On 22 March 2013, circuits were being conducted to both runway 31 left (31L) and 31 right (31R) at Moorabbin Airport, Victoria. The aircraft in the two circuits were operating on different frequencies and being controlled by different air traffic controllers under the visual flight rules (VFR).
At about 1625 Eastern Daylight-saving Time, a Cessna 172S aircraft, registered VH‑EWX (EWX), entered the Moorabbin control zone from the south-east and was instructed to track for base as number 1 in the landing sequence for runway 31R. Another aircraft, a Piper PA-44 (Warrior) aircraft, had been instructed to follow EWX as number 2 and a Piper PA‑28 aircraft, registered VH‑TXH (TXH), was number 3. A number of aircraft were operating to the west of Moorabbin in the circuit for runway 31L.
As EWX approached base, at about 1626, the pilot became aware of TXH in his 2 o’clock position, tracking contrary to the runway 31R circuit pattern. TXH was observed to pass under the nose of EWX, about 100 to 150 m in front and about 50 ft below. To avoid the other aircraft and to keep it in sight, the pilot of EWX turned to track behind and subsequently follow TXH. As the pilot executed this manoeuvre, Moorabbin Tower broadcast a safety alert.
TXH crossed the runway centreline for both runway 31R and 31L before joining final for runway 31R from the west. Both aircraft subsequently landed without further incident.
While pilots conduct a pre-flight inspection of their aircraft to determine airworthiness, this incident highlights the importance of pilots also assessing their own status. Personal minimums should be considered prior to flight, as well as the impact of stressors such as being unfamiliar with operations from a particular runway or the need to change aircraft due to an unserviceability.