Alternative clearance problems

[Expeditedescent]

During work yesterday, our sector had problems with aircraft of the World's favourite airline after issuing new clearances.

Several times, I and collegues were asked after issuing a new descent/climb/heading if the new clearance invalidated the old one.
Towards the end of shift, I had an A319 inbound to EGBB which was cleared as standard FL220 Level HEMEL. I put the aircraft direct to WELIN and the aircraft then proceeded to cross HEMEL at about FL250.
The change of track was not significant, only about a 5 mile or so shortcut, so it wasn't as if I gave a drastic turn.

On chatting with the pilot he told me that their ops dept had just issued some papers saying that ANY new clearance invalidates the old clearance COMPLETELY. So if you put an aircraft on a heading for example, then they assume that the previous clearance is no longer in effect, whether it contained a level restriction or not.

Now surely this has serious implications, after all how many of us have time to keep re-issuing the previous clearance when issuing a new one?

In these days of multiple sectors with vertical splits, the whole thing will fall apart if aircraft don't adhere to standing agreements, simply because they were put on a heading or descended/climbed etc.

Cheers

Expedite

[squawk 6789]

a sign of things to come? airlines making up atc rules as they go along?

[identnospeed]

Expedite,

Thanks for the warning.
This is alarming and very dangerous ! Did anyone file any paperwork !

If the ops dept of said airline is saying that the new clearance COMPLETELY invalidates the previous one that means that they (A319) should have stopped descending immediately on receipt of the WELIN routing !!

Absolutely fukking barmy.

This is, without fear of contradiction, the most pinheaded interpretation of the rules I've ever heard.

Cheers

INS

[10W]

Expeditedescent

The answer is .... it depends.

For example if I issue a new climb/descent clearance and the previous one had a level restriction, then yes, the previous restriction is cancelled unless restated (see MATS Part 1).

But if I simply put the aircraft on a heading (but don't touch the vertical element of the clearance), then I would expect the restriction to be complied with. The pilot should still have some idea of the location of the restriction point and arrange the flight to meet the restriction abeam it.

The difficulty you cite in the WELIN case is probably related to the Flight Management System. The pilot will have the original restriction for HEMEL programmed in, however as soon as he executes the route direct to WELIN then ALL previous waypoints are erased from the system. HEMEL simply ceases to exist as far as the aircraft and the pilot are concerned and the restriction will drop out of the FMS. In this case you could argue that he will no longer be crossing the restriction point (even if in reality he does as near as damn it) and therefore the restriction is void.

The company notice about any new clearance cancelling ALL of the previous one is not in my opinion correct. It should only override the revised elements, i.e if I give a new level instruction, it doesn't cancel the previous route clearance does it ?



------------------
10 West
UK ATC'er
[email protected]

[Expeditedescent]

INS,

We did not file a 1261, but in work today I took the matter up with TC Ops, who were "extremely concerned".
They are going to pursue this with BAW ops, so hopefully we can get this sorted soon.

Anyone for amending the AIP and MATS Part 1 to state:

"Any alternative clearance shall invalidate the previous clearance, except for clearances which contain level by or level abeam instructions, whereby the pilot will still be expected to maintain the vertical profile required to comply with the previous clearance"............or something along those lines?

It doesn't bear thinking about what chaos will happen if pilots are going to interpret the BAW memo so literally http://www.pprune.org/ubb/NonCGI/frown.gif

Expedite

PS: This is also happening with pilots from Go as well.

[Expeditedescent]

Hi 10W,

I would agree in part about the FMC, but:

a) This has not cropped up before when controlling FMC aircraft........even with various headings (occassionally in TC we have to use some very creative headings :) )aircraft still make the standing agreement level, or get very close to it.

b) I asked the pilot initially if he had been cleared to FL220 level by HEMEL, and rather than mention that he missed it because of the FMC he started talking about me cancelling the previous clearance, which leads me to believe that the FMC was not the prime factor in them missing the restriction.

The problem is we would all expect the pilot to comply with the vertical element of the previous clearance when using a heading, but the point is I have practical experience of this not happening, and the pilots thought that what they were doing was absolutely OK.

I really think it is time the AIP and MATS Part 1 were updated with relation to clearances to take into account places such as LATCC where it is imperative aircraft make standing agreement levels.

Expedite

[eyeinthesky]

The R&N thread on this makes interesting reading. Seems that we all agree that the situation needs clearing up. The short answer is that if they think that a direct route means they can descend to be level where they like, then we won't send them direct!

Anybody fancy taking up the issue to get SRG or whoever to put an AIC out??

------------------
"Take-off is optional, Landing is mandatory"

[MidOcean]

Expedite,

As a BB based pilot (trainer), I find the logic of our 'BIG' colleagues interpretation of the rules somewhat stupid!!

Certainly having ONLY been given a lateral clearance change then we have NO right to change the vertical clearance. Please do be aware though, as 10W says that when cleared lower, we CAN ignore the earlier descent restriction unless you restate it.

Personally I always operate to it, and teach others to do the same, as I appreciate that in your minds your expecting us to anyhow, and it's better safe than sorry.

There have been many occasions when you could get caught out however if people applied the letter of the law. The number of times I've been released clean by LMS at say FL260, cleared FL200 when ready level by HEMEL. On first contact with COWLY/WELIN have been cleared say FL180. I have the right now to ignore completely my HEMEL restriction - I don't, but please do be aware that someone may! As always the time it'll happen is when you really don't want it to :-)

Whilst with you, is there really any ATC value in us BB outbounds having to work CAPITAL outbound? So far I've only ever been on freq a matter of seconds ( climb FL220, and chucked to LMS). From our point of view it's a 'pain' but happy to be educated in a reason for it.

Regards
MidOcean

[Expeditedescent]

Hi Midocean,

We all keep a careful check when issuing new descent/climb clearances that the previous standing agreement will be maintained...usually the most problems are when BB are landing on 15 and the pilots like to waffle down at 500fpm !

IMHO, Capital is a waste of time...it was only ever brought in as a NERC political project and to a lesser (but more important operationally) degree with RVSM coming in, LUS would have had far too many levels and it was necessary to move LMS upwards :)

If we have time we will get FL210 (not 220 !!) from Capital and hand you straight to LMS. But on Midlands we frequently run without a coordinator so it is easier when busy just to transfer you to Capital.

Cheers

Expedite

[MidOcean]

Expedite,

Thanks for the Info. Sorry I got the level
wrong, but a sector change just for a 2000' transit makes it even worse than for 3000'.
I'm sure however the Capital's SC is just as displeased with a pile of 'strips' for nothing.

So anyone can anyone else give me a good reason why BB outbounds must work Capital outbound?

Regards
MidOcean