Originally Posted by Dallas
In civvy world when a flight plan is addressed a copy is sent to the alt(s) by AFTN, so in theory, provided the AFTN address is actually read by someone, they will see the FPL and you would hope, remain available for it! But in the commercial world there's no guarantee of either!
NOT if the plan only gets sent (as 99.999% are) to the collective IFPS address if IFR, or the FIR collective address if VFR. IF you want it to go to the Alternate you have to make sure it's addressed to them - it won't go there as a matter of course.