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

Investigation number AO-2007-006
With no communications, an Aeroprakt Foxbat ultralight aircraft was reported to have
entered runway 21 and taken off while a Beech Baron aircraft was on approach to
runway 03. The Foxbat continued in the circuit and joined final approach for runway
21 while a de Havilland Canada Dash 8 aircraft was on short final for runway 03. The
crew of the Dash 8 did not hear any broadcasts by the crew of the Foxbat on the
CTAF and elected to go around.
The investigation determined that the following safety factors contributed to the
incident.
The Foxbat’s radio volume was selected to a low setting, which did not allow the pilot
to hear the broadcasts made by the Dash 8 and Baron pilots on the CTAF.
The pilot of the Foxbat was aware of the AFRU at Port Macquarie aerodrome, but did
not hear a response from the AFRU due to his low radio volume level. The AFRU, or
‘beep-back’ unit, allows the pilot to confirm that the aircraft radio is transmitting on
the correct frequency. The AFRU does this by automatically transmitting a voice
identification of the aerodrome name in response to any transmission on the CTAF.
The pilot had not fully considered the safety implications of a lack of response from
the AFRU.
Source: ATSB, 2008a
In addition to these two events at Port Macquarie, the ATSB investigated a traffic
confliction near this aerodrome in 1999 involving a Piper Chieftain, a de Havilland
Canada Dash 8, and two Beech 1900 aircraft. At this time, Port Macquarie was a nontowered
aerodrome within a Mandatory Broadcast Zone (MBZ).
In this event, the investigation cited a number of significant factors including
frequency congestion and a failure by the crew of several of the aircraft involved to
make the appropriate position and intention broadcasts. This resulted in a lack of
situational awareness of traffic on the part of the crews and an airprox event occurring
between two RPT aircraft (ATSB, 1999).
Source: photo courtesy of Jonathan Rankin (Dubbo Aerodrome, NSW)
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