If given an ATC speed, do Speed Limit Points still apply?
Joined: Jan 2007
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From: Up North UK
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).
Joined: Jul 1999
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From: all over Europe
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?
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?
Joined: Jan 2007
Posts: 95
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From: Up North UK
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.
Joined: Nov 2000
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From: Greystation
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.
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.
Joined: Sep 1999
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From: Scotland
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?
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?
Joined: Jan 2007
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From: Up North UK
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.
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.
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Joined: Jul 1997
Aviation Qualifications: PPL
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From: Europe
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.
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.
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.
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.
