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Duplication of QNH on Clearance callup

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Duplication of QNH on Clearance callup

Old 13th Aug 2007, 10:47
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With regard to the initial question, our local instructions ask pilots to make first call with the information letter and QNH thereafter it is only mentioned again if there is a change
As long as we're mentioning this, I wish there would be some consistency in ATIS broadcasts, sometimes between checking the ATIS initially and checking in with ATC, there will be a change, problem is, at some locations you have to listen for too long to get the relevant information, taxiway closures, how to make a read back to clearance delivery and other useless items, meanwhile, only one pilot is in the very busy loop.
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Old 13th Aug 2007, 11:02
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UK ATC is the best in Europe, bar none, and by some margin too.
The majority of congestion is caused by poor pilot R/T which causes elongated exchanges. ATC stick to the book, if we all stuck to the book too, congestion would lessen dramatically.

UK airspace has many light aircraft flying around in proximity to ILS's. I believe the procedure of not clearing for descent on the ILS until established on the localiser is to ensure that your path ahead will be clear when the descent starts. Makes sense to me.

I just wish ICAO/NAA would agree that a change of one millibar (or even two) is of no interest to anyone, with todays modern aircraft,
Yeah that's real sensible. 1MB is ok, but is another 1, or maybe 2.... Hey, why not just fly 10 knots fast and 10deg left of assigned heading, sure it hardly matters at all really.
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Old 13th Aug 2007, 11:09
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AT my location, Dreamland, the reason for the significant change flashes for a period of time on the controllers display screen. So if you call up with the previous letter, the controller can tell you the information has changed and what the change is.
The problem with the equipment is that the change does not flash for long enough sometimes to be noticed (this is, we hope, going to be changed) and if you are more than one letter out then any previous significant changes may have been lost. I am currently suggesting that a line on the screen that is very infrequently used be utilised to type in what the last significant change was so that it is permanently available to the controller (or at least until the next change!)
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Old 13th Aug 2007, 11:13
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Surely another purpose of confirming the QNH is that you or your oppo hasn't been a muppet and copied down QFE instead - then it can make a difference.
Does anyone still use QFE? Even American Airlines gave up on it after a couple of near crashes a while back. Why is it still on the ATIS at all?


411A You are right, our methods are pedantic but for a reason.
Well, the reason that's been given to me in the past by one of my Brit friends is that it comes from the nautical tradition of making navigation procedures so complex that the enlisted men couldn't understand them and mutiny. After flying a few UK SID's, I don't think he was joking.
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Old 13th Aug 2007, 11:47
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UK ATC is the best in Europe, bar none, and by some margin too.
CamelAir, I'm afraid you are a tad wide of the mark.
Now, I feel that I can speak with some authority from a pilots perspective when I say this as I have personally been flying to Europe/UK since 1973...quite a long time.

I would agree that the UK ATC used to be the best, but I'm afraid that progress has been rather slow in the UK but more rapid elsewhere, so, give me FRA or AMS...yes, even ZRH, every time.

AMS especially, is very good, in my humble opinion.

And, as for HLLT (Tripoli, for those of you so blessedby not going there) hasn't improved all that much in the last thirty years either, especially with more than two aircraft on the frequency.
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Old 13th Aug 2007, 12:07
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Ahahahahaahah! You've really come up trumps this time 411A. ZRH ATC good? Dream on man, dream on! Perhaps you haven't actually been to ZRH since 1973, although I suppose their style of clearance suits the reckless 'dive and drive' approach style you so often advocate. I guess they are the indians to your cowboy. FRA? At least at LHR you'll know which ILS you're flying before base leg. And you'd better hope you never have an emergency on departure there because they are grade 1 hopeless, even after you've declared it.

Originally Posted by Airbubba
Does anyone still use QFE? Even American Airlines gave up on it after a couple of near crashes a while back. Why is it still on the ATIS at all?
Because there are a lot of Russian, Ukrainian and other Eastern Bloc airlines flying into the UK and they use QFE at home. Plus as someone noted if we they just said altimeter 992 someone from the states would set 29.92 instead of 992mb.
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Old 13th Aug 2007, 12:31
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hand solo..................

thank god, i thought i was going mad. ZRH..............i've been there 3 times recently, on two of those occasions we were asked "could we make it" because of the insane radar vectored approach - their words , not mine!!

Without getting into we are better than you, no your not, yes we are - ner ner na ner ner.................standard RT. Non of us are perfect. If we play nicely with all the other people we all go home safely.........THE END!!
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Old 13th Aug 2007, 13:16
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Interesting to see the reasons behind that weird clearance mumbo jumbo around the ILS.

1. Glide path signals are only protected to a range of 10 miles outside of this they may be corrupt.
Certainly very interesting, over here the GP is usually protected to 25NM, any reduction is communicated via NOTAMs and/or ATIS. But then, procedures require a GP intercept as far out as 15 NM in the first place.

