"Level by..." question into London

[flying finn]

A couple of questions from a newbie, if you don't mind:

1st q: If you get cleared say FL150 level SABER coming in from the East, then get passed to the next sector who clear you lower, do we still need to make the restriction from the previous sector? The reason I ask is that I've heard both answers from the guys I've flown with - and would like to know if there's something definitive written on this.

(I've seen this discussed here before, but can't find the original thread & don't remember the answer)

2nd q: At LHR, is there an order in which the four stacks are emptied? It seems to go very quiet on the r/t at times when you're at BNN or LAM, so I wondered whether that's when the south holds have their turn?

thanks very much

[Findo]

Q1 - Absolutely. Scottish will clear you to FL310 level LARDI and transfer you to London. They may continue your descent immediately. I can assure you if you don't cross Lardi at FL310 you are likely to meet a westbound crossing you at Godos at FL320.


If in any doubt ASK !!

:ok:

[Warped Factor]

2nd q: At LHR, is there an order in which the four stacks are emptied? It seems to go very quiet on the r/t at times when you're at BNN or LAM, so I wondered whether that's when the south holds have their turn?

Essentially first come first served but may be manipulated otherwise to ensure best overall landing order taking into account the wake vortex categories of the traffic in the stacks.

Also the Traffic Manager may request a particular stack be given priority if the traffic into it is particularly heavy.

Given the way the system works it's quite possible to hold for 10 mins at BIG and be the only a/c on the INT S frequency whilst waiting for a bunch of traffic that arrived ahead of you at BNN and LAM and working INT N to land first.

WF.

[BOBBLEHAT]

In answer to your first point. Any reclearance replaces the previous one. End of story. That is what our rule book says.

Inbound LAM, what should technically happen is that you should be told to "descend to FLxxx to be FL150 or below by SABRE." As I'm sure you are aware this rarely happens due time constraints and R/T congestion.

The problem is that most controllers will expect you to still make the initial level restriction as my colleague above mentioned. If it were a level restriction used to guarantee seperation,personally I would be extremely careful with any reclearances.

[Captain Airclues]

As BOBBLEHAT says, if you go by the rule book then any new clearance form the new controller cancels the old clearance, so technically you do not have to be FL150 at SABRE unless the new controller restates that restriction. However, as many controllers assume that you will still make the restriction, then in your own interest, I suggest that you do it anyway.
There was another thread on this subject where PPRuNe Radar quoted the rule, but I can't find that thread.

Airclues

[fourthreethree]

This seems like another common sense vs rulebook debate. Yes any clearance given overrides the last one, and a good controller will specify the restriction within the new clearance, especially if there is a safety reason behind it. But as this is not always done, I would suggest the use of common sense and adhere to the old restriction given, rather than quoting the rulebook in a subsequent incident investigation.

This kind of answer tends to upset a lot of controllers and I am yet to understand why. The basi rule is, as Findo said, if in doubt, ask.

[Dan Dare]

You could have a look through MATS Part 1 (http://www.caa.co.uk/docs/33/CAP493PART1.PDF) Section 1 Chapter 4 Page 4, but be warned that it is a 2.1Mb file. The relevant paragraph says 6 Amendments to Clearances
6.1 When an amendment is made to a clearance the new clearance shall be read in full
to the pilot and shall automatically cancel any previous clearance.Controllers must be
aware,therefore,that if the original clearance included a restriction,e.g.'cross ABC
FL 150 or below'then the issue of a revised clearance automatically cancels the
earlier restriction,unless it is reiterated with the revised clearance.

[Middle Earth]

The good book does indeed say that any new clearance given negates the previous, but you have to use common sense too. Personally when you're busy you don't have time to start re-iterating level restrictions, you'd never get any air traffic done. We also tried to get this changed so that any new clearance given does not cancel a previous restriction unless the control specifically takes it off, but ICAO threw a wobbly and told us no. Oh well so much for commen sense.

[TrafficTraffic]

Oh well so much for commen sense.

Common sense says - dont transfer the acft!
Common sense says - parallel means not converging!
Common sense says - Scandanavia is North of Cyprus
Common sense says - Restate the requirement
......

Oh dont bother common sense is a 2.1mb file and you wouldnt understand it if you downloaded it anyway.....

[**777lover**]

Hi,

In reply to the holding question most aircraft entering the hold from the east will decend from there previous altitude to FL150. The controller normally asks them to decend further as they get closer to their previously cleared altitude. Normally they ask aircraft to be level (between FL 90 -110) 5 miles before Lambourne. They then transfer to the director which controls the traffic from the north and the south side of the thames. Which ever has heavier traffic normally gets prioty but this varies tremendously! If I am a wrong please don't shout at me because all this info I get Is from spending an hour listening to my Airband radio and trying to make sense of it all! Please correct me if am wrong as i personally would like to learn more about the holding patterns for LHR.

Many Thanks

Dave:D

[Middle Earth]

Common sense says don't transfer the aircraft.

So you'd let every outbound aircraft level off before transferring it ?

