Aircraft proximity event between a Piper PA-44, VH-MHZ and a Hawker G36, VH-JKL, 4 km west-north-west of Bankstown Airport, New South Wales, on 19 January 2013

On 19 January 2013, when at the ‘2RN’ VFR approach point, the pilot of a Piper PA-44 aircraft, registered VH-MHZ (MHZ), attempted to broadcast an inbound call to Bankstown Tower, however, the pilot reported that the call was over-transmitted. Shortly after, a second inbound call was broadcast, which the pilot reported was again over-transmitted. The pilot of MHZ determined that communications with Bankstown Tower could not be established due to radio congestion and he elected to maintain his current heading and altitude. The aircraft subsequently entered the Bankstown control zone (CTR) without a clearance.

Soon after, the pilot and passenger of a Hawker G36 aircraft, registered VH-JKL, observed an unidentified aircraft in their 2 o’clock position at about the same altitude. Shortly after, air traffic control advised the pilot of JKL of an unidentified aircraft to the south, about 0.5 NM away. The pilot replied that he would descend and monitor the aircraft. The pilot reported descending 50-100 ft and conducting a slight right turn. As MHZ passed overhead JKL, vertical separation reduced to 200 ft and then increased to 400 ft as JKL descended.

The Civil Aviation Safety Authority visual flight rules guide recommends that pilots should consider initiating radio contact with air traffic control far enough away from the CTR boundary to preclude entering Class D airspace before two-way communications are established. This is particularly important when operating into busy airports such as Bankstown.

Aviation Short Investigation Bulletin - Issue 18