2 VFR/SVFR or even IFR traffic may be transiting below, through the localiser.
That of course is a question of airspace structure and local procedures, the brits seem to be a bit more liberal in regard to VFR traffic, its way more heavly regulated here and therefore you normally have a bigger safety margin.

3 Descending below the glidepath outside of the protected range may have terrain/ controlled airspace issues.
Yup, but an ILS clearance doesn't allow to descent below the glide, just to descent on the glide and the GP has a protected range, of course we are at point 1 again here.

4 False localiser capture. Just the other week I saw a modern aircraft of a respected Western fleet, twice report established some distance from the actual localiser (over high ground in IMC). The ILS was taken out of service and checked but was found to be operating perfectly. The fault was in the onboard equipment.
Yes, false capture can and does happen, but thats the case everywhere.

That said UK ATC is of course one of the best at least in europe, but i wouldn't single them out as the single best. There are some things we see that work quite well if done differently like the ILS clearance.
The need to issue a QNH for startup has allways struck me as odd but not all that important to be honest, however getting a new ATIS if it is has indeed changed is not that a big issue on the ground in the first place, it is quite different in flight which is probably the reason that most ATCOs worldwide have to give the QNH if they cleare you to an altitude.
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Old 13th Aug 2007, 14:03
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It looks to me as though everyone has missed the point of the original post on this thread. A remider:
...why the need has emerged for the seemingly redundant callout of QNH in addition to the ATIS identifier most recently monitored. I thought that copying the ATIS, and confirming it on initial callup, conveyed that the requisite info, ie wx status - and QNH - had been received?
Whilst it is of little real importance due to the seemingly miniscule extra effort needed, the point is that we are constantly being told to keep it as short and concise as possible yet here we have an anomaly where we are asked to repeat something we have already acknowledged we have received!

It would appear to me that the original posts was referring to the habit of being asked to repeat the QNH when acknowledging receipt of ATIS when INITIALLY contacting CLEARANCE DELIVERY or APPROACH. Most of you know how it goes:

YOU: "Megaplane 123, B744, gate 45, information 'Q', requesting clearance for New Francisco".
CLNC DEL: "Megaplane 123, information 'Q' current. Cleared to New Francisco. Boviley 3 Alpha. Squark 6543. QNH 1013". (Thinking to yourself, if he/she has just agreed that ATIS information 'Q' is current, why repeat the QNH?)
YOU: "Megaplane 123 is cleared to New Francisco, Boviley 3 Alpha, squark 6543".
CLNC DEL: "Megaplane 123, readback correct. QNH 1013".
YOU: "Megaplane 123 affirm. QNH 1013" (thinking to yourself, why on earth has he/she asked me to read back the QNH when they have acknowledged that the ATIS I confirmed as having received is the current one.)

It all boils down to the extra few seconds it takes to confirm something you have already confirmed as having received. There are more important things in life and this is just one of those small irritations that don't help when it is not clear why they have to do it.
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Old 13th Aug 2007, 15:08
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Here here Danny....that one always make me shake my head..sometimes the law is an ass...

As for JFK controllers....4 runway changes within 5 minutes, and a clearance to land and hold short of the intersection for the 777 rolling from right to left.....
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Old 13th Aug 2007, 15:21
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Fair enough Danny, I guess it has gone a bit off topic, however the resulting topic is far more interesting then the initial question of the qnh.

Yes it is a bit over the top in some respect. But then again if you had an old ATIS (which is not unlikely with them changing every 15 minutes) at least you have the latest qnh. I personally cannot be bothered always to recheck the ATIS to see if it is still few at 1400 or now few at 1500. This is all offcourse assuming itīs a nice weather day, because obviously on a bad day I want the latest!
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Old 13th Aug 2007, 16:37
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Whilst agreeing with the annoyance factor in principal, Danny (trust me controllers find it every bit as annoying having to prompt for mandatory read backs), I believe that a seperate QNH check is a necessity due to possible transcription errors and the importance of correct pressure setting for seperation, terrain and avoiding level busts.
If any of the other information taken from the ATIS was incorrect then the problem would be readily apparent from controller clearances, information or other sources (except perhaps temperature and dew point!) with little impact on the safety operation.
However, with inbound aircraft in particular, an incorrect QNH is likely to go unnotticed until after the event has occured.
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Old 13th Aug 2007, 16:51
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Airbubba wrote:
Does anyone still use QFE? Even American Airlines gave up on it after a couple of near crashes a while back. Why is it still on the ATIS at all?
QFE on ATIS? Not in the UK...

and who uses it? Well at the airport where I work one of the North Sea helicopter Operators still does and so do many of the light aircraft not to mention Her Majestys Royal Air Force of which we see a fair few in our neck of the woods.