You don't work TC Capital by any chance do you ?

[Scott Voigt]

Guess I am going to rub a few controllers the wrong way here. Common Sense says that you do your job the way that you are supposed to do it. If you apply a restriction and you need it, you either keep the aircraft until the restriction is met, or you call the next controller and pass on that restriction as you SHOULD do. You don't leave separation up to "common sense." You leave it up to positive separation and being a professional.

We expect pilots to do the right thing, so why shouldn't WE! I also don't want to hear the "I am too busy to do it right." BS! As the sector controller, YOU control the real flow demand into your sector. If you are too busy you control that. You may not get pilots what they want, and you may not get other controllers all of what they want. Such is life. We are here for ONE purpose and that is to provide a SAFE environment for pilots to fly in. We get them to where they want when they want as a secondary consideration. If it isn't safe then the rest of it doesn't count. If you are BETTING that an aircraft is going to follow a clearance that you gave and didn't tell anyone else about it, then you get what you get.

Sorry about the rant, but I hear this all too often.

regards

Scott H. Voigt
NATCA Southwest Region
Safety and Technology Chairman

PS. If you don't like how the book is written, get together with your representatives and get it redone... We do it here all the time.

[StillDark&Hungry]

Yes we have been here before but for educational & safety reasons there's no harm in going over it again!

Findo is wrong.:p

If in his/her example: if descended to 310 by LARDI and transferred to London, who subsequently clear you to a lower level (All still with me on this one!) and you are passing, say, FL325 All us ATCOs must be aware that a pilot's responsibility is only to maintain a rate of descent of 500fpm or better, so if a conflict occurs because of crossing traffic at FL320 then, I'm afraid, that it's Findo's fault! As was said earlier in the thread, If you are applying a restriction because of your own traffic then why are you transferring the aircraft if it is still in conflict with one of your own planes?
However, if the restriction is, for example, to apply seperation for the recieving sector (eg FL140 40DME OCK which ensures seperation from the 150 downbounds) and the flight is transferred to the Terminal Sector who give further descent, they themselves are immediately taking responsibility for resolving the conflict!

(Just re-read all that myself and it only just makes sense! Probably would have been better if I posted at the beginning of my night shift not the end!)

P.S. Scott - Common sense says RIGHT ON!:D :D :D

[flying finn]

Many thanks for all your replies.

I take it then that, unless specifically stated by the next sector, there is no need to meet the previous restriction.

This only actually came into play the other (busy r/t) night coming into LHR from the east: Cleared FL150 by Saber after passing Logan at 250 - now have 10000 ft to lose in 25 miles: Add to this going into cloud (anti-ice on), a tailwind and wanting to slow down from a high speed descent due turbulence, and it all got a bit sporting... until reaching 150/Saber by which time we only had about 3000 ft to lose before going into the hold at LAM (30 miles away). Just left me thinking whether we did actually need to keep up the downward dash having been transferred and recleared before reaching Saber (which we did)

I should -of course- have asked, but that's what this post was for!

[fourthreethree]

Scott
Well said, you just put in words exactly what I wanted to say but far more eloquently:D

My whole philosophy when giving ATC service is to err on the side of caution and therefore safety. I am not going to assume that everybody is doing their job correctly, or that everybody is applying ICAO law to the letter, I just make sure that safety is number one. I can never be too busy to do that, the day that happens is the day I think about my future in the job.

flying finn

You can read the replies to your question any way you like, but I would suggest that if you are not going to meet the restriction given by the previous controller you inform the new controller of this, because I would bet that he is still expecting you to meet the restriction, even if he has not restated it. Yes this is a mistake by the controller(s) and not you, but like I said before lets not get into a blame situation, lets just avoid the incident.

Nine times out of ten the restriction given will be to comply with an LOA, and not due to traffic, so the restriction will apply to whichever controller you are talking to, all it means if you cant meet the restriction is that a call needs to be made to get approval for late descent, but 2 points....
1) if its busy these calls are a real pain in the @rse, and will not be appreciated
2) what about the other one in ten?

Its a team game chaps, lets admit we all make mistakes, we all get lazy at times and work together to improve things.

[Slippers]

Flying Finn,

As you can imagine the London TMA is a mass of crossover routes and confliction points, and in your case the problem is a/c departing Gatwick heading for Northern Europe and Scandinavia. These depart on a CLN SID which routes DET - DAGGA (a point on what used to be R123 SE of Stansted) -CLN, which as you can see cuts right across the LAM3A arrival. We aim to have these a/c about FL170 or above by Dagga to help out against all the Heathrow traffic departing on BPK SIDs which are climbed to FL150. In order to achieve this, once clear of the BIG hold the KK CLN traffic is put on a heading of about 030 to avoid anything at LAM and climbed in stages to the previously mentioned FL170. This 030 heading take the a/c roughly through BRASO. So we are looking for you to be FL150 level Saber to assist the controller in achieving the FL170 for the KK outbound (if you're high at Saber it becomes more difficult for the outbound to climb through your level).

So essentially your descent profile is penalised in order to benefit the climb profile of others.

