The crew of VH-XDZ, a SAAB 340 operating an IFR category flight taxiing at Mt Isa was not passed traffic information on VH-XDA, another SAAB 340 operating an IFR flight inbound to Mt Isa on the same track to be used by the departing aircraft. The flight service officer was not aware of this omission until the aircraft had passed in flight at 1750 EST.
The incident occurred during a peak in traffic movements, with multiple transmissions from aircraft on both VHF and HF frequencies in airspace that encompassed a large and complex geographical area. The work position comprised 2 HF networks, each with three frequencies, as well as four VHF repeaters. Because of the size and complexity of the airspace, the console needed a large chart display on a mobile trolley placed at 90 degrees to the console operator's position to supplement the overhead map display. The flight service officer reportedly had about 15-18 active flight progress strips for aircraft movements within his area of responsibility at the time of the occurrence and 12 aircraft on frequency. Geographical display bays were not used for the flight progress strips; they were sequenced in a chronological order.
The flight service officer had been on duty for five hours before the incident and had worked the position for most of that time. During the previous three days, the officer had worked a 10-hour shift, a 7-hour shift and a 9.5-hour shift, none of which agreed with the planned roster. Staffing throughout the day of the occurrence had been difficult as three staff were on sick leave.
Team leader coverage was required in the centre between the hours of 0600 and 2000 daily. The sole team leader available for duty on the day of the occurrence had worked from 0700 to 1700 hours and was required to stand-down because 10 hours was the maximum shift length allowable. A relief team leader was not available.
The flight service officer elected not to ask for support during the increased workload because of staff availability. Three other flight service officers were on duty. One was absent from the centre preparing a meal; one was working the FIS 3 position; and, the evening shift officer was eating a meal at the utility position. The evening shift officer intended to provide relief at one of the two consoles and had completed a 7-hour night shift earlier that morning.
Earlier that day, all flight service officers on duty at the Brisbane centre were briefed at a meeting on the imminent closure of the flight service function and the potential ending of their employment with Airservices Australia.