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

3.4 Where were the most occurrences?
Most occurrences were in operations to and from an aerodrome, and within 10 NM
from the aerodrome reference point (n=538). Aircraft that were assessed to be enroute
were involved in 169 occurrences.
The intent from an occurrence analysis perspective was to look at safety trends in all
occurrences across all non-towered aerodromes, rather than looking in detail at
specific aerodromes. This was largely due to the limited amount of available data at
the aerodrome level. A traffic mix analysis was however completed for the nontowered
aerodromes with the most movements, in order to investigate patterns
between occurrence types, operation types, and aircraft sizes. This analysis is
discussed further in Chapter 8.
Occurrences relative to aerodromes
There were eight non-towered aerodromes in Australia that each recorded over 15
occurrences related to airspace use and operations between 2003 and 2008. Not all of
these aerodromes were included in the movements analysis group of 20 non-towered
aerodromes:
• Newcastle (RAAF Williamtown), NSW (26 occurrences)
• Avalon, Vic. (23 occurrences)
• Geraldton, WA ( 23 occurrences)
• Dubbo, NSW ( 23 occurrences)
• Broome, WA ( 23 occurrences) 18
• Port Macquarie, NSW (19 occurrences)
• Mildura, Vic. ( 19 occurrences)
• Wagga Wagga, NSW (15 occurrences)
Newcastle and Avalon, as well as Class D aerodromes that were designated as
General Aviation Aerodrome Procedures (GAAP) during the period of this study,
have been excluded from further analysis as a full air traffic control service is
provided at those aerodromes at some times of the day 19 .
• Camden Aerodrome, while operating as a non-towered aerodrome during
weekdays, did not have sufficiently complete movement data available for the nontowered
time periods (as a proportion of total movements) to allow a fair
comparison of occurrence rates with other non-towered aerodromes.
Occurrence rates for the 20 non-towered aerodromes analysed (outlined in section
2.1) were normalised by the estimated number of movements across the reporting
period. The highest occurrence rates were at:
• Geraldton (2.7 per 10,000 movements)
• Mildura (2.4 per 10,000 movements)
18 While Broome was a non-towered aerodrome during the period of this study (Jan 2003 – Dec 2008),
a certified air/ground radio service (CA/GRS) was in operation. A CA/GRS provides a limited air
traffic service to pilots upon request. These services are discussed further in section 6.3.
19
Operating hours for air traffic control services at Australian aerodromes (where provided) are shown
in the En Route Supplement Australia (ERSA).
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