Climb Sequence,
You are absolutely right, the ATR FCTM is not intended to replace FCOM, as it is the case for the Airbus one as well. The page 1 of Introduction of the Airbus 320 FCTM states that in case of conflict, the FCOM is the over-riding authority. It even states that airline policies may vary as well, and that airline policies will be then the overiding authority. In order of priority, it seems clear that :
1- FCOM
2- Airline policy (SOP's, variants, etc)
3- FCTM
ZFT: correct about the variants vs "groups of variants", just that in today's operations, a 42 "non-PEC" is a 42-300, or a 72 "non-PEC" is a 72-200, not much else, if you exclude the 201-202, etc.
There will be a complete change in the way the operating procedure will apply with the -600 series coming soon, it'll be interesting to see how to implement so many changes in the current state of things, while trying to keep commonality, but this is another subject, and I apologise for deriving from the intended question from midcon385.
Flex