Aviation safety investigations & reports

Boeing Co 767, ZK-NCJ

Investigation number:
Status: Completed
Investigation completed


A Boeing 767 (B767) was en route from Auckland to Hong Kong on air route B333. The crew had been cleared to conduct a cruise climb from FL310 to FL330. While FL310 was a standard level for the track being flown, FL330 was not. A Boeing 737 was en route from Sydney to Port Vila on air route B580. The crew of this aircraft had been cleared to, and was maintaining FL330, which was a standard level for their track. The routes cross at LEMIB a waypoint located approximately 490 NM east of Brisbane. The aircrafts' estimates for LEMIB were within three minutes of each other.

Five minutes prior to reaching LEMIB the crew of the B767 received a traffic alert and collision avoidance system traffic advisory warning. The traffic alert and collision avoidance system indicated that an aircraft was passing from left to right 900 ft above the level of, and 12 NM ahead of the B767. The required separation standard was 2,000 ft vertically.

Air traffic controller training was being conducted at the control position responsible for the area at the time of the occurrence. Following a query by the B767 crew regarding the crossing aircraft to air traffic control and a check of the flight progress strip data it was established that a separation standard had not been applied between the aircraft. There was a breakdown of separation.

Organisational aspects

The trainee was a group leader in the Brisbane Centre responsible for the management of the Tops/Ocean/West group. The group was divided into a number of sectors. Tops consisted of sectors 11, 11k and 12. West consisted of sectors 5 and 5D while Ocean had sectors 8, 8O and 10. Sectors 5D and 8O were radar sectors while all the other sectors were procedural control sectors except sector 11K which was a composite radar/procedural sector.

The group leader had previously held ratings and endorsements for all Tops sectors but had let two endorsements lapse due to workload and retained only the sector 11K endorsement.

The Ocean sectors were to be the first of the group to transition to The Australian Advanced Air Traffic Control System. The Ocean sectors had limited experienced staff plus there were other concerns for management that they believed could be suitably handled by the group leader becoming part of the Ocean teams. He also believed that if he obtained Ocean sector ratings he would be able act as a relief controller if required. Consequently, it was agreed that the group leader would transition with the Ocean sectors.

The group leader intended to undergo training to obtain the appropriate endorsements for the Ocean sectors. On completion of training he would function as one of the three Ocean team leaders as well as retaining group leader responsibility for those sectors. The En-route manager was to assume group leader responsibilities for the Tops and West sectors during the transition. To enable the group leader to commit himself totally to the training, an interim group leader was to be appointed to manage the group. The interim leader took over the group in the week immediately prior to the occurrence.

The Ocean sector staff had, and were, undergoing considerable changes due to: the reorganisation of the sectors; developments relating to contingency plans for Papua New Guinea airspace; management of Honiara airspace; and the transfer of the provision of directed traffic information from flight service international to the sectors and changes required for The Australian Advanced Air Traffic Control System transition. There were also a number of staff management issues that limited the options available to the group leader to meet operational demands.

Training plan

The Ocean sectors had a comprehensive training plan with workbooks for trainees and a training guide for the controller supervising the training. However, the supervisors training guide was unapproved and was in draft form only. The training guide and workbook were developed with the intention of providing a basis for ab-initio training. Training normally commenced with the trainee undertaking four weeks familiarisation at the sector operating positions followed by four days of classroom work, approximately one month in the simulator and finally six weeks of on the job training. During the on the job training phase the trainee would be assessed for competency by the supervising controller.

As the group leader already held radar and procedural ratings and an endorsement for sector 11K he elected to rationalise the ab-initio training program to reduce the time spent training. This aspect was in accordance with Airservices Australia's Civil ATS Operations Administration Manual which described "refresher training" for controllers as:

"training which focuses on change in a person's required competence and includes training concentrating on what a person once knew; what a person should (or does) know but hasn't been applying; and what a person hasn't had an opportunity to apply."


The Civil ATS Operations Administration Manual also detailed "local training strategies which recognise refresher training responsibilities include (but are not limited to):

  1. personal study of material, including videos, collated and provided by at the direction of team leaders or line mangers;
  2. use of simulator sessions, either specific to refresher training topics or included in ongoing training; and
  3. use of computer based training (CBT)."

The group leader had reviewed the training material for sector 8 but had not undertaken any classroom or simulator training for the sector. Due to other training commitments the simulator was not immediately available. He planned to join the scheduled Ocean simulator-training program at lesson ten (three weeks after the date of the occurrence) and to complete the lessons through to 23. During the interim period the group leader was to undertake familiarisation training under supervision. He had discussed his training plan with one of the Ocean team leaders responsible for training. There was no process to assist rated controllers intending to train for other ratings/endorsements to develop a suitable training plan.

Supervising controller

A supervising controller had been appointed to oversee the training of the group leader. The group leader's training commenced two days prior to the occurrence. During that time he and the supervising controller had spent approximately three hours together on the first day, none on the second and three hours on the morning of the day of the occurrence. The interruptions to the group leader's training were due to a prior commitment on the first day and the lack of a training position as a result of another controller undergoing familiarisation on the second day.

After spending three hours together on the morning of the occurrence the group leader and the supervising controller conducted a handover of sector 8 to enable them to take a rest period. Subsequently, the supervising controller returned to the console and assumed responsibility for sector 8O, the radar sector.

At 1100 Eastern Standard Time the group leader was waiting at the console expecting the next rostered controller to takeover sector 8O to enable the supervising controller to train the group leader on sector 8. A recently arrived controller offered to supervise group leader on the console instead of taking over sector 8O. Subsequently, this controller and the group leader assumed responsibility for sector 8. The controller had recently completed a stint as a supervising controller for another trainee and had considerable training experience. The nominated supervising controller for training the group leader remained on sector 8O.

The controller was not aware of how much training the group leader had completed and was therefore not aware of the latter's level of knowledge in the position. They did not conduct a pre-training brief to discuss learning aspects to be addressed during the session.

Sector 8 was the only procedural sector that used controller pilot datalink facilities to communicate with flight crews. Between 10% and 20% of all the flights operating through the sector used the controller pilot datalink. As the group leader was unable to operate the controller pilot datalink the controller was required to operate the facility. The controller was also directing and explaining the operation of sector 8 to the group leader while reviewing the flight progress strips for conflictions.

The controller and the group leader were at the position for approximately two hours during which the number of aircraft under their control steadily increased. The group leader noted a number of procedures that were different to what he expected to experience and he found it increasingly difficult to maintain an appreciation of the traffic situation. During this period it became apparent to the controller that the group leader was unfamiliar with the operation of the position.

Just prior to the occurrence the group leader received a request for a clearance from the pilot of an aircraft to enter the oceanic control area on climb to FL250. Because of the proximity of the aircraft to other flight information region boundaries the controller had to coordinate with Nadi and Auckland Centres prior to issuing a clearance. At about the same time, a flight information region boundary position report was received on the controller pilot datalink from a flight. The controller should have transferred this flight to Nadi Centre prior to the position but had not instructed the crew to transfer. Consequently, the position report had to be coordinated by voice intercom.

Flight progress board management

Details of the B737 were annotated on a blue flight progress strip and the sector 8O controller had coordinated the flight at FL330. The B767 flight was on a buff flight progress strip. Blue and buff coloured flight progress strips were used to differentiate between eastbound and westbound flights respectively. Coordination on the B767 was received from Auckland Centre and a clearance for the crew to conduct a cruise climb in the block level FL310 to FL330 was concurred. Requests by crews to conduct a cruise climb were regularly received and approved by the sector 8 controllers.

