What Is CTAF? Common Traffic Advisory Frequency Explained

At a towered airport, a controller keeps everyone neatly separated. But that isn’t the case at the thousands of non-towered airports across the US, where there is no controller. 

Who keeps the airplanes apart, then?

You do, along with everyone else flying nearby. You’ll talk to each other on one shared frequency called the CTAF. 

It sounds like a complicated system, like the organized chaos of a radio hive mind, but it works. And it gets a whole lot easier when you use it correctly. 

Let’s find out what the CTAF actually is, and how you can find the right CTAF for any airport. We’ll even guide you on how to make clean, confident radio calls when nobody is there to answer.

Key Takeaways

• CTAF is the shared frequency pilots use to coordinate at airports without an operating control tower.
• CTAF is a designated function, not one fixed frequency, so the number changes by airport.
• You find an airport’s CTAF on the sectional chart, the Chart Supplement, or an EFB.
• Good radio calls state your aircraft, position, and intentions, bookended by the airport name.

What Does CTAF Stand For?

CTAF stands for Common Traffic Advisory Frequency. When you find yourself in the vicinity of an airport that has no operating control tower, you’ll use this radio frequency to talk directly to other pilots.

Now, what trips up new pilots is that the name is singular. “Frequency.” Just to be clear, CTAF is not one specific frequency reserved nationwide.

According to the FAA, it’s a frequency designated for conducting airport advisory practices while operating to or from an airport without an operating control tower.

Notice the word “designated.” The actual number changes from one airport to the next. The CTAF may be a UNICOM, MULTICOM, FSS, or tower frequency, depending on what a given field has been assigned.

So it helps to think of CTAF not as some universal channel, but as a role that some frequency has been handed at a particular airport.

Airports and the CTAF

At a non-towered airport, or when the tower is closed, there’s nobody on the ground clearing you to land or telling the other traffic to give way.

That job falls on you and everyone else flying nearby, and the CTAF makes it all work. You broadcast your position and intentions, so others know where you are.

We call this self-announcing. Pilots broadcast their position or intended flight activity or ground operation on the designated CTAF.

Pair those calls with looking out the window, and you get the see-and-avoid system, which keeps uncontrolled airports in order.

How to Find the CTAF Frequency

So you’ve picked your destination, and you need its CTAF. Where do you look?

You’ve got a couple of reliable places to check.

Sectional Chart

First, check the sectional chart. Every airport has a data block printed beside its symbol. The CTAF sits right inside it.

You’ll find the frequency marked by a solid circle containing a white “C” placed next to the number. Also, that circled C is printed in the same color as the airport symbol. Blue means the field has a control tower. Magenta means it doesn’t.

The top line shows the airport name and identifier. Under that comes “CT” with the control tower frequency.

Now, don’t get this number mixed up with the CTAF. While they’re usually the same frequency, don’t assume it’ll be the case everywhere.

The tower frequency is flagged with a star when the tower runs part-time. Then, the circled-C CTAF, then a weather frequency like ATIS.

The block closes with field elevation, lighting information, and the longest runway length given in hundreds of feet.

Chart Supplement and EFB

Your second source for finding the CTAF is the Chart Supplement (formerly the Airport/Facility Directory). It lists the CTAF in its communications data.

Or, you can check your EFB like ForeFlight, which pulls all of this into the airport page for you.

No Written Frequency

What if there’s no CTAF explicitly written on the chart?

When the tower is closed, the CTAF defaults to the tower frequency. Then to the FSS local airport advisory frequency, then to UNICOM.

And where there is no tower, FSS, or UNICOM station on the airport, use the MULTICOM frequency 122.9.

Facility at Airport	Frequency Use	Outbound	Inbound
UNICOM (No Tower or FSS)	Communicate with the UNICOM station on the published CTAF frequency (122.7, 122.8, 122.725, 122.975, or 123.0). If unable to contact UNICOM station, use self‐announce procedures on CTAF.	Before taxiing and before taxiing on the runway for departure.	10 miles out. Entering downwind, base, and final. Leaving the runway.
No Tower, FSS, or UNICOM	Self‐announce on MULTICOM frequency 122.9.	Before taxiing and before taxiing on the runway for departure.	10 miles out. Entering downwind, base, and final. Leaving the runway.
No Tower in operation, FSS open (Alaska only)	Communicate with FSS on CTAF frequency.	Before taxiing and before taxiing on the runway for departure.	10 miles out. Entering downwind, base, and final. Leaving the runway.
FSS Closed (No Tower)	Self‐announce on CTAF.	Before taxiing and before taxiing on the runway for departure.	10 miles out. Entering downwind, base, and final. Leaving the runway.
Tower or FSS not in operation	Self‐announce on CTAF.	Before taxiing and before taxiing on the runway for departure.	10 miles out. Entering downwind, base, and final. Leaving the runway.
Designated CTAF Area (Alaska Only)	Self‐announce on CTAF designated on chart or Chart Supplement Alaska.	Before taxiing and before taxiing on the runway for departure until leaving designated area.	When entering designated CTAF area.

