material batch for which retests were performed. Is this batch for which retests were performed. Is this applicable to the material acceptance spec?applicable to the material acceptance spec?


Process SpecificationProcess Specification

Should Section 2.3 on Materials be included, or just Should Section 2.3 on Materials be included, or just reference the material specification?reference the material specification?

Bagging materials should be controlled in some Bagging materials should be controlled in some manner, perhaps in Section 2.4manner, perhaps in Section 2.4

Section 2.7.1 says that at least two thermocouples Section 2.7.1 says that at least two thermocouples should be used for each panel. Perhaps more useful should be used for each panel. Perhaps more useful to define a ratio for number of thermocouples to to define a ratio for number of thermocouples to panel area.panel area.


Process SpecificationProcess Specification

I recommend Section 2.8.2, Inspection and Process I recommend Section 2.8.2, Inspection and Process Monitoring, references the material specification or Monitoring, references the material specification or the material specification references this one rather the material specification references this one rather than put in both places.than put in both places.

Section 2.8.3, Panel Inspection, includes a check on Section 2.8.3, Panel Inspection, includes a check on panel thickness. Is this unique to LRM or also in panel thickness. Is this unique to LRM or also in prepreg? If values are normalized by ply thickness, is prepreg? If values are normalized by ply thickness, is this necessary?this necessary?


RecommendationsRecommendations

Table of standard tolerancesTable of standard tolerancesFlammability TestingFlammability TestingEffects of lightning mesh (included in the samples or Effects of lightning mesh (included in the samples or not)not)For us, Environmental/Variability Factors are a big For us, Environmental/Variability Factors are a big part of what we get out of laminate tests. Can that be part of what we get out of laminate tests. Can that be discussed in this document?discussed in this document?E/V Factor = E/V Factor = Mean Strength at Test EnvironmentMean Strength at Test Environment

BB--BasisBasis Strength at HWStrength at HW

lrm material and process spec revie · process specification i recommend section 2.8.2, inspection...

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