1.1 Radio Communication Channels: FSS, CTAF, UNICOM, MULTICOM

In this lecture, our objective is to impart knowledge on crucial concepts such as radio phraseology, the application of the phonetic alphabet, and understanding radio frequencies, including the Common Traffic Advisory Frequency (CTAF), a key communication channel utilized across all airports. By delving into these aspects, you’ll gain a comprehensive understanding of effective communication protocols and essential terminology essential for safe and efficient operations in aviation.

FSS
CTA
UNICOM
MULTICOM
ATIS

Key Notes:
The ability to read a TAF report is essential for effective flight planning and safe execution of missions. It allows pilots to align their flights with favorable weather windows, optimize routes based on wind patterns, and make informed decisions to avoid hazardous conditions. The date and time information, along with details about wind speeds and gusts, play a crucial role in these planning and decision-making processes.

Study Guide

CTAF vs. UNICOM vs. MULTICOM vs. ATIS

tagline

While CTAF focuses on pilot-to-pilot communication, UNICOM serves as a channel for pilots to interact with airport personnel and seek information or services.

CTAF | Communication for Pilots

Common Traffic Air

  • Pilots use CTAF to communicate and coordinate with each other.
  • It facilitates mutual understanding of positions, altitudes, and intentions.
  • Especially vital when operating in airports without control towers.
  • Functions as a customer service desk for pilots, typically at small airports.
  • Allows pilots to communicate with airport staff.
  • Used for inquiries about weather conditions, requesting fuel or services, and obtaining updates on airport conditions.

MULTICOM | No Tower, No FSS, No Unicom

  • Multicoms are generally used at airports that do not have a fixed base operator (i.e. there is no tower, FSS or UNICOM station at the airport).
  • They are used for activities of temporary, seasonal or emergency nature.
  • Multicom frequencies are not specific to just one airport or area. The common multicom fequency is 122.900

ATIS | Automated Recording

  • ATIS, or the Automatic Terminal Information Service, delivers continuous recorded aeronautical information in busy airports.
  • Pilots tune in to ATIS before reaching out to the local air traffic controller, streamlining communication and aiding flight preparation.
  • ATIS broadcasts cover crucial details such as weather conditions, active runways, available approaches, and relevant NOTAMs.

Untowered Airports & UNICOM

UNICOM = COMMUNICATE W AIRPORT STAFF

The primary purpose of an air traffic control tower is to manage and coordinate the movement of aircraft on the ground and in the immediate vicinity of an airport.

Towers provide crucial instructions to pilots, ensuring safe takeoffs, landings, and taxiing, and contribute to overall airspace safety.

1. Communicate with UNICOM Operator

UNICOM frequencies are often used at airports, especially those without control towers (untowered airports). Think of UNICOM as a customer service desk for pilots. UNICOM allows pilots to communicate with airport staff.

  • These frequencies can be utilized for various purposes, including broadcasting weather information, providing airport advisory details, and facilitating communication between pilots and ground services.

Common UNICOM frequencies in the United States for airport communication typically fall within the range of 122.7 MHz to 123.0 MHz. It’s important to note that specific frequencies may vary by airport, and pilots should check the appropriate charts or airport information for the exact UNICOM frequency to use at a particular location.

2. When UNICOM & CTAF are the same frequency

When reaching out on a combined CTAF/Unicom frequency, follow these steps:

  • Use “Traffic” on CTAF when you’re updating your position without expecting a reply; it’s for communicating with other aircraft in the vicinity.
  • Opt for “Unicom” when you’re looking for a response from ground station personnel.

2. Communicate with Flight Services Station (FSS)

  • Untowered airport pilots can access Flight Service Stations (FSS) for essential information on weather conditions, NOTAMs, and other pertinent flight data.
  • Communication with an FSS is facilitated by tuning in to the designated frequency on the aircraft radio.
  • In the United States, FSS can be contacted using frequencies such as 122.2, 122.3, 122.4, 122.6, and 122.65 MHz.
  • Pilots are recommended to verify accurate frequencies in their operational area through charts or by contacting ATC.

