FAQ n.104933

If the change to STC is Basic and does not require a change by the Certification Authority to STC, how does the operator/CAMO know the change is directly accepted?


As a matter of principle, when a Basic major design change does not affect the TC, TCDS, TCDSN, its approval by the CA (under provisions of TIP §3.3) is considered as a valid approval by the VA and will be accepted without any review and without any issuance of a VA approval.

In the specific case of STCs:

  • If the Basic major change is brought by someone else than the STC holder, then it will trigger another STC (hence to be approved following the streamlined path)
  • If the Basic major change is brought by the STC holder:
    • If STC was revised to cover this change: to be approved following the streamlined path
    • If there was no need to revise the STC: the mutual acceptance path (as per TIP §3.2) is applicable.

      This is a very rare case where the major change to STC would be already covered by the documentation quoted on the STC certificate. This could be the case for an update of AML, update of ALS when no date is indicated on the certificate (ref. mention …”or later revisions of the above listed document(s) approved/accepted under the EASA system”).
      In this very specific case, as for basic accepted design changes, the modality of approval by the CA serves as “proof”/indication that the change is directly accepted.
      It is in the interest of the design approval holder to maintain a clear status of the nature of its changes approvals (validated or not, basic or non-basic). In case of doubt, confirmation should be sought from the CA.

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