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

[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"??

[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.

[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.

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???

[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!)