Horizon Air

Paragraph (g)(2)(ii) last sentence states “The approved repair must specifically reference this AD.” As a foreign manufacturer Bombardier references the Transport Canada Airworthiness Directive not the United States Airworthiness Directive on Repair Drawings (RD). This requirement to reference a US AD has never been included in any previous US AD. The proposed rule does not provide a reason why an RD issued to correct damage found during this AD inspection must reference the US AD when in the past an RD referencing only the Canadian AD was sufficient. We feel the reference to the Canadian AD is sufficient and the final rule should be changed to allow a reference to the Canadian AD. Bombardier responded to our inquiry about referencing a US airworthiness directive on their repair drawing and they stated they do not reference US airworthiness directives on their repair drawings. A copy of their response is attached to this comment. Paragraph (g)(3) states “ Install new brackets and associated hardware…” we feel the word new is unnecessary and limits operators to only installing new brackets if they are removed at some point in the future even if the remove brackets are serviceable. We understand that the sentence comes directly from the Canadian AD but based on the FAA policy (as stated by the FAA office assigned to our certificate) of strict interpretation of the word new as a zero time part the sentence places an additional requirement on US operators to ensure that only zero time brackets are installed if they are every removed. We feel the word new should not be included in the final rule for this reason.