Start with the Right Study Plan

Use the sheet as your roadmap, then reinforce with lessons and quizzes.

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CTAF vs. UNICOM: What’s the Difference?

One is a place you call, and the other is a channel you broadcast on.

UNICOM

The Pilot/Controller Glossary defines UNICOM as: A nongovernment communication facility which may provide airport information at certain airports.

On request, the operator might pass along the wind and the runway in use.

But UNICOM is not air traffic control. It issues no clearances and provides no traffic separation. Sometimes, the station could even be unstaffed (or simply not pick up).

CTAF

CTAF is broader than people assume. Yes, its primary use is self-announcing your position and intentions. But sometimes, it can also be the frequency with which you call a UNICOM or FSS.

And whenever possible, you can use the CTAF to control airport lighting systems at airports without operating control towers.

Why the Confusion?

At many non-towered airports, the CTAF and UNICOM frequency is one and the same. The Chart Supplement labels it as “CTAF/UNICOM.”

Even so, the CTAF is not always a UNICOM. Rather, the CTAF may also be a UNICOM, MULTICOM, FSS, or tower frequency.

CTAF, UNICOM, and MULTICOM Frequencies Explained

At a non-towered airport, your CTAF is usually the field’s assigned UNICOM frequency. And when there’s no UNICOM at all, it’s MULTICOM 122.9.

Let’s break it down by airport type.

Non-Towered UNICOM Frequencies

Seven UNICOM frequencies are assigned to airports without an operating control tower. 122.700, 122.725, 122.800, 122.975, 123.000, 123.050, and 123.075.

The recommended procedures table shows a shorter example set, but the full FCC allocation for non-towered fields is the seven listed above.

In most of these fields, the assigned UNICOM frequency doubles as the CTAF, so the number you’d call for fuel is the same one you self-announce on.

UNICOM 122.950

122.95 is the UNICOM frequency for airports with a control tower or FSS on the airport.

Again, UNICOM, not CTAF. Wind direction and runway information may not even be available on UNICOM frequency 122.950.

It’s used there for non-control services like requesting fuel or parking from the FBO.

How to Make CTAF Radio Calls

Since we’re dealing with a frequency with no operating tower, your radio calls will obviously go a little differently.

But talking on the CTAF only sounds intimidating until you realize every call follows the same simple template. 

The structure is always the same. You open with the airport name followed by “traffic,” then give your aircraft type and call sign.

Then your position, your intentions, and you close with the airport name one more time.

Why repeat the airport name at the end? Well, a nearby airport could be using the same UNICOM or MULTICOM frequency. 

You should transmit the airport name at the beginning and end of each transmission so nobody confuses one field for another.

Sample Radio Calls

Here’s how it sounds around a typical flight.

Departure Calls

Taxiing out, you might say:

“Prescott Regional traffic, Cessna Four Three Quebec, north ramp, taxiing to Runway Two One Right, Prescott Regional.“

Rolling for departure and then leaving the area, you’d fold both moves into one call:

“Prescott Regional traffic, Cessna Four Three Quebec, departing Runway Two One Right, right downwind departure, Prescott Regional.“

Now nobody is left guessing where you went.

Arrival Calls

When you’re coming back, your first call goes out early.

Monitor and communicate on the designated CTAF from 10 miles to landing. Somewhere around that distance, you’d announce:

“Prescott Regional traffic, Cessna Four Three Quebec, one zero miles north at two thousand, Prescott Regional.”

When you’re about 5 miles out, update your position and tell everyone your plan.

“Prescott Regional traffic, Cessna Four Three Quebec, five miles north at two thousand, we’ll be overflying the airport, north to south at two thousand. Prescott Regional.“

After that, you call each leg as you fly it. If you’re coming from an overflight, entering the pattern sounds like:

“Prescott Regional traffic, Cessna Four Three Quebec, over at the airport, maneuvering west of the airport to enter on a forty-five for right downwind for Runway Two One Right, Prescott Regional.” 

Once you’re established on downwind, you advise where you are. Mention if you’re landing for a full stop, a touch-and-go, or a simulated go-around.

“Prescott Regional traffic, Cessna Four Three Quebec, right downwind for Runway Two One Right, full stop, Prescott Regional.” 

Then you repeat the idea when turning base, and again when turning final. Keep each call to your position and your intention, nothing more.

And once you’ve rolled off the pavement, give a quick:

“Prescott Regional traffic, Cessna Four Three Quebec, clear of Runway Two One Right, Prescott Regional.”

That’ll tell the next pilot the runway is theirs.

CTAF Best Practices and Common Mistakes

You don’t need to aim for sounding like an airline captain to make a good CTAF call. It’s more about giving other pilots a clear picture as efficiently as possible.

