Leaving the hold..
Thread Starter
Joined: Oct 2000
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From: Berkshire, UK
Leaving the hold..
When ATC issues instructions to leave a holding pattern in the form of, for example, "continue the right turn heading 130" why do some pilots head back to the holding facility before taking up the heading? It seems to be a procedure which many crews have adopted in the last few years and I wonder if that's what they're trained to do? If so, why? If I want you to set course from the facility I would use the phrase "return to XXX and leave heading 130", etc. Sometimes we want you to turn directly on to a heading to save time and by returning to the facility you could delay your place in the sequence.
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Interesting question HD. Bin a while since I did this but didn't the instruction include "take-up" or "turn onto" once upon a time? Phrased like you describe could it not be mis-understood? "Continue the turn onto 130" is less ambiguous as would "continue the turn and take-up a heading of 130" be. Just a thought. Like I said, it's been a while.
I will watch with interest.
I will watch with interest.
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From: Inside the M25
There are variations on the precise wording.. ."Next time over BNN, make your heading 130.". ."Continue the turn back to BNN and leave heading 130.". ."Continue the right turn onto a heading of 130."
So partly different behaviour follows different instructions.
Also, partly, it is laze. There is a button on the CDU/MCDU of most modern airliners labelled "Exit Hold." You press this, and the aircraft turns back to the holding facility and points downroute. You can then select the heading and change mode, without having to wind the heading bug round and round and living with the worry that, in the event of a power glitch it might suddenly start turning in the other direction if you rotate it more than 180 degrees from your current heading.
Oh, the anxieties of the airliner driver!
Interestingly, the Boeing FMC seems to do lazy turns in LNAV but 30 degree banked ones in HDG SEL, whereas the Airbus does 30 degree ones in NAV but 25 degree ones in HDG.
You can do the aviation equivalent of "cutting up" an aircraft underneath you if you are both cleared outbound at the same time and you get back there first. But not very often .....
So partly different behaviour follows different instructions.
Also, partly, it is laze. There is a button on the CDU/MCDU of most modern airliners labelled "Exit Hold." You press this, and the aircraft turns back to the holding facility and points downroute. You can then select the heading and change mode, without having to wind the heading bug round and round and living with the worry that, in the event of a power glitch it might suddenly start turning in the other direction if you rotate it more than 180 degrees from your current heading.
Oh, the anxieties of the airliner driver!
Interestingly, the Boeing FMC seems to do lazy turns in LNAV but 30 degree banked ones in HDG SEL, whereas the Airbus does 30 degree ones in NAV but 25 degree ones in HDG.
You can do the aviation equivalent of "cutting up" an aircraft underneath you if you are both cleared outbound at the same time and you get back there first. But not very often .....
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It could be that many FMC's take you back to the entry hold point, which is then used as the exit hold point.. .Depending on where the aircraft is in the hold will determine if it does a full hold or turns straight towards the holding reference.. .Just a thought, but saying something along the lines of 'heading now xxx' should do the job. On Mr Boeings finest, this should prompt the driver to do it with 'Hdg select', bypassing the FMC's desire to exit via the reference point.. ........ .ooops crossed with groggs who posted a far more eloquent explanation
[ 07 February 2002: Message edited by: Manual Reversion ]</p>
[ 07 February 2002: Message edited by: Manual Reversion ]</p>
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From: UK
Heathrow Director - as a pilot I quite agree with you - I cannot imagine why anyone would do other than select HDG and then fly the requested HDG!!
What the FMC etc is programmed to do is surely irrelevant, subject to flight safety this is a clear ATC instruction which should be complied with!
What the FMC etc is programmed to do is surely irrelevant, subject to flight safety this is a clear ATC instruction which should be complied with!
Thread Starter
Joined: Oct 2000
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From: Berkshire, UK
fireflybob and others. Many thanks for the comments. I appreciate that in this case different controllers have different ways of issuing an instruction but it's probably born from experience - ie issuing the one they think will work. Orbits, circles, 360s and other "leaving hold" type instructions aren't fully covered by our bible! Given a "continue right onto..." instruction I think most of my colleagues would expect a pilot to do just that, rather than turn towards the VOR. It's particularly noticeable at BNN in a northerly wind.. as they turn outbound we say "continue right to 130" and at least 50% will then turn north until they are north of BNN and then go through strange gyrations to get back over the VOR before heading 130. Meanwhile we've snatched three other a/c to fill the slot.
