"Descend FL130, level ......... "

[andy.summers]

Apologies if this is a revisited topic....

"Flipflop 123, descend FL130 to be level GWC"

"Descend FL130 level GWC, Flipflop 123"

"Flipflop 123, contact London frequency 123.45"

"London 123.45, Flipflop 123"

"London, Flipflop 123 descending FL130 to GWC"

"Flipflop 123, descend FL120"

We are currently passing FL150 with high speed (about to reduce!) and the speedbrake out. Can we now reduce our rate of descent as I believe our restriction at GWC has been cancelled. However, the chaps next to me who have far more experience and responsibility say that we still have to make the 130 at GWC. I was under the impression that the rules changed in 1997. Often it's too busy to trouble the controller to ask, so we make the 130 anyway. Obviously such situations are repeated all over the UK and do result in extra periods of flying level (bad for noise, fuel consumption etc).

Finally my questions - who is right in the above scenario, and what is the reason that we have such restrictions in the first place when they often seem to be subsequently lifted?

Thankyou in advance for answering my little bugbear!

[Scott Voigt]

Last I heard it was the same in the UK as it is in the US. A new clearance negates the previous clearance...

regards

[eyeinthesky]

Scott: Whilst you're correct in what you say, I believe that in that case we were talking about being told to be level by a certain point and then being cleared to one beyond. The consensus then was that the original level restriction was cancelled (not something with which I personally agree as sensible).

In the case here, I would argue that as you are still going to the same point, you should still comply with any restriction based upon that point unless specifically advised otherwise by the controller. In the case given here the clearance really is: "Descend FL120, cross GWC 130 or below".

I have long believed that this issue should be resolved by the insertion of something along the lines of the following in the AIP:

"A clearance to a new point along an aircraft's route does not remove any restrictions given with reference to intermediate point(s) unless specifically stated by ATC."

OR:

"A new clearance in a horizontal sense does not negate a clearance or restriction in a vertical sense unless specifically stated by ATC."

There is far too much doubt in some pilots' minds about this. Just remember, in the UK many of these restrictions are given to keep you separated from traffic on crossing routes or to keep you outside the airspace of someone who is not expecting you.

Like all of these things, however, if you are not sure at the time, don't ASSUME, ASK!!

[Over+Out]

This thread has come up before.
The rules say that a new clearance cancels an old one.However ATCO's in the UK want all level by clearaces complied with unless they are cancelled.The reason for the difference is something to do with ICAO rules (I think?)
Pilots, many of our separations rely on you making levels within the LTMA. E.G. KK ins FL150 level 40 DME MID keeps you clear of SS Deps on CPT which have been climbed to FL 160. This happens throught the LTMA.

[scran]

Been a while since I was in active control, but surely if the first requirement still stands, then it should be re-iterated in the further clearance.

Controllers expecting the previous requirement should be met just because they didn't cancel it sounds rather dangerous to me.

[Scott Voigt]

The controllers may want you to do it <G>, however the reality is that if they do not restate it and they needed it for separation, then they buy the deal and not the pilot... If you issue another clearance and don't restate the old restriction, that restriction no longer applies.

regards

[bobby-boy]

Re-itterating what over+out said, The TMA would not function properly without standing agreements with level restrictions.

Even since Sept 11th the TMA is still very busy and us controllers do not have time to use long extended RT to clarify whether the previous level restriction is still valid.

Anyone who disagrees obviously is not a VALID TMA controller.

I realise that technically a new clearance replaces an old one, but common sense tends to support the fact that the previous level restriction is still valid.
In my experience the level is far more important than the speed limit point.

Please continue to adhere to the level restriction as it makes everyone's lives easier.

[Captain Windsock]

Esential Traffic I think you are setting yourself up for a fall. Most of what you say is true about it being busy and levels more important than speed. However if you are relying on a cancelled level by restriction to provide your separartion I think you will be looking at a red square before too long.

[250 kts]

Agree with Scott on this one. ET, if you work on that basis then at some stage you WILL have an incident. I regularly see traffic cleared to a FL by Maastricht, and then when we give a reclearance the rate of descent changes and they fail to make the original level restriction.

If you want the rules changed then you'd better get on to TC ops to get on to it. I was asked this question on a visit by flight crew and although the correct answer is rather unpallatable to ATCO's , that's the way it is.

