Initial Contact

[733driver]

Dear fellow aviators and ATCOs,

I was wondering if you guys could answer the following question:

When and where is a pilot required to state both the passing as well as cleared level/altitude on initial contact? Just on first contact after departure? Whenever transferred to a new ATC unit? Or on every frequency change?

What are the ICAO recomendations and what are the rules in your country?

Any information greatly appreciated!

[happ1ness]

Hi there,
From a UK perspective try looking on the CAA website at CAP413 latest version just out 1st May 2006 you can download it for free.

Chapter 3 page 4

Initial Call - IFR flights


1.3.1 Pilots of aircraft flying Instrument Departures (including those outside controlled

airspace) shall include the following information on initial contact with the first enroute
ATS Unit (see also Chapter 6 Approach Phraseology Paragraph 1.1.2):
a) Callsign;
b) SID or Standard Departure Route Designator (where appropriate);

c) Current or passing level;
PLUS


d) Initial climb level (i.e. the first level at which the aircraft will level off unless
otherwise cleared. For example, on a Standard Instrument Departure that involves
a stepped climb profile, the initial climb level will be the first level specified in the
profile).
Hope this helps or at least should open up some interesting comments from other ATCO's

[Gary Lager]

And on every other occasion, i.e. not immediately upon departure (the rest of the relevant bit of CAP413):

1.3.2 Unless otherwise instructed or paragraph 1.3.1 applies, when changing communication channel to an ATC unit (including changes within the same ATS unit), the initial call on the new channel shall include aircraft identification and level only.

1.3.3 When making an initial call (as described in paragraph 1.3.2) and the aircraft is in level flight but cleared to another level, the call shall include the aircraft identification followed by the current level and the cleared level.

1.3.4 When making an initial call (as described in paragraph 1.3.2) and the aircraft is not in level flight, the call shall include the aircraft identification followed by the cleared level only.


In other words, there is no need to keep giving your passing level every time you change frequency - SSR is already verified upon first contact with a radar unit (see para 1.3.1. above) and it reduces RT loading.

Edited to add: I just noticed you are based in Germany - CAP413 (the UK R/T Manual) does not mention the above in the 'differences from ICAO' section so it ought to be safe to assume that it is also the case elsewhere (unless it's different!). Regards, GL

[ive348]

there is no need to keep giving your passing level every time you change frequency - SSR is already verified upon first contact with a radar unit

With reference to a different tread on this forum, I would say do it anyway as it seems most pilots don't have a clue whether they are transfered within the same unit or to a different unit.

[Gary Lager]

Would you say that in response to a genuine question from a pilot asking ATCOs how to do it properly?

Then you will have missed a chance to make a positive improvement in pilot performance - something the we in professional aviation should make the most of.

Sincerely sorry if it's all got a bit personal for you, ive - but people in glass houses shouldn't throw stones.

GL

[Spitoon]

In other words, there is no need to keep giving your passing level every time you change frequency - SSR is already verified upon first contact with a radar unit (see para 1.3.1. above) and it reduces RT loading.

Edited to add: I just noticed you are based in Germany - CAP413 (the UK R/T Manual) does not mention the above in the 'differences from ICAO' section so it ought to be safe to assume that it is also the case elsewhere (unless it's different!).Sadly life is not as simple as this. The ICAO rules on both initial call and SSR procedures are a bit ambiguous.

On the initial call, the UK's book was updated to clarify the situation and to set out what was considered to be the best way of working. I think it's compliant with ICAO - but goes a bit further than the international rules. I believe the clarification was done because the question was asked of the CAA so I guess credit goes to them for responding to the query.

On the SSR side, again, as I recall ICAO is a bit wooly and the UK has refined the procedures. What happens (subject to a few conditions and exceptions) is that the first radar unit checks the SSR (A, and C if you have it) and as long as you are handed from one radar unit to another each controller can assume all is ok unless told otherwise. I can't remember exactly what ICAO says on either topic and I don't have the books to hand but I'll try and dig out some references if I have time. And if anybody cares - I've just realised how sad the last sentence sounds!

