Originally Posted by chevvron
the ATC unit involved would need to phone D & D to establish contact with the aircraft first and that would take time, especially if they were busy.
..And with what would they be busy then?
I whitnessed once a landing clearance being issued on the 121.5 (in Porto) to an aircraft on finals.
Just before that he was told to switch over from approach to tower, and from that moment on, he was unreachable. So instead of letting the aircraft go in the Missed Approach, someone got creative and made the call on 121.5. So somehow this switching/requesting to make calls on 121.5 doesn't take all ATC units a long time.
Edited for chevvron. If still unclear, I'll edit again!
