When operating in the vicinity of an aerodrome published on aeronautical charts, use the CTAF (MULTICOM 126.7MHz or the discrete frequency) as published.
Anywhere within a Broadcast Area, use the dedicated Broadcast Area CTAF.
Otherwise, it is recommended pilots use the Area VHF. This frequency may provide the best means of gaining assistance from ATC or other pilots in the event of an emergency. In the vicinity of uncharted aerodromes, pilots have discretion to use the most appropriate frequency that ensures safe operation. This may be MULTICOM 126.7MHz. However, pilots should be aware that transiting aircraft may be monitoring Area VHF. To ensure mutual traffic awareness, it is recommended that pilots using an alternative frequency also monitor Area VHF.
You are ‘in the vicinity’ of an aerodrome if you are flying:
- within 10 nm of an aerodrome, and
- at a height above the aerodrome that could result in conflict with operations at the aerodrome.
In the vicinity of an aerodrome, the most hazardous area for a collision is within a cylinder of airspace 5 nm in diameter and up to 3000 ft above the aerodrome.