The recognition and resolution of potential conflicts at positions in the sector where tracks crossed was a regular part of a controller's task. The crossing point of the aircrafts' tracks, LEMIB was not annotated on either flight progress strip. After flight progress strips were activated by a departure report or coordination from another air traffic service unit they were passed to the sector 8 controller for placement on the board. The controller would place flight progress strips under an appropriate designator and then review all flight progress strips for conflictions. Conflicting flight progress strips would then be "cocked" to highlight a problem for subsequent action. Controllers "cocked" a flight progress strip by partially moving a strip out of the display bay.

If the controller identified that there was a potential conflict at a crossing point like LEMIB, a separation standard would be calculated and the respective flight progress strips would be annotated with the position. Once the separation procedure had been applied the flight progress strips would be returned to the bay. In the occurrence the flight progress strips for the aircraft were placed in the bay under the same designator without being cocked. The investigation did not establish why the flight progress strips were placed in the bay without being actioned.

Controller pilot datalink facilities

When the controller pilot datalink had been introduced a simulator had been provided to assist in the training of controllers. The controller pilot datalink simulator had subsequently been removed from the centre following training of the initial group of controllers required to operate the system. There were no facilities to assist controllers to learn how to operate the system prior to conducting the on the job training phase of their training. There was no controller pilot datalink reference material in the training guides. The group leader was not familiar with the operation of the controller pilot datalink.

With the introduction of the controller pilot datalink, two additional positions on sector 8 had been established for a controller to specifically operate the facility during the morning and afternoon shifts. At the beginning of 1998 these positions were disestablished to provide an additional team leader and to enable a controller to undertake operational development tasks. Sector staff had discussed the decision to remove the dedicated controller pilot datalink controller and believed that a controller could adequately manage both the controller pilot datalink and the sector 8 position. There was no workload or safety review conducted prior to amending the roster.

Team management

On the day of the occurrence there were no team leaders rostered for duty to oversee the management of the sector. A full performance controller was fulfilling the team leader functions. This controller had not completed team leader training.

Sector 8

Sector 8 was a procedural sector managing the Class A oceanic controlled airspace east of the coast of Australia, extending to the flight information boundary with New Zealand and Nadi, from just south of Tasmania to a line joining Brisbane and Port Vila. The operation of the sector was considered by controllers to be significantly different from other procedural sectors because of the inclusion of the controller pilot datalink and the different separation standards and procedures used for oceanic control compared to sectors over continental Australia.

Operating position

The sector 8 operating position consisted of a console with a flight progress strip display with the controller pilot datalink keyboard and monitor located on a table on the left side of the console. The sector 8 controller operated the controller pilot datalink and managed the separation of aircraft using flight progress strips placed under location designators on the board. The layout of the facilities required the controller to turn 90 degrees to the right each time the controller pilot datalink was operated.

The sector 8O radar position was located to the left of the procedural console and a map display was fixed to the floor in front of, and midway between both operating positions.

The layout of the operating positions and the additional facilities only enabled a single controller to sit and operate sector 8. Controllers supervising training were required to sit or stand behind the trainee.


Organisational aspects

The group leader had a number of projects and staff issues that had to be addressed and that were constraining his ability to effectively manage the Ocean sectors. Taken individually these issues were probably not significant, but collectively they established the environment in which the Group was required to operate. The en-route manager and the group leader developed a plan to overcome these issues and in the long term develop staff in the Ocean sectors. Part of this plan was for the group leader to train for and obtain Ocean sector endorsements.

Training plan

The group leader developed a revised training plan that was constrained by staff commitments and scheduled ab initio training. However, he was not aware of the differences in the operation of sector 8 in comparison to other procedural sectors. Had he undertaken the classroom or simulator training prior to on the job training, he probably would have had an understanding of the unique aspects and a better overall understanding of the operation of the sector.

The group leader and the nominated supervising controller had only spent a short time together but the latter was aware of the training aspects that had been covered up to the morning of the occurrence. Because of this aspect he probably had a better appreciation than the sector controller did of the group leader's ability. Consequently, he would have been in a better position to recognise that the trainee was not maintaining the traffic situation. He might have been able to assume control of the position at a sufficiently early stage to recognise the conflict.

