It is quite amazing to realize how little aircrews actually know about ATFM. Mixing up airport slots with ATFM ones will not help you much in your quest to understand the big picture.
(Now I have to defend the CFMU ! Big change )
(To the Guvnor : Avman is on leave but is not, and by far the only man in Eurocontrol in this Forum.. By the way I am still waiting for the contact in AAA you promised me months ago, I still need those DC8 engine fuel igniters knobs... )
Back to our subject :
I am amazed by the first post by Twistedfirefighter who called it "madness"to have his slot cancelled.. Which means he would have rather liked to have the CFMU kept its original CTOT just because it was issued, instead of releasing him once the ATFM restriction that caused his delays was no loonger active ?
ATFM restictions can be put in place for various reasons, capacity is one , but often it is staff shortage ( as explained already) but also equipment failures. Those comes without warning, and when the systems comes back it is also generally sudden. So ACC ( the Centres) lift the restrictions at once, and then the CFMU try to cancel as many CTOT as possible...
Complaining about this may send the wrong signal to CFMU operators my friend....
Incidentally do you prefer to hold en route or in the ground , bearing in mind that if you all hold en route, you will increase the delays for the others on the ground ?