We are in the process of introducing a new electronic flight strip system called EXCDS in to our London Terminal Control Centre, which manages the airspace over London and the South East, some of the busiest and most complex airspace in the world.
With demand for our airspace growing, it is essential that we modernise the tools and technologies we use to manage airspace in order to increase capacity and ensure safety as traffic increases.
Further information about EXCDS and what we are doing to manage the transition in order to try and minimise disruption for our customers and their passengers can be found below.
What is EXCDS?
Blogs about EXCDS
Find out more about our transition to EXCDS in these posts published on our Corporate Blog.
- Preparing for a challenging transition – Pete Dawson, General Manager, London Terminal Control.
- Making paper strips digital – Chris Edwards, TC Transition & Integration Manager
- Replacing paper strips with digital: the human dimension – Lisa Aldridge, Senior Human Factors Specialist
- Managing the transition from paper to digital – Pete Dawson, General Manager, London Terminal Control
- Pencils down, please! NAV CANADA helps bring electronic flight strips to NATS’ London Terminal Control – Stephan Radatus, Manager, ATC Commercial Systems Engineering, NAV CANADA.
What is EXCDS?
EXCDS is a new electronic flight strip system that we are currently introducing in to our London Terminal Control Centre, which manages flights entering and departing London and the South-East, some of the busiest and most complex airspace in the world. It will replace the existing paper strips system, which has served us well but will not cope with the demand that is forecast for the future. A flight strip is one of the core elements of an air traffic control system, providing an air traffic controller with all the relevant information about each individual aircraft, including its speed, altitude and destination.
Why are you introducing this new tool?
Our controllers currently use paper strips to manage air traffic within London Terminal Control. Whilst this has served us well, we need to move to an electronic system in order to meet future growth. EXCDS is part of a broader ten-year £1bn technology transformation programme at NATS, which will update many of the core systems used to manage air traffic in order to meet forecast growth, improve efficiency and reduce our impact on the environment, whilst also maintaining and improving our already high safety levels.
What benefits will EXCDS deliver?
EXCDS offers two main benefits compared to paper strips. Firstly, it simplifies coordination between air traffic controllers, thereby reducing controller workload. Currently, Air Traffic Controllers have to call each other to pass aircraft between sectors. This is time consuming and adds to controller workload in what is already a complex operation. Introducing electronic coordination reduces the time spent on the phone, freeing up Controllers to manage the growing volumes of traffic being seen and laying the foundations for future growth.
Secondly, EXCDS introduces a conformance monitoring tool in to the London Terminal Control operation for the first time. This will automatically alert Controllers if an aircraft takes actions different to those instructed. This will enable the Controller to take remedial action swiftly and is expected to help reduce level-busts, whereby pilots mistakenly enter a different flight level to that which has been instructed.
What airspace is covered by this transition?
This particular transition includes controllers who manage the airspace immediately around Heathrow and Gatwick airports and extends to the South and South-East coasts of England and out over the English Channel.
Why will these changes cause flight delays?
The London Terminal Control operation is one of the most complex and busy airspace operations in the world. Transitioning our controllers on to new equipment in this operational environment requires very careful management. To help with the transition we will be limiting the volumes of traffic that enter the airspace they control for a short period during the initial stages of the transition.
For the first ten days there will be a 20% reduction in the maximum volume of traffic handled by those sectors, which will then reduce to 10% for the subsequent 10 days, though these rates may gradually increase during these phases as controllers gain confidence. Measures have been put in place to mitigate the impact, including for example by re-routing aircraft through other sectors. This has been planned in close cooperation with the airports and airlines most affected by this transition.
Why can’t you do this overnight when there are fewer flights?
Whilst the system itself will be implemented overnight, this is about providing our controllers with a new tool that they can use at all times to help manage growing traffic levels safely and efficiently. Our controllers have received significant training to prepare for the introduction of this tool. However, due to the scale and complexity of the London Terminal Control operation, it is necessary for us to reduce traffic levels slightly for a short period of time while our controllers get used to using the tool in that busy operational environment.
Am I likely to experience delay?
We do anticipate some delay during the initial phases of the implementation and we apologise to passengers for this. We have been working closely with the airports and airlines for over a year to put in place a comprehensive plan that will minimise the disruption caused by the transition. The introduction of EXCDS is an essential step in ensuring we can safely and efficiently manage future traffic demand and maintain the UK’s status as a global aviation hub.
How long is my flight likely to be delayed?
Many flights will experience no delay. Of those flights that do, most should experience only a short delay. However, there may be spells when the delay has a noticeable impact on passengers and for that we apologise. We have worked closely with airports and airlines in the lead up to minimise any disruption and will continue to do so throughout the transition.
Are any flights likely to be cancelled as a result of the disruption?
We do not anticipate any flights being cancelled as a result of the introduction of EXCDS. However, this would be a decision for individual airlines.
What have you done to mitigate potential disruption?
We are doing everything we can to minimise disruption to our customers and the flying public. The airports and airlines understand the importance of this change to the UK’s air traffic management infrastructure, and they have worked with us in advance of the transition to put in place the best possible plan to ensure the smoothest possible transition. Airlines and airports will also be present at our Swanwick Operations Centre during the transition so we can work together to put in place the right tactical measures during the initial days to minimise disruption.
Why do these changes have to be made now (broad timescale)?
