Lesson 26: advanced radio

Welcome to part three of our radio chapter! This will be our last lesson on radio. 

In this lesson, we’re going to cover the many different ways that pilots can still talk to folks on the ground near airports, when there’s no Air Traffic Control around to help. 

In order to do that, pilots need to tune into a variety of radio frequencies that have different purposes. We’ll learn about the most popular ones today!

But first, we just wanted to remind you that you don’t have to be an expert in talking on the radio. We just want these acronyms and concepts to feel familiar.

As a drone pilot, you also don’t actually need a two-way radio! Just one to listen to pilots with. 

And having a radio can help you out when you’re flying in areas that have lots of air traffic.

Now let’s start by talking about some radio frequencies that pilots use all the time that drone pilots should know about to improve
our situational awareness. 

Each radio frequency is like a radio channel that has a specific purpose.

And just like the channels on a TV or on a radio in a car, they each have different numbers.

For the radio, we call them frequencies!  

Frequencies are measured in MHz, or MegaHertz. 

We’re just mentioning it because you’ll see MHz at the end of a radio number. 

If the MHz isn’t listed next to the number, it’s implied! 

Ooh, just like knots are when pilots are talking about the direction they’re flying in, or the wind speeds, over the radio! 

Often, "122.9 MHz" is just written as "122.9."

We have many different frequencies to cover! But before we talk about each one in depth, let’s have a brief overview of the most important ones.

Every time a pilot needs to land or take off, they need to make a self-announce broadcast –a procedure where pilots broadcast their aircraft call sign, position, altitude, and intended activity.

And just a reminder! When we say ‘non-towered airports,’ that means that the airport doesn’t have a control tower, or it’s not always operating. 

And when there is no Control Tower, there’s no handy Air Traffic Controller to talk to who can help us out. That’s why we have different channels! 

How Pilots Communicate
When there’s no Air Traffic Controller!  

Popular Radio Frequencies for Pilots 

CTAF 

UNICOM 

MULTICOM

ATIS 

CTAF 

First up is the CTAF! That’s the Common Traffic Advisory Frequency. 

Pilots use it at non-towered airports when there are no Air Traffic Controllers to state their positions and intentions with other
aircraft in the area.

UNICOM  

Next up is UNICOM. UNICOM is a specific radio frequency used at smaller non-towered airports. 

UNICOM allows pilots to communicate with the airport to get
important information like weather, wind direction, and
runway details.

MULTICOM 

MULTICOM is like a shared frequency. It is used by pilots at non-towered airports or other communication services to talk to each other! 

MULTICOM lets pilots talk directly to each other to share important information about their location and intentions! It’s like their very own
Discord server. 

MULTICOM is the only station that has a permanent, set frequency for pilots to use at airports without operating control towers.
It’s always on channel 122.9.

ATIS  

And finally, let’s talk about ATIS! ATIS is short for the Automatic Terminal Information Service. 

ATIS is a continuous broadcast that’s always running at busy (towered) airports and provides pilots important information about the airport! 

ATIS gives pilots critical information like weather, active runways, and any special notices for pilots. 

This helps pilots stay informed without having to contact the busy
air traffic controllers directly for basic updates.

If you remember from the last lesson, it’s the third thing that pilots have to announce when they’re entering an airport.

They say the airport name, their aircraft, _____…. 

Those were wonderful explanations! Now, let’s dive into each one in more depth. 

Let’s start with the CTAF, or the Common Traffic Advisory Frequency.

How Pilots Communicate
CTAF   

CTAF → “Common Traffic Advisory Frequency.” 

It is the frequency pilots use to talk to each other directly when there’s no control tower at the airport.

The CTAF radio station helps pilots
coordinate landings, take-offs, and other maneuvers safely.

Awesome! How do I find a CTAF frequency?   

The CTAF Frequency of an airport is actually listed directly on a Sectional Chart!

Check it out: look up an airport on a Sectional Chart, and find that string of airport info.

Let’s check one out ourselves!
Look up a non-towered airport on a Sectional Chart, and find that string of airport info. 

Find a CTAF 

Step 1:

Find the Circle “C” symbol.

