Australia is a vast and sparsely-populated continent, with a highly active general aviation sector, and a healthy charter and scheduled passenger air transport sector servicing regional centres.
These factors are among those which contribute to Australia having more than 330 certified aerodromes (as defined by the Civil Aviation Safety Authority), and more than 2,000 defined aircraft landing areas (or ALAs). The vast majority of these are non-towered, with no separation or traffic guidance provided by a ground-based controller, as you would have in a major airport.
Without a ground-based controller, pilots are responsible for maintaining separation between one another. This practice of ‘self-separation’ relies on pilots making regular and clear radio calls, and paying attention to the calls being made by other pilots sharing the same airspace.
The ATSB often receives reports from pilots that another aircraft has flown too close to them in uncontrolled airspace. Not surprisingly, three quarters of these reports involve pilots flying within 10 nautical miles of a non-controlled aerodrome.
Twice as many near-collisions are reported to the ATSB where pilots had no prior warning of other aircraft in their vicinity, compared with situations when a pilot received an alert by radio or a traffic alerting system like TCAS. Insufficient communication between pilots operating in the same area is the most common cause of safety incidents near non-controlled aerodromes.
The ATSB’s publication A pilot’s guide to staying safe in the vicinity of non-controlled aerodromes outlines many of the common problems that occur at non-controlled aerodromes, and offers useful strategies to keep yourself and other pilots safe.
The Civil Aviation Safety Authority's Pilot Safety Hub also has extensive information on non-controlled operations.
Recent ATSB investigations involving multiple aircraft around non-towered aerodromes
AO-2020-062 Separation occurrence involving Airbus A320-232, VH-VGP and Jabiru J230D, 24-7456 near Ballina Byron Gateway Airport, New South Wales, 28 November 2020
The flight paths of a Jabiru recreational aircraft and a Jetstar Airways A320 with 170 people on board intersected, with just 600 ft of vertical separation, near Ballina Airport, NSW. The ATSB’s investigation found the pilot of the Jabiru was unaware of the presence of the A320 before their flight paths intersected, and the A320 flight crew were unaware of the impending conflict until alerted by their aircraft’s traffic collision avoidance system (TCAS). Read more
AO-2020-051 Collision on runway between Extra EA-300 aeroplane, VH EXR and Guimbal Cabri G2 helicopter, VH-LTO Caloundra Airport, Queensland, on 18 September 2020
An Extra EA-300 was conducting circuits at Caloundra Airport, Queensland, when a Guimbal Cabri G2 helicopter joined the circuit and conducted a stop-and-go on the active runway. The Extra landed on the runway and, during its landing roll, collided with the rear of the hovering helicopter, resulting in substantial damage to both aircraft but, fortunately, no injuries. Read more
AO-2020-012 Mid-air collision involving Piper PA-44-180 Seminole, VH-JQF and Beech D95A Travel Air, VH-AEM 8 km south of Mangalore Airport, Victoria on 19 February 2020
Two twin-engine light aircraft operating under the instrument flight rules (IFR) collided mid-air in non-controlled airspace south of Mangalore Airport, Victoria. All four pilots (two in each aircraft) were fatally injured, and both aircraft were destroyed. Read more