IFR clearance silently terminated in the UK

Are these UK deviations from PANS ATM published in the UK AIP?

They are not.

UK ATC claim this is widely accepted practice. It is certainly widely known - to those who know it :) It is a trap for pilots visiting the UK.

My understanding is that terminating a clearance upon CAS exit is fine if either (a) ATC advises the pilot he cannot re-enter CAS later or (b) ATC had earlier issued the pilot with a specific clearance limit. Neither of these happens in the UK - or anywhere else I have flown, and I have done a fair bit around Europe
http://www.peter2000.co.uk/aviation

A related aspect is that any number of routes which are partly (or wholly) in Class G *do* validate through IFPS. This is fine, because the UK has a lot of Class G and it has to be this way otherwise Class G airports would be inaccessible under IFR. But since the UK does not notify most DA/RA (danger / restricted area) activity to IFPS, you can get valid routes which ATC will either not let you fly on the day or which will result in a DA/RA bust which in the current CAA policy is same as a CAS bust.

For example the D036-D040 complex is not notified to IFPS.

In case anyone is interested in more detail, here are some notes on actually flying this

https://www.euroga.org/forums/flying/12076-any-way-to-fly-a-tb20-egka-e…

I missed this topic... Peter, thank you for sharing this information with the community! We are going to have a closer look on our side.
Dominique

Dear Peter,
Dominique alerted me to your question, which we had both somehow missed and we agreed, I'd try to take a shot at answering it. I am not sure I have understood your question fully, because the UK terminology and ATM system are at times a little different, but let's give it a try.

This is going to be a bit long, but please bear with me:

"Silent termination" should not happen, but I think we have two separate, though intertwined, things at play here, namely:
• Validity of an IFR flight plan, and
• Clearance limit and whether it can be "silent".

First issue is that it is expressly forbidden in SERA.5015 (c )(3) for ATS to even suggest to a pilot that they should close a flight plan before landing:
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“(3) Change from IFR flight to VFR flight shall only be acceptable when a message initiated by the pilot-in-command containing the specific expression ‘CANCELLING MY IFR FLIGHT’, together with the changes, if any, to be made to the current flight plan, is received by an ATS unit. No invitation to change from IFR flight to VFR flight shall be made by ATS either directly or by inference.”
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Pre-EASA it was for example common in some countries that ATC would close the IFR flight plan when the aircraft left controlled airspace in order to land at an uncontrolled airfield. This should not be done because the aircraft may. need to go missed and the ATS system must be able to take it back into controlled airspace or provide other IFR-related services without any interruption. Therefore the IFR flight should remain under IFR from departure to arrival, unless the pilot makes the decision to cancel IFR.

Second issue is that a clearance covers only those portions of the flight that are in controlled airspace. This is evident in the quotes you make from ICAO PANS, but more relevantly for us in the EU, also if we look at SERA.8001, SERA.8005 and SERA.8015 as well as at Part-ATS point ATS.TR.235 (ATC Clearances). As these provisions are quite long, I will only paste some of the key points from SERA (Reg 923/2012) and Part ATS (Reg 2020/469) below:

(N.B. Part-ATS provides largely identical rules to SERA, but adds a little more detail from the ATS providers viewpoint, especially in the AMC/GM.)
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SERA.8001 application

Air traffic control service shall be provided:
a) to all IFR flights in airspace Classes A, B, C, D and E;
(b) to all VFR flights in airspace Classes B, C and D;
(c) to all special VFR flights;
(d) to all aerodrome traffic at controlled aerodromes.
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SERA.8005 Operation of Air Traffic Control Services

(a) In order to provide air traffic control service, an air traffic control unit shall:
(1) be provided with information on the intended movement of each aircraft, or variations therefrom, and with current information on the actual progress of each aircraft;
(2) determine from the information received, the relative positions of known aircraft to each other;
(3) issue clearances and information for the purpose of preventing collision between aircraft under its control and of expediting and maintaining an orderly flow of traffic;
(4) coordinate clearances as necessary with other units:
(i) whenever an aircraft might otherwise conflict with traffic operated under the control of such other units;
(ii) before transferring control of an aircraft to such other units.

