Hold/Stack Questions

[zoink]

Hi All

A question from a newbie got to do with Holds/Stacks on approach

Is there any rule or controller preference to remove aircraft from the hold/stack before they reach the bottom FL? ie would an AT controller bring all the heavies (B747, A340) off the stack in sequence even though they were not in consecutive FLs so he/she/they/the airport can land similar type aircraft together to make more efficient use of the minimum separation on approach?

Would anybody have any more information on how holds work, URLS etc..

Thanks in advance and apologies if i get the terminology incorrect!!

Zoink

[ferris]

It will work differently at different places, but in general you bring them in any way you see fit. ie. whatever suits at the time.
Airlines offering controller discounts first, then those which piss you off least on a regular basis, in descending order, etc. etc.

[Bright-Ling]

Airlines offering controller discounts first, then those which piss you off least on a regular basis, in descending order, etc. etc.
That is a simply disgusting attitude Ferris. Not least because no-one would ever land if you applied that criteria!!!!!! :)

http://www.stopstart.freeserve.co.uk/smilie/hyper.gif

On a serious note, LHR approach is explained here....

LHR Approach (http://www.pakaviation.com/PVA/Library/Docs/atc_pia_approach.html)

B-L

[zoink]

Thanks BL

appreciated!! :)

[055166k]

zoink In a holding situation it is likely that a pilot has been advised of his/her Expected Approach Time [EAT] if the delay is going to be 20 minutes or more; based on this information a pilot may make a series of calculations regarding possible diversion alternates, remaining fuel etc. If a controller starts interfering with the anticipated landing order without amending the EAT of disadvantaged traffic there is a definite safety risk to that traffic. If you ever become aware of such a practice I suggest you take it up immediately with the ATC unit concerned so that all R/T and Radar tapes can be impounded for investigation, as well as paper flight strips if they are used.

[Scott Voigt]

166;

"in case of controllers interfering with the landing order." WHAT! Who do you think comes up with the landing order? We pull them out of the stack in usually the order that they come in, or sometimes you pull out one that is closer to the arrival fix since you don't want to waste a slot space due to the lower aircraft already being on an outbound leg vrs, the one above who is on an inbound leg.

As to knowing about changes to your expected clearance time, you aren't going to notice a difference since you are only going to get a difference of a minute or so between aircraft...

regards

Scott

[AirNoServicesAustralia]

Do as we do, unless the hold is for more than 30 minutes we don't have to tell the aircraft.

ABC: How long can we expect to hold
Controller: Not more than 30 minutes

End of conversation.

Agree with Scott, we make the order and pull guys out of hold in whatever order makes for the most efficient use of the airspace available.

[Jerricho]

Just as an aside, even though we try and ensure the first to the stacks are "first served", we do try to group like type wake vortex categories (for example, a run of heavies, or 757's, not heavy, medium, heavy, medium). Also, if we're in major holding, to get the optimum vortex order on final, sometime an aircraft is taken off a hold that isn't the bottom one, especially a light or a small (that great UK category). Although, usually if you tell the other guys and gals holding why, they play the game.

[Quokka]

Hi ANSA,

I wonder if it's not a case of "we don't have to tell them", or, more a case of the FLOW controller doesn't know... I've yet to see a FLOW controller advise a Stack Departure Time for an aircraft in the sequence. The nearest advice I've been given has been "expect a six minute delay", which to me is an expectation, not a Stack Departure Time. Often, these expectations aren't very accurate. But, I guess, any advice to the pilot is better than no advice. The one thing I hate saying to a pilot enquiring about the delay is... "I don't know".


Jerricho,

We work on the same principle: defering the priority of one aircraft, where a significant economic benefit will be gained by a number of other aircraft. Thereby delivering a overall benefit to the industry.

[AirNoServicesAustralia]

Hey Quokka, its a bit different over here, as we don't have a flow controller. I suppose you could say we are masters of our own domain ;) We as the executive controller, decide when we are going to hold aircraft and all we have to do is, work it so they come in 10 NM in trail. We release the guys from the hold as we see fit and in whatever order allows us to achieve the 10 NM in trail.

[ILS 119.5]

Sometimes this is dependent on where the hold is situated and also what kind of approach the pilots wish to make. At larger airports most a/c and pilots are equipped to make cat 3 approaches, therefore can make an approach at anytime on a "first in, first out basis". However at smaller regional airports not all a/c or crew are equipped to make cat 3 approaches. So the situation arises when the no.3 a/c in the hold can accept a cat 3 approach but no.1 and no.2 cannot therefore no. 3 is now no.1. My personal opinion is that on a normal day with all things equal then "1st in, 1st out" should apply.

Overheard from a/c routing to BOV in 1990 (World Cup), "Hello London it's Alitalia XXX, what is the Italy/England score" "Alitalia XXX London Control it's one nil to Italy so have to put you into the hold" Stunned silence!

To the member from Abu Dhabi, don't use the last as an excuse as the UAE will never get free tickets to the world cup!