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

10 CONCLUSIONS
10.1 Summary of findings
10.1.1 Findings from occurrence reporting data
The need for good communication and awareness of procedures when operating in the
vicinity of non-towered aerodromes is shown by the bulk of the 709 airspace use and
operations-related occurrences at non-towered aerodromes in Australia between 1
January 2003 and 31 December 2008.
While this report looked only at incidents and accidents prior to the introduction of
the 3 June 2010 changes to Civil Aviation Regulation (CAR) 166, the non-controlled
operating nature of non-towered aerodromes remains fundamentally the same. Pilots
must still be aware of the types of occurrences that are likely to happen in the vicinity
of non-towered aerodromes, and what their responsibilities are when flying in their
vicinity to help avoid these situations.
Occurrence types in the vicinity of non-towered aerodromes
The most common airspace use and operational-related types of occurrences at nontowered
aerodromes were related to communication breakdowns or insufficient
communication between pilots. Many of these led to reduced situational awareness of
the pilot, and reduced separation or conflicts between aircraft. Non-compliance with
published information, notices to airmen (NOTAMs), and procedures also occurred
frequently (approximately 20 per cent of occurrences).
Types of errors contributing to non-towered aerodrome occurrences
An analysis of the errors that contributed to all occurrences showed that both
procedural errors (action and decision-related) and communication errors
(information and action-related) were most prevalent (about 30 per cent of cases for
each), followed by situational awareness and position/proximity errors (separationrelated).
Conflicts and separation issues (air-air and air-ground)
Conflicts and other situations where a separation issue occurred between two aircraft
(such as airproxes) were also very common. Conflicts are situations where the actions
of an aircraft or ground vehicle interfered with the flight of another aircraft. Conflicts
do not necessarily result in reduced separation At non-towered aerodromes, there
were 501 conflicts between aircraft and other aircraft or vehicles (71 per cent of
occurrences). These were mostly due to reduced separation between aircraft in the
circuit, conflicts between aircraft on base, approach and final, or runway incursions.
Airproxes accounted for almost all serious incidents (55 of 60) in the vicinity of nontowered
aerodromes. Separation issues generally occurred between general aviation
(GA) aircraft, or involved a GA aircraft and a passenger transport aircraft. There were
very few conflicts involving two passenger transport aircraft. Most runway incursions
involved a backtracking aircraft coming into conflict with an aircraft on landing or
final approach to the same runway.
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