Obtaining IFR clearance

[GADD45B]

Does ATC care one way or the other when someone copies their IFR clearance from ground or Clearance delivery? When I initially learned, I'd always obtain it after engine start up, just before I'm ready to taxi. Flying with others since however, I've learned that it's much easier just to walk out to the plane, call ATC to get the clearance ahead of time, so that when I'm ready to go, I'm not sitting there figuring out my route with the engine running and my money burning away.
What would be the time limit in doing it this way -- copying the clearance ahead of time?
Thanks

[daveatc]

There's no real cut-off time, persay. Typically, clearances are kicked out of the computer to the controllers 30 minutes prior to whatever you filed as your proposed departure time. If you call before that, they just have to do a touch more digging (or calling someone, depending on where you're flying out of) to get you the clearance. However, to do that they have to change your P-time to get the computer to give you a code. No big deal, unless you plan on sitting on the ground for two hours, in which case the computer deletes your clearance.

Short answer, most places, controllers don't care when you get it!

[mtsu_av8er]

When I fly these days (Freight-type), after I've gotten the airplane ready to go, and I'm just waiting for my courier(s), I'll get the ATIS, then call CD and pick up my clearance. That way, once I'm loaded, I call ground and get my taxi clearance.

If I'm flying into an uncontrolled field, and it's going to be a quick-turn, I'll even get my outbound before I land (usually with me, it's 0230 anyway . . .).

[Van_Hoolio]

We have to get an ADIZ clearance for every flight which are handled somewhat like IFR clearances. On our DA20's the hobbs doesn't tick until the oil pressure is up so we can use the radio without using hobbs time. When I have 141 students that are pushing their time I use this method to save hobbs time, and ATC doesn't seem to mind the 10 minute gap between obtaining the clearance and taxiing.

At times the clearance frequency can get quite busy so catching them when they're available can save time.

Mike

[mtsu_av8er]

Originally Posted by Van_Hoolio

. . . ATC doesn't seem to mind the 10 minute gap between obtaining the clearance and taxiing.

I'll sometimes get it 20 or 25 minutes before taxiing. Ask some of the airline guys how early they get it.

[wheelsup]

Originally Posted by mtsu_av8er

I'll sometimes get it 20 or 25 minutes before taxiing. Ask some of the airline guys how early they get it.

It could be over an hour prior to taxing if we are delayed due to mx, boarding, bags, etc.

If they want you to go at a specific time you'll get an EDCT time.

[cre8flyer]

Flying out of KLGB 2 days ago, C/D gave me a clearance with a "void if not off by . . ." time. They gave me about 50 minutes.

[MikeD]

Sometimes, ATC will state in the ATIS whether or not to contact Clearance Delivery prior to engine start.

[daveatc]

Originally Posted by MikeD

Sometimes, ATC will state in the ATIS whether or not to contact Clearance Delivery prior to engine start.

Usually see that when there's ground stops, gate holds, etc. Save you the time, money, energy, etc of getting all spun up just to sit there and do nothing.

[mbtrebbe]

it will stay in the system for an hour and a half after your filed time. If you are going to be longer than that just tell them and they can bump the time back for you. The joys of charter, doing that two and three times for late pax. lol