[GroundBound]

I would certainly have thought that a clearance such as "descend FL120" without any stated restriction would over-ride any previous clearance to FL130.

Why not make the clearance (in the specific instance quoted), "afer passing GWC descend FL120"? This would clearly show that the "new" clearance was specific to a point beyond the present clearance and that the present clearance (130 at GWC) still applies. It would also get around the "new" replaces the "old" argument, wouldn't it?

[moleslayer]

A purely personal pilots point of view......

If cotroller'A'clears me to descend to a FL by a specific point,and then hands me over to cotroller'B'who then gives further descent,I will continue to descend at the original rate to make the first restriction.I know that technically its not a requirement to do so,but it just makes a lot of sense to me.Neither controller'B'or myself are aware of why controller'A'set that restriction,so I for one am still going to respect it !

[greg1]

GroundBound,

IMVHO you are spot on! Following initial contact report by Flipflop 123 (great callsign! cheers Kwimper) correct R/T by the second ATC (that presumably still works with the level by restriction) in my mind should be "after GWC descend FL120".

Same with a lateral clearance?
“Flipflop 123, cleared dir ABC”
“Direct ABC, thanks, Flipflop 123”
“Flipflop 123, contact SomebodyElse on 123.45”
“123.45, seeya, Fliflop 123”

While on the way to ABC:
“SomebodyElse, Fliflop 123 hdg dir ABC”
“Flipflop 123 cleared dir DEF”

Now that clearly replaces the previous hdg clearance. If that was not the intention then the new instruction should be: “Fliflop 123 roger, after ABC fly dir DEF”

“…and that’s what I think about that.”

[eyeinthesky]

'After GWC descend FL120' wouldn't work because then you might level off at FL130 if that comes up before GWC, and then you'd be moaning for further descent.

All I have to add is to say that while technically a clearance to a lower level than the one originally mentioned in the restriction cancels the restriction, you would be have to be pretty low down in the common sense queue to assume you can blindly ignore a restriction. IF IN DOUBT - ASK.

It is apparent that most UK ATCOs who contribute here seem to agree that they want to reduce not increase RT loading by assuming that you will comply with previous restrictions unless they cancel them. For example, an initial clearance through COA might be 'Descend when ready FL 300, expect FL 250 by or abeam LOGAN'. The onward clearance to FL250 might come in several stages, and I would argue that you have been given the restriction in the 'Expect' and unless that is cancelled you should comply with it. To restate it every time would massively increase an already busy R/T.
Might it not be a good idea when flying in UK airspace, therefore, to keep this in mind??

[moleslayer]

Eye-I-T-Sky......

I agree 100%,and I hope my fellow pilots would agree (although I know they dont!)

But how do we get it made a legal requirement,tell me who to write to,I'll do it now.

[bobby-boy]

Captain Windsock

Thankyou for your concern but don't worry I certainly do not rely on level restrictions to provide separation, they purely assist in setting up separation. So hopefully I'll be Red Square free for a while longer.

Think Rate

As for your analogy of flight levels and direct routings, it is different.
If an a/c is told to route direct to abc by controller A then after frequency change is told to route dirct to DEF thus missing out ABC it is not the same as:
A\c descending FL130 level GWC from controller A then after frequency change told to descend FL120 by B, will still obviously pass through FL130 on the way to FL120, unlike the different routing instructions.

I totally agree with the previous pilot who said that when given subsequent descent clearance, the descent rate will remain the same therefore satisfying the previous level restriction

[Scott Voigt]

Hmmmmmm, if we don't have time to do it right the first time, when will we find the time to correct it when it isn't working due to an invalid assumption? <G>

I do know what the work rate at the TMA is. I've watched it, however, I hate to tell you, there are places just as busy and busier that do comply with the technical instructions. It can be done and a lot of folks who say that they don't have the time to do it by the book are just not wanting to comply with the book for whatever reason...

regards

[eyeinthesky]

Scott: I think the point is that the book may well need amending in this case. I will try and find out how to achieve that.

[PPRuNe Radar]

Got to agree with Scott 100%.

ICAO, and even the US ;) has a procedure which everyone wherever they fly in the world knows to be the same. The UK just finally caught up a couple of years ago.

It is crazy that with our level of international traffic in the UK we are talking about doing something 180 degrees out from everyone else.

