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]

Speed limits

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!

[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!
Take care all
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]

Airline IFR world

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!!
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.