Step 2: The CTAF frequency is the number that’s right before it! 

The CTAF for Payson Airport is 122.8. 

You might be wondering: why should we know about all this stuff that has to do with manned aircraft if we’re unmanned aircraft pilots? 

If you answered ‘safety’ or ‘situational awareness’, you’re correct!

Nice work! We should familiarize ourselves with the recommended traffic procedures manned aircraft pilots follow, like self-announcing
their position and intentions.

That way, we can keep tabs on what pilots are up to and where they are.

Here’s a table from the Aeronautical Information Manual that sums up these procedures.

Find a CTAF 

That’s so much! It’s such a dense and ugly chart.  

Don’t worry! The main part we have to look at is the second column, which says “Frequency Use”.

You’ll see that some of the rows start with “self-announce”. 

This describes when a pilot should broadcast their position or intended flight activity or ground operation on the designated CTAF.

This tells a pilot when they should announce their position and what they’re planning to do while flying or on the ground, using the special radio channel called CTAF.

This procedure is mainly used at airports that do not have a Flight Services Station (FSS). 

Hold on – what is a Flight Services Station?  

It’s time to peel the onion! 

How Pilots Communicate
Flight Services Station (FSS)    

A Flight Services Station (FSS) is like a special help center for pilots. It gives pilots information and services before, during, and after flights. 

Pilots can call them to get weather updates, announce flight plans, and receive safety tips. They can also ask for emergency help if needed. 

A Flight Services Station (FSS) is an air traffic facility that gives aircraft pilots information and services before, during, and after flights.

FFSs are run by the FAA and the US government.

Air Traffic Controllers give pilots instructions and manage the flow of air traffic.

But unlike ATC, FSS is not responsible for giving instructions. They’re just there for basic support! 

If a pilot wants to communicate with a flight service station (FSS), they will address them as “Radio”.

Here’s a cool Example:

“New York Radio, Cessna Seven Five Niner Foxtrot Romeo calling on 122.2, Over.”

Okay! Now that we’ve covered CTAF and the FSS, let’s take a deep dive into MULTICOM, and how pilots self-announce on this frequency.

How Pilots Communicate
MULTICOM    

Unlike the CTAF frequency, the MULTICOM frequency is the same everywhere!

And MULTICOM is always set to 122.9!

MULTICOM serves as a general communications frequency for pilots in areas where there are no specific CTAF or UNICOM frequencies designated. It's used for announcing positions, intentions, and coordinating with other pilots in the area.

MULTICOM is a special, general radio channel that pilots use to talk to each other when there are no control towers or other frequencies (like CTAF or UNICOM) to use. 

MULTICOM

Pilots use MULTICOM to tell other pilots where they are (their position) and what they’re doing to stay safe, like when they’re flying in and out of airpots. 

MULTICOM stands for “Multiple Communications” – so pilots are talking to each other!  

MULTICOM

MULTICOM serves as a general communications frequency for pilots in areas where there are no specific CTAF or UNICOM frequencies designated. 

MULTICOM

It's used for announcing positions, intentions, and coordinating with other pilots in the area.

Let’s look at some examples!

Let’s say a pilot is approaching Strawn Airport in Texas, and they’re self-announcing on the MULTICOM frequency.

Here’s what that pilot might say to another pilot: 

Here’s what that pilot might say to another pilot: 

“Strawn traffic Apache Two Two Five Zulu clear of runway one seven Strawn.”

Here’s what that pilot might say to another pilot: 

“Strawn traffic Apache Two Two Five Zulu clear of runway one seven Strawn.”

Huh? Why’d they say the name of the airport twice?

You see, lots of airports that are in the same area might use the same frequency.

So when self-announcing, pilots should always begin and end with the name of the airport they’re trying to talk to. 

Remember, pilot communication is all about being clear and concise!

Here is the template for how pilots announce themselves on the MULTICOM (not to ATC):

How pilots introduce themselves on the MULTICOM 

1. Who they’re calling 

2. Who they are (call sign) 

3. Where they are 

4. What they want 

5. Who they’re calling (again)

The two main differences when pilots announce themselves to ATC versus MULTICOM are: 

1. They don’t state ATIS (weather) information  

2. They state the airport name twice! At the beginning and end of the announcement, 

Awesome! I think we’re ready to move onto UNICOM. 

