One year on: Results of Time Based Separation at LHR

Andy ShandGeneral Manager of Customer Affairs

Kevin HightowerAviation Chief Technologist

The Need for Time Based Separation

Runway Throughput Benefits (May – July)• Across all wind conditions

– Saving is 78NM per day– Increase of 20 movements per day

• In strong wind conditions– Saving is 178NM per day – Increase of 49 movements per day

Wind Conditions

Extra Movements17-hour

scheduled period

Per Hour

All AWE 20 1.2Strong AWE

(>20kts) 49 2.9

Wind related ATFM delay reduced by 62%

November ResultsEstimate over 25,000 minutes of delay saved in November versus

distance based separation

15 days of strong headwinds

Nov 10th: Zero minutes ATFM delay with 40 knot Headwinds

5nm becomes 3.7nm in 60 knot headwind

Summary of Findings

Reduced cancellations

No Increase in Go Arounds or Wake Turbulence Encounters

62%reduction in ATFM

wind delay

178NM of spacing saved per day

in strong wind conditions (>20kts)

+2.9 movements per hour in strong wind conditions

83% of aircraft experienced smaller Arrival-Arrival

separations

78NM of spacing on approach

saved per day, on average

+1.2 movements per hour across all wind conditions

No pilot inquires or comments

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