Section 21 (2) of the Transport Safety Investigation Act 2003 (TSI Act) empowers the Australian Transport Safety Bureau (ATSB) to discontinue an investigation at any time. Section 21 (3) of the TSI Act requires the ATSB to publish a statement setting out the reasons for discontinuing an investigation.

On 12 July 2010, the ATSB commenced an investigation into an aircraft proximity event that occurred at about 1230 Eastern Standard Time on 8 July 2010 and involved a Reims Aviation S.A. F406 aircraft, registered VH-YZF (YZF) and a Bell Helicopter Co. 412 helicopter, registered VH-EMZ (EMZ). YZF was being operated on a search and rescue flight under the instrument flight rules and was on descent from 10,000 ft tracking 254° towards Badu Island, Queensland at the time of the occurrence. EMZ was operating under the visual flight rules on a northerly track between Thursday Island and Saibai Island. The crew of YZF reported that they saw the helicopter just after it passed beneath their level and to their right.

An initial examination of this occurrence showed that all parties to the event complied with the existing regulatory and procedural requirements for operations into Badu Island. However, in this instance, the pilot of EMZ did not hear the descent broadcast that the pilot of YZF reported making on Torres (Horn Island) Common Traffic Advisory Frequency (CTAF) 126.5 MHz.

The ATSB's primary focus is on enhancing safety with respect to fare-paying passengers and, in particular, those transport safety matters that may present a significant threat to public safety or are the subject of significant public concern. The ATSB therefore directs considerable attention to identifying systemic failures in aviation, marine, and rail mass public transport systems.

The Civil Aviation Safety Authority (CASA) released an aeronautical study into operations at Horn Island, including in relation to the airspace and radio frequency arrangements in the Torres Strait in October 2009.1 The results of that study included that the airspace classifications around Horn Island were appropriate to the volume and complexity of the traffic in that area, and that the level of air traffic services and facilities was sufficient and provided an acceptable level of safety. In addition, the study included some recommendations for improvement. Since then, CASA has also implemented revised procedures for operations in the vicinity of non-towered aerodromes.

The ATSB therefore considered there was limited potential to enhance transport safety by continuing this investigation, and has elected to discontinue it. However, the data already collected may be used by the ATSB for future statistical analysis and safety research purposes.


1 See