Joined: May 2001
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From: London,England
I agree with the poster above, if I am in hold at LHR (as I seem to be twice a day sometimes) I would take up an assigned heading as soon as it was given. If the intruction was return to BNN and leave heading xxx then thats what I would do. Some controllers seems to use the phrase "heading now. 130" which would seem to clear up any confusion.
By the way, I assume that all the app. controllers for London TMA are now at Swanwick with everyone else, how is going there?. Seems to be OK from our point of view.
By the way, I assume that all the app. controllers for London TMA are now at Swanwick with everyone else, how is going there?. Seems to be OK from our point of view.
Thread Starter
Joined: Oct 2000
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From: Berkshire, UK
Max.. no we're still incarcerated at West Drayton along with those for Gatwick, Stansted and Luton and the TMA controllers. Terminal Control is not expected to move down to the seaside for some years yet...
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From: Arizona USA
The Heathrow Director has raised an interesting point...I wonder if "newer" guys/gals are so ingrossed in the FMS that they do not actually "listen up"? I have watched on many occasions where a new pilot watches the aeroplane do something unexpected only to find that the FMS was programed incorrectly...or malfunctioned.
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I agree with fireflybob - if the instruction was issued as quoted by HD in his first post, then the obvious thing to do is go to HDG and select 130. Can't see any problems there!!
I suspect 411A may have a point - I wonder if it isn't the newer boys 'n gals who are reluctant to take command of the FMS? It's not their fault tho' - the training system these days seems to suggest that the FMS is God.
I suspect 411A may have a point - I wonder if it isn't the newer boys 'n gals who are reluctant to take command of the FMS? It's not their fault tho' - the training system these days seems to suggest that the FMS is God.
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From: Camp X-Ray
As a reasonably recent graduate of the flying school sausage factories, my understanding of the rules is that when instructed to 'leave the hold heading xxx' one should continue the hold then leave on that heading next time over the holding fix. If instructed 'fly heading xxx' then that should be carried out immediately. Suppose its down to how the instructions issued.
It's not just an adventure....
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From: Philippines
What about that old favourite everywhere else in the world:
"For Vectors to Final or Vectors for Spacing...Turn Right Heading 130."
Seems simple to me.
Cheers <img src="eek.gif" border="0"> OffshoreIgor <img src="eek.gif" border="0">
"For Vectors to Final or Vectors for Spacing...Turn Right Heading 130."
Seems simple to me.
Cheers <img src="eek.gif" border="0"> OffshoreIgor <img src="eek.gif" border="0">
Thread Starter
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From: Berkshire, UK
I don't think that phraseology is UK approved! However, there is no reason to believe that it would have any effect. I mean, how much more precise do you need to get than "turn right heading 130".... and why do some crews not do just that thing? It's always "vectors to final" at Heathrow so that should be understood.
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From: Canada
DIRECTOR, OWTTE = or words to that effect, sorry.. .If someone returns to the hold fix after acknowledging, f'rinstance, "Hold cancelled, turn right/left to 130" then they could not have understood the instruction. Why I can't imagine. I do not know how much clearer it should have to be.
Thread Starter
Joined: Oct 2000
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From: Berkshire, UK
Thanks everyone.. doesn't seem to be a simple answer does there? I'll continue with the phrase one I've had some success with: "Continue right heading 130, no need to go back to Bovingdon"!!
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From: Canada
Hello again Director, I hope I am not sounding argumentative, but, you suggested the use of:. ."Continue right heading 130, no need to go back to Bovingdon"!! . .I wonder if the addition of "no need to go back to Bovingdon" just adds to the opportunity for confusion. Particularly if one the recipients is busy at the time (advising company of delay, advising F/A's, pax and so on).. .All they have to do is garble the "no need" part and now Bovingdon is in the transmission muddying the thoughts. I can hear it now, "Whadesay? Back to Bovingdon?" and so on. . .I still like "Hold cancelled, right turn to 130"