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Conditions for approval required by: Julien Gauther
Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
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On ASD-CERT website, EN/AS9100 certificate validity is expired (11/06/2019).
On FAIR, for all EN4133 part references, in column “Character. Designator”, it is written “minor” for all characteristics.
How do we interpret “minor”?
If we consider ISO9152, table 3, dimensional characteristics have not the same category of defects.
Some dimensional characteristics are considered major with AQL = 1%, other dimensions are ranked as minor with AQL = 2,5% or 4%.
So, for acceptance, do we have sample size for dimensional inspections as per ISO9152, tables 3 and 4? On FAI, sampling was done as per ANSI/ASQ Z1.4 general control level II and WI-SYS-30, but we do not have AQL applied.
ISO9152 sampling (tables 3 and 4) is based on ISO2859-1, table II-A, single sampling, normal inspection. ISO2859-1 and ANSI/ASQ Z1.4 are really similar. From my point of view, this is the same way of sampling. Could you please confirm on your side?
On FPI report for EN4133-050, batch size is 7430 bolts.
200 bolts were FPI inspected, which is in line with ISO9152, table 4. In this case, we do not have any down arrow.
On FPI report for EN4133-060, batch size is 1269 bolts.
125 bolts were FPI inspected.
However, as per ISO9152, tables 3 and 4, AQL = 0,065% for discontinuities detection.
Thus, in ISO9152 table 4, column AQL 0,065%, we have a down arrow marked against production batch size “1201 to 3200”. This down arrow means: “Use sampling plan below (sample size and Ac)”. In the case of sample size is equal to or greater than the batch size, a 100% inspection shall be performed.
In this case, down arrow leads to sample 200 parts (with Ac = 0). So, 200 bolts should have been FPI checked instead of 125.
This topic was already discussed in ASD-CERT Mechanical Workshop minutes (released in March 2019).
These QTR was done before March 2019 since it is dated November 2018. This might explain why there is this sampling issue for FPI. If it is, could you please confirm that actions have been taken to apply right sampling plans?
On FPI report for EN4133-080, batch size is 151 bolts.
32 bolts were FPI inspected.
However, as per ISO9152, tables 3 and 4, AQL = 0,065% for discontinuities detection.
Thus, in ISO9152 table 4, column AQL 0,065%, we have a down arrow marked against production batch size “151 to 280”. This down arrow means: “Use sampling plan below (sample size and Ac)”. In the case of sample size is equal to or greater than the batch size, a 100% inspection shall be performed.
In this case, down arrow leads to sample 200 parts (with Ac = 0). So, since this sample size (200) is greater than manufacturing batch (151), a 100% inspection should have been performed instead of 32.
This topic was already discussed in ASD-CERT Mechanical Workshop minutes (released in March 2019).
These QTR was done before March 2019 since it is dated November 2018. This might explain why there is this sampling issue for FPI. If it is, could you please confirm that actions have been taken to apply right sampling plans?
Hydrogen content on EN4133-050, -060 and -080 bolts: in QTR, table 1, it is stated that 5 bolts were tested and results are recorded in Annex 4 (CoC). However, in Annex 4, we have only 3 results.
As per ISO9152, for qualification, 3 bolts shall be tested for hydrogen content. For Acceptance, 1 bolt has to be hydrogen content tested.
For fatigue test on EN4133-050 bolts, could you please precise which loads and frequency were applied?
For double shear test on EN4133-050 bolts, could you please precise if these tests were stopped after applying 26,2 kN load without carrying on tests until break?
For fatigue test on EN4133-060 bolts, could you please precise which loads and frequency were applied?
For double shear test on EN4133-060 bolts, could you please precise if these tests were stopped after applying 37,2 kN load without carrying on tests until break?
For fatigue test on EN4133-080 bolts, could you please precise which loads and frequency were applied?
For double shear test on EN4133-080 bolts, could you please precise if these tests were stopped after applying 66,2 kN load without carrying on tests until break?
Many thanks in advance for replying.
Have a nice day.
Julien
Thank you for replying. So, after reading your answers (additional documents section), the only remaining topic that needs to be clarified, for me, is sampling plans for non-destructive testing.
This topic will be processed later.
Best regards,
Julien