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.
