Direct to and alt clearances

[kick the tires]

some advice from ATC please!

Radar clears us direct to XYZ but to cross it at FL200 or below.

a few mins later we are recleared to ABC, a 20 degree turn away from original track.

Are we still obliged to make the FL200 or below when we pass abeam XYZ?

Some say yes, some say no!!

[square circuit]

Strictly speaking the new clearance cancells the previous one.
The ATCO should include any restriction in the new clearance.

If in doubt ASK. If aircrew keep making the point, maybe we'll all start doing it properly!

[Hoover Pilot]

Sorry but I have to slightly disagree with the above posting. There is no "strictly speaking" needed in the answer. The clearance is cancellled. End of story.

When ATC issue a descend instruction without a "at your discretion" addition then I take it to mean descend "now" and comply immeadiately - and that's how it should be. Similarly, in the above question - the conditional descent is cancelled following a reclearance.

No ambiguity.

HP

[MancBoy]

I'm afraid I disagree with the above.

Descend now doesn't mean leave that second. I'm not sure of the time scale but the aircraft only has to descend within a certain time parameter, ie. 30 secs of the clearance.

Similar to the minimum descent rate ot 500fpm.

[anotherthing]

I agree with MancBoy,

the crew need a little bit of time to set the descent up, under normal circumstances.

Whereas a transmission of "Oh F:mad: :mad: k, ABC123 Descend now...." is more likely to require an immediate descent.

However, it's not standard R/T!!

[JAR]

I attended an ATC Level Bust meeting in Brussels a few years ago and asked the same question.

NATs controllers said the second clearance negates the level restriction unless it is reiterated.

The rest of ICAO expect the level restricion to be maintained.

Good eh?

[anotherthing]

JAR

In my opinion (maybe being a bit silly or pedantic) surely NATS has it correct insomuch that a new clearance is just that - a new clearance - it negates the old.

A lot of the time, if an ATCO gives a more direct routeing, the pilots will be unable to comply with a previous level by/abeam instruction. I know pilots can ask if it is still required, but why not just put it in the new clearance if it is still needed?

We do not have the luxury of spare time on the R/T for pilots to quiz us on what exactly is expected when issuing updated clearances!!

Otherwise it could get very confusing - what parts of the old clearance are still extant in the new one, if they are not reiterated etc. Or was the consensus that it was just the level restriction that remained extant?

Either way, it would be nice to have a definitive answer for everyone to work to - no wonder pilots get confused!!

[Spuds McKenzie]

a new clearance - it negates the old
I don't agree.
If you clear flight XYZ to FL140 to cross waypoint BLABLA FL160 or below and later clear it to FL120 (which is a new clearance) then the level restriction is not being negated, is it.

[anotherthing]

Short answer - yes!!

[Spuds McKenzie]

May be so with NATS... :hmm:

[Bandbox4Training]

Why bother with the ambiguity?

If it still matters then re-state the original clearance restriction...

ie "route direct XYZ the XXXXX restriction still applies"

always works for me.

[tailwheel76]

Found this thread on a search and have had this same discussion recently and am trying to find a definative answer.

I've read somewhere, that when given another clearance it negates the need to comply with the previous clearance unless specifically asked to do so.

However, I can't find where I've read it, its not in CAP413. Does anyone know where its written? I've asked the CAA who asked NATS, NATS have passed my question Swanwick, I've had no answer.

Thanks.

[belk78]

I am not a nats controller, in fact, i am not a controller yet, i am still at the atc school, down here in Spain, and to us, with a new clearance you cancel the previous one and its restrictions, unless you repeat them. I believe it is the safest way to proceed as well, don´t you agree?

[PPRuNe Radar]

However, I can't find where I've read it, its not in CAP413. Does anyone know where its written? I've asked the CAA who asked NATS, NATS have passed my question Swanwick, I've had no answer.

One would have hoped that the CAA knew their own documents by now :=

CAP 493 MATS Part 1 Section 1 Chapter 4

7 Amendments to Clearances

7.1 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.

