On 3 March 2011, a Tiger Airways operated Airbus Industrie A320-232, registered VH-VNG (VNG) and a Pilatus Aircraft Ltd PC-12/45, registered VH-FMP (FMP), were on approach to Alice Springs Airport, Northern Territory. Both aircraft were operating under instrument flight rules (IFR).
The Alice Springs tower was closed, giving the pilots responsibility for organising their own separation. Both flight crews provided a number of updated estimates for their arrival into Alice Springs during the approach. The pilots of VNG estimated their position to be established on finals at time 11 (1941 CST) and FMP estimated their position established on the Instrument Landing System (ILS) at the same time. The conflict between the estimates was not initially recognised by either crew.
As both aircraft approached the initial approach fix, the potential conflict was realised, and separation was organised. During the separation manoeuvring, the pilot of FMP turned towards VNG, and a Traffic Collision Avoidance System Resolution Advisory warning was activated. The pilots of VNG conducted a missed approach and FMP continued the turn behind VNG.
Tiger Airways have conducted a risk assessment on operating into non-towered aerodromes. As a result of that assessment, they have rescheduled all Alice Springs flights so that they operate within active tower hours. They have also made a policy decision that flights will not be scheduled into CTAF aerodromes outside of tower hours for all future schedule developments.