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

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9.1.1 Parachut<strong>in</strong>g operations<br />

A number <strong>of</strong> reports were raised regard<strong>in</strong>g parachut<strong>in</strong>g operators at <strong>non</strong>-<strong>towered</strong><br />

<strong>aerodromes</strong>, particularly <strong>in</strong> <strong>the</strong> Sunsh<strong>in</strong>e Coast area (Qld) and near Geelong (Vic.). In<br />

seven cases, it was reported that parachutists were dropped over an active circuit area,<br />

com<strong>in</strong>g <strong>in</strong>to conflict with helicopters or GA aircraft. These cases raised issues <strong>of</strong><br />

situational awareness <strong>of</strong> o<strong>the</strong>r aircraft <strong>in</strong> <strong>the</strong> circuit, due to a comb<strong>in</strong>ation <strong>of</strong> not<br />

monitor<strong>in</strong>g <strong>the</strong> Common Traffic Advisory Frequency (CTAF), not mak<strong>in</strong>g positional<br />

and <strong>in</strong>tentional broadcasts, and <strong>in</strong> some cases not be<strong>in</strong>g aware <strong>of</strong> <strong>the</strong> regulations<br />

regard<strong>in</strong>g parachute drops.<br />

Civil Aviation <strong>Safety</strong> Authority Instrument 405/09 and <strong>Australian</strong> Parachute<br />

Federation Operations Regulations 5.2.15 (a) and 5.2.15 (b) provide direction to<br />

parachute operators about how <strong>the</strong>y must safely release parachutists, <strong>the</strong> radio<br />

broadcasts <strong>the</strong>y must make at <strong>non</strong>-<strong>towered</strong> <strong>aerodromes</strong>, and how <strong>the</strong>y must give way<br />

to passenger transport aircraft operations at all times.<br />

9.1.2 Frequency congestion and <strong>in</strong>terference<br />

There are practical limits on how much voice traffic very high frequency (VHF)-band<br />

frequencies such as those used for CTAF can efficiently carry. For this reason,<br />

frequency congestion issues can occur at <strong>non</strong>-<strong>towered</strong> <strong>aerodromes</strong> at times <strong>of</strong> high<br />

circuit traffic. Interference issues can be due to aircraft operat<strong>in</strong>g at nearby<br />

<strong>aerodromes</strong> us<strong>in</strong>g <strong>the</strong> same CTAF frequency allocation, o<strong>the</strong>r ground-based radio<br />

transmitters, or due to shield<strong>in</strong>g by natural features.<br />

Eight REPCON and CAIR reports were received between 2003 and 2008 relat<strong>in</strong>g to<br />

congestion and <strong>in</strong>terference issues on CTAF/CTAF(R) and MBZ frequencies <strong>in</strong> <strong>the</strong><br />

vic<strong>in</strong>ity <strong>of</strong> <strong>the</strong> follow<strong>in</strong>g locations:<br />

• Mount Oxley (NSW)<br />

• Lizard Island (Qld)<br />

• south <strong>of</strong> Kempsey (NSW)<br />

• Port L<strong>in</strong>coln (SA)<br />

• nor<strong>the</strong>ast <strong>of</strong> Cooma (NSW)<br />

• south <strong>of</strong> Wagga Wagga (NSW)<br />

• south <strong>of</strong> Broome (WA).<br />

Forums such as RAPACs also allow airspace users to raise issues such as frequency<br />

congestion at <strong>the</strong>ir local <strong>aerodromes</strong> on <strong>the</strong> standard 126.7 MHz frequency usually<br />

allocated for CTAF. Congestion issues <strong>of</strong>ten raised <strong>in</strong> <strong>the</strong>se meet<strong>in</strong>gs relate to pilots<br />

operat<strong>in</strong>g <strong>in</strong>to a smaller aerodrome near a busy aerodrome where <strong>the</strong> same CTAF<br />

frequency allocation is be<strong>in</strong>g used, or <strong>in</strong>terference from relatively distant <strong>aerodromes</strong><br />

us<strong>in</strong>g <strong>the</strong> same frequency (e.g. Goolwa and Port L<strong>in</strong>coln <strong>in</strong> South Australia).<br />

Ano<strong>the</strong>r issue that has been raised through RAPAC meet<strong>in</strong>gs was <strong>the</strong> absence <strong>of</strong> a<br />

mechanism to allocate discrete CTAFs to <strong>non</strong>-registered aircraft land<strong>in</strong>g areas<br />

(ALAs), fur<strong>the</strong>r <strong>in</strong>creas<strong>in</strong>g congestion on <strong>the</strong> exist<strong>in</strong>g CTAF for that area (CASA,<br />

2010d). One solution that has been suggested to relieve this issue is to allocate unique<br />

CTAF frequencies to busier <strong>non</strong>-<strong>towered</strong> <strong>aerodromes</strong>. This however may reduce <strong>the</strong><br />

situational awareness <strong>of</strong> transit<strong>in</strong>g pilots, as <strong>the</strong>y would be required to monitor more<br />

than one CTAF to be fully aware <strong>of</strong> nearby traffic.<br />

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