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SERA.8015
(d) Contents of clearances

An air traffic control clearance shall indicate:
(1) XXX
(2) clearance limit;
X
X
X
(f) Coordination of clearances

(1) An air traffic control clearance shall be coordinated between air traffic control units to cover the entire route of an aircraft or a specified portion thereof as described in provisions (2) to (6).
(2) An aircraft shall be cleared for the entire route to the aerodrome of first intended landing:

(i) when it has been possible, prior to departure, to coordinate the clearance between all the units under whose control the aircraft will come; or
(ii) when there is reasonable assurance that prior coordination will be effected between those units under whose control the aircraft will subsequently come

X
X

(6) When an aircraft intends to leave a control area for flight outside controlled airspace, and will subsequently re-enter the same or another control area, a clearance from the point of departure to the aerodrome of first intended landing may be issued. Such clearance or revisions thereto shall apply only to those portions of the flight conducted within controlled airspace.
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Part-ATS,

Point ATS.TR.235
(a)
(3) ATC clearances shall be issued early enough to ensure that they are transmitted to the aircraft in sufficient time for it to comply with them.
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AMC1 ATS.TR.235 (b)(2)

SPECIFICATION OF CLEARANCE LIMIT
A clearance limit should be described by specifying the name of an appropriate significant point, or aerodrome, or controlled airspace boundary.

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These provisions make it clear that a clearance is issued only in controlled airspace to aircraft under ATC control. Obviously there cannot be any ATC in uncontrolled airspace.

When the clearance is issued, it must include a clear clearance limit after which it is no longer valid. Clearances are also coordinated before transferring control to another unit, but in your case, the transfer was not always to another unit, but to uncontrolled airspace. As can be seen from SERA.8015(f) and ATS.TR.235 (h), the intention is to coordinate the clearance between all units along the entire flight, but there are cases where it is not practicable. However the downstream unit should at least have the flight plan data and know to expect the flight so as to be able to deal with it without disrupting the flight. It is also possible to have a single clearance that covers those sections of the route that are in controlled airspace, even if the flight has also segments outside of controlled airspace.

So in conclusion, the “silent termination” should never happen because the clearance itself should include a clearance limit, which makes the termination clear. However it has to be noted that it is also evident that a clearance cannot continue into uncontrolled airspace where ATC is not able to provide any control service (only FIS). There is also no requirement for the IFR flight to even remain in radio contact with any ATS service in uncontrolled airspace so the “clearance” would not achieve much and the border of controlled airspace is thus a fairly natural point which to use as clearance limit if it has not been possible to coordinate for your entire route.

The fact that the clearance cannot cover the pieces of the route that take place in uncontrolled airspace, does not mean that the IFR flight plan would be terminated. That can only be done by the pilot and the pieces of controlled airspace the pilot flies through, must already have the flight plan details and be prepared to provide a service in normal manner.

I hope this provides some clarity on how the system should work.

Regards,

Jyrki

P.S. as regards your comments about the way the IFPS system works, I cannot comment on those as IFPS is run by Eurocontrol, not us at EASA or Commission. Perhaps there is someone from Eurocontrol on this forum that could shed light on how they receive information about airspace restrictions?

Dear Jyrki, The problem can be illustrated by the following example. I have not experienced this myself, but from many discussions with UK pilots, this is what I have been told will happen.

(Peter, please correct me if I got something wrong.)

A flight plan is filed from Stuttgart EDDS to Farnborough EGLF. For whatever reason (e.g. icing) the pilot selects the rather low cruising level of FL60. The following route validates. (It is even the "Eurocontrol suggestion".)

VESID4B VESID Y127 UBEGA Z818 RINEX Z12 XIDOD Q762 RUDOT DCT NIVNU DCT ASDAK DCT GIKLI DCT OB DCT BARTU DCT SKARD DCT KONAN DCT LYD DCT EVATA SOKDU1V

The route segment KONAN-LYD is in London FIR. Part of it will be in class G airspace.

At departure the pilot will get the clearance: "Cleared to EGLF via (route)..." and eventually assigned the requested cruising altitude of FL60. When leaving Brussels FIR at KONAN, (s)he will be handed over to London information. So far so good -- the flight is now in uncontrolled airspace after all.

However, when approaching controlled airspace again shortly before LYD, the pilot will be told to remain outside controlled airspace. The clearance to EGLF which should remain valid as the flight re-enters controlled airspace has been silently terminated without notice. Worse, if the pilot requests a new clearence to EGLF, most likely London control will not have the flight plan. So the pilot now finds him/herself in uncontrolled airspace, possibly in IMC, unable to continue the flight as planned and without assistance from ATC. Clearly, this is a potentially very dangerous situation.

Dear Jyrki,

"So in conclusion, the “silent termination” should never happen because the clearance itself should include a clearance limit, which makes the termination clear. "

This "clearance limit" is never issued, IME, in the UK or anywhere else.

"However it has to be noted that it is also evident that a clearance cannot continue into uncontrolled airspace where ATC is not able to provide any control service (only FIS)."

That is understood.

However, what happens in the UK is that if you later need to re-enter CAS (all this is on the Eurocontrol-filed flight plan, so your intentions were never "secret") you have no assurance you will be able to, because the original flight plan has been discarded (practically speaking) upon the first instance of leaving CAS, and you have to hassle the next CAS owner to get you a fresh clearance.

