Originally Posted by
misd-agin
Read transport jet certification standards. They do test to a full side slip and rapidly release the rudder. It's the opposite rudder (doublet) immediately after that to a sideslip in the other direction that steps outside of the 'certified' envelope.
Please do not take that as an endorsement of doing sideslips. Just explaining the certification process.
But bear in mind that a "full sideslip" for cert may be less than what you could get if you applied the full rudder at a given speed. Especially above Va, where there's no need to be able to apply full rudder.