Thanks for all your replies,
The main reason being offered is stable approaches. If I wanted an aircraft to fly faster than 160 inside seven miles it would be a request, not an instruction. I wouldn't rely on it in my planning and I wouldn't position another aircraft 'tight' behind unless I had the pilot's agreement.
Is 160kts by 7d and until 4d acceptable ? If not I think we should have notice on first contact with final director.
We do appreciate the need for stabilised approaches and I'll always allow a bit more spacing if an aircraft is particulary high or fast. But surely if you are ignoring an instruction you should ask first ?
If it is all down to sesma/other company procedures is it best to handle this with an MOR, so the relevant airline department can get involved ? We might then be able to work towards a solution together.
The last couple of days the headwind component at 3000' has been very small (and generally CAVOK) but would that require an unrequested reduction to 160kts at 9/10 miles by 737,744 and 757 aircraft ? Is a speed reduction that far out done in order to stabilise the approach ?
LOST SOUL,
I'd be very wary about adding a ten knot tolerance on final approach speeds. 210/220 even 230 kts shouldn't make much difference but if you are four miles behind a 757 going ten knots faster from 12 miles out you will catch up and seriously erode vortex spacing.
On the other hand, if you request 170 to four on first contact with final director we can sometimes accomodate. I'd better be careful here as many of my colleagues will not thank me if every 737 starts asking on first call, but I'd rather know that's your preference and try to help out. I should also point out I can't do it if delays are excessive or wind or viz is particulary bad.
Thanks for the replies, keep them coming