7.2 Similar care must be exercised when a controller issues a clearance, which amends the route or vertical profile of an aircraft on a standard instrument departure (SID). For example, 'Climb FL 120' automatically cancels the vertical profile of the SID. If the profile contains a restriction which provides vertical separation from conflicting traffic on another SID route, the restriction must be reiterated, e.g. 'climb FL120 cross XYZ 5000 feet or above', unless separation is ensured by other means.

7.3 Similarly, when controllers issue instructions, which amend the SID route, they are to confirm the level profile to be followed e.g. 'fly heading 095 degrees, climb FL 80' or 'route direct to EFG, stop climb at altitude 5000 feet'.

Similar words also appear in the FAA's documentation for US operations. (That's where we plagiarised it from :p )

[tailwheel76]

Thankyou, I can sleep at night now! :)

[Emma1974]

I dont know how it could be changed,but would it be difficult to distinguish between an "executive instruction" and a "clearance"?
i.e.an a/c told to descend FLXXX level at/abeam and is then given further descent with a restriction on another freq/or on same freq.Surely in this instance commonsense(maybe not so common these days) would indicate that these restrictions should still be complied with.
Dont know how this could ever be achieved.
You can understand if you are given a new clearance on the ground,or a new routing,that this should negate the previous.
I think that,too often,pilots think that these level restriction are just there to annoy them and if an opportunity arises to ignore the restriction then they will(as is their right in this case).

Not long ago I cleared a pilot to FL310 Level LARDI.(LL arrival).The readback......"Why?".There followed an explanation of why we have Standing Agreements etc(And it was a British pilot of a very well known carrier)

[tailwheel76]

I know this has been discussed at length and I have read most of the other posts to find an answer to this but can't.

We were given a condition clearance by a french controller recently eg "descend FL300 to be level by ANNET" coming back into the UK, and on passing FL330 we were handed over to London who gave direct to somewhere and didn't mention the previous restriction.

After a short discussion on the flightdeck, we asked London if they still wanted us at FL300 by ANNET and they said yes as this was a french requirement.

My question is, does the statement in CAP 493 about the cancelling of conditional clearances ONLY apply to ATC transmissions within the UK, from one UK controller to another, and not when entering and leaving UK airspace?

As an aside do the controllers in London know what the controllers in Paris and Brest are asking us to do and visa-versa?

[av8boy]

Similar words also appear in the FAA's documentation for US operations.

And here's a bit of that...

7110.65 4-2-5. ROUTE OR ALTITUDE AMENDMENTS


b. When route or altitude in a previously issued
clearance is amended, restate all applicable altitude
restrictions.

EXAMPLE-
(A departing aircraft is cleared to cross Ollis intersection
at or above 3,000; Gordonsville VOR at or above 12,000;
maintain FL 200. Shortly after departure the altitude to be
maintained is changed to FL 240. Because altitude
restrictions remain in effect, the controller issues an
amended clearance as follows):
“Amend altitude. Cross Ollis intersection at or above
Three Thousand; cross Gordonsville V-O-R at or above
One Two Thousand; maintain Flight Level Two Four
Zero.”

(Shortly after departure, altitude restrictions are no longer
applicable, the controller issues an amended clearance as
follows):
“Climb and maintain Flight Level Two Four Zero.”

NOTE

Restating previously issued altitude to “maintain” is anamended clearance. If altitude to “maintain” is changed or
restated, whether prior to departure or while airborne, and
previously issued altitude restrictions are omitted, altitude
restrictions are canceled, including SID/FMSP/STAR
altitude restrictions if any.

[peacock1]

One says yes, the other says no.
Such a state of ambiguity.
Ambiguity is a threat to safe flight operaations.
Thank you to a previous post, for the relevant quotation from the CAP 493.
Until this is in common usage by ATC, I'll be looking for confirmation in the event of a reclearance with a altitude restrictions.

