Sequencing choices...how do YOU like it?
 

hey jet-jockey's,

So I need to make a sequence of two aircraft into a class C areodrome, I need 10NM between them by 40NM from the field. I can:
* Vector the 2nd aircraft (at high level) to achieve the 10NM and then give him profile speed on the drop?
* 2nd aircraft to min clean in the cruise, and not abv 250k on the drop?
* Leave on profile in cruise, not abv 250k on drop and then vector at about 50NM to achieve the 10NM spacing if I don't already have it?
* (Prob the most preferable...?) but give the 2nd aircraft a time and speed to cross a feeder fix at 50NM a while out?

I am asking which the crew prefer by way of pax comfort and fuel usage. I use most of these each day and want to see which you guys prefer? Assume the speeds on the drop are given way in advance of TOD.

Thanks and look foward to your answers.

GD.

Clean/250
 

GD,

Personally I prefer the second choice (min clean to 250 knot descent) if that gives the reqired separation.

The Required Time of Arrival (RTA) function of some FMS used to meet the feeder fix times is a little suspect on descent. Basically the dynamic conditions experienced changes the profile too often and by large speeds/thusts. If we could get ATC on our flight decks again I would gladly demonstrate.

From a fuel efficiency point of view I cannot emphasise enough the importance of getting the descent speed prior to TOD.

I find the feeder fix at a particular time works best. It keeps things simple and all that the crew need to do is alter speed to arrive at the fix at the correct time.

I find that with vectoring we could be taken anywhere. As far as im concerned its always nicer to know where we are going.

Tiger

* Vector the 2nd aircraft (at high level) to achieve the 10NM and then give him profile speed on the drop?

That sounds like the best option to me - a little correction a long way out and then a nice efficient descent - at least until we get dicked around close in:hmm:

* 2nd aircraft to min clean in the cruise, and not abv 250k on the drop?

Do that and we'll have the speed brake out on descent (almost all the way down) unless you give us reasonable warning so we can program that and start descent further out.

* Leave on profile in cruise, not abv 250k on drop and then vector at about 50NM to achieve the 10NM spacing if I don't already have it?

That seems to be what usually happens:ugh:

* (Prob the most preferable...?) but give the 2nd aircraft a time and speed to cross a feeder fix at 50NM a while out?

That works but often we don't get told until we almost can't slow down enough to comply.

In the end the best laid plans of mice and men do oft go astray:ok:

Quote:

---

Sequencing choices...how do YOU like it?

---

I like it (ie this evening) when the nice lady approach controller makes me No. 1!

Qlink XXX: Townsville approach, Qlink XXX cleared to nine thousand, visual, with India
TL Appr: Qlink XXX, you're number two to a Bonanza tracking for right base zero one. Would you prefer vectors to a ten mile final runway zero one, or overfly for a left base?

YES! :E

Dr :8

And you fly all the way to landing thinking about how your V tail resembles two fingers to the following aircraft....right? :E:ok:

I like time over the feeder fix, achieved by lowering the speed via changing Cost Index (if not already too low, of course!). We can lose 4 minutes from 200nm out with no other drastic action. That reduces the cruise speed and the descent speed nicely so the enviro-nazis :cool: are happy too. If we can't reduce, then most of the track-stretching at high alt with a little more down low if required would be the best.

The pax are always comfortable in our machines...:ouch:

Just do a bit of tactical vectoring.. and ask one to accept a short visual approach :ok:

Back in the real world, how about getting the trailing traffic to come back to minimum clean....get the 10 miles, and give them an unrestricted descent.

Feeder fix works best for me. We can put the time to cross the fix in the FMS and as long as its not below min clean the aircraft will do the work. We then always know how many track miles to run ( we dont know if you start vectoring us) and the FMS cant work out the most economic profile to save fuel.

Trent,

No argument from me there re the speed prior to TOD. If you do it in selected speed on a profile for a different managed speed you are adjusting with thrust or spped brake. Not really what the beancounters (or pax apparently) want.

GD,

I hope I am not stating something way too obvious to say that no matter what method you use the more notice we get the easier it is to achieve what you want.

I know we don't have the big picture in the FD but sometimes we get the instructions too late to do much about it. If it is due to last minute changes in sequence or a pop up etc a quick mention over the radio will do the trick and pacify the personalities that tend to get agitated over such trivialities.

So the more less thought out mice plans often work quite well, if mice just wing it and go with the flow?

Thanks for all the feedback.

Feeder fix works for me too. Sharing information (as in how much time I need to lose) is always helpful too. Don't forget that changing the descent speed changes the top of descent point (sometimes quite considerably when comparing a high speed descent to a low speed one) and so that factors into our thinking also.

Aint that the truth - the planes get cleverer (and more of them) - the pilots get less cleverer - and the number of runways stays about the same - the number of ATC staff decreases - the noise complaints increases.

Despite the best intentions in the world there is not a damn thing anyone can do to improve the situation to where we won't get vectoring/speed control/all of the above between TOPD and landing unless more runways exist with less noise constraints.

Anyone who gets overly stressed about this perhaps picked the wrong job.:ok:

You could perhaps speed up the first guy.

Feeder time seems to be the best for all. After a long 12+ sector, I agree with the Dugong pilot (the only time I will..hehehe). Hong Kong do the Slam Dunk when coming from Europe, be we all know its coming. Not in Sydney ( my home town). SYD has a very bad reputation internationally, good to see a good controller asking very sound and good questions.
I look forward to next time I come down.

Is Big Al still in Sydney APP/TWR. Bloody great controller. He and all the guys used to slot the Duck in like a well oiled machine:ok: