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Departing an uncontrolled airport IFR




At FlightInsight we think small airports are the best and most fun airports, and we wouldn’t want a thing like IFR weather conditions to stop us from exploring some of these gems. So let’s talk about departing an uncontrolled, or as they’re officially known, “pilot-controlled” airport under IFR, from picking up a clearance, to departing and contacting ATC.

Let's we’re on the ramp at Carroll Country, a class E slash G airport northwest of Baltimore.


Getting your IFR clearance


Now, filing an IFR flight plan out of an uncontrolled field is no different than from a towered field. But to pick up the clearance, we’ll need to find out a bit more information specific to the airport. Take a look at the communications section of the Chart Supplement page for Carrol County:

First we notice a GCO available on 121.725. We also have a phone number to contact Potomac Approach. Both the GCO and the phone number will connect you to the same place at Potomac TRACON.

Also, if you have an airport diagram you’ll see the GCO frequency here as well (see picture on the left).


A GCO is a Ground Communication Outlet, it uses a radio receiver to connect through a modem to the controller issuing clearances. To use a GCO, you click the mic four times and it dials the number for Potomac, and connects you directly to them via radio.

If that doesn’t work, you can call the number listed on the Chart Supplement and the same person at Potomac will pick up. Some uncontrolled airports have a remote outlet that connects directly to clearance delivery, instead of through the telephone like our GCO.

To get your clearance, you can use the GCO; tune your radio to 121.72, click the mic four times, make contact with Potomac, and say “Potomac Clearance, Cessna 9334H on the ground at Carroll County requesting IFR clearance to Allentown “.


Now you can write down the clearance, using the CRAFT acronym, Clearance limit, Route, Altitude, Frequency, Transponder. ATC will come back and say, “N9334H, Potomac Clearance. Cleared to Allentown Airport via direct Baltimore, V93, Lancaster, V39, East Texas, direct destination, maintain 3000, expect 7000 10 minutes after departure, departure frequency 125.52 squawk 3217. Hold for release”.


Hold for release, that’s something you don’t typically hear at a non-towered airports. There’s no takeoff clearance needed without a tower, but until you get the OK, the release, from approach, you can’t depart IFR.

So you’ll then readback that clearance and they’ll say “Cessna 9334H readback correct advise ready for departure.”

And they may ask you which runway you’re going to depart from.

Let’s take a closer look to the route ATC assigned you. It’s starts with the Baltimore VOR, and joins V93. If you pull up a low enroute IFR chart, you’ll notice that this is pretty much the opposite direction from the one you want to go, but this beginning part of the clearance serves as lost communication procedure too. If you don’t make contact with approach after departure, they want us to head toward the VOR on your assigned altitude. It could also help approach pick us up on radar to start flying towards BWI. Every airport or region has their own typical IFR departure instructions, and it’s a good idea to ask around local pilots for what those might be in advance.


From Baltimore you’ll fly V93 to the Lancaster VOR, where you’ll join V39, to the East Texas VOR, and then on to Allentown airport. Next set up your squawk code, your frequency for Potomac Departure, and the VORs for Baltimore and Lancaster. And then you’re ready to taxy to runway 34.

Now, you can’t depart under IFR until we get a release from ATC. A release is a window of time that you’re able to depart in. At uncontrolled airports, only one aircraft is able to depart or land under IFR at a time.

So when you’re released for departure, no other IFR aircraft can land or depart. An inbound aircraft will have to hold here and wait until you’ve departed, before ATC will give them clearance to proceed with the approach and land.

By the same token, if one aircraft lands under IFR, taxis onto the ramp and shuts down but doesn’t close it’s flight plan, the airspace still belongs to that plane, and anyone else trying to arrive IFR will have to hold. That’s why, the right time to close your IFR flight plan is right after you’ve landed and taxied off the runway, and not an hour or so later when you’re hanging out with your friends and suddenly remember.


Getting off the ground


Once you’re ready to depart you can ask Potomac for a release, you’ll contact them again either through the GCO or with your cellphone, and say, “Potomac Clearance, Cessna 9334H is number one and ready Runway 34 at Carroll County”.

They’ll want to know which runway you’re departing so they can make sure you’re properly spaced with other IFR aircraft that may be in the area. They’ll reply back with these instructions, which you’ll want to jot down:

“Cessna 34H, released for departure at 1950z, time now 1948z, clearance void if not off by 1955z advise intentions no later than 2005z upon entering controlled airspace, fly heading 020”

Ok so they spit a bunch of stuff at you. They’ve told you that you’re released at 1950z. This is the earliest you can depart. For reference they gave you the current time of 1948z, so your release begins in two minutes. They also told us the clearance is void after 1955z. That’s when your window closes, if you’re not airborne by then, the airspace around you opens up again to IFR aircraft. This clearance void time is when you need to be wheels up by, not the time you need to contact ATC by, or enter controlled airspace by, you should take off and leave the ground by 1955z.

If you don’t take off by 1955z, you need to get in touch with Potomac and let them know what your plan is by 2005z, or else they start getting worried and may think you took off and never made it up to altitude, they may start going through their search and rescue procedures. So definitely get in touch with them by this time. Remember that you don’t have to take off by 1955z, if you don’t feel you can’t take off, just call them back before 2005z and they’ll give you a second release.

OK, so lastly they told you to enter controlled airspace heading 020. You’re familiar with ATC giving you vectors when you’re in flight, but this isn’t really a vector. Taking off from an uncontrolled airport, you start in Class G airspace, in other words uncontrolled airspace, where ATC doesn’t give us vectors. Once you climb above 1200 AGL, you’ll be in Class E, controlled airspace. So what ATC is telling us is that when you climb out above 1200 AGL and enter controlled airspace, you should be on that 020 heading.



Take a look at the abbreviations I would use when writing down this clearance. Feel free to use these, they’re standard.




Departing the airport


So here’s how you’ll depart: The runway elevation is 774 feet. After takeoff, you’ll climb to 400 feet AGL, which is the standard departure altitude to start our first turn. At that point you’ll turn left heading 020. you should be on that heading when you enter controlled airspace here, at 1200 AGL. Once you’re clear of the traffic pattern, you’ll switch over to the Potomac departure frequency you were assigned in your clearance: 125.52, and say:

Potomac Departure, Cessna 9334H departed Carroll County climbing out of 1,300 for 3,000, on assigned heading 020.”

Then you should hear something like this: “Cessna 34H, ident.” Approach needs to radar identify you, and one of the ways they can do that is by having you hit ident on your transponder, which causes your target on the screen to “blossom” It’s kind of like trying to find your friend in a crowded stadium, you tell him on the phone, I think I see you, but just wave to me so I know it’s you. So by identing you’re giving the controller a wave. They’ll then say

“Cessna 34H radar contact 2 miles north of Carroll County 1,800 feet.”


Now there are a few things you might hear at this point. Here’s one possible instruction:

“…leaving 2,100 feet turn right heading 060 and proceed direct Lancaster when able.”

What this means is that ATC wants to give you a vector of 060. However, you’re still too close to the ground for a vector. There are minimum vectoring altitudes based on terrain in the area. So you should stay on your assigned heading of 020, and then at 2,100 feet turn right to 060. Also, you should tune the Lancaster VOR, 117.3, so you can fly inbound to that when you pick up the signal.

What ATC has given you is what’s known in the lingo as a shortcut. Instead of doing that big detour to Baltimore from your cleared route, you can proceed direct to the Lancaster VOR, saving you a bunch of time.


So that’s a typical IFR departure from a pilot controlled field like Carroll County. A lot of things work differently than at a towered airport, since you’re working directly with ATC to coordinate your release, instead of having a tower controller do it. But don’t let that stop you from exploring the little airports out there under IFR!







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