Just recieved a phone call from a W/Body Capt. regarding speed restrictions given after Top of Descent(TOD). The question was why is that speed restrictions are given after they have commenced their descent. This happens most of the time when they are inbound from the south (Abm Arama) and PK.
Good question Capt. The reason is speed restrictions are imposed by the Flow Controller as soon as he/she decides on the sequence into KLIA. Once this is done, the Sector Ctler will advise the acft accordingly when in contact.This phrase 'when in contact' can be when one has already started their descent in SIN a/space (eg just before VJR) or well before PK depending upon the height.
Pro active CTlers like me will call up SIN and advise SIN ATC to advise the acft regarding descent speed so that one can adjust their speed accordingly. Not many ATClers do that for reasons best known to them. I know it is very frustrating to receive a restriction when one is already too close.
My advise is that when you are inbound into KUL the next time, check with SIN ATC whether there are any speed restrictions in your descent. This helps eliminate a lot of frustration for both flyer and CTler. Many times SIN ATC swithches frequencies right on the dot at ABM Arama or PK. By that time you are already well past your TOD.
