With respect,

It would be a big help if you all used standard phraseology. At least one post above offers three alternatives, none of which are correct.

And yes, HDG SEL Is the only way to go, and go now...

Well don't keep us in suspense, set us all straight then.

NorthernSky... With respect, the whole point of my original posting was that standard phraseology doesn't always work! It seems to be a problem which has started in recent times and, judging from earlier comments, possibly attributable to various flight management systems. If pilots responded to standard phraseology in the situation referred to this thread wouldn't exist.

Well, the bloke in exile wrote:

"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."

None of which (if memory serves) feature in the Part 1.

He continues:

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.

He's part of the way to being right, but the wrong-way turn has nothing t do with power glitches, just the type/variant being flown, and the EXIT HOLD prompt does different things on some types (some will complete that 'lap' of the hold, others will turn immediately to the fix and leave), and in any case using EXIT HOLD in rersponse to an instruction to leave the hold on a heading would be poor technique.

More...

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.

Here, he's plain wrong. Both aircraft, in NAV or LNAV, will use various rates of turn at various times. How they choose to do this is real rocket science. In HDG SEL, both types will use a pre-selected angle of bank, selected on the MCP/FMP.

No offence to Exile, but a little knowledge is a dangerous thing.

Director,

We both posted simultaneously. My gripe is not so much with sparing use of non-standard phraseology, but failure to use standard phraseology and 'best practise'.

I don't mind 'ABC001 Fly heading 130 degrees, turn right onto that heading now' (standard phraseology backed up with a little nudge for common sense), but I loathe 'ABC002 right now one three zero'. Another good example is 'XYZ003 contact London 118.82, that's eighteen eighty-two' used when an aircraft has missed the frequency first time.

Yes, what I wrote was a drastic oversimplification. But I was talking particularly in the context of holds. In a B737, if you take HDG SEL and 30 degrees of bank, you will do a 30 degree banked turn onto a heading. If you stay in LNAV, then it will fly round its nice tidy racetrack, with (in some winds) as little as 5 degrees of bank to keep it sweet. In an A320, you may be turning back to the hold with a 30 degree turn in NAV (which a B737 will rarely use, as it works out its nice tidy racetracks). If you pull HDG, it will slope it off to 25 degrees. And if there's a way to override this 25 degree turn in HDG at that level, with no other modes engaged, then I don't know what it is. Yes, a little knowledge is a dangerous thing. Perhaps you might like to explain how that can be achieved then?

The point I was making is that pulling HDG in an A320 will not necessarily improve your turn. In a B737, selecting HDG SEL and a 30 degree AOB will give you the best turn. This has a bearing if you are told to "tighten up the turn" - a subject which is related.

I would have written a full behavioural explanation of the autoflight systems of the B737 and the A320, but I thought it might cause people's optic nerves to leap down their throats and strangle them before they died a horrible death of boredom.

The radio calls are not standard. They are all used, and are all precise instructions. I don't know to what extent HD or others were aware of the variations used by other people. I guess the LATCC crowd are pretty aware. Others might not know all the details of this argument but might be interested.

Exile.. points noted. As I mentioned earlier, the "non-standard" R/T instructions are a result of controllers finding out from experience which ones produce the required result - ie which ones the crews immediately understand. As for the technical explanation - much appreciated but even that doesn't explain the following typical scenario: Bovingdon hold - roughly southeasterly inbound track with a right turn outbound... As an aircraft starts it's right turn I say "xxx turn right heading 130 degrees" (perfectly standard and non-ambiguous phraseology). The aircraft now turns on to a northerly heading to take it north of BNN... then turns right to the VOR to pick up a heading of 130.. (Happened to me the other afternoon). In miy mind the crew believed that my instructions intended them to start the heading from the VOR.

When started this thread I was expecting someone to say "yes, we're trained always to fly to the beacon before taking up the heading"... but nobody has. Incidentally, in my experience it is only British pilots who do this. Americans, Europeans, South Africans, etc, all simply turn on to the heading. Maybe my colleagues will comment otherwise...?

Heathrow Director

As a "baby" IR (qualified last June!) I would continue with the right turn, rolling wings level to take up a heading 130.

