On 3 July 2014, at about 1940 Eastern Standard Time an instructor and student pilot of a Bell 206 helicopter, registered VH-XJA (XJA), approached Sunshine Coast Airport, Queensland to conduct night circuits. An Airbus A320 aircraft, registered VH-VGJ (VGJ), was inbound to Sunshine Coast from Melbourne, Victoria via the area navigation (RNAV) required navigation performance approach to runway 18. When about 30 NM from Sunshine Coast, the first officer of VGJ broadcast on the common traffic advisory frequency (CTAF), inbound and did not receive a response.
When about 10 NM from the runway, on a downwind leg and approaching a base turn for runway 18, the first officer broadcast on the CTAF that VGJ had left 3,800 ft and was conducting an instrument approach to runway 18, expecting to land at time 2001, and did not receive a reply.
The instructor of XJA heard the call from VGJ and assumed that the aircraft was then about 15 NM away. He expected the crew of VGJ would subsequently broadcast when 10 and 5 NM from the runway, and he elected to continue the circuit and monitor the CTAF for those calls.
The instructor of XJA broadcast when on a 3 NM final, but the crew of VGJ did not hear this call. About 70 seconds later, the first officer of VGJ broadcast on a 2 NM final. Hearing this call, the instructor of XJA turned and sighted the landing lights of VGJ close behind, diverged to the right and commenced a climb. Radar data indicated that the two aircraft passed at an altitude of about 200-300 ft with a lateral separation of about 370 m.
This incident highlights the importance of using both unalerted and alerted see-and-avoid principles and maintaining a vigilant lookout at all times.