Proven Solution

Minimum disruption, maximum benefit

Adopting Intelligent Approach requires little or no change to flight deck procedures. Aircraft continue to be radar-vectored onto final approach in the same way and at the same speeds as under the previous procedures.

It integrates easily with existing systems with little training required for the Controller as proven with the successful implementation at Heathrow.

The main difference under Time Based Separation (TBS) is that air traffic control separates aircraft on final approach by time, not distance.

In practice this means that aircraft may appear closer on Traffic Alert and Collision Avoidance Systems during headwind conditions although the actual separation will be constant in time.

It is important that aircraft maintain controller-assigned speeds as accurately as possible in order to deliver the maximum benefit possible from TBS.

A proven solution at Amsterdam Airport Schiphol

Capacity for aircraft landing at Schiphol Airport during high wind conditions has increased by 3 – 6 additional aircraft per hour, per runway. That’s an enormous benefit that’s going to make a real difference in terms of on-time performance and the noise impact for local residents, and it’s been achieved without the need for any new equipment or infrastructure at the airport itself.

Intelligent Approach is an aircraft spacing tool developed by NATS and Leidos that allows air traffic controllers to improve the consistency of spacing between arriving aircraft. That helps maximise runway capacity, reducing delays and emissions and – for LVNL – the noise impact on local residents.

A proven solution at Heathrow Airport

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

This was upgraded to enhanced TBS in March 2018 bringing with it a more refined set of wake categories developed by Eurocontrol, 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 enhanced TBS operations 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 TBS.

That is the equivalent of extending Heathrow’s operating day by 30 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 1.5-2.5% 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 23.5 minutes

* 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.

Video – Intelligent Approach

Find out more about Intelligent Approach in our video below.


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