Schiphol ATC Implements Time-based Approach Separation
Airports Innovation

Schiphol ATC Implements Time-based Approach Separation

DALLAS — Dutch Air Navigation Service Provider (ANSP) LVNL has announced the successful implementation of a new system at Amsterdam Schiphol (AMS), which separates landing aircraft by time rather than distance. The system became fully operational on January 26, following a three-year testing period. In the past, aircraft were separated on approach by a distance determined by the difference in size between the leading and following aircraft.

Landing aircraft are spaced apart to mitigate against the following aircraft being disrupted by wake turbulence, which is spiraling air vortices that form at the wingtips of aircraft. The larger the leading aircraft, the larger the separation gap that is required. However, the conventional system was unable to account for the effects of wind, since a stronger headwind on approach lengthens the time between landing aircraft and gives wake vortices more time to dissipate.

Time-based separation is dynamically adjusted to the ambient wind conditions, allowing air traffic controllers to potentially position landing aircraft closer together when headwind conditions permit. Ultimately, the technology can increase landing rates by accommodating two additional aircraft per hour under the least favorable wind conditions.

Resident carrier KLM will benefit most from the enhanced efficiency that Time Based Separation will create. Photo: Adrian Nowakowski/Airways

Going Back In Time

The transition to time-based separation was first initiated at London Heathrow (LHR) in 2015, and last year the concept was expanded to Toronto Person (YYZ). NATS, the UK-based ANSP, has claimed that time-based minima have resulted in delays due to headwinds being reduced by up to 60%.

Implementation of the new system at AMS, called Intelligent Approach, was first announced in 2019 and came as part of a partnership between LVNL, NATS, and technology firm Leidos UK, as well as further implementation support being provided by Think Research.

Featured Image: AMS Control Tower. Photo: Ikreis. Wikipedia Commons CC BY-SA 4.0. Own work

Aviation author and commercial pilot based in the UK, with close to twenty years in the industry.

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