Instead of changing the book, if we really can't cope with the traffic levels, then get those sector capacities changed downwards. Don't introduce a procedure which will serve to cause confusion and the possibility of pilots reverting to the different system used worldwide in error.

Passing the restriction with an amended clearance is fail safe. Assuming the pilot is still going to comply if it is not stated isn't.

[Euroc5175]

I believe that an SI was issued within TC not that long ago to stress the need to reiterate any previous restriction that the controller still wanted to apply when clearing an aircraft to a revised Flight Level or Altitude.

Despite being busy on frequency, if you want an aircraft to adhere to a previously issued restriction when you are clearing it to a new FL, you should reiterate the restriction. This ensures that you are in positive control of the aircraft and won't be caught out by crews interpreting instructions in differing ways.

Just a thought :p

[89 steps to heaven]

The phrase we would use is:
descend to FL130, requirement, reach F130 by .....

Longer, but little room for misunderstanding. A subsequent lower level assignment does not remove the requirement unless advised so with the lower level.

The only exception to this is when assigned a visual approach (not an intermediate visual level), any requirements have to be stated with the clearance for a visual approach.

[GroundBound]

If you read back through the pages, doesn't it indicate there is much confusion? I'd say most of the London controllers think you should (apparently in contradiction to the rest of the world) and most of the airbore side think you shouldn't (like when they fly elsewhere). Seems that London are not even sure of their own rules. Now what's THAT doing for safety? Good one to raise with the safety lads, don't you think?

[expediter]

It is very apparent from this topic that the majority of people are unaware of jusy how imperative level restrictions are!! We don't put them in for a LAUGH, they are imposed to ensure separation. So if in doubt it is a very good idea to comply, irrespective of any subsequent clearances. Or would you rather we increased R/T loading; "descend FL120, the previous restriction still applies"?? :eek: :eek:

[moleslayer]

It appears that most,(but not all),seem to agree that compliance with the original FL restriction is a very sensible idea.However until it is a legal requirement,any ATCer who relies upon it for separation would be the one to get it in the neck if it all goes horribly wrong,not the pilot.
As i've said before, I will continue to fly the original profile to comply with the first cleared level(it seems the only foolproof safe method)but others cannot be blamed if they are within their rights to do differently.
How do we get the rules changed?does anybody else think we should lobby for change?if not why not?

[tired]

The trouble is that the LTMA controllers don't sing from the same hymnsheet - when queried, some want us to comply with the previous restriction unless cancelled, others don't. After many years of using airports in the LTMA I still don't know what it is you want me to do.

I try and keep as close as possible to the original restriction, but as far as I'm aware I'm under no legal obligation to do so and I don't bust a gut trying to. So if you guys want to cut down on the RT work, then please make it clear whether the original restriction applies or not, it saves us having to ask. As I said above, you seem to be divided about 50/50 between those who do and those who don't.

[5milesbaby]

They don't publish these levels on the approach charts just to fill up a space, THEY ARE IN PLACE FOR A BLOODY GOOD REASON. What do you want us to do when its balls out??? Let you level off at the level at the point and then immediately clear you down further just to avoid the wasted seconds saying, "the level restriction still applies"???? The amounts of time these restrictions are used now, it should be the reverse you're willing to hear and abide by, thats ATC telling you the level restriction DOESN'T apply. I feel that if I have imposed a restriction, have never lifted it, complying is MANDATORY, even if another level is offered. I'll certainly be looking further into this.......

Ever tried a stepped climb under a Tristar on a summers day????? Could get nasty. :confused: :confused: :confused:

[5milesbaby]

I think my rambled rant above means I'm in the lobby for a change to procedures, wholly on the grounds of safety (simply that everyone knows the score) ;) ;)

[Scott Voigt]

5milesbaby;

Hmmmmmmm, we get to step climb folks here just because we can't get jets to all fly the same speed <G> (damn citations <G> ).

But, it appears that the UK is one of the few places where y'all have some of these problems. <shrug> It doesn't take all that long to do it the right way and NOT have any problems.

regards

[5milesbaby]

Just a thought, when one controller issues an instruction and transfers to next frequency, then the next controller gives a further instruction, how does that fit into ICAO's definition? i.e. Is it ATC in general, even different centres et al, or just a particular controller on a frequency??? In the original post the senario is to descend FL130 lvl GWC issued by Latcc AC Hurn Sector 19, any further descent would be by Latcc TC Willo sector on a different frequency, so does the TC Willo instruction override the instruction of a different controller on a different frequency controlling a completely different area of responsibility??

