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

6.2 Why weren’t pilots monitoring the CTAF or making
broadcasts?
Almost all of the occurrences in the reporting period involved aircraft that were
equipped with a radio. While there is flexibility in what broadcasts can be made when
operating at non-towered aerodromes, it is important that all pilots with a radio
actively monitor the specified CTAF and make at least the standard broadcasts at a
minimum using the correct phraseology. Effective use of the radio makes the job of
seeing other aircraft in the circuit and approach areas easier for all pilots.
In 146 of the 709 occurrences, pilots had tuned their aircraft’s communications
(COM) radio to a frequency which was not the CTAF frequency (often the area
frequency, or a CTAF frequency that was no longer current), or did not hear or
respond to broadcasts for an unknown reason.
Almost all of these occurrences (96 per cent) happened within the 10 NM (18.5 km)
area defined by CAR 166 and the CAAPs in which broadcasts should be made.
In 52 occurrences, a pilot operating at or near a non-towered aerodrome reported that
they could not transmit or receive broadcasts due to a radio problem. Only 24 of these
occurrences involved instances where a pilot was unable to communicate on the
CTAF due to a suspected radio failure. In these cases, CAR 166(E) and the ERSA
EMERG procedures require pilots to rock their aircraft’s wings from side to side, turn
on any external landing or navigation lights, broadcast intentions as if the radio
transmitter was working (prefixing broadcasts with ‘TRANSMITTING BLIND’),
turn on their transponder (if fitted) to Mode C squawk 7600, and land at the nearest
suitable aerodrome. In these cases, circuit entry should only be made on crosswind.
The remainder of these occurrences were generally due to the radio volume being
turned down so that broadcasts from other nearby aircraft were not audible. There
were three instances of language difficulties contributing to a breakdown in
communication between pilots and other pilots or air traffic services (ATS) personnel.
Some of these occurrences were due to reported congestion on the CTAF (two aircraft
transmitting at the same time, radio chatter), or confusion between pilots of aircraft
operating into two different aerodromes in close proximity using the same frequency
allocation. 28 This has the potential to occur at places such as Lismore and Ballina.
While sharing of a single CTAF at nearby aerodromes has the potential to ensure
situational awareness of other aircraft is gained, pilots need to be especially vigilant
that they broadcast their location and intentions accurately.
28 The ATSB was not able to determine from the reported information whether the pilots involved in
these occurrences were following the correct CAR 166 broadcast phraseology, in which the pilot
must start and end all broadcasts with their location.
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