[ive348]

Would you say that in response to a genuine question from a pilot asking ATCOs how to do it properly

What I meant with my comment was that, regardless what it says in the book, it doesn't harm to give the info. I know it increases RT load, but in this case I'll gladly accept that. Having said that, I shall not argue that ICAO or CAP413 is wrong, and if this is what it says in the manual, this is what pilots should do
One could argue however that the possibility exists for a fault to develop between the initial SSR verification and your subsequent transfer to/call on the next frequency. Therefore it never harms to double check.

Keep in mind as well that due to the slowness of the radar system, what you are reporting as passing level, and what I'm seeing on my screen could be different, but I will assume it to be correct if it is within certain limits (I believe these limits are described somewhere in our OPS manual). If outside these limits, I will ask the pilot to report passing level again. Only when the aircraft levels off, I can be 100% sure the mode C indication is correct. Luckily I would say this is the case in 99.9% of all flights

[Gary Lager]

So do we use CAP413 or the AIP?

The section quoted from CAP413 comes is in the 'IFR flights' section specifically, whilst I understand that bit of the AIP to apply to all flights, eg. C152s in the open FIR etc. So that considered and having been brought up in the LTMA environment, I usually err on the side of less RT, not more, and stick with the cleared level only (unless in level flight).

Colleagues of mine have different habits, however.

Keep in mind as well that due to the slowness of the radar system, what you are reporting as passing level, and what I'm seeing on my screen could be different,

So I'd argue that's a reason for NOT giving the passing level, unless requested, since verification (particularly at high rates of climb/descent) is harder, and may lead to assumptions of Mode C/Altimeter problems.

On a similar note, can anyone provide me with a reference for info reqd on first contact with approach radar (on descent, not departure)? CAP413 (and my gut) tends to just stick with cleared level & ATIS letter (along with Hdg, Spd instructions if applied by ATC), but I am getting frustrated with the length of some initial calls from folks who insist on giving Arrival routing, ATIS QNH (even when descending to a FL), and aircraft type (which is always the same inour company) and blah blah blah etc. But are they more technically correct? And/or does airmanship come into it as well?

[anotherthing]

ive 348

It is incumbent on the ATCO to check MODE C regardless of whether the pilot states a passing level - it is part of a radar controllers duty to monitor Mode C when an A/C is on frequency.

Not continuously - we don't have time for that as you know, but a check every now and again when doing your radar scan is all thats required.

As you stated - Mode C is reliable and that the best time for us to check its veracity is when the A/C is in level flight - so why in your opinion, as per your first reply, should people report it (the passing level) as a matter of course when not required to, if as you state, the radar lags behind (by up to 6 seconds), and it is not the best way for us to check?

I know that tolerances are laid down (it's +/- 400 feet in the anticipated direction), but if the passing level is not needed on a call, why add it to a busy frequency?

Mike,

The note in the excerpt you gavefrom the UK AIP, say to me that you only give passing level if changing from say London to Manchester etc etc. I must admit I do not understand the logic of this - What about from London En Route (Swanwick) to London TMA (West Drayton) - both are called London control, but are different centres!!

Not shooting the messenger by the way - just wonder why that note is there in the first place, surely if Mode C is validated and verified, it is validated and verified and only the continual checks an ATCO should make as part of his or her duty would suffice?!!

[733driver]

Thanks to all of you who have taken the time to answer.

Its a shame it has to be so complicated. CAP413 and the AIP stating different requiremts doesn´t help.

Also, which pilot can say he knows the AIP of every country he operates to?

We have ICAO, we have the JARs and (soon) EASA, but still we are all doing our own thing. Bit frustrating really.

Well, maybe one day with a single air traffic control agency in Europe this will change for the better.

[Gary Lager]

There's optimism! .

anotherthing - I read the AIP the same as you, it does seem a bit out-of-date, doesn't it?

[PPRuNe Radar]

know that tolerances are laid down (it's +/- 400 feet in the anticipated direction), but if the passing level is not needed on a call, why add it to a busy frequency?


The 400' tolerance is not for Mode 'C' checks but for level occupancy purposes, i.e. using Mode 'C' to allocate a level without requiring pilot reports that it has been passed or vacated. The tolerance for being at a level is +/- 200'. For checking a passing level, you'd want the pilot to say exactly what he's passing, and then correlate that with what's on your display, noting that there might be some lag between his report and the radar data.

[anotherthing]

Yep, my mistook;

A hurried, tired and inaccurate post by me I'm afraid :zzz: