Glasgow and Prestwick SIDs and STARs
I am aware that certain SIDs and STARs were changed with effect from 11 December 2014. I am curious what prompted these changes although I understand the Dean Cross VOR was withdrawn from the same date.
Specifically, I see that the former New Galloway and Turnberry SIDs have been truncated at NORBO - what is the benefit in the SID terminating closer to the departure point ?
Finally, I've always wondered, why do such changes always happen on a Thursday?
Any information would, as always, be much appreciated.