Aeronautical radio frequencies
Aeronautical radio frequencies
This domain tests your knowledge of the VHF aeronautical band, how frequencies are assigned, and which frequency to use for routine, advisory and emergency communications.
Core rules
- Civil VHF air-ground radio uses 118.000-136.975 MHz. New Zealand primarily uses 25 kHz channel spacing, so use the frequency published in the current AIP NZ rather than assuming an 8.33 kHz channel is available.
- 121.5 MHz is the international aeronautical emergency frequency. It is monitored by ATS and many aircraft; use it for distress, urgency and radio-failure attempts, not routine chat.
- 243.0 MHz is the military emergency frequency.
- Aerodrome frequencies are published in AIP NZ: ATIS, clearance delivery, ground, tower, approach and centre. At unattended aerodromes, use the published common or advisory frequency and make standard blind calls.
- Before transmitting, listen; select the correct frequency, check volume and squelch, and use the correct callsign.
Worked example
You are VFR near an unattended aerodrome and hear no ATC. You intend to join downwind. You select the published aerodrome frequency, listen for two minutes, then transmit: 'Springfield traffic, ZK-ABC, Cessna 172, 5 miles south, joining downwind runway 18, Springfield.' This is a broadcast, not a clearance; other traffic may not answer. If you have an emergency, switch to 121.5 and make a MAYDAY call.
Traps
- Calling on 121.5 for a routine position report.
- Assuming a frequency from an old chart or app is current.
- Transmitting on a tower frequency without listening first.
- Forgetting that ATIS is one-way information, not a clearance.
Aeronautical radio frequencies
Frequency discipline starts with confirming the source: current AIP, NOTAM and ATIS take priority over memory or third-party apps.