By Ian Elchitz

What this lesson covers:

To understand the components of an IFR clearance, how to get one, and what to do with it.


What this lesson does not cover:

Picking up an IFR clearance while already in the air.


  • You are connected to Vatsim at a gate/terminal of the airport you wish to depart
  • You have arleady filed a valid IFR flightplan
  • You are on the frequency of the appropriate Controller responsible to issue IFR Clearance



You have already connected to Vatsim, are sitting a gate at your departure airport, and have already filed your IFR flightplan.

You switch your radio to the Clearance Delivery controller and then all of a sudden you realize that you don't even know what an IFR clearance is, how you get one, or what you do with it. Do not worry, most of us were like this once - after this document you should be ready to ask for and understand your IFR clearance as well as a professional pilot.


The Flight Plan:

For the purposes of this training lesson - we will pretend that you have connected your Boeing 737-700 to KLAX (Los Angeles International) and are currently connected to the Clearance Delivery Controller on 121.40. You have filed the following Flight Plan to CYYC (Calgary International Airport): 




IFR Clearance - What is it?

A clearance issued by ATC is predicated on known traffic and known physical airport conditions. An ATC clearance means an authorization by ATC, for the purpose of preventing collision between known Aircraft, for an aircraft to proceed under specified conditions within controlled airspace.

For those of us who aren't lawyers - what this actually means is that a your IFR clearance is the authorized route for you to conduct your flight under Instrument Flight Rules. This is generally issued to you in order to ensure your safety within the Air Traffic System. An IFR Clearance IS REQUIRED for all aircraft operating IFR. 

The pilot-in- command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.

This means that as the pilot, you still have a choice to accept or ask for an ammendment to your clearance if you think it will jeopardize your safety.

Think of a this as a Contract

Why are we going through all of this? You need to think of an IFR Clearance as something similiar to a contract. A contract is always between two people. Both people have a goal in mind and they somehow interact with each other. One person makes a proposal, the other person reviews it, they may or may not have some negotiations on the terms and conditions, and finally they agree on a contract and shake hands (or sign it). The IFR Clearance is similiar- the pilot wants to get from point A to point B. The Controller wants the pilot to get from Point A to Point B as safely as possible. The Pilot submits a flightplan, the Controller accepts and/or ammends it and presents it to the pilot - once the pilot accepts it - this becomes the "Contract".


Requesting your IFR Clearance

Once you are connected to the appropriate Clearance Delivery Controller, all you have to do is ask for it:

"Clearance Delivery, good morning. Air Canada 301 requesting IFR Clearance to Calgary"

It is highly recommended that when you request your IFR clearance - you have a pencil in your hand and be ready to copy down the details of it. You just asked for it - so the controllers can only assume that you are ready to receive it.



CRAFT is a commonly used acronym for IFR clearances. CRAFT stands for Clearance Limit, Route, Altitude, Departure Frequency, Transponder. 

  • Clearance Limit - This is almost always the destination airport.
  • Route of Flight - This is the route of flight you will fly. It must be checked as described below.
  • Altitude - This is composed of an initial and final climb altitudes as described below.
  • Departure Freqency - This is the frequency of the radar facility handling departures.
  • Transponder - This is transponder beacon code assigned for your flight.

"Air Canada 301, Los Angeles Clearance Delivery. Cleared to the Calgary International Airport via the Gorman Four Departure, Shafter Transition, then as filed. Maintain 5000, Expect Flight Level Three Four Zero - five minutes after departure. Departure Frequency 124.30, Squawk 7201. Good Morning."


(Note, that the departure frequency in some countries follows the clearance and therefore is not a direct part of the clearance)

Components of the Clearance

"Air Canada 301"
That's you. Make sure you always listen for your callsign.

"Los Angeles Clearance Delivery"
That's the controller identifying themselves. They will usually only identify themselves the first time they speak to you.

"Cleared to the Calgary International Airport"
This is your Clearance Limit. They have cleared you all the way to the Calgary Airport.

"via the Gorman Four Departure, Shafter Transition, then as filed"
This is your Route of Flight. You are expected to fly via the GMN4 departure, EHF Transition as depicted on the SID chart. Once you reach EHF you are expected to continue your flightplan from that point on, which would be LLC REO J537 ONEAL VUCAN THIRD3 CYYC

"Maintain 5000, Expect Flight Level Three Four Zero - five minutes after departure"
This is your Altitude Clearance. It is broken into a few different portions:

"Maintain 5000"
This is your initial climb altitude. You are not at this point cleared any higher than 5000 feet. You should not climb above 5000 feet under any circumstances except if your safety is in jeopardy, or for reasons mentioned below. Controllers generally rip their hair out when aircraft "bust" their altitude clearance.

"Expect Flight Level Three Four Zero - five minutes after departure"
This is what you can expect as your cruise altitude. They tell you to expect that altitude within 5 minutes because in the event that you lose all radio communications. You can then climb to FL340 after 5 minutes. Note that this is ONLY if you lose radio communications. Also this part varies in different countries.

"Departure Frequency 124.30"
This is your Departure Frequency. This is the controller you are expected to contact once you are airborne. In most cases the Tower controller will tell you when to contact that controller. If you lose communications with the tower once you are in the air - this is the controller you should contact.

"Squawk 7201"
Transponder. This is the code you should type into your Transponder. It is a unique code - specially reserved for YOU. You should type it into your transponder as soon as possible, without it - the controllers may have trouble radar identifying you.


Responding to the Clearance

Once the Controller has issued the IFR clearance to you, they expect you to read back the clearance in order to acknowledge that you have received it, understand it, and accept it. You should go ahead with your readback immediately following the controller's transmission (unless told otherwise) - this is why you had that pencil ready to write it down. Your readback might sound like this:

"Cleared to Calgary via the GMN4 departure, EHF transition, then as filed. Initial altitude 5000, expecting 340 in 5, departure on 124.3, squawk 7201, Air Canada 301"

The controller would usually tell you that your readback was correct and pass on other relevant information. If part of your readback was not correct, they will tell you what parts were incorrect and expect you to readback the portion that was incorrect.

"Air Canada 301, Readback Correct"


There are some variations to the readback. If your clearance contained no ammendments to the initial route and altitude that you filed, you can simply readback your squawk code:

"Squawk 7201, Air Canada 301"

in this case, the controller would respond with

"Squawk readback correct"


Variations on IFR Clearances

Sometimes the route that you filed may not be valid or acceptable to the controller for a number of reasons. In most cases they will issue you an ammended IFR clearance. These differences are mainly to be found in different countries. As example we take Germany:

"ACA234 heavy, you are cleared to your destination xxx via SID, flight planned route, squawk 1234."

"ACA234 heavy, cleared SID, squawk 1234"

"ACA234 heavy, readback is correct, qnh NNNN, departure frequency 123.450"

As you can see, the clearance follows an equal scheme. 


What do I do with my clearance now?

Since the controller has issued your clearance, you have read it back, and they have confirmed the readback - you now have a legally binding contract for how you will conduct your IFR Flight.

You are expected to comply with the route of flight. If you were assigned a SID - you should be prepared to fly it as depicted on the chart. If you do not have the SID chart or do not understand how to fly it, you should not file it or not accept it when issued by the Controller. 

If you were assigned an initial altitude, you are expected to climb to and maintain that altitude unless otherwise instructed by a controller.