If given an ATC speed, do Speed Limit Points still apply?

[aac747]

I have searched for this but with no success.

It is my belief that if ATC give a speed to fly, then all speed limit points thereafter should be disregarded unless ATC specifically tells us otherwise. Is this correct?

The reason I ask is that a have worked with a few others who believed that all SLPs should be adhered to, even if ATC has previously given a speed to fly. Of course, these two different opinions will cause a real headache from a separation point of view.

Any feedback would be much appreciated.

[MancBoy]

no slp's as far as im concerned.

if we tell you to do 300kts then i would expect you to until told otherwise.

there may be occasions when the controller has forgotten or it wasnt given in a handover so you would have to query it.

you are right that if suddenly you came back to minimum clean to enter a hold when i was expecting you to still be going a bit faster then you could compromise separation but i wouldn't expect a decent controller to be giving you crazy speeds when holding is occuring anyway.

this is similar to clearances where the current clearance negates the previous one regardless of levels that may occur in a STAR.

[peatair]

Obey the last order! Speed limits are set down as "basic procedure" - i.e. in the absence of any other instruction then you comply with the speed limit.

[aac747]

Thanks for the info. You have confirmed what I thought and have been practising so far - I will continue to do so!:ok:

[corfiotpilot]

Thanks guys also! One of those on and off questions, espec some atc in greek airspace, there are two types, some brilliant! Some the opposite! But Most are brilliant! :D
Take care all :D
Mixales

[coracle]

However, if given a speed to fly then subsequently told by, for example, the next controller to "resume normal speed", then I would expect an aircraft to obey the SLP and enter the hold at it's holding speed.

[MancBoy]

erm, yes.

is that not standard procedure?

[atr_in_himalaya]

http://www.pprune.org/forums/member.php?u=29766

I think Mancboy is right. In the practical Airline IFR world when ATC clears you for a high speed decent its just so she can pile up other aircrafts at the back of yours to maximize airspace usage. ATC is also doing this because it doesnt expect any delay for you, so putting you in a hold is out off question. So you expect to go in all the way to deceleration altitude computed by the FMC.
i.e in many airliners its comman to ask for a high speed decent from atc when it clears you to decent out off your cruise altitude or somewhere already into descent but well above 10000ft where the very first speed restriction comes in I.E.250KIAS.

300IAS * 10 = 3000AGL which includes configuration(drag manegment) on schedual after shutting throttles to flight idle as you decent through 3000AGL.
If there is a speed restriction. Lets say 250 below 10000 or 210 below 3000 in terminal airspace then that you can ignore because ATC has already cleared you for high speed. But you have to double check well before you enter any other local speed restriction mentioned in the STAR.
But dont follow it if ATC clears you for high speed. If you cant do high speed then tell ATC you cant so she can manage the lateral seperation for aircraft behind and ahead of you if any.
cheers.

[coracle]

You would think so, but alas i'm afraid not!!:ugh:
It's a bit like squawking ident without being asked, but that's a whole different topic.

[I Just Drive]

Also, am I right in my belief that if you are given a level restriction during an arrival, if you then are given a direct, the level restriction is cancelled unless you are told to still be level abeam. Im thinking 180 at IDESI and 120 LAPRA going into STN primarily.

[Bagheera]

Sorry people to add another fly into lessening ointment but as this is a topic for everyone and not just those who fly into major airports. In the UK speed limit points may be ignored when instructed by ATC in class A-D airspace only. In class E-G airspace you are expected to be less than 250 knots below FL100 under the see and be seen principle. Whilst this may seem like a mute point dont forget that Glasgow Airport still has class E airspace around it and there are many more airports becoming busier in open FIR.

[coracle]

I Just Drive.

Not too sure about this one to be honest! However just remember what the EAST controller is trying to achieve. They have to get the CLN Departures from Stansted and Lon City up to FL210 through the inbound Stansted/Luton/Cambridge routing IDESI - LAPRA - ABBOT and Norwich inbounds IDESI - BANEM to leave CAS.

The IDESI - LAPRA track is beneficial to the EAST controller as it gets the inbounds out of the way of the outbounds and so you can give climb/descent. Once the outbound is through the inbound then you can turn the inbound (normally before LAPRA) direct to ABBOT. Now the track miles fron ABBOT to a 10 mile final for RWY23 at SS is not a lot, so by slowing your descent rate down (remember you must do at least 500 f.p.m.!!), you could increase the miles flown as you have to be dog-legged to get the height off.

Hope this helps, but you're more than welcome to come and see as it is easier to explain with a radar in front of you than it is just through words.

[oceans 11]

Not sure what the correct answer is according to the book, but for instance in the Hurn sector if I cleared a Stansted inbound to FL190 by Avant, then subsequently gave direct Midhurst, I would still expect that A/C to be FL190 abeam Avant.

