A Lockheed C-130J Hercules (Hercules) had conducted a practice Instrument Landing System (ILS) approach to runway 35 at Canberra followed by a touch and go landing and departure to the northwest. A Boeing 737-376 (B737) was simultaneously radar vectored for an instrument approach to runway 17. Both aircraft intended to use the same runway surface but in opposite directions. The Canberra Approach East (CBE) controller became concerned that the separation standard of either 3 NM laterally or 1,000 ft vertically would not be maintained between the aircraft and issued turn instructions to both crews. While complying with the instructions the two aircraft passed with approximately 2 NM and 100 ft separation. There was an infringement of separation standards.
The Hercules crew had requested an ILS approach to runway 35 at Canberra for instrument flight rules (IFR) flying training purposes. An ILS is a precision instrument approach that provides centreline and glideslope guidance to the pilot, aligned to the landing runway and is primarily used during periods of low cloud and/or poor visibility. Runway 35 was the only runway serviced by an ILS approach at Canberra. The En Route Supplement Australia (ERSA) required crews planning instrument training at Canberra to contact Canberra air traffic control to book an approach time slot for air traffic control traffic management purposes. The service provider reported that the Hercules was running late and had missed its booked slot.
The CBE controller planned to sequence the Hercules between the second of two aircraft taxiing for a departure from runway 17 and the B737, which was the first of a number of arrivals for that runway. The CBE controller was aware that the Hercules' practice ILS approach might be delayed by up to 45 minutes if he was unable to sequence that aircraft ahead of the B737. The CBE controller stated that he felt some pressure to provide a good service to the Hercules crew.
On first contact with the CBE controller the B737 crew was told to expect a Very High Frequency Omni-Directional Radio Range/Distance Measuring Equipment (VOR/DME) approach to runway 17. At various times thereafter, the crew was assigned radar vectors and a speed restriction of 270 knots indicated airspeed to position the B737 behind the Hercules and provide sufficient spacing to maintain the required separation standard. The CBE controller had asked the crew of the Hercules to maintain their best speed once established on the final approach track. That was a request only and the crew of the Hercules was under no obligation to comply. From that point, the Hercules was capable of maintaining an indicated airspeed between 10 to 20 kts faster than that which it would routinely maintain. The crew of the Hercules could not recall whether they had complied with the request.
The CBE controller was concerned about the application of separation between the B737 and the Hercules after the Hercules had completed its touch and go landing. The Letter of Agreement between the Canberra Tower and Canberra Approach Control stated that the approach controller was responsible for separation assurance during reciprocal runway operations unless it was assigned to the ADC "by mutual agreement". The CBE controller advised that his contingency plan was to instruct the B737 crew to terminate the approach if it became apparent that separation between the two aircraft may be infringed.
The CBE controller reported that he had based the traffic management plan on his expectation that the Hercules would be operated at a higher speed along the final approach path. The CBE controller also reported that the Hercules had commenced its turn later than he had expected following the touch and go landing. He could not see the Hercules on radar following the touch and go landing and was unsure of the position of that aircraft in relation to the B737. The CBE controller asked the ADC to confirm when the Hercules had commenced the turn and was visually clear of the inbound path of the B737. The ADC was unable to provide visual separation between the B737 and the Hercules before radar and vertical separation were infringed.
The CBE controller reported that his workload was very high at the time of the occurrence. He did not provide either crew with a safety alert in respect of the other aircraft, as required by MATS, despite the distance between the two aircraft being less than that prescribed by the applicable separation standards.
Both aircraft were equipped with a traffic alert and collision avoidance system (TCAS). The crew of the Hercules did not receive either a traffic advisory (TA) or a resolution advisory (RA) on the TCAS. The crew of the B737 did not report receiving a TA or a RA either during, or after, the occurrence.