Intelligent Approach

Intelligent Approach is a suite of controller tools that safely optimise arrival spacing to maximise runway capacity, maintain operational resilience and provide better on time performance.

Refining separation standards can provide significant benefits to airports during peak times or disruptive conditions.

The Intelligent Approach suite of tools is based on a common platform that’s designed to help all airports increase capacity and resilience at a fraction of the cost of adding taxiways and runways. By optimising the safe separation of aircraft, Intelligent Approach can help to decrease delays and cancellations caused by poor weather conditions.

Intelligent Approach also reduces the need for stack holding, saving fuel and decreasing detrimental environmental impacts.

Intelligent Approach is made up of the following three core modules that can be tailored to the needs of the airport operation and provide benefits to airports, airlines and ANSPs.

• Distance Based Separation improves the consistency of approach spacing all the way to the runway threshold, by using optimised wake spacing rules that provide controllers with a visual indication of the required separation between aircraft.
• Time Based Separation provides resilience to headwinds by reducing the wake turbulence separation based on the live wind conditions and therefore improves operational and safety performance.
• Optimised Mixed Mode has been specifically designed for mixed mode runways to safely reduce inbound separation by taking account of departure runway occupancy.

All modes take into account runway occupancy to optimise efficiencies. Each module can apply any of the following wake turbulence separation criteria:

• ICAO: The standard wake turbulence model
• RECAT (EU or US): Enables increased capacity by optimising wake separations
• Pairwise: Enables significant capacity gain by taking account of individual aircraft wake
• Custom: Any custom wake separation system approved for your airport

The use of Intelligent Approach positively impacts the entire airport operation and has been proven to enable more flights with fewer delays and cancellations. This results in benefits for all involved including:

• Improved on time performance and lower fuel costs for airlines
• Operational efficiencies for the airport to control costs by improved resilience and generate revenue through increased movements
• The effective management of controller workload for ANSPs
• The positive environmental impacts of lower fuel burn as a result of reduced airborne holding times
• Consistent delivery of increased capacity

All of which help to achieve the best customer experience possible.

• Investors will benefit from return on investment.
• Technical teams can easily integrate the solution into existing systems and hardware.
• Users find an intuitive suite of tools to use and minimal training is required.

Intelligent Approach is a proven solution developed by NATS and Leidos and has been in continuous operation at Heathrow since March 2015.

The system was upgraded in March 2018 to implement RECAT-EU wake vortex separation rules, as well as improvements to the tool to provide separation to the runway threshold. These enhancements have helped make the operation more resilient against delays and disruption.

The first four months of operations following the upgrade saw a tactical capacity gain of approximately 1.4 additional aircraft landings per-hour in all wind conditions, with an additional 1.6 arrivals in strong headwinds over and above the 0.8 additional landings (2.6 additional in strong winds) already achieved by the original system.

That is the equivalent of extending Heathrow’s operating day by 24 minutes, delivering valuable operational resilience that helps ensure the airport can deliver to plan, airlines can keep to their schedules and local communities are not affected by late running arrivals.

Heathrow is capped at 480,000 movements per annum so this additional tactical capacity is all translated into improving on-time performance and a better passenger experience.

Benefits already achieved include:

• Average tactical capacity gain of 2 aircraft landings per hour in all wind conditions
• An improvement of 2.5% in airport punctuality
• An average saving of over 1,410 seconds per day in arrival separation on final approach – the equivalent to extending Heathrow’s operating day by 24 minutes
• A 60% reduction in delays due to headwinds
• A saving of 15kT of fuel per year due to reduced airborne holding
• Tactical capacity gains quoted are for Heathrow which was already using 6 Wake Categories so may be higher for some airports. Gains are baselined against original distance based separation.