Digressing again.... (apologies Danny but I have to correct a widely held misconception) Denti Wrote :

Yup, but an ILS clearance doesn't allow to descent below the glide, just to descent on the glide
INCORRECT (in the UK anyway) To give a quick example: Heathrow 27L PUBLISHED ILS procedure commences at 2500' If you intercept G/P at a higher altitude (and I expect you usually would) and are "cleared ILS" it is legit to descend immediately (below G/P) to 2500' (platform altitude) - not necessarily a good idea with all the London Heli routes nearby. No doubt the reply will be "nobody would do that!" Well they have in the past.....

DD
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Old 13th Aug 2007, 17:33
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Danny

Just a minor point. It is my understanding that here is no requirement to read the QNH to APPROACH/DIRECTOR when checking-in in the UK. It is normally only a requirement to read the QNH to DELIVERY.

In my opinion the QNH is really the only part of the ATIS that has a major impact on ATC if copied incorrectly. The visibility, cloud base and wind don't really affect separations between aircraft (unless there are IFR/VFR operations being undertaken simultaneously). With that in mind, the altimeter setting is the only part of the ATIS that needs to be checked by ATC. Thus it makes sense to read it to them to make sure we are both using the same setting.

One technique used by controllers in the UK of which I am strongly in favour is just reporting the significant elements that have changed if I check in with an out of date ATIS letter. This is a much better method than that used in certain parts of the world where they keep badgering and bleating at you as to whether "you've got ATIS Joooliet" yet at 3000' on approach on a CAVOK day. Bizarre.

G W-H
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Old 13th Aug 2007, 17:43
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And then at some units we get passed the QNH when we call for taxi as well...

This is a much better method than that used in certain parts of the world where they keep badgering and bleating at you as to whether "you've got ATIS Joooliet" yet at 3000' on approach on a CAVOK day. Bizarre.
If you really want some fun when it's not too busy at such airports tell them you have received "Kilo" when the ATIS is radiating "Juliet" (etc) but I am not saying I would ever do such a dastardly thing!

Also, slightly off the thread yet relevant I think, the difference in ATIS at some units with rate of speech (so fast you can hardly understand it to so slow you almost doze off whilst copying it), background noise (conversations, radios blaring etc), information given in non standard order (mainly non UK) and then when it's something unusual you have to listen to the whole broadcast again to try and piece together what has been said only to find it's something like helipad out of service....end of rant!

I almost forgot - the variability of the wind direction when it's less than 5 kts - when I get bored I work out the average wind direction from the "variability" to see if it's the same as the mean wind direction.

Last edited by fireflybob; 13th Aug 2007 at 17:56.
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Old 13th Aug 2007, 17:45
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Just general comment---at AMS or FRA etc the controllers and procedures are wonderful, exept when something goes wrong then chaos results, at LHR etc when somthing goes wrong, no change, it was chaos to start with!! Still wonderful tho.
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Old 13th Aug 2007, 19:00
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At Manch, we are particularily pernickerty because we have an "Arrival and Departure" ATIS......Thirteen letters out of phase. eg Arr "A" correolates to Dep "N"...same QNH, different info....
bb
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Old 13th Aug 2007, 21:43
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Fireflybob
And then at some units we get passed the QNH when we call for taxi as well
There's a very simple reason for this.
On the controllers flight strip (be it electronic or conventional) they have a box where they have to note down the QNH that you have read back. If the box is blank when you call for taxi, they will give you the QNH so that they can note in the box the QNH that you have read back. They can't just write in 1002 because you've copied XRAY, they need to hear the words ONE ZERO ZERO TWO.

Why did they wait till you were taxying?

1) they forget to write it in the box when you read back the QNH with the clearance,
2) they forgot to give you the QNH with the clearance,
3) they don't have electronic flight strips and the ground controller has a responsibility to check QNH and cannot reference the QNH that was read back on the delivery frequency possibly an hour earlier.

Either way, is it a hardship?

I also agree that the person noting down the ATIS (Captain or FO) could write it down incorrectly. 1002 instead of 1022 is a massive difference and yes you should notice that the airfield elevation doesn't match your altimeter when doing your instrument check but it's belts and braces and why do away with the braces for the time it takes to say ONE ZERO ONE ONE?

I personally donít usually say the words QNH or Millibars I simply say Iíve copied XRAY ONE ZERO ONE SIX, itís quick and ATC know I have the correct QNH.
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Old 13th Aug 2007, 22:24
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411A
Some of the worst controlling I have ever seen has been in the US. BOS, JFK and SFB are particuarly bad. Their (US) colloquialisms are terrible as are their standards. There also seems to be a big confusion with the terms altitude and flight level in the US and Canada! The UK may not be the best, but they are a hell of a lot closer to the top spot than the US!
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Old 13th Aug 2007, 22:25
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Thank you Danny, you have captured my point,and the diversion from same, perfectly. Enough of the old belt & braces guys, the point is - where does it all stop?? We are all supposedly professionals, and the gross error check of altimeter vs field elevation should catch the problem. It's the principle gentlemen. If you've got the wrong ATIS - copy the right one.

PS: Thanks Skywave for the first lucid explanation of why this exists - although it is still just a case of checking the box...
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