We are running out of airspace to cater for the UK’s future air travel needs. The tools and technologies we use to manage air traffic have a direct impact on the volume of traffic we can safely manage. While the tools and technologies in place today have served us well, we need new tools and technologies like EXCDS to help us manage future traffic growth.
What benefits will these changes bring in the long run?
We need to modernise our airspace and the tools and technologies we use to manage it in order to deliver the capacity required for the future and to maintain safety as traffic rises, while also reducing our impact on the environment.
The changes we are introducing as part of our wider technology transformation programme will deliver many of the benefits airlines and local communities want to see, including increased capacity and efficiency and alternative ways of managing noise.
Why are you doing this over Easter when people are travelling back from their holidays?
Planning the sequencing of the transitions within the Operations Room required consideration of a number of factors, including the time required to train controllers, a desire for that training not to impact day to day operations in advance of the transition, and the benefits that would accrue based on the order of the transitions within the Operations room.
Our skies are some of the busiest and there is never a good time to reduce capacity. We have worked closely with airports and airlines in the lead up to minimise any disruption and will continue to do so throughout the transition.
Is this the first transition of EXCDS?
We have already successfully completed two out of five transitions. The first transition took place in November and the second at the end of January. Both of these transitions went very well and the controllers from those sectors are now operating at full capacity using EXCDS.
Are these the only changes you’re making to ‘modernise’ the skies?
EXCDS is part of a wider £1bn technology transformation programme which will provide us with the tools and technologies required to meet growing demand for air travel, to ensure safety as traffic grows and to help reduce the environmental impact of the industry.
Why does airspace need modernising now? (It’s been fine for all these years, why fix it if it’s not broken?)
We are running out of airspace to cater for the UK’s future air travel needs. Designed in the 1950s and 60s for aircraft that have long since retired, UK airspace handles traffic levels that have increased more than one hundred fold with traffic levels expected to increase by a further 40% by 2030. Imagine trying to put today’s road traffic through the road network of the 1960s. It would simply not work.
Neither is our airspace optimised either for communities close to airports or the global environment. We need to modernise our airspace to improve safety and deliver capacity, while reducing our impact on the environment. This will require close collaboration with our airport and airline industry partners, as well as the regulator and the Government to set out the case for change to secure buy-in from local communities.
Modernising our airspace will deliver many of the benefits airlines and local communities want to see – improved safety, increased capacity and efficiency and alternative ways of managing noise. Change is often difficult and we need to work closely with local communities to ensure we find solutions that strike the right balance between the needs of the country and our customers, and the impact felt on the ground.
EU law requires new navigational standards to be implemented by 2023; so doing nothing is not an option. What we are trying to do is find the best way of implementing change, at the same time delivering significant environmental benefit and improving capacity to address future growth.
Why are flights landing earlier in the morning at Heathrow?
For safety purposes, the transition from paper strips to electronic strips will temporarily reduce the volume of aircraft air traffic controllers handling traffic arriving and departing Heathrow will be asked to manage. As part of plans to minimise the disruption this causes, a request has been made to the Government to allow a small number of long-haul flights (up to 8) which currently enter London Terminal Control airspace before 6am but aren’t usually permitted to land, to be able to do so. This will have a significant impact on the likelihood of delay to later arriving aircraft. This exemption has only been requested for the first ten days of the transition.
Will the 8 additional flights in the early morning be counted towards Heathrow’s night quota period?
The Government has given permission for 8 flights to be dispensed each day (i.e. not counted towards the night movement limit set by Government).
How will allowing aircraft to land earlier help minimise delays?
During 06:00-07:00 the average landing rate at Heathrow is around 42 per hour. This is normally achieved by using both runways under a procedure known as Tactically Enhanced Arrivals Measures (TEAM). It is complex for the controllers to achieve this and keep the aircraft spacing of all arrivals at the optimum level required to deliver the required landing rate. Landing some aircraft before 6am will reduce the need for TEAM, providing the Controllers with the chance to build their confidence before taking on this additional task.
I’m noticing more flights in the evening. Is this linked to EXCDS?
Airlines’ summer schedules came in to operation on the 25th March. This brings with it a traffic increase of around 10% compared to the winter schedule. Whilst there is a possibility that aircraft patterns might vary slightly due to EXCDS, any changes being noticed may also be a result of the summer schedules.
Why are flights landing later into the night at Gatwick?
For safety purposes, the introduction of EXCDS in London Terminal Control will temporarily reduce the volume of Gatwick arrivals and departures handled by air traffic controllers at any given time. As part of plans to minimise the disruption this causes, a request was made to Government to allow some arrivals which would normally be affected by the Gatwick night jet restrictions, which limits landings after 23:30, to be permitted.
Demand for arrivals in to Gatwick is particularly high between 21.00 and 22.00, which means there is an increased risk that the reduced capacity in place to help manage the implementation of EXCDS may have a knock on impact to the number of aircraft arriving after the start of the night jet restrictions. Permitting some aircraft to land after 23.30 will help us minimise the disruption caused by the transition. This exemption has only been requested for the first ten days of the transition.
How many additional flights have you been permitted to land during the usual night jet restrictions?
The Government has given permission for up to ten flights per day to land outside of the normal night jet restrictions during the first ten days of the transition.
I’m noticing more flights in the evening. Is this linked to EXCDS?
Airlines’ summer schedules came in to operation on the 25th March. This brings with it a traffic increase of around 10% compared to the winter schedule. Whilst there is a possibility that aircraft patterns might vary due to EXCDS, any changes being noticed may also be a result of the summer schedules.