It varies from unit to unit
we are limited by the normal 7 day FTL rule although we work a variation on the roster
(the 7 day rule being, no more than 60 flying duty hours (not flying hours) in any seven day period.
we work 12 hour shifts
5 days on
5 days off
5 nights on
1 rest day
4 days off
back to 5 days on etc. ad nauseum adnauseum
No fatigue here