They are under no obligation to do this and indeed often they do not; they just leave you hanging there in Class G, with no way to continue the flight other than in Class G (which can be a descent into hazardous wx, etc).

This issue doesn't arise with turboprop and jet traffic because FL200+ is Class C and thus continuous CAS.

Dear Peter,

I am puzzled... You state This "clearance limit" is never issued, IME, in the UK or anywhere else."

Every time I am flying IFR in Germany, my initial clearance has a clear limit...

Dominique

I have not flown VFR in Germany for many years. In IFR (Eurocontrol system etc) I have never heard the phrase "clearance limit". You just fly... under ATC control the whole way.
The context of my original post is IFR in CAS.

It looks like at least in the example Lars-Henrik was giving, a clearance limit has actually been issued and you are cleared to destination. This implies that co-ordination between all the ATS units along the route has been performed.

The fact that you fly a portion of that route in uncontrolled airspace does not change the fact that the clearance covers all the controlled airspace along the route. Obviously, it can be amended depending on the traffic situation, but not discarded without warning.

If the problem you are encountering is with re-entering controlled airspace, it sounds like something causes the flight plan to be lost when you leave controlled airspace and possibly that the flight plan never was co-ordinated with all downstream units as required by ATS.TR.235 (h) and SERA.8015 (f). This should not happen without your explicit instruction to the controller. The controller must not change you from IFR to VFR (see SERA.5015(c )(3)), nevermind actually close the flight plan mid-air, unless you initiate the change (see SERA.4020).

From other contacts, I gather that this however does not happen every time, but only occasionally. Could it be just an issue at local level with controller methods? Have you tried calling the supervisor at these sectors to ask why this is happening? Or perhaps one of the UK GA organisations would have a contact-person at NATS for this kind of GA-specific questions?

Peter,

the words "clearance limit" are actually not used in radio phraseology. If you see in SERA Appendix 1 to AMC 1 SERA.14001 (ATC phraseologies), examples 1.2.2 and 1.3.2 indicate that the clearance limit is the part which says "Cleared to (clearance limit)".

I could not figure how to paste here the table that is there or edit it into this text, but you can find the entire SERA tome here - just search for "clearance limit":

https://www.easa.europa.eu/sites/default/files/dfu/Easy%20Access%20Rule…

Jyrki, yes, spot on. The phrase "cleared to [destination airport]" is indeed widely used.
The discussion then gets more involved. Funnily enough the UK stopped using this phrase some years ago, and documented the change. I can't tell you where to find it though. They said they stopped using it because of this very issue: if a route has any OCAS segments, then the phrase is obviously an empty one.
Last week I departed from Aosta LIMW to Shoreham EGKA. LIMW was VFR-only so I got the IFR clearance from Geneva, as I was climbing out of the Alps around FL130. And it said the classic words "cleared to Shoreham" which made me smile because once London Control drop out out of CAS you are in Class G, your flight plan is binned (in the practical sense of IFPS distribution along the filed route; the destination only has still got it) and you are definitely not cleared to go anywhere then :)
There is definitely a problem with FP distribution in the UK, if a route contains Class G segments. AIUI, IFPS *always* transmits a validated filed FP to the country concerned (I was told this by an IFPS employee). Even a trivial (and practically meaningless) one like EGKA-EGMD 2000ft, which validates, gets transmitted by IFPS to, I believe, LTCC.
The problem starts somewhere later.
LTCC then looks at whether it is wholly in CAS and if so (Class G at the two ends is acceptable) it distributes it along the route, and you get the normal IFR coordination.
If it is not wholly in CAS (like the EGKA-EGHE one at the top) then it works with the first unit (Solent, a.k.a. EGHI) and when the route passes into Class G after Solent, the distribution ends. I know this for a fact because I have asked the various succeeding units if they have it.
LTCC seems to be using some algorithm, or a human procedure, for limiting the distribution in this way. It may have been done to ensure that the traffic actually flying that route is forced to negotiate a fresh clearance. Another aspect, which may or may not be relevant, is that the UK blocked the Autorouter (an electronic route generator / FP filing tool) from messaging pilots with the Eurocontrol-allocated txp code; the only explanation I can think of for this is again to force pilot-ATC interaction for CAS entry. Well, there is another explanation which is that setting a Eurocontrol txp code prevents the CAIT (infringement detection) software working :)
This main topic has come up many times on pilot forums but one can never find a UK ATCO commenting usefully. They have all signed the Official Secrets Act but really somebody in the "system" ought to know what is going on and more relevantly whether there is any will to fix it.
Elsewhere in Europe, and to a large degree in Scotland, if you go into Class G you can pick up the clearance later and the ability to do so is assured.