Cleared to a FL - stop climb altitude @ LHR northbound ?

[noblues]

Hi,

Last week on a LHR northern departure on contact with 118.82 we were given climb to FL110, upon passing FL50 we were told to stop climb at altitude 6000.

At this pint we are doing 4000ft/min and only due the fact I was hand flying the a/c did I managed to capture the 6000ft. The automatics would have overshot it by a considerable amount.

After levelling @ what we thought was alt 6000 I noticed we were still on STD having been already cleared to a FL.

Luckily on this occasion the QNH was only 5 millibar from 1013 giving a discrepancy of around 150ft.

Looking back at this in retrospect it is a level bust waiting to happen - we are going up like a rocket and given a level out with less than 1000ft notice.

On TCAS I could not see any conflicting traffic and were not given an explanation by ATC or even a 'thankyou'.

Three points -

1) Having cleared us to a FL why not tell us to level @ a FL ?
2) Some reasoning as to why this instruction was given would be appreciated. I do accept you guys (and girls) are busy and the freq is manic at times but just a few words please.
3) Had the QNH/STD split been greater than 10 millibars we would be looking @ a level bust ....

PS : I wanted to file an ASR but my colleague was not keen.

Any LATCC controllers care to comment ?

[BOAC]

noblues - from the use of 'ASR' I take it you are BA? Please NB that ANY MEMBER OF THE CREW can raise a safety report/MOR ('ASR'). It does NOT depend on the 'colleague', so if you feel it warrants one, write it! Indeed, it is your DUTY to do so.

PS Check 'Tech Log' and 'Standby altimeter setting' thread - it is relevant to this.

[Captain Windsock]

I'm guessing at a couple of things here but given climb to FL110 rather sugests that Heathrow were on easterlies. In which case your flight would cross the track of Heathrow inbounds leaving LAM on a heading, usually 265, for positioning downwind left hand. The inbound would leave LAM descending to FL70 or 80 depending upon the QNH. If you were suddenenly given stop at 6000 ft it suggests that the TMA dep controller had made an initial bad error of judgement and was now trying to correct the matter. He probably thought you could out climb the inbound before your tracks came close. Given that your climb rate was 4000 ft/min it looks like a very bad initial judgement but a very good decision to stop you off before safety was compromised. Did you get anything on TCAS?

Now for the sobering up bit. Late last year there was an airprox caused by a climb to a FL followed by a stop off at an altitude. On this occasion there was a big difference between 1013 and the QNH. The pilot stopped of at FL60 when the controller was hoping for 6000ft and then there was a loss of separation. I guess technically the controller should give the QNH but in the heat of the moment it was forgotten. And the pilot didn't pick up on it.

[foo fighting]

noblues,

Some answers and info that may help you from an ltma north valid person.

It is likely you were stopped off at 6000 ft due to your impending proximity to inbound traffic off either BNN or LAM depending on which end you had just departed.

Frstly, some causes of this , not in any particular order,

1.Poor judgement on our part of your climb rate and position regarding inbounds.

2.Traffic avoiding weather in or around the holds

3.LLdir takes traffic off LAM/BNN last minute when we (tma) expect it to continue in the hold.

4...plus many other scenarios.

As for why you are asked to stop at altitude 6000 rather than a flight level is the fact that the traffic you are probably being stopped off against will be at ' minimum stack level ' which is the first flight level above 6000ft which provides 1000ft minimum vertical separation ( sorry if thats something you already know ).

The tcas issue could be covered by the fact that the traffic you might be being stopped against may be some distance away from you, at a very strange bearing turning away from you, ie you off 27l/r against aircraft at BNN just starting a tight turn to leave BNN on a heading. not a tcas expert, just a thought.

As for why you didnt get a sorry, well the controller has probably just done something rather exciting and is a tad focussed on the outcome and the actions to resolve it and in contact with, if necessary, other controllers whose traffic they have nearly smote a blow with.

Please also be very aware that our radar picture is a few seconds behind reality and that whilst you amy be soaring past 6000ft our radar screen could be showing anything between 5-5700 ft - somebody will provide a more accurate figure involving radar update/real time delay.


I am sure that virtually all of us appreciate the consequences for you of such a late instruction however in my opinion its by far a better option than avoiding action a few miles later.

As for going into paperwork, entirely your decision. Last tip, take the time for a visit to LTCC, 10 minutes drive from LL with lots of easy parking - until the suits arrive from hq.

hope that is a little for you to go on.

[noblues]

Thanks for the interesting comments - BTW it was westerlys.

Please don't let this stop you chaps giving us continous climb when you can (we can be over STN at FL200 on a BPK departure and out of your way, plus it does wonders for our arrival fuel !).


