Freezing a slot?

[CRJ2]

Hello,

is it possible to freeze a slot?
For example: scheduled departure is at 04:20, we got a slot at 04:30. Is it possible to freeze this slot at 04:30 to get no worse one?

[niknak]

No.

A slot of 0430, means you can depart between 0425 and 0440.
If you can't make that time window the flight plan must be delayed and you may get another slot which is within a few minutes of your ideal departure time or it may be 2 hours later.

That said, if you get a new slot which incurs a long delay, you can always ask your op's to send a ready message, which may or may not improve the situation, depending on the reason for flow restrictions being imposed in the first place.

[flowman]

CRJ2
Hello,
If you receive a delay and decide for whatever reason that you do not want an improvement, send a Sip Wanted Message (SWM).
Then, if an improvement becomes available, you will be sent a Slot Improvement Proposal message (SIP). You can then either accept the improvent with a Slot Proposal Acceptance message (SPA), reject it with a Slot Reject Message (SRJ), or you can ignore the offer and do nothing.
The last two options mean you will keep the delay.
:ok:

[CRJ2]

Hello,

thanks for the answers!

@flowman,

what will happen, if we send an SWM and there is an impairment to our slot. Do we still have the "frozen" slot then, or do we have to accept the worse one?

Last week it happend to us, that we first got a slot 5 minutes after our scheduled departure but a few minutes later we got a slot 1.5 hours later and there was no improvement to it! So we had a delay of 1.5 hours! The reason for the slot was bad weather at destination.

Our ops-control said after that, that there is a possibility to "freeze" a (good) slot, but I've never heard about it!

[crjlover]

With the SWM you can freeze a slot to avoid an improvement but you can not freeze a slot to avoid a worse one.
To get an improvement there are many ways to work:

1- send a RFI (request for direct improvement) normally your guys at the OPS control send it as standard if they think that the flight can catch a better slot
2- REA message (ready message) it can be ask from the crew on frequency when they are ready to go before a slot. don't ask to the dispatch for this message they can't send it.
3- phone call to the CFMU help-desk with a sad a voice to ask if they can give a better slot

Bye
Mattia

[prospero]

Gentlemen
Flowman is on his rest days so I as a colleague of his here in the capital of Europe I shall answer by cocurring with crjlover's comments, he is correct in his answer.
Chris
PS The sad voice is good but a sexy female voice is a dead cert if I answer the phone.:O

[PPRuNe Radar]

A slot of 0430, means you can depart between 0425 and 0440.

It actually means ATC have the discretion to let you depart between 0425 and 0440. Pilots are supposed to be ready to depart at the CTOT, and might be disappointed occasionally if they call with insufficient time to make the issued TOT (based on actual OBT and taxi time) and are depending on the extra 10 minutes in a busy ground traffic situation.

[galaxy flyer]

And a load of bollocks to EuroControl. In the US, you can file a flight plan from an East Coast airport, run out to the plane and get a clearance and depart. Even from airports busier than anything in Europe. Rarely with a delay. Only five "slot" controlled airports and they still don't have slot times, the slot is merely the number of operations an airline can schedule. General aviation can call and get a reservations, often without problem.

Never figured out Europe's slot regulation--wait 2 hours for a CTOT, get airborne and immediately sent direct across the country. What's up with that??

GF

[Jerricho]

Rarely with a delay

Kind of deflated your own argument there :rolleyes:

I'll give you a little hint.......lack or airspace.

[galaxy flyer]

Hate to be disagreeable, Jerricho, BUT, delays in US airspace are virtually always severe weather. Chicago has delays, but it is at the end of Tornado Alley. Slot regulation, in my 18 years experience, is all the time, clear weather included. You could sunbathe everywhere in Europe and be regulated.

I think it has more to do with the arcane division of airspace, aka national boundaries, and ATC inflexibility. The boundaries, ATC can do nothing about, but ATC could allow a merger of all the nation's ATC to form a more American (Canadian?) integrated system that would be flexible. European ATC seems to users (yanks, admittedly) to be run for ATC, not the customer; the attitude is that of dear PATCO (which still exists, believe or not). Sadly, ATC in Europe seems tied to national interest (read: self-interest) rather than European integration.

But as American ATCOs retire in record numbers, expect all sorts of US ATC problems, delays, close calls etc.

[Jerricho]

Galaxy, I agree while weather can take a huge hit to traffic on this continent, from what I have seen operationally of the North American system and "delays", you cannot really compare it to Europe. My airspace comment still stands.......a lack of combined with a huge amount of traffic.

You could sunbathe everywhere in Europe and be regulated.

This is true. However, the system here in North America (I'm including Canada here as well, as Toronto does some major sequencing into Chicago/Cleveland etc.) is to take the delay hit in the air. Sequences involves huge downwinds, speed controls and various other airspace structuring and techniques. The airspace is there to do it. And while we're talking about the weather (and not that it happens very often) if a line squall were to park itself over the English Channel, there suddenly becomes even less room for the drivers to get around it (At this point, I heartily agree that a unified ATC system in Europe would be a bloody excellent idea........ :ok: )

And to digress a little, let's not forget good old Cancun, where we often get a request here in Winnipeg for our 3 Saturday morning bucket and spade brigaders to be 10 minutes in trail........and we're christ knows how many miles away.

[galaxy flyer]

Jerricho:

Thanks for the comments; they helped get my shorts untwisted. When you put North American ATC techniques of "vectors to parallel" or delaying vectors in European airspace, I can see where it would be tough to do. Hadn't thought of it that way, we do have much more flex than, say, Belgium. Dip clearance problems for mil traffic is also a burden.

I am a passing understanding of ATC and airspace having been a airfield commander; you should hear the guys who expect Rhein Radar to act like Salt Lake Center.

GF

[Jerricho]

they helped get my shorts untwisted

Nah mate. Good discussion topic. :ok: