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CTAF Usage on VATSIM

Understanding Common Traffic Advisory Frequency operations

What is CTAF?

CTAF (Common Traffic Advisory Frequency) is a radio frequency designated for aircraft operating at non-towered airports or when tower services are not available. On VATSIM, CTAF allows pilots to coordinate with each other when no ATC is present.

At most US airports, the CTAF frequency is typically 122.800 MHz(also known as UNICOM). Some airports may use different frequencies - always check the airport information.

When to Use CTAF

Use CTAF when:

  • Operating at a non-towered airport
  • Tower is closed or not staffed on VATSIM
  • Flying VFR in uncontrolled airspace
  • Coordinating with other traffic in the pattern

Do NOT use CTAF when:

  • Tower is online - use the tower frequency instead
  • In controlled airspace with active ATC coverage
  • You have been instructed to contact a specific ATC frequency

Note: You still use CTAF when only Ground is online - Ground does not control the runway or airspace.

Standard CTAF Phraseology

Entering the Pattern

"[Airport] traffic, [Callsign], [location] inbound, landing runway [number], [airport]"

Example:

"Republic traffic, Cessna one two three four Bravo, one zero miles northeast inbound, landing runway one niner, Republic"

Pattern Position Reports

Downwind:

"Republic traffic, Cessna three four Bravo, left downwind runway one niner, Republic"

Base:

"Republic traffic, Cessna three four Bravo, left base runway one niner, Republic"

Final:

"Republic traffic, Cessna three four Bravo, final runway one niner, Republic"

Clear of Runway:

"Republic traffic, Cessna three four Bravo, clear of runway one niner, Republic"

Departures

Before Takeoff:

"Republic traffic, Cessna three four Bravo, departing runway one niner, [direction] departure, Republic"

Example:

"Republic traffic, Cessna three four Bravo, departing runway one niner, northeast departure, Republic"

CTAF Best Practices

  • Always state the airport name at the beginning AND end of your transmission
  • Listen before transmitting - make sure the frequency is clear
  • Keep transmissions brief and to the point
  • Make position reports at key points: entering pattern, downwind, base, final, clear of runway
  • Use standard pattern altitudes (typically 1,000 feet AGL for single-engine aircraft)
  • Announce your intentions clearly - other pilots need to know what you're doing
  • Monitor CTAF continuously while in the vicinity of the airport
  • Be courteous and patient with other pilots

Common Mistakes to Avoid

  • Using CTAF when tower is online - always check for active ATC first
  • Forgetting to say the airport name at the end of your call
  • Making excessively long transmissions that block others
  • Not listening to other traffic before transmitting
  • Using non-standard phraseology that confuses other pilots
  • Staying silent - if you're in the pattern, other pilots need to know

Finding the CTAF Frequency

To find the correct CTAF frequency for an airport:

  1. Check airport charts or information (usually listed as CTAF or UNICOM)
  2. Look up the airport on SkyVector or AirNav
  3. Most US non-towered airports use 122.800 MHz
  4. Some airports use 122.700, 122.725, 122.975, or 123.000 MHz
  5. Verify the frequency before your flight

Additional Resources

For more information about CTAF operations:

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