Use the national clearance delivery phone number to obtain your clearance: (888) 766-8267.

Note: Also use this phone number if you need to cancel an IFR clearance on the ground at an airport without a clearance delivery frequency.

Provide the following information:

  1. Tail number
  2. Departure airport name, identifier, and state (this is based on the information requested in the announcement when you call the phone number).
  3. Destination airport name, identifier, and state.
  4. Departure runway.
  5. Which obstacle departure procedure (ODP) you're planning on flying at the departure airport (if any)
  6. How much time you need prior to takeoff. 

You'll get a clearance that sounds similar to this:
"November 245 sierra romeo is cleared... <your clearance here> ... release time 1426 void if not off by 1431. Time now is 1416."

  • You may also hear, :...if not off by 1431 advise ATC of intentions no later than 1436" or something along those lines.
  • You may also hear "...hold for release.", which typically means you need to call ATC back when you are at the runway ready to go. This might happen if you are flying near a large airport. (This happened to me at a small airport outside of Philadelphia -Dave Todaro)
  • You might also consider picking up your clearance in the air if you can safely depart VFR, and maintain VFR until your clearance is received.
  • At DAW, you can also try calling “Bangor Radio” on 122.25 through the Waterboro RCO – sometimes they can only receive your transmission when you are at the high point of the airport near Glenn’s maintenance hangar. Turn off the squelch so I can hear their transmission.

As you can see by the above, ATC expects you to be airborne within a certain time window.

See 5-2-6 Departure Restrictions, Clearance  Void Times, Hold for Release, and Release Times in the Aeronautical Information Manual for more details.