QAR: Click Here
Conditions for approval required by: Julien Gauther
Certification of Aerospace Products to international quality Standards
Certification of Aerospace Products to international quality Standards
Form restricted to registered, logged in users. Please return to the home page and use the Create Account option.
This MRC deals with silver plating outsourcing.
Reusability test at ambient temperature (12 cycles) has been carried out by HFS to verify if locking torques are still conform after changing silver plating source.
Adhesion test after 450°C baking was carried out as per EN3299 and EN2786.
In addition, EN3299 requires a reusability test at ambient temperature after 450 °C baking (5 cycles).
Apparently, this reusability test after baking was not carried out although silver plating has changed.
Is locking torque test after 450°C baking also compliant?
Last version of EN3299 is: EN 3299:2019.
Which version of EN3299 is applicable for this MCR dated July 2020?
Indeed, as per EN3299:2019, bolt material for reusability – 12 cycles is A286 uncoated, while as per EN3299:2007, bolt material for reusability – 12 cycles is alloy steel with 58 HRC minimum (uncoated as well).
Many thanks in advance,
Regards.
The assumption that the “reusability test after baking was not carried out” is entirely correct.
Only the “Reusability test at ambient temperature (12 cycles) has been carried out”
The ACP008 procedure for Manufacturing Change Request Approval (MCR) in the ASD-Cert Quality Manual, issued 19/12/2017 (ASD-Cert site), page 49/62 indicates the following:
“ASD-CERT Secretary General will forward the MCR to a nominated Auditor to request for his recommendations & proposed costs for the audit or review. If agreed, the manufacturing route used to manufacture the parts, shall be accordingly changed, proven (by any applicable testing required by the auditor), established, agreed, stamped and sealed”.
As designated auditor in this MCR procedure, I agreed as an applicable test to what was proposed in the QTP of this MCR as test (page 5, point 5.4.1.1. Self-locking torque at ambient temperature (12 cycles)).
Hence the “reusability test after baking” has not been performed.
In this case it was sufficient to demonstrate that the outsourcing of the silver plating had not affected the self-locking effect.
With regard to the question which version of the EN3299 was used, the QTP on page 2, Note 1.1, gives an answer. It shows that the EN3299 should be read as EN3299:2007.
Hope this explanation has answered the questions.
Regards
Thank you for replying, it is clear.
Approved.
Best regards.