The current training guide and workbook were based on training ab initio controllers. There was no procedure to assist controllers from another group to modify the training to suit their specific requirements. There would appear to be scope for development of a process for peer review of revised training programs that would ensure that essential training aspects are included in a program.

Supervising controller

The sector controller that offered to supervise the group leader was unaware of the trainee's level of sector knowledge. They did not pre-brief and consequently they probably both had different expectations as to the level of participation of the other in the operation of the sector. This aspect in conjunction with his operation of the controller pilot datalink probably caused the sector controller to be distracted to the extent that he was unable to maintain an adequate scan of the flight progress strips.

Flight progress board management

The approval for the B767 to operate at a non-standard level for the track flown cancelled the defence normally provided to the air traffic system by the use of standard levels.

Controller pilot datalink facilities

The lack of a controller pilot datalink training guide or training aid provides an opportunity for controllers to become distracted to the detriment of the management of aircraft separation. Controllers should be able to develop their controller pilot datalink system skills remote from the operating position.

Operating position

The positioning of the controller pilot datalink and the sector 8 operating console restrict the ability of controllers to maintain an effective scan of the flight progress strip board. Controllers are required to divert their gaze and attention from the board to operate the controller pilot datalink keyboard. Modification of the console layout to enable more ready access to the controller pilot datalink or alternatively, provision of a controller to operate the controller pilot datalink during busy traffic periods would alleviate the problem.

Significant Factors

  1. The considerable number of changes and staff issues within the Ocean sectors in the period prior to the occurrence.
  2. The lack of a procedure to assist rated controllers to develop an inter-group training program.
  3. The inadequate preparation of the group leader for on-the-job training.
  4. The lack of a training pre-brief by the group leader and the sector controller.
  5. The approval of the use of non-standard level by the B767.
  6. The inability of the group leader to maintain an appreciation of the traffic disposition.
  7. The lack of controller pilot datalink training aids and the inadequate installation of the facility at the console.
  8. The distraction and subsequent failure of the sector controller to regularly scan the flight progress strips.

Safety Action

As a result of this and other similar occurrences, the Bureau of Air Safety Investigation is currently investigating two perceived safety deficiencies. The deficiencies relate to training requirements for air traffic service officers as a result of changes in airspace and the operation of controller pilot datalink facilities by air traffic service officers.

Any safety output issued as a result of these analyses will be published in the Bureau's Quarterly Safety Deficiency Report.

Local safety action

As a result of the occurrence and the subsequent investigations by the Bureau of Air Safety Investigation and Airservices Australia, the Northern District En Route manager implemented the following safety actions:

  1. Establishment of a local training assessment panel for non-ab initio controllers transferring inter-group.
  2. Establishment of controller pilot datalink facility fault reporting and monitoring procedures.
  3. Establishment of monthly meetings to monitor the performance of the SITA (Societe Internationale de Telecommunications Aeronautiques, communications network) controller pilot datalink.
  4. Review and amendment of controller pilot datalink controller operating procedures.
  5. Provision of sufficient staff to enable rostering of three team leaders.
  6. Completion of an audit of operating procedures with a view to standardising flight progress strip marking in the group.
  7. Review of the sector 8 (procedural) training course and initiation of action to amend documents and to re-introduce computer based training for some elements of the course.
General details
Date: 19 July 1998   Investigation status: Completed  
Time: 0250 hours UTC    
Location   (show map): waypoint LEMIB    
State: International   Occurrence type: Loss of separation  
Release date: 01 January 1999   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 767  
Aircraft registration ZK-NCJ  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Auckland, NEW ZEALAND  
Departure time 0041 hours UTC  
Destination HONG KONG  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer The Boeing Company  
Aircraft model 737  
Aircraft registration YJAV18  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Sydney, NSW  
Destination Port Vila, VANUATU  
Last update 13 May 2014