While Air Traffic Control (ATC) manages communication in controlled airspace, there are several other important radio frequencies used for communication in uncontrolled airspace, or in areas where ATC is unavailable. In this lesson, we’ll cover UNICOM, MULTICOM, ATIS, and AWOS frequencies, which all play vital roles in enhancing situational awareness and flight safety.

• UNICOM (Universal Communications) is a frequency used for general communication at airports without an operating control tower, allowing pilots to communicate their intentions to other aircraft.
• MULTICOM is another frequency used in areas without ATC services, providing a communication channel for non-towered airports or remote locations.
• ATIS (Automatic Terminal Information Service) provides automated broadcasts of essential airport information such as weather, runway status, and active approach/departure procedures.
• AWOS (Automated Weather Observing System) is a system that broadcasts real-time weather information to help pilots make informed decisions based on current conditions at or near an airport.

By the end of this lesson, you’ll have a better understanding of how and when to use these frequencies to communicate effectively, improve your flight planning, and ensure safer operations.

Unlike CTAF, which is used for pilot-to-pilot communication, UNICOM allows pilots to communicate with airport staff for information and services.

For instance, a drone pilot near a small regional airport without ATC services would tune into the designated UNICOM frequency to announce their plans and coordinate with any manned aircraft in the vicinity.

Shared Frequency Possibility:

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

MULTICOM frequencies are vital for communication at airports without control towers, Flight Service Stations (FSS), or UNICOM stations.

For drone pilots operating in uncontrolled airspace, monitoring MULTICOM frequencies is essential to stay informed about nearby aircraft and potential hazards.

Unlike UNICOM, which is typically used at specific airports, MULTICOM is a nationwide frequency designated for communication in uncontrolled airspace. The most commonly used frequency in these areas is 122.900 MHz.

These shared frequencies allow pilots to exchange position reports, traffic advisories, and other critical information to ensure safe operations in airspace without direct air traffic control oversight.

ATIS provides recorded, repetitive broadcast of non-control information in a specific terminal area at busy airports. It provides essential information to pilots, including weather conditions, active runways, airport notices, and other operational information like NOTAMs. ATIS reports are updated at regular intervals and whenever significant changes occur.

Sky Conditions and Visibility

When an ATIS broadcast does not include information about sky conditions or visibility, it generally indicates that:

• Ceiling: The cloud base is at least 5,000 feet above the ground.
• Visibility: The visibility is 5 statue miles or more.

Mandatory to Check ATIS?

Pilots are required to check ATIS before talking to the local ATC, which helps streamline communication and flight prep. It’s mandatory for pilots to listen to ATIS before contacting ATC to stay updated on their flight details.

AWOS is an automated system that provides real-time weather observations. It reports various meteorological conditions, including temperature, wind speed and direction, visibility, cloud cover, barometric pressure, and more.

AWOS delivers specific weather data crucial for flight operations, including pilots’ pre-flight planning and in-flight decision-making.

(It is not mandatory that pilots check AWOS)