I will now shutup as I am "uncomfortable" with the level of experience here as compared to mine!

All the best to you all - hope things get better.

Out.

As an even younger IR, I was told (in America) that the American way was to fly from wherever you are, and the British way is the go back to the fix and fly from there. So I was certainly taught to go back to the fix, although with your terminology I would probably have done what you wanted. However, I am still wet behind the ears.

How about: "xyz, fly heading 130" or if you want xyz to execute the turn after the fix:"xyz, reaching zyx, fly heading 130". .". .Should there be doubt as to the direction of the turn, ie the long way around, one could say: "xyz, turn left heading 130"

But given a heading,with no other instructions, I would certainly hdg-sel and turn promptly.

As a middle-aged (Brit) IR, I cannot for the life of me understand why pilots would not take up that heading immediately.

Were the phrasing to be "Leave the hold heading 130 degress" or "Next time over the beacon head 130 degrees", then perhaps...

Well, if its the British Way then its news to me!

Heathrow Director,

As a matter of interest, how often are you talking about? 10% of the time? 1%? Or what?

Are there any operators that do it more often?

There are certain types of finger trouble that can catch any of us out, if the rate of occurance is very low I would suggest that error is a more likely cause than deliberate policy.

CPB

Capt Pit Bull. I would guess that BA is the winner with a few BM types too. With foreign ops it's virtually nil, which prompted me to wonder if it's something which is taught in the UK. I'm not trying to get at anyone; I'm simply curious, as are some of my colleagues. Maybe it's our fault? So often we say "return to XXX and leave heading xxx" that when we ask them simply to continue a turn onto a heading they interpret as meaning return to the VOR.

I'm a night freight pilot and never have to hold anywhere ,almost always get direct routings.Only holding I ever do is on instrument renewal tests. <img src="smile.gif" border="0"> <img src="smile.gif" border="0"> <img src="smile.gif" border="0">

I'm a regular at BNN(20+ years),the most often heard clearance is 'next time over BNN leave on a hdg of xxx'.Followed by 'next time over BNN,one orbit right,then xxx'.Occasionally 'no need to complete the hold,just turn on to hdg xxx'.

All this seems quite unambiguous.

However,a couple of nights back,when all aircraft were being given headings to take up directly,I heard a classic,the like of which I'd never heard before.'Midland xxx can you see that Swissair 320 below going down your left hand side'...Affirm,'good then turn left and follow him'.. .Absolutely brilliant :) That wouldn't be you would it HD :) :) . .A very slick operation it was too.

. . <img src="wink.gif" border="0">

[ 18 February 2002: Message edited by: moleslayer ]</p>

Well, I guess in summary: as somebody who frequents BNN, if I was told to take a heading of 130, that is what I would do. If there was any doubt, I'd clarify it - "Would you like us to route via BNN?" But as HD points out, and as the other example clearances suggest, such ambiguity is rare. LATCC doesn't have the slack to allow it.

HD...

The many ways of "leaving the hold" expressed by ATC, and the rumours of what "they really mean" occupy our brains, and the Route Checkers even more...

Maybe if you think you have said something clearly, and we do not "obey", a little jibe or question might help all... As a QPQ, if we are unsure, maybe we could ask.

IMHO, blaming the FMS is weak - we are supposed to know what the FMS will do (I don't half the time!), but can always override it if we don't like it (so I have to...!)

BRegrds. .NoD

Moleslayer... it wasn't me if it was very recently because I am on days off. However, it is a procedure which I do use to great effect in VMC conditions! Maybe it was somebody who has benefitted from my vast experience over the years. (But don't tell him. Tee Hee!!)

Having watched the a/c track carefully the other day whilst leaving the hold the other thing that occurs to me is that no matter what you do the a/c ends up pretty well over the beacon when you leave the hold. Most of the heading assignments are almost aligned with the hold anyway so if you are given a heading to steer from most parts of the holding pattern you are going to pass over or very close to the beacon.

Max Angle. Have you heard Fred's corollary to Sod's Law? It goes like this: Given two identical aircraft at an identical position in the hold and both instructed to "continue right turn heading 130", the one above always ends up exactly 2 miles in front!