:D

[brimstone]

noblues - the radar that we use displays vertical position as altitude below the Transition Altitude (6000ft) and this is shown as two digits irrespective of your altimeter setting and as Flight Level which is shown as three digits when above Transition Altitude.

I would guess that the controller was either still thinking "altitude" when you were stopped off or he/she is ignorant of the fact that you are permitted to change to Standard Pressure Setting as soon as you are cleared to a Flight Level.

I note that you say the QNH was only 5mb different from 1013 and I am guessing that it was 1008 as you expressed concern about a potential level bust. If that was the case then the minimum stack level referred to by foo fighting would have been FL80 and stopping you at FL70 would obviously have been an acceptable solution if the conflicting traffic was at FL80.

I think you have good grounds for filing a report of some kind because irrespective of the problem that occurred on the day you received a solution which put you in a difficult position and I think these things should be brought out into the open.

[055166k]

Well........another good reason for bringing back Familiarisation Flights!

[5milesbaby]

If you feel the 'stop off' is going to be tight then, if able, let us know as if avoiding action is nessessary we can give it in good time.

Filing on this is purely your own decision. It may take time once your back on the ground, but safety issues need to be raised so both ATC and Pilots alike are fully aware of certain consequences.

Alternatively, thought about putting it in CHIRP?

[Preppy]

Just a thought .............. would raising the Transition Altitude to say 18,000 feet not resolve this problem?

:D :D :D

[spekesoftly]

My thoughts exactly! Now I'm sure they already do that in another country? ;)

As the saying goes - "KISS" :ok:

[Capt H Peacock]

A little bit of airmanship would help here. Look at the departure plate, look at the stop alts and ask why. There are four stacks round Heathrow, with traffic doing continuous descent approaches. You know very well that you’re rarely going to get anything above 6000 ft in the first four minutes unless it’s very quiet. Hence after thrust reduction, go to VS 1500fpm. You reduce noise, fuel burn, power changes, and I bet you you’ll enjoy continuous reclearances. You’ll also avoid scaring Captain Nigel in his –400 going round and round at BNN as his TCAS shouts ‘TRAFFIC’.

Once you get about 40nm away from London and clear of the stacks you can open it out a bit. Think about the airspace you’re in and its construction, think of your dynamic profile in relation to other traffic and how you can fit in.

Be a pilot and an airman.:cool:

[Second Grace]

First, noblues, would you check your PMs please? (Down the bottom of the Forums page).

Captain Peacock,

I don't think there was anything wrong with noblues' airmanship etc. If given a GOOD climb close-in in the TMA, getting the height on will help ATC significantly. You're right about lessening the rate near cleared level though, and this should IMHO become a SARP.

Before we tinker with the TA, you need to review what ICAO says about it, and recognise that four of the five criteria are met in the UK with the present arrangement. Just like TCAS and Lake Constance, the problem lies at the very depths of industry legislation. That said, various ongoing projects towards the 'single sky' for Eurpoe will eventually get around to this.

[Capt H Peacock]

What I said previously applies even more so in the event of a TCAS resolution. With V/S engaged, the flight management is in a 'speed' mode and therefore the vertical profile remains constant. In an open mode such as FLCH or CLB, constant thrust is played against pitch to (paradoxically) maintain a climb airspeed. Such a mode can lead to short term variations in vertical speed/profile which deviate from the TCAS computed solution.

Either way V/S 1500 is a sensible compromise.

[fireflybob]

I thought it would not be long before this thread strayed onto the topic of the TA in the UK.

Another thread has been running on another forum which has also touched this issue and it is quite illuminating to see the various different interpretations on an important subject where there should surely be uniformity. Here is the link:-

Transition et al (http://www.pprune.org/forums/showthread.php?s=&threadid=89867)

[noblues]

Capt H Peacock - I took the view that if we are given further climb out of LHR and it looks clear on TCAS to give a good rate and get out the way into the upper FIR asap. I accept the risk of TA's and even RA's around the inbound holds but anyone with any airmanship would monitor this and adjust rates of climb accordingly.

Climbing for long periods in V/S is a debatable issue in itself ....

On this occasion the main point is the very short period of time given to level off at an altidue having already been cleared to a FL, and the associated CRM and cockpit workload issues, that left us with maybe 15 seconds to capture an a new altitude and change the alt setting.

The main pionts to be learnt from this are that we as a crew we failed to correctly reset back to QNH (although not an issue with that days value close to STD) and the controllers failure to maybe empahise the ALTITUDE part of his clearance.

Their are lessons to be learn't on both sides from this, and at the end of the day is a combination of circumstances that were high workload for both parties.

By discussing these issues on an open forum such as this maybe we can all learn from a situation where no harm was done, and store this away for future reference ......

