I posted this on my ARTCC's website but thought everyone may benefit from the points bring up.
I'd also be curious if anyone has had any reliable success with speed restrictions working at the en route level.
En route Spacing is probably not something many controllers think about if they aren't working center. A tower controller typically knows what the minimum separation is between departures depending on the aircraft size.
A TRACON controller also knows about minimum separation which is three miles or 1000 feet or 5 miles for aircraft departing on the same initial route (per LOA).
However, the one many people dont think about is the separation needed between aircraft on the same route between centers and that one is 10 miles. In the real world, controllers virtually never have to deal with the same time departure of 20+ planes all going to the same airport, but on VATSIM this is a common occurring during events.
While it may be tempting for that tower controller to shoot them off as fast as minimum separation will allow what they probably arent thinking about is the ripple effect it causes down the line. Now the departure controller must get them separated to that 5 mile minimum separation before handoff to center right? Well if departure gets them all to 5 miles, while yes, they are separated "per policy", however then what does center have to do? Separate them out to 10 miles.
And as easy as it sounds, it really isnt easy at all. Especially considering speed restrictions are usually useless on VATSIM either because the pilot doesnt follow them, or they could be using one of 4 different weather engines, or they could be at different altitudes etc.
So now, this is three separate times a controller has taken some action to get planes separated to their respective minimums. Anyone see an inefficiency here?
Who do you think the single most important controller for attaining proper en route separation? Center? Nope. Tower. If planes are separated properly on the ground the ripple effect of separation never begins.
Granted, there is no single end all solution. Center will still have planes that hang in the for a couple seconds loading scenery, planes that take forever to climb or fly too slowly, etc. But, when tower starts them off right, center's job is so much easier and we can therefore provide better service to pilots.
Here are a few tips to tower/ground controllers for handling a fly out event where all the planes are going to the same airport.
Make sure the planes are on the same route. Having the group diverge and re-converge with itself due to pilots wanting to fly different routes is a nightmare for centers to work with. Although we cant REQUIRE this, we can sure do our best to encourage it. It should be noted that if the route can divert and make use of two different STARs into the same destination airport, that would be best(HR).
Set aside one runway for the group to use. Then use another runway for all the other traffic. For example, if you have a group flight to LAX, put them all on the 34L and then reserve 34R for other flights.
Dont machine gun them off as fast as you can. A plane at 450 kts flies 7.5 miles per minute. If you have at least 70 seconds between departures, thats a huge help.
A TRACON controller can use vectors to separate them. Rather than rty to describe it here, I made a short video illustrating how to use nothing but vectors to separate planes regardless of the rate tower sent them off.
Here is the video:
http://www.noahbryant.com/separation.avior
http://www.noahbryant.com/separation.wmvNotes:
I used DSR mode with a vector length set to 10 miles to illustrate the 10 miles separation needed by center. This also makes it easier to see the vector the plane is on. The situation simulates a tower controller who isn't being incredibly considerate of the 5 or 10 mile rule and shows some things the TRACON controller can do about it.
The first 3 or so planes were all simply given "cleared direct BAYLR." As you can see, they were pretty close to each other and sometimes inside of that 10 mile range (however, still within D01's 5 mile limit).
After that I started shooting them of pretty quick and used vectors to get them separated more. It looks weird, and is probably confusing to the pilot, but it works.
