AD's
AD's are not unusual for any type of aircraft, rotary or fixed winged, and quite normally are issued before a new aircraft takes to the air for the first time.
Some C of A's I have done have involved checking the compliance of 100+ pages of AD's listed against a single aircraft registration (B737).
99.9% of AD's are called up to inspect something first and the next step is to replace it in due course of time or cycles.
In all cases there is a Lead-Time to get all the spares available - though MD seem to have more spares troubles than most other manuafacturers.
However, all manufacturers are a bit 'lazy' when it comes to doing these seemingly urgent things - it all costs money - and even 'they' don't like paying for open-ended overtime!