Breakdown of co-ordination

Hudson 587 [HS748] was proceeding on a flight from East Sale to East Sale via Dubbo at Flight Level [FL] 170. While under the control of Melbourne Sector 2 the pilot requested a climb to FL190 and a diversion east of track for weather avoidance. The request was approved by air traffic control who then co-ordinated the changes with Sydney Flight Information Service [FIS] 6 as the track would take the aircraft outside controlled airspace [OCTA] for 8nm before entering Sydney Sector 6 airspace.

Some confusion arose as to which FIS position was responsible for the airspace because officers were still unfamiliar with recent boundary changes. The FIS 6 position was the wrong position to which to direct the co-ordination as FIS 2 had responsibility for that portion of airspace. The FIS 6 operator misjudged the actual track of Hudson 587 believing that the aircraft would remain in controlled airspace and, as such, the Melbourne Sector 2 controller would co-ordinate directly with the Sydney Sector 6 controller. On that basis the FIS 6 operator decided that no further action by him was required.

The Melbourne Sector 2 controller, although co-ordinating with the wrong FIS, instructed Hudson 587 to call Sydney on the correct frequency, which the crew did. The FIS 2 operator heard the call but was not expecting the aircraft as no co-ordination had been received by him. He immediately commenced co-ordination checks with Melbourne Sector 2, FIS 6 and Sydney Sector 6 to establish the current status of Hudson 587. Finally, Sydney Sector 6 issued an airways clearance for Hudson 587, but, as the aircraft was only OCTA for approximately three minutes, the clearance was not issued in time to prevent Hudson 587 penetrating controlled airspace without a clearance.

Significant Factors

1. The co-ordination procedures for the revised airspace boundaries were not adequately documented.

2. The Melbourne Sector 2 controller co-ordinated with the wrong FIS operator.

3. The FIS 6 operator miscalculated the track of Hudson 587.

4. The FIS 6 operator did not co-ordinate the position of Hudson 587 after accepting the report from Melbourne Sector 2.

5. There was no breakdown in separation.

The Sector was operated by a trainee under the supervision of a training officer. The trainee was nearing the final stages of both sector training and the end of training to obtain an air traffic control licence.

Enroute after passing Oodnadatta at Flight Level 260 the crew requested and were approved for climb to Flight Level 280. This change of level was not passed on to Darwin. No loss of separation occurred.

The attention of the controllers on the Melbourne sector was diverted when they received co-ordination on an aircraft for which no details were held. Traffic conditions were busy.

Significant Factors

The following factors were considered relevant to the development of the incident:

1. Controller attention diverted by another task.

2. Both the trainee and the supervising controller overlooked the need for co-ordination with Darwin.

VH-ANA [B727] was enroute from Brisbane to Sydney at Flight Level [FL] 330. At 0949 hours EST the crew were authorised by Sydney air traffic control [ATC] to descend, when ready, to FL 280. One minute later this clearance was cancelled by ATC and VH-ANA was required to maintain FL 330. The aircraft had not commenced descent.

All Nippon Airways 914 [B747] had departed Sydney for Narita [Japan] and was climbing to an initial altitude of FL 280. The track of this aircraft would cross that of VH-ANA approximately 120 NM north of Sydney.

All Nippon Airways 914 was given climb to FL 310 at 0946 hours and, due to a busy period of air traffic, this change of level was not co-ordinated until 0949 hours. On receiving the notification of the level change, the controller responsible for VH-ANA took immediate action to reintroduce procedural separation before radar separation was lost.

The aircraft passed at 0951 hours with 2,000ft vertical difference. There was no breakdown in separation standards.

The crew of VH-TJG, enroute to Perth, made a position report at Kapna. The Melbourne air traffic controller was required to co-ordinate details of this report to the Perth Sector Two controller. This was not done. There was opposite direction traffic which could have come into conflict but there was no loss of separation.