3. Self-announce Broadcast on CTAF

Pilots use CTAF to communicate and coordinate with each other. Making a self-announce broadcast involves the pilot transmitting essential information about their position and intentions over the radio for other nearby pilots to hear. Common traffic advisory frequency (CTAF) is often used for self-announce broadcasts by small UA pilots near untowered airports.

How Find to a CTAF Frequency:

tagline

Description

Option 1: Look at the Aeronautical Chart

Aeronautical charts provide vital details on airspace and airports, including the CTAF frequency, located near the airport symbol.

Option 2: Look in the Airport Directory
Using an airport directory, you can look up the airport you’re planning to fly to and find its CTAF frequency listed. Below you’ll notice the CTAF frequency is listed as 120.1.

Chart for Radio Comm Procedures:

When a pilot is flying inbound and approaching an airport with no tower in operation but with a Flight Service Station (FSS) open, a pilot should communicate with the FSS on the common traffic advisory frequency (CTAF) at 10 nautical miles out from the airport.

What is the definition of CTAF?

A. The frequency utilized to gather information from Aeronautical Advisory Stations

B. The pilot-to-pilot communication system enabling pilots to directly communicate with each other.

C. The frequency that automatically disseminates real-time weather information at airports

Correct Answer: B – The pilot-to-pilot communication system enabling pilots to directly communicate with each other.

Description: The Common Traffic Advisory Frequency (CTAF), specifically designated for pilots to engage in direct air-to-air communication while operating to or from an airport without an operating control tower.

Click image to expand

(Refer to Figure 23, area 4.) You’re hired to inspect a tower by Planation Airport (JYL). Which radio frequency would you tune into to listen to manned aircraft chatter from incoming or outgoing pilots?

A. 118.375

B. 118.75

C. 122.8

Correct Answer: 122.8

Description:
The radio frequency used to listen to listen to manned aircraft chatter from incoming and outgoing pilots is the Common Traffic Advisory Frequency (CTAF).

On a sectional chart, the CTAF (Common Traffic Advisory Frequency) you should use is indicated by the presence of a circle symbol with the letter C inside. To locate the CTAF frequency, look for this symbol, and the frequency will be directly before it.

The CTAF frequency is consistently positioned in relation to the circle C icon on the chart.

Click image to expand

1. (Refer to Figure 79) What’s the UNICOM frequency at Sioux City Airport?

A. 118.7

B. 119.45

C. 122.95

Correct Answer: 122.95

Description:
Figure 79 in the Chart Supplement provides comprehensive details about Sioux City airport, including essential communication information. To locate the UNICOM frequency, refer to the Communications section within Figure 79.

Click image to expand

(Refer to Figure 20, Area 2.) Which radio frequency should you select to listen to manned aircraft announcing their approach to Chesapeake Regional Airport (CPK)?

A. AWOS 123.675

B. Multicom 122.9

C. UNICOM 123.075

Correct Answer: C. UNICOM 123.075

Description:
sUAS operators can listen to manned aircraft communication by tuning into the Common Traffic Advisory Frequency (CTAF). The CTAF frequency is consistently positioned to the left of the circle C icon.
As is in the case of Chesapeake Regional Airport, along with many other airports, CTAF/Unicom are combined.

The UNICOM frequency is the same as the CTAF at this airport.

FAQ:

Understanding the nuances of CTAF and UNICOM frequencies is crucial for effective communication in aviation. Let’s delve into the distinct purposes and shared possibilities of these frequencies.

  • Shared Frequency Possibility: Sometimes, CTAF (Common Traffic Advisory Frequency) and UNICOM frequencies coincide. In such cases, pilots utilize the same radio frequency for both intra-pilot communication (CTAF) and interaction with airport staff (UNICOM).

When you call on a combined CTAF/Unicom, who you are talking to depends on what you say: You call “Traffic” on the CTAF when you are self reporting your position. You are not soliciting of expecting a response. You are talking to other aircraft. You call “Unicom” when you are expecting a response from someone at a ground station.