Aviation Radio Frequencies Explained
The complete sequence of ATC frequencies from pre-departure to landing.
Why Frequencies Matter
Aviation radio frequencies are the backbone of air traffic control. Each frequency serves a specific purpose in the ATC system, and knowing which frequency to use — and when — is essential for safe flight operations.
AviatorWX displays all published frequencies for any airport, so you can plan your communications before you fly. Look up an airport to see its ATIS, Tower, Ground, Approach, and Departure frequencies.
The Full ATC Communication Sequence
Before contacting ATC, listen to ATIS to get the current information code, active runway, and weather. Report the information code when you first call ATC (e.g., "Information Bravo").
If flying IFR, contact Clearance Delivery to receive your IFR clearance before taxiing. At smaller airports, clearances may be issued by Ground or Tower.
Request taxi clearance from Ground. Ground controls all aircraft and vehicle movements on taxiways and ramp areas. Do not enter a runway without Tower clearance.
When instructed by Ground, switch to Tower frequency. Tower controls the active runway and the immediate airspace around the airport. Tower issues takeoff and landing clearances.
After takeoff, Tower will hand you off to Departure Control. Departure provides radar vectors, climb instructions, and separation from other traffic in the terminal area.
Departure hands you off to the Air Route Traffic Control Center (ARTCC) for en-route services. Center provides separation at cruise altitude and routes you efficiently to your destination.
Center hands you off to Approach Control as you near your destination. Approach sequences arriving aircraft, issues approach clearances, and provides separation.
Approach hands you off to Tower for landing clearance. After landing, Tower instructs you to contact Ground for taxi to parking.
Non-Towered Airports: CTAF and UNICOM
At airports without an operating control tower, pilots self-announce their positions and intentions on the CTAF (Common Traffic Advisory Frequency). This allows pilots to coordinate with each other without ATC.
CTAF Calls Include:
- • Taxiing for departure
- • Departing runway XX
- • Entering the pattern (each leg)
- • Final approach
- • Clear of the runway
Common CTAF Frequencies:
- • 122.8 MHz (most common UNICOM)
- • 122.7 MHz (private use airports)
- • 123.0 MHz (glider operations)
- • 122.9 MHz (multicom)
Frequently Asked Questions
What frequency do pilots use in an emergency?
121.5 MHz is the international aeronautical emergency frequency (Guard). All aircraft are encouraged to monitor 121.5 MHz. Military aircraft also monitor 243.0 MHz (UHF guard). In an emergency, declare "MAYDAY" three times on the frequency you are currently using, then switch to 121.5 MHz if needed.
What is CTAF and when do pilots use it?
CTAF (Common Traffic Advisory Frequency) is used at non-towered airports or when a tower is closed. Pilots broadcast their position and intentions on CTAF to coordinate with other traffic. The CTAF is often the same as the UNICOM frequency (122.8 MHz is common) or a designated frequency published in the Chart Supplement.
How do pilots find the correct frequencies for an airport?
Airport frequencies are published in the FAA Chart Supplement (formerly Airport/Facility Directory), on sectional charts, and in aviation apps. AviatorWX displays all available frequencies for any airport — including ATIS, Tower, Ground, Approach, Departure, and CTAF — when you look up an airport.
Look up frequencies for any airport with AviatorWX — ATIS, Tower, Ground, Approach, Departure, CTAF, and more.
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