Canoehead,
As I should think you are aware, arrivals manager trials are pending in the UAE centre.
Rule 3
Are you suggesting that a reduction over 5 miles, approx 45 seconds an aircraft is only going to lose 20 knots slowing from 310 to 290. I don't think so
Depends on how it's done but I would be very surprised to see ANY modern widebody, flown within the prevalent SOPs of today's operators, maintain 300+ kts until 5 miles before a given waypoint, be instructed to reduce to 250 5 miles out and cross the given point at less than 280-290. We all know it CAN be done but then I refer you to the answer given by the honourable (?!) Oakape some moments ago.
Oakape
Believe me, we are not complete imbeciles and do have some understanding of aircraft performance - there tend to be a fair number of flyers in atc and no, they don't all fly c152s!
The problem with constant descent approaches such as you advocate, is that they really require modern equipment (on our side) and procedures - both of which are sorely lacking in this part of the world. The radar is on the way but don't hold your breath..... As for the procedures - good luck.
As Ferris has stated, the whole of the UAE's procedures are extremely dated but the danish dolt absolutely refuses to allow anything to be changed, after all, they must be perfect as he wrote them!! This leaves the controllers both in Dubai and (particularly) the UAE centre with at least one hand firmly tied behind their backs at all times. Add to that the "f*%K it up and you're gone" mentality and it's clear to see why some allow a margin for error.
With particular regard to Dubai's Bubin arrivals - when it's busy and you call approach at bubin (for RWY30L), there are basically 2 choices for the arrivals controller - direct (or a heading towards) sedpo or right heading 330 or so. IF there is a gap for a straight in, the next factor is your altitude and speed. 11,000ft and 250 kts or so - good chance of the straight in - 17000ft and 300kts - not a hope!
The only other option would be to give a heading of 300 or so, see how you descend and fit in the sequence as appropriate - this however puts you head on to all of the desdi arrivals, neccessitating vertical separation be maintained between the protagonists and I can pretty much guarantee that SOMEONE (esp. if there's a 380 involved!) will be descending at 200fpm or so - thus removing that option or leaving EVERYONE too high.
Therefore, descend at a reasonable rate (in my book 500-1000fpm - if I need more I WILL say so)
or suck up the miles and I'll let you know the track miles when it becomes apparent where you will fit in the sequence
. We don't have the space to do anything else. Sure, you could hold at bubin but they don't have the space either!
Pretty much the same goes for 12L but then you get the occasional added fun of US mil firing fighters off from a carrier directly under you (dont laugh, it happened AGAIN this week) WITHOUT EITHER PRIOR WARNING OR RADIO CONTACT and/or sending a p3 across the CTA who, funnily enough, needs to descend through all of your levels and then immediately climb back through them again. Sometimes they even tell us in advance!