Also, we are aware that a late descent clearance after Logan can make it bloody difficult to achieve the FL150 restriction. If you can't make it, I would prefer that you let me know and gave me a idea of what you can make. I am then in a position to co-ordinate with the next controller as necessary.

(Edited after being made aware of some speeling mistokes)

[**777lover**]

Since I joined I have had so much fun reading everyones forums all I can say is i've learnt so much in the past month and i think i will learn a lot more in the coming years before hopefully i become a Professional Pilot!!!

Thanks Dave 14:ok:

[eyeinthesky]

The rules say that one overrules the other, but airmanship says check before you fail to comply with a previously-given restriction!

By the way:

It's SABER (not SABRE)
and
it's DESCENT (not DECENT). So "your decent profile is penalised " has a very strange meaning! ;)

[Findo]

StillDark&Hungry Thank you for telling me I'm wrong then proving me right. I used that example because Flying Finn will probably know the routine. As you say if the restriction is at the behest of the receiving sector then they will ensure it happens.

In this case LACC have imposed the arrival level restriction due crossing traffic. I give an instruction to be there at the level agreed. If either a pilot or an ATCO changes that in my airspace then I need to know because quite rightly I am putting other aircraft into the same area basing separation on the instructed level and position :eek: (plus a little bit extra for the pension) Aircraft are always handed over clean but there can be many different conditions attached to that assumption. This is one of them.

Back to common sense. If you've been given a position and level and you think something has changed then ask. That won't kill you but not asking might. :ooh:

[StillDark&Hungry]

Sorry for the accusation Old Boy! As an LACC South-banker was misunderstanding the reason for the restriction (just look at the timing of my last post for my excuse!)

However - I still stick by my point. In your case you've done what you can to comply with the "book". If the next controller continues the descent they are now responsible for any separation that may be eroded if the pilot no longer complies with your restriction. If it was me on the other end I'm not sure you'd get a phone call though! May be too busy giving avoiding action:{

[Findo]

What about this scenario.

BAW 123 clear to join overhead SAM climbing to maintain FL160.

Seems fine

I want to build a bit in so I say BAW123 cross SAM level FL100. I've changed a bit of the clearance but does that cancel the original clearance to FL160 ? Maybe .........

Then I feel bold and say BAW123 cross SAM FL130 or above. Have I cancelled the original clearance or just added a bit ?

Or in another case BAW123 route direct XXX. I have cancelled the original clearance, full route to destination ? No I have just changed an intermediate bit and the rest of the route after XXX remains as previously cleared.

My view is that take off to touchdown ATC is a series of interacting instructions not simple clearances. You comply with them all unless told to ignore or if you think they are incompatible i.e keep your speed up .... then expedite descent !!! :D We know that one is popular.

Someone could write a book of rules round this lot and still not capture all the possible scenarios. :confused:

[fourthreethree]

Findo
Theres a difference between a clearance and a restriction.
A clearance is not changed by adding a restriction, so by telling a pilot to cross XYZ FL100 does not change his clearance to FL160.

Similarly a route clearance Flight planned route to destination is not altered by a DCT, all this does is puts the a/c on his FPR at a later stage whereby he will continue as per his route clearance.

I do agree though there is no rule book to cover all possible scenarios, which brings us back to the old mantra

If in doubt.........ask!!

[Findo]

fourthreethree where is that written ?

[Yankee_Doodle_Floppy_Disk]

Someone could write a book of rules round this lot and still not capture all the possible scenarios.

They did and it didn't.:D

[fourthreethree]

Findo
First you implore the use of common sense and then you want to know where it is written that a clearance and a restriction are two different things, or that a DCT is not a new clearance limit. Make your mind up old chap:O

[Scott Voigt]

When you say that a clearance is not the same as a restriction, that all depends on what country you are in... A clearance and a restriction are one in the same in the US. We consider a restriction a clearance...

For findo, if we are going to add a restriction to an aircraft then we must add the rest of what we want the aircraft to fly. In your case is would be cross SAM at or above one three thousand, climb and maintain one six thousand, in our venacular. I am sure that with your own phraseology in the MATS part one it would be very much the same... It is unambiguous and the pilots would understand it. It would also ensure separation.

regards

Scott

[scroggs]

Findo, if you clear me via SAM climbing to FL160 and subsequently tell me to cross SAM at FL100, I will take FL100 as my climb limit until I am recleared otherwise. If you tell me to cross SAM 'at or above FL130', having previously cleared me to FL160, I will assume that FL160 is still my climb limit. In your other scenarios, if you change a lateral clearance by re-routing me then I will obey any earlier altitude clearance unless you tell me otherwise.

In the descent clearances scenario, I will always assume that a 'decend FLXXX by...' clearance stands through controller changes unless I am told otherwise. Equally, if, after a controller change, I decide I can't make the restriction imposed by the earlier controller, I will tell the current ATCO of the problem. Sometimes circumstantial evidence (TCAS, other clearances) will suggest that the restriction may no longer be necessary, but I'll still check!