On a side note (sort of fits in, but not quite), and maybe starting up a 'new' thread, when holding is taking place and even EAT's are being given, many a/c ask to reduce speed, but don't want to lose their place in the stack.

1. Reducing speed half way through descent phase may knock a couple of minutes off the stack arrival time, not much more, and rarely affects the landing order. The consideration of a/c type is also used to aid better runway utilisation.

2. By reducing speed, you still have to hit the agreement points at the right level. They are in place for a better flow of traffic, not to get you down for the stack.

3. If you have an EAT, you also have an approach sequence number, this rarely changes so speed reduction is actually favoured to help reduce the number of a/c in the stacks.

Hopefully someone will correct my limited knowledge of the TMA and fill in the spaces.

[Scott Voigt]

Hi 5 <G>;

If the next controller indeed does issue a different altitude then the former restriction is indeed canceled. Can't speak for the UK rule book as I haven't seen it in a bit, but the ICAO agrees with the US book here. If you put a restriction on an aircraft and need it for separation and you don't pass that on to the next controller you can't expect it to be complied with. It has been that way for the last 26 years that I have been doing this...

regards

[tired]

5milesbaby - I'm not sure that I completely understand your original post, so we might be talking at cross-purposes here, but on the charts I use (Jepp - used by most international airlines these days) the crossing heights that we are discussing are written in the following form: - EXPECT FL130 by Hazel,(or 130 at Nigit, or 140 40D before Lambourne etc etc) however actual levels will be given by ATC". No sign of a firm restriction there.

Secondly, your colleagues do not always give us these specific levels and points on the day - presumably depends on the traffic situation.

Thirdly, as the whole point of this thread testifies, sometimes they cancel them once further descent is given, sometimes they do not.

Fourthly, as a pilot I have absolutely no idea what your local agreements etc are - maybe the shorthaul guys who do 2 or 3 arrivals a day into LHR have worked them out through long familiarity, but I'm a longhaul pilot and I do a max of about 5 arrivals there a month.

As I said at the beginning, I hope I'm not talking at cross purposes to you.

t

[5milesbaby]

Scott and Tired, thanks for the reply's, they both clear up some confusion for me at least. :D :D :D

Tired - you managed to rearrange my garble into the sense I meant from the looks of things!!! I know that the levels I use for the London TMA arrivals will be used without question between 0600 and 2100, and often an hour or two each side. It is very traffic loading dependant and also how accommodating the other controllers around are feeling. Also nearly all of the ones I issue (bar 2 I think) are written on the Jepps charts, likewise for all other LonTMA arrivals. I can understand that these are sometimes cancelled, but what I think should happen is that you comply with them at all times unless ATC specifically cancels them. Is that unreasonable??? :confused: :confused:

[Recover]

For the benefit of the LATCC controllers, it may be worth noting that about a year ago BA 'reminded' its pilots of the rules, which agree with what Scott is saying. I.e unless given a 'new' restriction, another instruction cancels the previous restriction. So, with the original example, the crew COULD reduce their rate of descent and not bust a gut trying to make the 130 by GWC. I say this, not because I think BA are special, but because of the number of BA aircraft entering the London TMA.

On a personal note (and I'm sure most of my colleagues are the same) I go along with Moley. I will endeavour to comply with the original restriction and for various reasons: It complies with the vertical profile of the TMA 'wedding cake' and so makes life easier for the controllers. It's normally easier for me 'cos VNAV is using the restriction to provide guidance for me. It prevents 'problems' if the next controller forgets to tell me the restriction still exists and, judging by some of the confusion amongst some of the London controllers, it would seem sensible because I don't know which one of you is controlling and whether or not you are 'confused' by the ruling.

If nothing else I reckon this thread highlights a couple of points. One is that some controllers need to go and do a quick bit of revision. I know it sounds harsh, but if the majority are saying it is in the 'rule' book and a few are putting in their own interpretation, then someone is wrong. I don't particularly like the idea of being controlled by someone who doesn't know the rules or who is uncertain 'cos he hasn't read the books in a while. This is not a pilot dig. I genuinely respect the professionalism of the London controllers and know you guys know your stuff, but we all allow things to stray from our brains and a quick scan through the books can bring it all back. Secondly, if enough confusion exists then either the rules have to be changed or re-iterated. I would have to agree with a previous contributor and have the UK singing off the same sheet of music as the rest of ICAO. This means not changing the rules, but making sure everyone knows what they are....back to the revision.