[Spitoon]

We were given a condition clearance by a french controller recently eg "descend FL300 to be level by ANNET" coming back into the UK, and on passing FL330 we were handed over to London who gave direct to somewhere and didn't mention the previous restriction.

After a short discussion on the flightdeck, we asked London if they still wanted us at FL300 by ANNET and they said yes as this was a french requirement.

My question is, does the statement in CAP 493 about the cancelling of conditional clearances ONLY apply to ATC transmissions within the UK, from one UK controller to another, and not when entering and leaving UK airspace?
Given that:
the London controller knew that the level restriction still applied
and that you woud still route via ANNET on your new clearance
and the rules in the UK rulebook
it seems to me - in the absence of any other information - that the 'direct to' clearance should have included the level restriction.

If the 'direct to' clearance did not cross ANNET but only took you abeam I'm not so sure what would have been appropriate.

Of course, there may well be other circumstances that affect the situation, such as AIP entries and standing agreements. I'm not an area controller but the same principles apply and bitter experience has taught me that this is an easily misunderstood point. I'll always take care to stress what happens to the restrictions when I reissue clearances - it's just as bad to have an aircraft stop the climb/descent thinking a particular level has to be maintained until a specific point when the rest of my plan is built around them continuing to the cleared level! Such clearances are not often used or necessary where I sit so it's not too much of a problem but it may create a workload issue where there are many standing agreements between sectors etc. if it cannot be assumed that the pilot will fully understand the meaning of the clearance (and that's not intended as a slight on pilots but rather the lack of clear standardisation on this topic).

[millerman]

Tailwheel 76
The London controllers should know the clearances that the French guys have given you because the boundary crossing conditions are stated in the Letter of Agreement ( LOA ) between the two centres.
In your example there shouldn't be too much of a problem as the French controller wouldn't ( shouldn't ) transfer you until you are clear of any potential traffic.
Here in Maastricht we have an agreement with London that traffic to EGGW and EGSS has to be FL270 or FL260 by Gorlo. This restriction has been specified by London and put in the LOA so we have to deliver the traffic like that. If I give you the clearance to be level FL270 by Gorlo and then transfer you out of FL330 descending it is because I don't have any traffic to effect you and I don't really care what London do with you, as long as they don't turn you around and give you back to me:) If they want to turn you direct they have to give us a call and ask for a release. In which case if the direct turns you towards other traffic we will point it out and either say released for turn clear of XXX or released for turn out of FL290.
Sounds good in theory doesn't it ??? :ok:

[peacock1]

Thanks for the previous post.
As mentioned before, lack of standardisation, = ambiguity.
Ambiguity is a threat to safe flight operations.
Now, it seems that not only is there disagreement on this vital topic between UK and ICAO standards, but that there is disagreement between different functions within the UK too.
This needs to be sorted, quick.:}

[elcrusoe]

This is my understanding from the US side of things on the situation between transitioning from french to english control.

For one the restriction shall still apply to aircraft if only it is reiterated by the following controller. The mistake made by the english controller was that he did not instruct the a/c to apply any previous instructions.

I'm sure there is a letter of agreement or a facility procedure at the french and english side instructing that if a/c are routed via ABC to DEF they must be descending to or level at FL300 prior to Handoff status. Or maybe it was just for traffic and it that case well traffic for one must have been traffic for the other controller.

But overall if the 2nd controller does not reiterate the crossing restriction and reclears the a/c to a different waypoint or level of flight that previous restriction goes out the door. And if an error were to happen well the 2nd controller shall be fully responsible.

[tailwheel76]

Thank you for the responses. I think its an area that so many are uncertain of and does not seem to be widely publicised, unless you go hunting in CAP 493 people do not seem to be aware of it. Even those who have been in the industry for years.

It does make you wonder why this rule is there if not everyone understands or recognises it. I can see the benefits, reducing transmiting time, reducing workload and helping controllers plan 'their' aircrafts route.

As not everyone seems to be standardised I think the best course of action, as in most cases, is going to be to ask if in doubt - defeating the whole point of the rule in the first place!