CTAF Do’s

Listen before you speak, and that’s exactly where it all starts. 

All traffic within a 10-mile radius of a non-towered airport should monitor and communicate on the designated CTAF when entering the pattern. So, tune in well before you arrive.

Keep your transmissions brief. Remember that you’re sharing the frequency with other pilots. When you ramble on the radio, you’re taking precious time away from others.

Name your aircraft and call sign, then give your position and your intention, and let go of the mic.

Make sure everyone can understand your position, even pilots passing by. Not everyone knows the local landmarks, and a visiting pilot has no clue where “the old quarry” is.

So, how can you manage that? Anchor your position based on your altitude, and your distance and direction from the airport. Just like earlier, something as simple as “five miles north at two thousand.”

And don’t forget to mention the runway number as you’re entering the pattern.

When referring to a specific runway, pilots should use the runway number rather than vague phrases. “Runway two one right” beats “the active” every time.

CTAF Don’ts

Now the mistakes. The big one is using the phrase “any traffic in the area, please advise.”

The FAA flat-out calls out this faux pas. It’s not a recognized self-announcement phrase and should not be used under any condition.

It clutters the frequency and transfers your see-and-avoid duty onto everyone else.

Also, please use the published airport name instead of the town name to avoid confusion. 

Think about how multiple airports can sit near the same city. Local nicknames are not always obvious on the radio.

And there is no need to narrate your whole flight plan when a crisp position report does the job.

When the Tower Is Closed: Part-Time Towers

Now, not every control tower runs around the clock.

Where to Tune In

Plenty of airports have part-time towers that shut down at night or on slow days. And the moment the controllers go home, the airport behaves exactly like a non-towered field.

So, what frequency do you use? In most cases, the tower frequency itself becomes the CTAF. Then, you self-announce on it just as you would anywhere else.

In other airports, the CTAF is a separate frequency, but you’ll also be able to find that in the sectional chart.

Your instrument approach/departure plates help too. A particular airport’s CTAF is listed in the instrument approach and departure procedure charts.

How to Spot a Part-Time Tower

You’ve got a couple of clues for identifying a part-time tower.

On the sectional chart, a towered airport is printed in blue, and all others in magenta. But a part-time tower is flagged with a star next to its CT frequency.

The familiar circled “C” still marks the CTAF in the data block, so you read it the same way you would at any other field.

And as standard practice, check the current status before you rely on any of it. Tower hours live in the Chart Supplement.

A NOTAM will also tell you when a tower is closed at a time it normally wouldn’t be. And take note that a field scheduled to be open can close unexpectedly. That NOTAM is how you find out.

Once the tower is closed, the procedure is refreshingly familiar. 

If an airport has a tower and it is temporarily closed, or operated on a part-time basis, and there is no FSS on the airport or the FSS is closed, use the CTAF to self-announce your position or intentions.

Frequently Asked Questions

What Does CTAF Stand For?

CTAF stands for Common Traffic Advisory Frequency. 

It’s the shared radio frequency pilots use to announce their positions and intentions at an airport without an operating control tower.

In it, pilots coordinate with each other instead of with a controller on the ground.

What Is the Difference Between CTAF and UNICOM?

UNICOM is a nongovernment ground station, usually run by an FBO, that may pass along informal airport information when you ask.

CTAF is the frequency you self-announce on a non-towered field.

They often share the same number, which is why people mix them up, but they are not the same thing.

What Frequency Is Used at a Non-Towered Airport When UNICOM Isn’t Available?

122.9 MHz, the MULTICOM frequency. The FAA assigns it for self-announcing when an airport has no tower, FSS, or UNICOM.

If you see this one on a written test, that’s the answer they’re after.

Is CTAF Always 122.9?

No. CTAF is a function, not a fixed frequency.

The CTAF may be a UNICOM, MULTICOM, FSS, or tower frequency depending on the airport.

MULTICOM frequency 122.9 only comes into play when no other station serves the field. Always check the chart for the specific number.

Do I Have To Have a Radio To Fly Into a Non-Towered Airport?

Well, generally, no. 

Under 14 CFR 91.126 and 91.127, a two-way radio is only required at an airport having an operational control tower. So most non-towered fields in Class G or E airspace don’t legally require one.

That said, we still strongly recommend that you carry a radio for safety. If the field sits in or under controlled airspace that requires it, you’re going to need one.

And if your radio fails at a towered field, ATC can still clear you in with light gun signals.

Conclusion

At a non-towered field, you are the controller. 

Nobody is going to sequence you or call your traffic, so the CTAF is how you stay clear of everyone else out there.

How can you keep the common traffic advisory frequency in order? Look up the frequency before you ever leave the ground.

Make your calls short and specific enough that a stranger can picture exactly where you are. And whatever you do, keep looking out the window.

Remember, the radio only backs up your eyes. It doesn’t replace them.

None of this is complicated once it becomes a habit. It’s really just airmanship with a microphone in your hand.