TCM 2 392-1-14 LISI Aerospace [Bestas] Gazemir (TR) EN4137-100

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Conditions for approval required by:  Julien Gauther

3 Replies to “TCM 2 392-1-14 LISI Aerospace [Bestas] Gazemir (TR) EN4137-100”

  1. Tensile test on bolt: following calculation has been considered due to relieved shank if I am not mistaken.
    Tensile cross sectional area = (pi/4)D8² = (pi/4)x(8,3)²=54,106 mm²
    Minimum load requirement= 54,106×1100 = 59,5 kN.

    For double shear test, EN4137 does not remove this requirement.
    Could you please confirm that double shear was not performed due to relieved shank? Shall we consider that relieved shank length is too short?

    On FAIR, 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?

    Hydrogen content: as per CoC, 3 bolts were tested whereas in QTR, table 1, it is written 5.
    ISO9152 requires 3 bolts to be tested for qualification, so this is compliant.
    Sample size in QTR, table 1 seems to be a typo.

    On FPI report for EN4137H100064F, batch size is 1509 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). 200 parts should have been FP inspected instead of 125 for Acceptance.
    However, for qualification, ISO9152 requires only 5 parts, so, it is compliant for qualification.
    This topic shall be clarified in the future.
    Many thanks.

  2. Hello Nuray,

    Thank you for your comments in “additional documents” section.
    Qualification approved on my side.
    Best regards,

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