How does the IFR clearance process work ?

[gkrangers]

Ok...so I file...then what?

Who approves the clearance ?

Who ammends it ?

Who deems it acceptable ?

Does a computer see the routing and say "hell no", then formulate another route, or what ?

 

[sky37d]

It frequently depends on where you live.

Coming out of or into one of the metro airports, you'll file, they'll change it depending on what runway is in use at the big airport (you can substitute DFW, ORD, MDW, LGA, etc), and then change it again, because things have changed when you get there.

In non-metro areas, or once you get clear of them, it is not infrequent to get 'Direct'.

 

[gkrangers]

It frequently depends on where you live.

Coming out of or into one of the metro airports, you'll file, they'll change it depending on what runway is in use at the big airport (you can substitute DFW, ORD, MDW, LGA, etc), and then change it again, because things have changed when you get there.

In non-metro areas, or once you get clear of them, it is not infrequent to get 'Direct'.

Obviously...just curious why and who does what. Maybe one of the ATC guys will see this thread, and can explain why they do what they do...

 

[ISaidRightTurns]

Obviously...just curious why and who does what. Maybe one of the ATC guys will see this thread, and can explain why they do what they do...

I will use PDK to ORL. 2 high volume satellite airports that are controlled but to not have major carriers operating. This is just a guy and an airplane.

Most flightplans are filed on duats, and always direct. Everything from a lear to a cessna will try to file direct into the busiest airspace around.

So before you take off, your FP looks like this
/\ ORL..PDK \/

The tower controller at ORL knows you can't fly that way and the computer knows too. So something called a 'red' route is issued, the pref route. Now your flightplan resembles:
/\ORL..(AMG..DBN.TRBOW7).PDK \/

The tower controller will go threw the process of getting your type of airplane (Jet, Prop, Turbo-Prop) approved for departure, and then issue the clearance as necessary.
Cleared to PDK via Radar vectors to AMG, direct DBN and the trbow7 arrival to PDK.

Approach then climbs the a/c places it on a heading in accordance with LOAs, then switches to JAX center. JAX will normally give direct Alma or Dublin and climb to the appropriate altitude per LOA.

JAX Center switches to ATL center who then gives the a/c to approach. The entire process from the direct AMG or DBN to the TUCKR intersection on the arrival is all designed especially to keep that a/c out of every other a/c's way. It works pretty well.

When ATL approach sees the flight plan, now it just looks like:
ORL./.TRBOW7.PDK \/

As far as who approves it, its the controller who issues it initially. If I am in ATl and you are going to LAX via direct; I don't know those arrivals, or those routings. I will let you fly it until you find a controller who does know those routings. Might be Memphis, might be Dallas. Then they ammend it to be placed on the preferential routing.

 

[gkrangers]

As far as who approves it, its the controller who issues it initially. If I am in ATl and you are going to LAX via direct; I don't know those arrivals, or those routings. I will let you fly it until you find a controller who does know those routings. Might be Memphis, might be Dallas. Then they ammend it to be placed on the preferential routing.

Thanks. This was kind of what I was looking for. I'll get the most ATC friendly routing from the departing controllers...and let the arriving guys worry about it down the road.

 

[SiuDude]

I guy that works at Atlanta Center writes a fine column on avweb.com that answers all these questions:
http://www.avweb.com/news/columns/182651-1.html

 

[paulsalem]

Is there a way to file "I Don't Care" in the route? Or "your pick"

Here is why.

I was flying wit a private pilot (I'm just there b/c I'm instrument profficient, or atleast he thinks I am) out of GQQ (50nm N of CMH) to W00 (13nm SW of DCA)

I don't remeber the routing we filled on the way there, but getting near the ADIZ we got a reroute vor hopping.

Cool, not a problem gives me somthing to do.

So on the way out I file the same route they rerouted me on the way in.
There is no way to pickup clearance on the ground other than via the phone. So I call Patomic apporach to get my transponder code (W00 is in the Adiz) and IFR.

The woman on the phone looks at my IFR plan and says "Who let you file this?" To which I responded what do you mean? She said "you can't do all this direct direct between VORs here, and I'd be on hold for a while because they have to get out the low enroutes and plan my flight Like I should have done in the first place.
That got me a little irritated. So I ponited out there are no DPs or preferred routes, and this is the way the re routed me in.

Then we get in the air 10 mins later and the whole damn thing changed again.

I don't mind a reroute at all. I am not one to file gps direct either. But the fact that I got yelled at for filing the way they rerouted me on the way in pissed me off. Then while I'm compling with the clearance she gave me on the phone, I get a reroute 10 mins off the ground and have to get my charts out and figure it out all over again, in the busy DC airspace.

Sorry had to vent a little.

But controllers any explinations?

 

[FN FAL]

What about filing fuel critical? will that affect my wait and balance?

 

[SiuDude]

What about filing fuel critical? will that affect my wait and balance?

At busier airports, I find it very efficient to declare a fuel emergency and request and immediate takeoff.

 

[Vector4fun]

Paul,

I don't have any idea why the lady said, "Who let you file this?" , unless FSS in the area is supposed to be helping pilots file the correct routings. Obviously, a pilot can file anything he wants. (within reason) I'm not familiar with DC airspace, especially since the revised East Coast plan and 9-11 restrictions, so I can't speculate any further. Sometimes words just "pop" out of our mouths that don't really convey what we meant.

ISRT coverd most of the details. Pilot files. (By whatever means) Flight plan goes to the Center's Host, which compares the departure airport and initial routing with programmed list of preferred routings, and assigns a "red route" or "plus route" (on Center strips, it's most often in red, while at Tracons, the printers don't have color, so the route is set apart with + at either end.) We, (Tracons) are generally required to issue the pref route. It's most often a published DP at larger airports, but there are also many un-published pref routes that are based on LOAs between facilities, and the HOST is programmed to comply with those. Of course, programming pref routes is not a fool proof thing, there's always going to be the occasional flight plan that slips by the HOST without getting a pref route that needs one, or times when the HOST assigns one that's not necessary based on altitude or some other factor. (At 3 am on Sunday, you can get direct almost anywhere...)

All that said, each Center's computer system only knows the pref routes for it's own area. As ISRT said, the controllers and computers in ATL don't know what the pref routes and arrivals are in PHX and LAS, so you may get a re-route or two down the line. And nobody at ATL or ZTL knows the status of [insert SUA] 1000 miles down the line. At lower altitudes, pref routes may even change based on the runways in use in a particular area on a particular day. The only way to really understand it is to sit next to a controller for a few days and learn the flows and LOAs. When I'm flying 200 miles away from my own facility, I'm as clueless as any other non-controller pilot.