First of all, thanks for this great product, really enjoying it!!As I know a 'slot' system is used in Europe and as this is not modeled in RC4 I'm curious how this works in the real world. Does ATC give you a time you need to start taxiing when getting a clearance, or is the slot time known even before you board the plane?Furthermore, when during cockpit preparations do you need to get ATIS information and clearance? I guess the FO get ATIS as soon as the radios are powered and you get clearance when you are ready to taxi, or am I wrong?Kind Regards,Marcel

Marcel,Speaking for the States - Flow Control is an art, a constant work-in-progress. Sometimes it works, sometimes it doesn't. Many variables come into play.You ask how it works. Obviously, Flow's interested more in larger airports. The pilot calls CD for clearance. Delivery tells him they'll get back to him. They call Flow and ask for a release. Flow's located in Enroute Centers btw.Depending on airports, wx, volume etc, Flow may have to call headquarters and negociate a time. Several people may be involved.Believe it or not, alot of "I'll give you this, if you give me that" comes into play. KMEM Flow might want to jam another Houston flight into a 1hr push. Houston Flow (also on the phone) agrees, only if KMEM Flow accepts east coast flights on an abnormal routing that benefits KIAH departure sectors. Get the picture? Very often, agreements cannot be met. That's when headquarters plays referee and makes the call.Back to CD. Flow can release right away but more often than not, they'll give CD a window the flight needs to depart in. That may be a 5min window. CD issues the clr to the pilot, verifying the departure window can be met. The pilot accepts, or doesn't. If he doesn't, negociations start (so does lying :-) ). The pilot does't want to say no, knowing the next window of opportunity might be some 45min off.Anyway, assuming he accepts and can in fact meet the time element, more variables. Remember, that 5min window might've been issued 30min prior to push. Alot can happen in that time span. He's not the only one taxiing out. He's rarely first in line. Will there be any delay for landing xfic? Sooo many variables come into play.Flow Control looks awsome on paper. It's extremely difficult to implement in daily life!

Hi,usually the "slot" is a small window of time within which you have to be airborne. If you miss a slot, you'll have to request a new one, and sometimes this will delay you by several hours.Sometimes tower will try to take you up in the queue for departure if your slot becomes very tight.Sometimes you'll hear the very welcomed news tha "your slot is cancelled, start up at your discretion".Regarding ATIS (or met info if ATIS is not available), this is received during the cockpit preparations and sometimes re-heard during taxi to check for significant changes. Clearance will be asked when the crew is ready to go (usually a few minutes before, but this may change due airline policy or airport regulation; many airport put a remark into their charts stating, for example: "request clearance for start up 10 minutes before expected push back time").Regards

Thanks for your answers! Makes things a lot clearer for me.

Within Europe, the slot system is computer controlled from the Central Flow Management Unit (CFMU) in Brussels. You'll have to be airborne in a window 5 minutes before the time to ten minutes after. If an aircaft has missed a slot, a new one will be requested once the aircraft is ready. On occasion, the new time may be a few hours later. In this case, a "ready message" can be put into the computer, which will usually bring the time forward.sometimes the aircraft may be required to "remote hold", whereby it holds on an unused bit of taxiway for it's slot time, to allow the stand to be used by another aircraft.It will usually fall to the controller to tell an aircraft if he is has or is likely to miss the slot.The slot time will be passed to the pilot during the clearance, and will be known to the controllers prior to the pilot calling.-Phil

The slot time is usually passed to the crew when they get the briefing papers (or go to the AIS office); only if there's a slot change delivery or tower will tell them as soon as they receive the new slot time.And sometimes (in busy times and busy areas), the new slot time can be not a few but many hours later (heard sometimes ago a charter flight from LIMF to EGCC that missed the slot and got a new one 7 hrs later !).