[5milesbaby]

then you'd be wrong oceans 11 - if you clear an a/c to a point beyond that of one with a level restriction, then it's considered a new clearance and all previous restrictions are cancelled. Do a search on PPRuNe and find the many threads where all the in's and out's of this are explained. Likewise if you clear an a/c to descend FL180 level by say KATHY and then in a later transmission clear the a/c below FL180, say FL130 level GWC, you will need to re-iterate the FL180 by KATHY if you still wanted the a/c to still comply.

[MancBoy]

Alright 5, how's the head?

[A I]

I agree with you baby! In the long long ago when I did Hurn, direct MID level XXX abeam Kathy would be the norm. It's the same everywhere, certainly in UK airspace. Any clearance always cancels the previous.

[ElNino]

I remember seeing a CAA RT guide that talked about the cancelling of climb restrictions. Essentially, if cleared on a SID with climb restrictions, clearence to then climb further cancels the SID climb restrictions unless the restrictions are specifically re-iterated in the clearence.
I presume the same applies to descent?
For example, cleared on a BNN1B and cleared to FL200 (so level by Tobid). Now if I get put on a heading and get "descend to FL150, level abeam Sopit" do I still need to get down to FL200 abeam Tobid? I would think not, as the heading has cancelled the STAR, and with it the attendant STAR restrictions. And while still on a heading, am I right in thinking the speed control is cancelled unless "standard speed" is specifically ordered?
Any ATCO's care to comment?!

[zkdli]

Hi
This is something that comes up with great regularity on PPRUNE. :) The legal answer is that any ATC clearance cancels all previous clearances. :)
WE can debate this again! what the statement means is that if I, as an ATCO wants you to adhere to STAR restrictions, and have given you a heading or a different routing, I have to reiterate the level by restriction. E.G. if you are routing direct to LAM, ABBOT etc if I want you to be level or lower at a certain point I have to say descend FLxxx be FLxxx or below abeam yyy:)
Some people believe that in a busy environment that is too many words...
I will stand back now:)

[Not Long Now]

Quite agree it's been done to death about 'level by's. Had never considered that if you were on a heading you would think the speed restriction wouldn't apply unless explicitly stated. Considering the amount of headings used especially in and around the TMA that might make for slightly more RT if we were to have to reiterate the speed limit. Possibly not such a big deal for LL arrivals, as you'd probably be own nav to hold by 12DME (hopefully?) but for example for SS/GW from the north, SLP is CLIPY if I remember correctly, and you're virtually always on a heading past CLIPY. So if you're on a heading, and believe the SLP doesn't apply, when, if ever, would you slow down?

[ElNino]

So if you're on a heading, and believe the SLP doesn't apply, when, if ever, would you slow down?

Obviously that depends on the particular approach. The point is that the SLP's often bring one back to 250kts long before would otherwise be necessary from a flight deck point of view.

[Not Long Now]

Well exactly the point. Would you keep 320 to 8 miles, back to 250 below 80 or 100 depending on a/c type, it's a bit vague really...

[Pontius's Copilot]

Maintain the assigned speed (or heading or level etc) until released from it or another is assigned. On handover to another freq you must state any current constraints/conditions (speed/heading/vertical); if ATC's response does not confirm it - "continue as cleared" - then it no longer applies, or state another constraint then none apply (in that axis).

[isobar]

Ok, so here is another version.
Let's say during a descent on a STAR, ATC clears the aircraft direct to a fix towards the end of the STAR. If now there was an intermediate level restriction printed on the STAR plate would the aircraft have to meet the level restriction when passing abeam the fix?

The way I would see it is that the general STAR conditions still apply. Being cleared direct to point "XYZ" would not lift any other level or speed restrictions along the abeam points.

Any views, comments?

[Pontius's Copilot]

I agree; published procedural constraints - speeds, levels or routings - must still apply unless waived/varied by ATC. That includes terminal area speed limits that may be shown on the chart relative to published routes.

[5milesbaby]

Tricky one now, what happens if you are on a heading fast approaching GWC (slp into Gatwick) thinking "great, we're on a heading and we haven't been asked to slow down, lets do 340kts", then 2 miles to go you get own navved to GWC. If given an ATC speed restriction that compromises the SLP, then fly the speed assigned, if given no restriction then fly according to the SLP or ask ATC if the SLP still applies.

isobar - if cleared passed a point on a STAR that has a restriction then the restriction will need to be re-issued by ATC if they want it to still apply. We're all aware of what the restrictions are and will give those that we really need to apply. Think of it the other way around - inbound to LGW on the WILLO 4C, a restriction is published at DOMUT FL270. You've been given FL280 for initial descent and are approaching DOMUT, you aren't going to continue without clearance. Level restrictions are there purely for ATC separation issues and are printed for planning purposes only so you know what to expect, however if they need to be applied then the controller will state it in the clearance given.

[Kiltie]

Why is it, that on 90% of occasions (and in my experience I am not exaggerating) that when an approach controller is told of on initial contact, or issues, a speed instruction during the early stages of an approach, such as IAS 250kts, the instruction is never cancelled?

Theoretically, unless told otherwise, the last given speed instruction applies all the way down to the threshold, which is of course ridiculous.

Should the pilot start slowing for localiser and glideslope intercept on his/her own judgement, or would you ATCOs expect this to be queried and confirmed? Who has the responsibility to make the call?

[Pontius's Copilot]

Seems obvious to me that the speed instruction is only an INSTRUCTION to the extent that it does not compromise flight safety or aircraft limitations ... if you cannot (or can no longer) comply then say so. ASAP.

If you restate any imposed constraints to every new agency/frequency then sooner or later one of them is going to say it no longer applies. If not cancelled, then when you have to slow down - say so, then do it.

[PPRuNe Radar]

Caveat: applicable to UK procedures only, other States may differ.

I think some folks are reading in to the amended clearance thing a lot deeper than the CAA ever intended.

I believe that CAA intention was that an amended or new clearance cancelled only the restrictions which applied to the specific elements contained in the new clearance. There are three elements ATC will issue, namely vertical profile, horizontal profile (route or vector), or speed profile.
If I issue you with a new level (vertical profile), having already given you a previous speed to follow, why would that cancel the speed (speed profile) ?? The speed is an instruction, not a restriction. Similarly, if I issue a new speed to be flown, why would that cancel the radar heading (horizontal profile) I put you on previously ?? The heading is an instruction not a restriction. Otherwise, a pilot on being given a new level could decide he will now route direct to destination since this new clearance cancels his previous one in toto, including his clearance on his flight plan route. This is a dangerous interpretation to take.

If I issue you with a level clearance and specify a position to cross the level at, then I have given you 2 things .... an instruction which contains a cleared level, and a restriction where the level must be achieved by. When I issue you a new level, then the level restriction is cancelled unless restated, but as all other parts of your profile I have not amended, they still stand.

The slight exception to the above, and subject to specific CAA guidance, is on SID routeings which have level restrictions forming part of the clearance. If I give you a route which takes you off the SID, then the vertical profile is cancelled because you are no longer deemed to be on the SID but subject to a tactical routeing clearance, thus the SID level constraints don't apply, unless they are stated to you. Issuing a climb level above the SID also cancels the restrictions, in accordance with the CAA instruction that a new clearance (level profile) cancels the previous restriction (level profile).

Cancellation of STAR levels with a new clearance is a red herring since STAR levels as published are not instructions or restrictions. They are for descent planning purposes only. As clearly stated on the charts, actual descent clearance will be issued by ATC. So if ATC want you to meet a restriction, then they will actually state it. If they give you a new level and still want you to make a previously issued restriction, then it will be restated.

If you are vectored off a STAR or given a short cut, whilst in receipt of a level restriction for a specific waypoint, we have a grey area. Common sense dictates that you apply the restriction abeam the waypoint but CAA clarification needs to be sought so that this is adopted as the procedure. Personally I always issue an 'abeam' restriction anyway so that the restriction applies whether you go via the waypoint or not. The other way to get around the possibilities of misinterpretation is to use a restriction point X miles before or after a waypoint. Unless I've really taken you way way off route (and so the onus is on me to reassess your level restriction and formulate a new one for you), then you will still be passing X miles at some point on your new horizontal profile so you still have a restriction you can, and must, comply with.

Speed Limit Points are also generally well covered in most UK STAR charts, regardless of your actual horizontal profile, since many are given as DMEs or arc distances before waypoints. You'll pass that arc with a high degree of certainty, regardless of the route or vectors you have been given, so you kick in the speed limit to meet the restriction. For those that have SLPs at a specific waypoint or navaid, then there is a catch all of applying the speed limit 3 minutes flying time from the terminal holding fix, should you have been rerouted to avoid the SLP fix. Note that the SLP doesn't say you have to be going exactly to the terminal fix, it says 3 minutes before it, so you draw a 3 minute ring around the fix and comply when you cross it. And in certain parts of the UK, if you are still trying to wriggle out of finding an appropriate SLP, remember that 250Kts below FL100 is mandatory in certain airspace classes, unless ATC give you a clearance to do otherwise. Find the appropriate AIC if you don't know what classes I am talking about, then find the AIP to discover which airfields have such classes of airspace around them. :ok:

PS to answer the original query, if I have issued you with a speed 'instruction', then I am over-riding the SLP restrictions so you don't have to comply with them.