[5milesbaby]

Well said noblues, its just a shame the only place is an anonomous rumour web site. Bring back Fam Flights, and set up proper centre tours that include the controllers taking part/sim time/plugging in's again. <goes off to dreamland>

Preppy, raising the TA only raises the problem into someone elses airspace. :{

[BOAC]

As 5miles says, this needs to be raised more 'formally', hopefully to encourage some research into TAs and TLs. I think the 'CHIRP' suggestion is an excellent one if you are not going down the MOR route, NB - and I can assure you, from personal experience, of the discretion and application to flight safety of the CHIRP team.

(http://www.chirp.co.uk/)

[Topofthestack]

As previously stated, the original stop-off sounds like a last minute change of plan and an attempt to re-establish separation against traffic leaving one of the LL stacks. We'd all LOVE to get all those departures up and away (STN FL200) but the airspace around BPK is VERY busy. Perhaps you guys don't notice all the LC ins and outs (ever increasing!), the GW/WU departures via CLN & DET, and all those SS/GW inbounds to LOREL from the south. The climb after 6000ft is usually to FL110 and underneath these SS/GW inbounds descending to FL120 and needing further descent after BPK, and then the ATCO waiting for the cross before continuing climb to FL150. A HIGH rate of climb upto FL110 therefore can have TCAS implications!

As regards raising the Transition Level to 18000ft, this WAS seriously looked at the early stages of Terminal Control development, BUT, to use this only in the UK would necessitate some sort of boundary area with the adjacent FIR's who, at the time, didn't have any need for a higher TL. We're just about managing to convince our transatlantic cousins (with some interesting and exciting exceptions!) that we DON'T use altitudes below 18000ft, so any change to their system might confuse them even more!

Visits to watch this interesting area are readily available for pilots NOT of a nervous disposition!;)

[Second Grace]

noblues,

Please check your PMs again.

Thanks,

SG

[Kirk to Enterprise]

noblues,

Just a couple of points:

1. On your re-clearance to an altitude you should have been given the QNH, as a reminder at least.

2. If I'm thinking of jumping BNN with you, one of my deciding factors will be my assesment of your rate of climb in the first 4,000' or so. Give me 1,500'/min, then probably a non-starter. Give me 3,000'/min or more, then you've got a chance.
If nothing given by 5,000' then more than likely your going to stay at 6,000' for a while, so slow the rate to level.

Come for a visit, you guys are always welcome. The more we understand each others' needs the better we both become! :ok:

[Second Grace]

5milesbaby, and noblues,

Two people intimately involved in ATC safety issues have tried to get in touch with noblues via the pm system here to discuss further off-line.

noblues hasn't replied to my pms, nor, to my knowledge, to my colleague's.

A real shame - as noblues makes a good point, and we wanted to talk it through.

However, the person responsible for writing the CAP on avoiding action has been made aware of the issue and is pondering it for the next edition.

[Euroc5175]

On the subject of raising the Transition Altitude, there is currently a Eurocontrol initiative underway to raise the Transition Altitude to a common level throughout the European region. Several values for the Transition Altitude are being discussed.

Apparently the obvious one (18,000ft) doesn't provide adequate clearance for some of the European peaks.

Also, the raising of the TA could result in the loss of an exisiting holding level, and the consequence of this on capacity in busy Terminal Airspace needs to examined.

The UK is being represented on the Eurocontrol Working Group by a member of DAP (CAA). :8

[055166k]

Right. here we go, climbing and descending in dense airspace and having to be constantly alert to the fact that there might be a missing level or two due to the pressure, which of course has to be passed time after time after time with all the possibilities of wrong readback or in a low pressure situation the need to stress mB's rather than inches.....and everybody else using hectosomethings. I hope beyond all hope that the CAA will file one of its more sensible differences, especially as the high ground found in Europe and the US etc. is not a UK feature. Trying to achieve vertical separation in a dense traffic area is difficult enough when everybody is on the same datum, I hope that representative trials are carried out on a UK airspace model before this goes any further. Try to imagine the transition across national and international boundaries, and even from one ATC sector to the next. Another factor that only an operational controller or pilot will appreciate is the huge increase in RT traffic on already congested frequencies....also the useful ATC tool for predicting vertical profiles in use at Swanwick will be that much less dependable.

[Scott Voigt]

055166k;

Aww come on and try using FL180 as the transitiion altitude. You will come to love it <G>... We use it with no problems at all here in both the low lands and some of the higher ones...

As to the higher peaks in some areas, that isn't an issue either. Your minimum IFR altitude is known and you just can't use an altitude that will be in the rocks... NO PROBLEMS...

regards

Scott