Safety in the vicinity of non-towered aerodromes - Australian ...

suggested that they ignored the limitations of radio as an alerting tool, and increased
the risk of pilot complacency by creating the impression that all traffic was known to
all pilots in the MBZ area (Department of Transport and Regional Services, 2006).
The change to non-towered aerodrome procedures using CTAF and CTAF(R)
simplified operations for all pilots with the aim of improving situational awareness for
those pilots using non-towered aerodromes, by:
• standardising and simplifying broadcast phraseology
• standardising the positions where broadcasts were made
• introducing broadcast requirements inbound at 10 NM (18.5 km) for all
approaches, and additional broadcasts for straight-in approaches
• reducing unnecessary chatter and broadcasts
• separating high/medium/low performance aircraft into different circuit heights
(Department of Transport and Regional Services, 2006).
Broadcasting on and monitoring of the CTAF is a key way for pilots to establish
situational and traffic awareness at non-towered aerodromes. At busier aerodromes,
the requirement to carry and use a radio is very important for all pilots to achieve
radio-alerted ‘see-and-avoid’.
Another major change introduced in NAS 2C was the replacement of a marked MBZ
area with a defined radius from an aerodrome in which non-towered aerodrome
procedures (CAR 166) apply. Aircraft are now considered to be in the vicinity of a
non-towered aerodrome if they are within 10 NM of the aerodrome reference point.
Unlike MBZs (which were both a set of procedures and a radio frequency), CTAF
(and formerly CTAF(R)) is simply a radio frequency which allows pilots to
communicate with the ground and other aircraft when operating in the vicinity of a
non-towered aerodrome. It is intended to be used to support the operating procedures
(CAR 166) which pilots must adhere to at all non-towered aerodromes – for positional
and intentional broadcasts, and for providing air-ground radio services. The
requirements of pilots in CAR 166 are supported by Civil Aviation Advisory
Publications (CAAPs), and the relevant sections of the Aeronautical Information
Publication (AIP) and ERSA (see below).
From 3 June 2010, some refinements were made to the NAS 2C non-towered
aerodrome procedures. Radio carriage requirements were changed significantly – all
aircraft operating in the vicinity of all registered, certified, military and other nontowered
aerodromes now must carry a radio and use the CTAF (the term CTAF(R)
was removed from use). These changes are discussed further below.
1.1.6 Recent changes to non-towered aerodrome procedures
On 3 June 2010, CASA made some changes to the regulations governing operations
at and near non-towered aerodromes (CAR 166 Operations in the vicinity of nontowered
(non-controlled) aerodromes). The purpose of these changes was to mandate
the carriage of radio at all certified, registered, and military non-towered aerodromes,
as well as making some adjustments to circuit entry procedures, circuit heights, and
broadcast procedures. The driver behind these changes was the enhanced safety
benefits provided by using radio-alerted ‘see-and-avoid’ principles in maintaining
situational awareness of, and separation between, aircraft operating into and from
non-towered aerodromes.
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