A great, thought-provoking thread and one that, if nothing else, might have cleared up some 'confusion' with a few controllers out there, or got them to go and look it up and see whether they've been doing it right or not. I will remain pragmatic and continue to make the restrictions, but be VERY aware that many won't and they're in the right to do so (sensible or not!).

Have a great Xmas and I look forward to your continued excellent service in the New Year (good bit of leave you understand :) ).


And......


Recover

[The Sad ATCO]

I read this thread and have been trying to rack my brains as to where I had seen the rules about this written. I, too, thought that a new descent clearance cancels any previous level restriction. I even poured over our MATS pt 2 for almost 30 seconds to see if anything was in there! And then it came to me... in a round about sort of way and thanks to GATCO's impressive organ.

For any TC ATCOs (or others) who are interested in the debate started by this thread, when you have a spare minute in the ready room pick up a copy of GATCO's Transmit (Winter 2001) and turn to the bottom of page 17 and read 'Safety Matters'.

For those of you who don't have access, or who wouldn't be seen dead reading Transmit ;) , here is what it says (edited for relevance):

From NATS ATM Policy & Performance

A clearance issued with a restriction to be "level by" becomes null and void when a futher climb/descent clearance is issued before the original has been fully complied with. Where, according to Standing Agrrements, ATSUs are able to transfer aircraft in receipt of such conditional clearances, the receiving sector should be particularly cautious in issuing further climb/descent clearances. Further, controllers are reminded that any re-clearance instructions issued should also include the original climb/descent restiction where this is still required.


And that appears to be about the long and short of it.

[PPRuNe Radar]

It's in MATS Part 1. Will provide the reference once I've had a look ;)

[5milesbaby]

So is it worth trying to get this changed, who has objections, who feels what we have right now is fine? It would be interesting to hear from people at other centres, aerodromes etc that are affected by this. I'm not saying the 'clearence' bit is out of sorts, just the 'level by' thing, the times I've been bollocked by TC for being high, but we do chuck the a/c very early sometimes so may not be just us doing a bad job. Also how impeding is it to TC if a/c are a couple of 1000 high as from text here it say its often cancelled? I know why they are there, and will always abide, but not always needed????

[The Sad ATCO]

I don't think that it needs changing. I think that it needs publicising so that everyone on the ATC side of things is singing the same song. Maybe it is something for the LCE committees to look into.

If I need someone to still comply with the previous level restriction then I retstate it e.g " Descend FL XXX Cross XXX at FL XXX or below". This works fine and does not impact on RT loading. If you don't believe me, then come and watch the master at work (not)! :) It also ensures that any AC types who are waiting for levels based on the level by point are still likely to get what they need to chuck us more traffic.

That this topic has generated such differing opinions is testament to the fact that it is probably quite a safety issue and needs to be highlighted for action of some sort.

[PPRuNe Radar]

For the LCEs who need to educate, the reference is MATS Part 1 Page 1-27 Para 6.

Been in the book since September 1997 <img src="wink.gif" border="0">

[250 kts]

I canvassed opinion in AC a couple of days ago as to what their understanding of the rules are. Every one of the people I asked were aware that a clearance was overridden by a subsequent one.

[Captain Windsock]

Time to defend TC. There are about 250 valid ATCO's in TC and only one in this thread has said something which leads me to think he had a misunderstanding of the procedures. I for one find nothing wrong with the procedures and find them easy to understand. I would suggest the other 248 understand the fact that a new clearance cancels the old one.

[Sniff]

How about not changing the procedures at all. The ones above work fine, and if we introduce another national procedure it makes it hard for the foreign pilots to sing to the same hymnbook.

How about changing the aerodrome approach books with a suitable phrase. This will (ahem should) be read by all pilots so the level restrictions are adhered to be all pilots, without undue fuss?

p.s. as a driver I still make the levels (if I can!)

[andy.summers]

Restoring this thread for the benefit of other pilots...............

[spekesoftly]

Also see <a href="http://www.pprune.org/ubb/NonCGI/ultimatebb.php?ubb=get_topic&f=6&t=001404" target="_blank">web page</a>