North Atlantic Oceanic Clearances
 

In my experience, coming from Europe, westbound across the N.A. Shanwick will usually issue within 3 minutes your crossing clearance.

Coming from Canada, Gander will wait until the very last minute to issue.
I always send the request right at 89 minutes prior to entry.

Why the difference?

Can anyone shed some light?

I don't know the answer but, in my day the Clearance Delivery Officers at Shanwick were ATCOS &, if you were requesting clearances within VHF range of Prestwick you were talking directly to them. They had the necessary info. at their fingertips & were able to issue clearances pretty much instantaneously. On HF you are (& were) talking to Radio Operators in Shannon. They only relayed messages by telex to & from the ATCOS at Prestwick. So that accounts for delays to issuance of clearances on HF. I don't know what the mechanics are, specifically, nowadays; but I understand that you can still request & receive clearances by VHF & HF. I don't know if you are talking directly to ATC anymore. I also know that many a/c use CPDLC. I would have thought that, in both cases your requests would be dealt with by the appropriate ATCO & not suffer any delays such as are likely on HF.
I don't know what Gander does, but I would have thought that it was much the same. So, the equipment & procedures used for the request may have changed since my day & there is certainly a lot more traffic now. But, I don't know why there should be this discrepancy between Gander & Shanwick.

CDO's were ATCO's? Really...they weren't in my day. They were Clearance delivery officers and the guys I knew were ex ATCA's ...none of whom held an ATCO license.They certainly took requests on VHF but they were referred to the appropriate planner. The clearance came from the planner and was "read" to the aircraft by the CDO.

You are probably correct. Time has addled my brain, perhaps !

Who are the people on the Ocean at Prestwick? They were ATCOs in the 70s because I worked with some at Heathrow.

kcockayne
I think you are correct about the 2 Shanwick CDOs originally being ATCOs. That's what I remember when I did some Familiarisation back in 1970.
They used VHF Tx/Rxs from Davidstow Moor in Cornwall and one nearer home to maximise VHF coverage.

I seem to remember a change to ATSAs much later but memory!!!!

Thank you for that, qwerty. It is nice to know that I am not going Gaga, yet !

I worked on 'The Ocean' in '67. The CDOs were not ATCOs then. They simply read out the Planners' clearances. I'm not sure they were even ATCAs. I think they were some sort of Tels W/O communicators grade back then. The Planners were ATCO III/IV, and the Oceanic D-Men were ATCO II.

Thank you TDM . I was about there from 1978 onwards. The Oceanic controllers were of course ATCO's (HD) but the CDO's were as I described.

Is it possible that back in KCockaynes day the CDO may have been former RAF personnel ? I know that we used to have ex Flight Sergeant ATCO's who ended their civvy career as ATCA's.

Willit Run...so sorry for hijacking your thread. I am sure someone current will come along once the "lantern has stopped swinging".

I was there in '74/75. Have I lost it/losing it, or not? I am tending to think that the CDOs were on a desk with the ATCO Planners on the other side.
Anyway, the logistics were such that they were able to issue clearances pretty quickly, with only those being dispatched via the Radio Operators taking a longer time.

CDO's are ATSA's now.

This may come in handy. It's a 6 minute video by NATS explaining the Oceanic control from Prestwick/Shannon.

There is an hour long video that goes into much more detail.


https://www.youtube.com/watch?v=p9F9ZoovnpM

I was there around '74-75 and I don't remember ATCO's doing CDO, Lyn (wife) was an ATCA and she seem to think it was the Tels guys that manned the frequency.

Does that help....... probably not.

In Gander the Controllers and Radio Operators are in the same building, different rooms, and I believe the RO's rotate around the HF and VHF positions.
In this day of computerisation I am not sure why there would be a delay in issuing the clearance, unless it is being left to the last minute to somehow maximise airspace usage.

I understand that Gander take data from the adjacent NavCanada domestic (radar) centres to calculate the forward estimate for the Oceanic entry fix. Using this radar-derived information, together with the level/speed held in the FPL, Gander can prepare a provisional clearance ahead of time, without input from the Crew.

The flight data processing system used is the same in both Shanwick and Gander, and the VHF ACARS-based clearance request/delivery kit is likewise similar, so I can only assume the use of radar derived info and the reference to the FPL to produce a form of provisional clearance might account for the difference.

We (Shanwick) base the clearance purely on the info from the Crew in the request, without any radar-derived data (Too many separate ANSPs to the east) or reference to the speed/level in the FPL.

Also, most of our traffic departs within 2 hours flying time of our boundary and is fuel-heavy, so we're not in the same situation as Gander, where the traffic has often been up in the cruise for well in excess of 3 hours before entering Oceanic, so the traffic presents itself differently at each centre and that has created different methods of operation in each - that and the fact that Shanwick doesn't (yet) get the radar-derived estimates received at Gander.

So in short, Gander know you're on your way, approximately when you're going to cross the entry fix and what your speed/level is going to be before you've even made the request. As was hinted at in a previous post, they may keep that provisional clearance on hold to maximise capacity, and to do so they may possibly wait until all the FANS (CPDLC/ADS-C) logging on processes are complete before sending you the clearance.

Shanwick only know you're on your way when we receive the request, and we'll get the clearance up to you ASAP and on a 1st-come-1st-served basis.

Hope that helps a little.

Thanks, Rab. Very informative - especially for an "old timer" who still has an interest in The Ocean !