IFR Operations at Uncontrolled Airports

The procedures described here apply in the U.S. I don't profess to know the intricacies of such operations in other countries so I won't attempt to describe them.

So what is an uncontrolled airport? Simply put, it's an airport without an operating control tower. Takeoff, landing, and ground operations are at pilot's discretion and risk. Separation is provided by the pilot's eyes. Does that mean you can launch an IFR flight without any consideration of ATC? Absolutely not. Here's how it works:


To fly IFR in controlled airspace, a pilot MUST first receive a clearance from ATC. In real world operations, he has 3 choices:

  1. Launch VFR and pick up his clearance in the air.

    This is feasible (and common) when the weather is good. Note that until such time as the pilot is issued a clearance by the appropriate ATC facility, he MUST remain VFR and operate at VFR altitudes since he IS VFR, NOT IFR. If it is not possible to maintain VFR, potentially for an extended period of time, then this alternative is not viable and may not be used.

    This method of obtaining a clearance is particularly common in remote areas with poor ATC radar and radio coverage at low altitudes. The pilot launches VFR, climbs high enough to talk to Center and calls for a clearance.

  2. Contact ATC via radio on the ground and receive a clearance before departure.

    In this case, the pilot contacts the appropriate controlling facility (usually an approach control or an enroute center) via radio and requests his clearance. The clearance will be issued. Once any readback is completed and corrections made, ATC will issue instructions either to "HOLD FOR RELEASE" or "RELEASED AT THIS TIME, CLEARANCE VOID IF NOT OFF BY

    Actually the meaning is quite simple once you understand how departures work in the IFR environment. ALL IFR departures require a "release" by the controlling facility. In the case of airports with operating towers, the pilot rarely sees (or is aware of) this process. It's handled either controller-to-controller or is automatic by way of a Letter of Agreement. At an uncontrolled airport, however, this is not possible and the pilot must obtain a "release" from ATC. If he is instructed to "HOLD FOR RELEASE", he must remain on the ground until he receives a release. If he is given a clearance void time, he MUST depart by that time or the release is void, thus the phraseology "VOID IF NOT OFF BY

  3. Contact FSS (via radio or landline) and have them obtain and relay a clearance.

    This is similar to case #2 in operation except that it's used in remote places where direct contact with ATC is not possible. The primary difference is that clearances relayed via FSS will always include a release and a void time.

How Does This Work On VATSIM?


On VATSIM, option 2 is your best choice, with option 1 being second. Option 3 is not available in our virtual world. When you receive your clearance, you will be (or should be, if the controller is following proper procedure) issued a release with a void time or told to hold for release. You will not be (or should not be) issued clearance to start up, pushback, taxi or takeoff. You're responsible for selecting the correct runway, based on the weather information available to you and getting yourself into the air once you receive your release. If you're given a void time, be sure you're airborne by that time.


Airports without operating control towers are either Class E or Class G airspace. Most of the ones you will care about are Class E, to provide protection for IFR aircraft. However, that does not mean that you have any control over surface operations at that airport. You don't get to control taxi operations, runway selection, or VFR operations at all. You're simply responsible for separating airborne IFR aircraft from each other. Issue clearances to aircraft requesting them, then give them a release and a void time: "N4365Z, readback correct, clearance void if not off by 0245, time now 0232". Those times are UTC times, not local times. (For the purists, there is another phrase that follows in the real world but doesn't add much value in the virtual world. I'll leave that as an exercise for the reader!)


Here's the part that the least well-understood in our virtual world:

Mistake #1

At uncontrolled airports, it is the pilot's responsibility to select the landing runway and approach desired, based on the current weather and the aircraft he is flying. It is not ATC's responsibility to do this. Appropriate communication from the controller would be something along the lines of "N4365Z, weather at KMTV is . Say the type of approach you are requesting." or "N4365Z, weather at KMTV is available via ACARS. Say the type of approach you are requesting." It's not at all unusual to have to fly the full approach. Do not expect vectors into uncontrolled airports. In the real world, many don't have adequate radar coverage. In the virtual world, there are plenty that do not have the final approach course plotted in the sector file. Without that plot, ATC is not permitted to vector you for the approach.

Mistake #2

After clearing you for an approach at an uncontrolled airport, ATC MUST release you to switch to the advisory frequency (7110.65 4-4-8). Doing so automatically terminates your radar service (7110.65 5-1-13 b. 2. 2.). However, it does NOT terminate your clearance, close or cancel your IFR flight plan, or release the airspace for other IFR aircraft. It also does NOT free you to go on your merry way and do whatever you'd like. Note that while the .65 says it is not necessary to advise the pilot that radar services are terminated (see previous reference), the most common phraseology still is: "N4365Z, RADAR SERVICE TERMINATED, CHANGE TO ADVISORY FREQUENCY APPROVED. ADVISE YOUR CANCELLATION OR DOWN TIME THIS FREQUENCY OR ON THE GROUND VIA FLIGHT SERVICE."

Clearly, on VATSIM, we can leave out the part about Flight Service. However, the rest still works and is appropriate. What I have seen happen over and over and over again, however, is that pilots assume that ATC is finished with them and just buzz off into the sunset, never to be heard from again. Let's read that final sentence in the instruction again: "ADVISE YOUR CANCELLATION OR DOWN TIME THIS FREQUENCY..." That means that you, Mr. Pilot, MUST advise ATC when you are canceling your IFR flight plan (and continuing VFR) or when you have landed. I can count on 1 finger the number of pilots I've handled who have done this correctly (Thank you, Joe Clemmons!). I'm sure there are others out there who do it correctly as well, but I haven't had the privilege of working you.