Background and Planning
The pilot of VH-LRI planned a flight to Moorabbin Airport, having flown there only once previously. Preparations included consulting pilots familiar with the airport, reviewing the En Route Supplement Australia (ERSA), studying satellite imagery, and using an electronic flight bag (EFB) for runway configuration and GPS guidance. These measures were intended to improve situational awareness when approaching an unfamiliar aerodrome.
Errors in ERSA Review
During the review of ERSA, the pilot did not identify that the aerodrome reference point (ARP) was located distant from the runway 17R centreline. Additionally, the pilot did not note that the magnetic heading of the runway differed slightly from its designation. Consequently, the inbound track configured for guidance was offset and deviated away from the runway centreline.
Approach and Deviation
As the aircraft crossed the runway 17R centreline, the navigation unit indicated that the aircraft was still significantly to the right of the configured inbound track. It is likely that the navigation indications contributed to the pilot flying through the runway centreline of 17R and joining final for 17L behind VH-EUE. VH-LRI was not advised of VH-EUE by air traffic control (ATC) because the other aircraft was operating in the eastern circuit, which required an additional clearance to enter. Furthermore, VH-EUE was not equipped with ADS-B out and would not have been detected by a traffic awareness system.
ATC Monitoring and Intervention
The western circuit controller periodically visually monitored VH-LRI as it approached the airport. During this period, both eastern and western controllers were also attending to other traffic, likely looking away from the final approach path when VH-LRI crossed the runway 17R centreline and entered the eastern circuit. The deviation was not detected until the western controller re-established visual contact, by which time the aircraft was already on final approach for runway 17L.
Risk and Deconfliction
As the distance between the aircraft reduced while they converged on the same final flightpath, the pilot of VH-LRI reported maintaining visual contact, indicating there was likely no significant risk of collision. However, upon ATC intervention, the pilot of VH-LRI initially intended to orbit to the left, while the instructor aboard VH-EUE intended to climb. A climb by VH-EUE would have increased collision risk, while an orbit would have placed VH-LRI in conflict with other aircraft in the eastern circuit. Timely ATC instructions contrary to the pilots' intentions deconflicted the aircraft and directed them away from other traffic.