Circumstances

VH-OXC was proceeding on a flight from Williamtown to Coffs Harbour at 9,000 ft outside controlled airspace [OCTA]. The pilot made all position reports as required and was estimating Coffs Harbour at 0734 hours EST. Sydney Flight Service 5 [FIS 5] co-ordinated these details with Coffs Harbour air traffic control [ATC] and at 0724 hours the pilot contacted Coffs Harbour ATC prior to the control area [CTA] boundary for an airways clearance. ATC issued the clearance for VH-OXC to enter CTA on descent to 5,000 ft.

VH-CMR was proceeding on a flight from Williamtown to Coffs Harbour and was maintaining Flight Level [FL] 130 in CTA. The crew used a standard flight plan and the time intervals indicated an estimated time of arrival [ETA] over Taree of 0710 hours and Coffs Harbour 0744 hours. Sydney Sector 2 [ATC] identified VH-CMR 20 NM south of Taree and therefore there was no requirement for the crew to report over Taree. The aircraft passed Taree at 0707 hours.

Sector 2 then co-ordinated VH-CMR with Coffs Harbour ATC and gave the ETA as 0744 hours as per the flight plan times. The crew of VH-CMR elected to descend prior to the Coffs Harbour CTA steps and this necessitated flight OCTA for approximately three minutes. Sector 2 therefore co-ordinated the aircraft's position with FIS 5 giving the Taree position as 0707 hours, but again gave the ETA Coffs Harbour as 0744 hours.

The crew of VH-CMR reported leaving FL 130 to Sector 2 and were instructed to contact area frequency at that time. However they elected not to call on area frequency as they only had approximately three minutes OCTA and would need to contact Coffs Harbour ATC for a clearance prior to entry into the CTA step.

The Sydney Flight Service Officer [FSO] took the position report on VH-CMR from Sector 2 and wrote the information on the flight strip, but did not make a check of the time interval from Taree to Coffs Harbour or on the difference in the ETA and the actual time at Taree. This resulted in the FSO having a ten minute time difference between VH-OXC and VH-CMR at Coffs Harbour when in fact the information received indicated a time difference of seven minutes. The time standard for passing traffic is, within ten minutes at any particular point and the FSO decided that as there was ten minutes at Coffs Harbour there was no need to pass traffic to the aircraft.

At 0725 hours VH-CMR contacted Coffs Harbour ATC at 35 NM [the CTA step] and on descent through 8,000 ft to request an airways clearance. The controller immediately took action to establish vertical separation but this was not achieved until 0727 hours. During this two minute period the vertical difference between the two aircraft reduced to a minimum of 100 ft and the horizontal difference to a minimum of 2.3 NM. As VH-CMR had waited until the exact location of the CTA step to contact Coffs Harbour ATC, the controller was unable to establish separation until after both aircraft had entered the CTA step and therefore a breakdown in separation occurred.

Significant Factors

1. The crew of VH-CMR contacted Coffs Harbour ATC at the CTA boundary and not prior to that boundary.

2. The crew of VH-CMR entered the CTA without an ATC clearance.

Circumstances

Panther Cougar Section [4 X Macchi 32] were completing operations in Restricted Area R527. Williamtown air traffic control [ATC] commenced co-ordination procedures with Sydney Sector 2 for clearance to transit civil airspace in order to recover the section to Williamtown.

Due to Sydney ATC internal co-ordination requirements, Sydney Sector 2 were unable to issue a clearance immediately and themselves commenced co-ordination with Sector 1 and arrivals South. At the same time Sector 2 advised Williamtown ATC to contact Sector 1 direct for further instructions.

Williamtown ATC then contacted Sector 1 only to be told to contact Arrivals South. After establishing contact with Arrivals South, Williamtown were then told to contact Sector 2.

As a result of this uncertainty the 4 X MC32 aircraft were diverted clear of civil airspace by Williamtown ATC and the extra flight time resulted in the aircraft landing with eight minutes endurance remaining.

Significant Factors

1. The internal co-ordination requirements for Sydney ATC were cumbersome and unnecessarily complex.

2. The Sydney Sector 1 controller did not obey the principles of point to point co-ordination as specified in the Manual of Air Traffic Services [MATS].

