Exceeding Expectation

London Terminal Control is progressively implementing a project that replaces paper based flight progress strips with an electronic system.
This project, termed EXCDS, will provide a foundation for London Terminal Control (LTC) to meet future traffic growth, writes Ian Thompson.
LTC provides approach and departure services to the five London airports and airspace over the southern portion of England. It is one of the most complex and congested pieces of airspace in the world, with the five airports located approximately within 20 miles of each other.
The approach and arrival sectors are relatively small with aircraft entering and leaving these areas very quickly. Controllers have a highly tactical mindset of resolving immediate traffic issues and quickly transferring the aircraft to the next sector.
The LTC environment has been very labour intensive, with limited use of technology to coordinate the movement of aircraft between radar sectors. Often these strips contained very limited information about the aircraft while it was operating in the sector. There was also some variability in the data recorded on flight progress strips by each controller.
Peter Dawson, NATS’ general manager, LTC, explains: “The current technology, while fit for purpose, is not able to keep pace with the rapid growth in traffic that is being experienced today or predicted in the future. It is imperative that we replace paper flight progress strips since they limit the aircraft capacity that we can handle and our current approach to managing traffic. Electronic strips bring additional safety benefits around conformance monitoring of aircraft flight levels, while at the same time driving greater levels of standardisation among controllers operating in different sectors.”
EXCDS means that all air traffic controllers receive and record information about an aircraft on electronic flight progress strips in almost exactly the same manner. Introducing a level of standardisation helps with coordination between sectors. The electronic strips come pre-populated with information from the previous sector, with information updated as it is passed to the aircraft from controllers.
Dawson says: “Electronic recording of information and coordination enables controller workload to be managed and, hopefully, reduced. If we can provide more ‘head-room’ for the controllers by reducing workload we can then increase the number of aircraft handled by the sectors. Up to now the operation of LTC has been reliant on very high performance levels of the team of air traffic controllers. Our future operation involves the smoothing of traffic peaks between sectors. If this can be achieved we will have a greater overall capacity and a more manageable operation.”
The most significant benefits come from connectivity of operations within the LTC control room. EXCDS enables the activities of the various LTC functions to be linked together. In the future it is also envisaged that using digital tools like EXCDS will enable greater integration with airports. At present, the departure sector is aware of the aircraft that are about to depart but not exactly when it has departed. The control tower releases the aircraft in accordance with pre-set procedures. Under EXCDS aircraft will be placed in the pending bay close to when they will depart. It will help the departures controller to better anticipate the workload that is upcoming.
A NAV Canada product was chosen for EXCDS. Although it is technology used in other countries, EXCDS required considerable adaption to meet the operational requirements of LTC. The equipment delivers a number of benefits, provided that EXCDS is configured in a certain manner. The workflow logic of EXCDS, however, did not always correspond to LTC work practices. Resolving these problems required a combination of software adaption as well as changes to existing LTC processes and procedures to align with the workflow underlying the software.
LTC has had limited exposure to new technologies, with air traffic controllers needing to be convinced that new technology can improve, not hinder, their traffic handling capability. A previous attempt at introducing electronic flight strips was discarded due to the software product being inadequate for the LTC operational environment. Effective leadership and extensive staff engagement was crucial to managing programme activities and overcoming controller resistance.
“It is critical that the air traffic controllers are willing to accept the operational solution and have the confidence to use it”, says Dawson. “Previously the controllers did not have confidence in the solution proposed so it was not introduced. Three hundred very well established capable people needed to buy in to the notion that this was a good thing to do and would ultimately benefit the operation. Some people readily recognised the potential benefits, others took a little longer to support the project.”
Transition activities needed to take place at a time when traffic levels were reaching record levels, outperforming most forecasts. This meant that LTC did not have a lot of time or spare controller capacity to release staff to undertake large blocks of training. Considerable time was spent in developing a credible plan that took into account the scale of equipment adaptation required as well as staffing limitations. The training requirement could not be determined until the equipment functionality was defined, which, in turn, was reliant on the level of equipment adaptation required. That process took about a year to complete.
The first challenge was to move the project forward with a small team of people. It comprised an in-house team from NATS some of whom had been involved with introducing electronic flight progress systems in control towers. Engineering and project management staff were relocated from the corporate technical centre to the Swanwick operations centre. This integrated the project team with the operational staff.
A key decision involved determining the level of functionality required of the equipment. Pete Dawson explains: “Our controllers who sat on the core team naturally wanted the best tools money could buy. My job was to take their wish list, consider the constraints that exist with any programme – particularly budget and the time available – and discuss with them what the most important functionalities were for the task at hand and prioritise those requirements. There were some challenging conversations of course but the project team always had those conversations together and worked out a pragmatic way forward that ensured the project remained on track and would deliver a tool the controllers would be happy to use.”
A group of adaptation specialists from NAV Canada, with engineering and air traffic control expertise, joined the project. These people had both a high level of product knowledge and the experience of implementing the system in an operational environment.
Once adaptation issues were resolved, a delivery plan was developed for a staged implementation. The first step was performed by ELOS – evaluation limited operational service, which developed and brought the system in into operational service so that it could be seen controlling live aircraft on some of the sectors. It enabled equipment testing to be performed in the live environment, in its most basic form. ELOS was undertaken on spare consoles located in the operations room. This process provided a great deal of confidence that the solution would work well in an operational environment and helped to better inform and build controllers’ confidence ahead of training.
A part-task trainer was developed, which is a stepping stone between written training material and full simulation. The amount of training provided to individual air traffic controllers was determined by a training needs analysis. Training was provided to a level that enabled controllers to operate EXCDS at 80% of sector traffic capacity at commencement of operational service. Agreement was reached with airlines that lower traffic levels would be handled by each sector group during the first 10 days following the introduction of the tool.
Traditionally air traffic controller training involves taking large numbers of people away from the operation and placing them into a simulator that emulates the live operation. This process provides a very high level of fidelity but, at times, may only be teaching quite basic functionality. High volumes of traffic did not allow for controllers to be released for large blocks of time. Simulators are also very expensive to operate since a significant number of support staff are needed to ‘drive’ and manage the various elements of the simulator.
Dawson says: “While difficult to quantify, it seems that this training approach involving briefings, ELOS, shadowing and the part-task trainer could have reduced the simulator time by approximately 40%. The challenge, however, was convincing the wider business that the adaption and training efforts, which are both very costly, were sufficient to achieve the right level of capability for staff to begin operating in the live environment.”
Engagement activities to gain the support of operational staff were vital to the project’s success. Briefing sessions were provided to staff prior to the commencement of training about the project and capabilities of the equipment. LTC management, human factors specialists and project team members discussed the solution with staff and addressed concerns on a one-on-one basis. This meant that questions about the need for the project and functionality could be answered by those who held responsibility.
Spare consoles that had been used for ELOS were changed into a test and development suite that allowed people to shadow the live operation. This provided exposure to the equipment prior to the commencement of training or further exposure to those that had completed the training program.
The EXCDS programme has spanned more than three and a half years. Implementation of the project involves five stages, comprising each of the LTC sectors. The first sector to use EXCDS in the live operation did so in November 2017, with the second sector group following in January 2018. The remaining sector groups enter service between April and June 2018.
While not completely changing the operating environment of LTC, EXCDS is a starting point to introducing more sophisticated tools for the control of aircraft in one of the busiest and most complex pieces of