Originally Posted by pinseeker

You only get offered RAT if they change your original trip in such a way that you are put into sub, but the new modification still satisfies a legal sub trip. They will offer your trip back to you as a RAT trip first, then if you turn it down, they will offer it to you again as a sub trip.

The other way this could happen is if your trip was modified such that it took you past contract scheduled limits but still within FAR limits. Then they could offer it to you as a RAT trip, but you could turn it down and they couldn't offer it to you as a sub since it is beyond contract limits.

If the trip they offer you was never your original trip, it will be SUB.