1272020 Potential Benefits of a Timebased Separation Procedure

12/7/2020 Potential Benefits of a Time-based Separation Procedure to Maintain the Arrival Capacity of an Airport in Strong Headwind Conditions By: Elsa Freville (TRANSSIM) Jean-Pierre Nicolaon, Peter Crick & Antoine Vidal (EUROCONTROL Experimental centre) 5 th USA/Europe ATM R&D Seminar - June 23 -27, 2003 - BUDAPEST 1 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Objectives & Scope of the Time-based Project u To replace current distance separations by time-based separations : è Not to gain capacity è To recover part of capacity under strong headwind conditions u 2 / 25 To address single runway operations during the final approach phase EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Scope of Presentation 3 / 25 u Current separation procedures u What happens under strong headwind conditions ? u Why use time-based separations ? u Which time separations ? u Potential benefits for runway capacity u Next steps u Safety aspects u Candidate operational applications EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures Wake Vortex ICAO Separation standards: u u u Heavy: 136 000 kg or more Medium: less than 136 000 kg and more than 7000 kg Light: less than 7000 kg Radar separation minimum = 3 Nm or 2. 5 Nm applies in other cases 4 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures Operational Procedures: u Compression occurs during final phase of flight: è a/c speeds decrease significantly during the last phase of flight to reach the required approach speed (safe landing) Ex : B 737 -500, IAS = 180 kt at 6 Nm 114 kt at threshold è a/c approach speeds depend on aircraft weight and type: Ex : B 747 -400, IAS = 180 kt at 6 Nm 159 kt at threshold u 5 / 25 The controller must apply greater separations between a/c than ICAO requires : after the OM (Outer Marker) the pilot is in control of the aircraft’s speed EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures 6 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures 7 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures 8 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures 9 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures COMPRESSION ! ! ! 10 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Current Separation Procedures u Minimum safe distance separations to apply at 6 Nm from the runway threshold: 11 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 What happens under strong headwind conditions ? Under strong headwind conditions: u Ground speed decreases GS = IAS - headwind speed 12 / 25 u It takes more time to fly a given distance u The same distance separations induce greater separations in time between a/c u Time separations between a/c increase anywhere on the trajectory u Runway capacity decreases EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 What happens under strong headwind conditions ? Example: u 13 / 25 Wind scenario: EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 What happens under strong headwind conditions ? u Time to fly a given distance increases u Time separation increases è at threshold: no wind / wind 4 Nm 5 Nm 3 (2. 5) Nm 14 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 What happens under strong headwind conditions ? u Runway capacity decreases è Sequence of a/c at Paris-CDG airport (landings from 6 to 8 a. m. - 2 nd January 2001) è Loss 15 / 25 of 6 a/c per hour EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Why use time-based separations ? u Under strong headwind conditions, use constant time separations between a/c that do not depend on the wind conditions : u è to recover time separations at the runway threshold è to recover runway capacity Would reduce longitudinal distance separations without additional risk of wake encounters 16 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Which time separations ? u Operational Separations at 6 Nm from the runway threshold u Time to run under no-wind conditions the required distance separation : è operational distance separations at 6 Nm from the runway threshold è time the slowest Leader takes to fly the distance separation from 6 Nm u Example: H or M behind M a/c : 4 Nm intrail sep. at 6 Nm è Slowest Medium aircraft = B 737 -500 at minimum weight è Time to run a 4 Nm distance from 6 Nm under no wind conditions = 98 seconds = Time separation at 6 Nm 17 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Potential benefits for runway capacity Example: u 18 / 25 Wind scenario: EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Potential benefits for runway capacity 19 / 25 u Operational distance separations at 6 Nm: u Time separations at 6 Nm: EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Potential benefits for runway capacity u Time separations decrease : è u 20 / 25 At threshold : distance/time separations - headwind conditions Runway capacity recovery è Sequence of a/c at Paris-CDG airport (landings from 6 to 8 a. m. - 2 nd January 2001) è capacity recovery of 3 a/c per hour EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Potential benefits for runway capacity u Longitudinal separations decrease è Minimum 21 / 25 distance separations at the threshold EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Next Steps 22 / 25 EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Safety Aspects 23 / 25 u Compare reduced longitudinal separations with wake vortex characterisation data u Validate time separation between the landing of two aircraft u Required radar accuracy (operational concept dependant) u Sudden changes in weather/wind conditions (speed, direction, wind turbulence, wind-shear) u technical failures (system and support) EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 Candidate Operational Applications 24 / 25 u Intelligent speed vectors u Ghost positions u Pilot’s involvement EUROCONTROL EXPERIMENTAL CENTRE

12/7/2020 THE END !!! 25 / 25 EUROCONTROL EXPERIMENTAL CENTRE