We’ve encountered it before, but do we remember what it is?

Nice! UNICOM is a communication station that provides airport information at airports without
a control tower or Flight Service Station (FSS).

When airports don’t have operating control towers, they don’t have Air Traffic Controllers! But pilots still need to get and tell information from somewhere. 

UNICOM means Universal Communications. It’s a non-government frequency used by private pilots and small aircraft operators for local airport communications, such as requesting services to refuel or announce their intentions.

Pilots primarily use UNICOM frequencies when they are approaching, landing, taking off, or moving around at an airport, without ATC’s help.

UNICOM gives them information on weather, wind direction, recommended runways, and more.

UNICOM is a frequency used by private pilots and small aircraft operators for local airports without control towers to still communicate with people on the ground.  

Fun Fact: At smaller airports, the UNICOM and CTAF might share the same frequency. Check the border of the Sectional Chart or the Chart Supplement U.S. for this info! 

Look at that! The CTAF and UNICOM are both on 122.8! This screenshot is from a Chart Supplement on VFRMap.

Here’s an example of UNICOM phraseology.

In this example, a pilot is approaching the Frederick Municipal Airport in Maryland and self-announcing their intentions:

“Frederick Unicom, Cessna Eight Zero One Tango Foxtrot, 10 Miles Southeast Descending Through 2,500 Feet, Landing Frederick, Request Wind And Runway Information, Frederick.”

This chart from the Aeronautical Information Manual describes some common frequencies and their purposes.

Again, this is so much information!

But you don’t have to be an expert in FAA radio communications.

Here are the key takeaways from this chart:

When there’s a non-towered airport and UNICOM isn’t available, a pilot will use the 122.9 frequency to communicate.

When a pilot is flying towards an airport that doesn't have an operating control tower but does have a Flight Service Station (FSS) available, they should start communicating with the FSS on the Common Traffic Advisory Frequency (CTAF) when they are 10 nautical miles away from the airport. 

Awesome job so far! Now, let’s move onto our final frequency for the day – the ATIS. 

ATIS (The Automatic Terminal Service) is a continuous broadcast of recorded aeronautical information in busier airports.

They include information like weather, active runways, available approaches, and NOTAMs (remember those?)

Pilots will listen to ATIS broadcasts before contacting the local air traffic controller for information.

Awesome job so far! Now, let’s move onto our final frequency for the day – the ATIS.

Why do you think they might listen to these recordings instead of trying to talk to a real person right off the bat?

Air traffic controllers are busy people! And pilots need to make sure they don’t overwhelm them!

Something that’s pretty cool – ATIS broadcasts are released in batches, and each new update is named after a letter of the phonetic alphabet!

Okay, now we know about all these frequencies and the ways that a pilot might announce themselves at a non-towered airport.

And finally, let’s introduce our final term, something you’ll probably see a lot on sectional charts. 

Those are AWOS frequencies! You may have seen ‘AWOS’ somewhere on Sectional Charts before, too.

They look a bit like this! 

AWOS stands for ‘Automated Weather Observing System’.

Let’s define what it is! 

AWOS is a system that gives continuous, real-time weather updates like temperature, wind speed and direction, visibility, and air pressure.  

AWOS is mainly used at smaller airports to help pilots with weather information.

All right, how is AWOS different from ATIS?!

Great question! They are different, and let me explain why. 

Let’s remember that ATIS is found at busier airports and doesn’t just cover the weather!

ATIS Reports can tell pilots about stuff like active runways, NOTAMs, and other crucial details, along with the weather.

AWOS, on the other hand, is purely focused on the weather. They are automated systems that record and broadcast meteorological data. 

So both ATIS and AWOS are automated.

AWOS only shares information about weather, and ATIS shares other general airport information that pilots need to know. 

Awesome work so far, future remote pilots! 

Let’s recap everything we learned.

We learned so much, we might as well go out and fly a plane. Just kidding, of course. 

Great work! I see you’re all a few steps closer to becoming a certified drone pilot.