I was one of the lucky ones not to have an overload last summer, but, was also about when two of them happened and its not very nice.
Just to continue what some other people have said, it is regular to have several trainers in the system. As an example, on my last shift, there were two a/c filed to join at exmor, one routing Exmor / BCN / OF, the other, Exmor / Tinan / BIA (I think). They were both passed to me by Yeovliton 4 miles apart at FL60 and 65 respectively. ( The one at 60 might need to check their quandrantals! )
At the same time, there was a trng flight departing Brizzel, routeing BCN / Alvin / GST requesting FL90 and a C130 in the Cardiff hold descending FL100.
None of these aircraft want headings, the idea i would presume of training with reporting points is to actually use them (!), so, I level seperate them. Base level for most of their routes is either FL65 or FL75. So, One exmor Join Climbs FL80, The other to FL70, The brizzel Dep gets 90 C130 in the hold at FL100.
With a crap load of a/c outside of CAS playing perfectly by the rules and not on frequency and being too lazy / ignorant to think we might want to speak to them, so, the proper flights are being vectored all over the sky to get below the hold and the overflight trainers, and keeping their turns inside CAS against the unknowns outside. Easterly winds, so Bristol Inbounds from the north are still getting used to their new descent profiles / level restrictions which doesn't give them many extra miles to play with, especially when I lob in a wedge of speed control.
It was quite good fun, but, the lesser priority flights ( Sorry trainers but thats you (and u r also not revenue making - damn freeloaders (thats a joke))) were creating massive bottle necks in the system.
The best way to flow this situation so that everybody gets an acceptable service is to restrict the lesser categories of flight. As Gonzo quotes from the Mats part 1, thats the route which has been followed. I am sure training schools and trainees alike do not agree with it, but, its the rules!!
As far as restricting Filtons earnings potential, maybe the aircraft who wish to train at Filton can route outside of controlled airspace coming into you, and fly airways on the return flight instead? (subject to slot of course
).
Anybody free calling wishing to join without a slot (certainly when I am plugged in) will be turned away. This measure has been put in for the safety of the airways users (thats all the people that contribute here whether they be crew, pax, or anything else)
Sorry guys, SAFETY FIRST.
/end rant
TIO