Circumstances

RAAF Williamtown were operating FA18 aircraft in Restricted Areas R457 and R527. In order to return these aircraft to Williamtown at the completion of their task, it was necessary to transit civil controlled airspace under the control of Sydney Sectors 1, 2 and Arrivals.

Williamtown air traffic control [ATC] co-ordinated with Sydney Sector 1 for the recovery of two FA18 aircraft and Sector 1 issued approval and advised of civil aircraft with which Williamtown ATC needed to provide radar separation with their aircraft. Sector 1 also agreed to perform the co-ordination tasks with Sector 2 and Sydney Arrivals, which was correctly carried out.

Williamtown ATC then proceeded to recover their aircraft in accordance with the clearance issued by Sector 1, but as the FA18s were approaching civil airspace, Sector 1 advised of additional traffic VH-TAH whose track and altitude placed the aircraft in potential conflict with Shogun 1/2 [FA18].

Sydney Sector 1 believed that he had only co-ordinated an expectancy of approval with Williamtown ATC but Williamtown believed that they had received a clearance to transit the airspace.

As a result Williamtown ATC radar vectored its aircraft clear of VH-TAH and no breakdown in separation occurred.

Significant Factors

1. The co-ordination procedures for this section of airspace were complex and time consuming which led to confusion as to if an actual clearance was issued.

ASOR 9200127

Circumstances

VH-KLS departed Williamtown for Canberra at 1032 hours on a charter flight using IFR procedures. At 1040 hours the pilot contacted Sydney Flight Service and reported that he was on the 015 radial of the Sydney VOR and maintaining 6,000 ft.

The Flight Service Officer [FSO] held a flight strip on the aircraft but had received no co-ordination from Williamtown ATC. The FSO then contacted Williamtown ATC to ascertain the co-ordination required and was informed that VH-KLS had departed at 1032 hours.

There was no known conflicting traffic and therefore no breakdown in separation.

Significant Factors

1. Williamtown ATC did not co-ordinate the departure time of VH-KLS as required by the Manual of Air Traffic Services [MATS].

VH-STO [PA31] taxied at Port Macquarie for Williamtown at 0241 hours (UTC) and made his departure call on area frequency at 0246 hours.

VH-TQQ [DHC8] was enroute Sydney for Port Macquarie and passed overhead Williamtown at 0242 hours with an estimate for Port Macquarie of 0254 hours.

TQQ was under the control of Williamtown military ATC, and the controller did not pass this position and estimate to Sydney FS in the required time. As a result, the first the Sydney FS officer and the pilot of STO knew of TQQ was when the pilot of TQQ made his passing 10,000ft call on area frequency at 0247.30 hours.

The FSO immediately passed the two aircraft traffic on each other [at 0248 hours] and the Williamtown controller passed the coordination at 0249 hours, with an apology.

The two captains immediately initiated vertical separation until positive passing was established. TQQ maintained 5000ft on descent and STO maintained 4000ft on climb. This separation was established at 0249 hours, and the two crews attained a mutual sighting at 0250 hours. The pilots state that the two aircraft were on track and over the same location at the time of passing.

Weather was cloudy with some breaks and both pilots report being in and out of cloud. TQQ did remain visual throughout the lower part of its descent, but STO was in IMC most of the time.

Significant Factors

1. Williamtown ATC did not coordinate the Williamtown position report for TQQ to Sydney FS in the required manner.

2. Only appropriate and timely action by the Flight Service Officer and both crews avoided a separation incident.

The identification and planned level (FL290) of the aircraft was coordinated with the Melbourne Sector 12 controller. The aircraft was observed on radar to maintain FL250. The amended level was not coordinated with sector 12. There was no infringement of separation standards. 

An investigation by Airservices Australia found:

1. that the sector did not have specific procedures to ensure that controllers on adjacent sectors were notified when sector 12 opened/closed,

2. the Hume sector controller did not coordinate the change of level with the sector 12 controller,

3. a console display notifying active sectors had not been updated, and

4. that the display did not provide an indication of combined sectors. Consequently, there had been some confusion in relation to the required coordination between sectors. The investigation is continuing.