Originally Posted by
dragon man
How can they meet the requirements when there isn’t one and it doesn’t say how the inspection is to be done? I have never heard of retrospective signing off on an AD?
There are exceptions, but most of the time, an AD simply mandates an existing Service Bulletin (either airframer or engine). So if the existing SB has already been complied with, and the AD doesn't include any additional actions aside from what in the SB, then they could easily have already complied. It won't be official until the AD gets released (sometimes the released AD changes based on comments or new data), but it's not unreasonable for an operator to say they've already complied based on the preliminary version of the AD.
A primary reason for AD's is that Service Bulletins - even Alert SBs - are not mandatory So some operators don't bother unless it gets AD'ed.