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Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
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In Test Report, hardness test box shows a sample size equal to 3. However, as per EN3752, table 6, sample size is 13 for non-destructive test and 5 for destructive test by considering mfg batch size range from 501 to 3200 (in TR, mfg batch size = 2696 parts).
Hopefully, in “macro/micro” test box, we have 12 hardness results. It would mean that this test is considered as a non-destructive one, except we have 1 missing value.
In my opinion, this test is a destructive one since we will have indentations/marks after carrying out this test on nuts. Thus, 12 results against 5 is better.
Could you please clarify?
FPI: mfg batch size is equal to 2696 parts. For FPI, EN3752 tables 3 and 4 require the following sampling plan:
AQL=0,065%, down arrow marked against mfg batch size range from 1201 to 3200 parts to reach a sample size equal to 200.
Therefore, sample size should be 200 parts instead of 125.
Why only 125 parts have been FP inspected?
Many thanks in advance,
Best regards.
Julien
Good morning Julian.
Understand your comment
Discussed your comment to the manufacturer.
I got the following explanation:
We confirm that the hardness is a destructive test so we agree normally sampling of 5 parts is correct. We have 12 results so it is better that 5 and all the values are conform. Will discuss this internally because in addition to being incorrect, it also takes extra time!
Concerning the sampling size of FPI is an error of interpretation of the standard EN3752, tables 3 and 4. The interpretation of the sampling tables are complex.
With a correct interpretation of table 3 and 4, 200 parts should have been tested. However, They went on the same line from “Batch size” to “Sample size” (table 4) and then you come to 125 pieces.
Regards
Kees
Good afternoon Julien.
In the chapter Additional Documents you will find the adjusted TR 14835992 rev 2, ACP006 EN3720-060
In this revision the correct numbers are stated 200 instead of 125 FPI and these have also been tested now by HFS.
Regards
Kees
Following a review of Julien’s questions. i can confirm that the answers from Kees and Howment have answered them the questions and an updated report has been uploaded.
approved