Ansett .......received a service bulletin from Boeing two years earlier notifying the airline that the 767s needed to undergo the inspection on reaching 25,000
CASA recognised the seriousness of the Boeing alert service bulletin. While
the US Federal Aviation Administration at that time had not issued an airworthi ness directive mandating the alert service bulletin, CASA took action to mandate the service bulletin in Australia. The FAA followed suit
SO English comprehension isn't your forte there Lead Balloon.
To help you, the sequence was that ANsett missed the SB and then CASA took enforcement action, sometime later they raised an AD