Merging arrival flows without heading instructions Bruno Favennec, - PowerPoint PPT Presentation

Merging arrival flows without heading instructions Bruno Favennec, Eric Hoffman, François Vergne, Karim Zeghal, EUROCONTROL Experimental Centre Ludovic Boursier, Direction des Services de la Navigation Aérienne, France Aymeric Trzmiel, Steria Transport Division, France ATM seminar, July 2007 European Organisation for the Safety of Air Navigation 1

Merging of arrival flows with open loop radar vectors � Efficient and flexible But… � Highly demanding as it imposes rapid decisions for the controller and time-critical execution by the flight crew Consequences � Peaks of workload � High frequency occupancy � Lack of anticipation � Difficulty to optimise vertical Paris CDG, 2002, source: ADP profiles and to contain the dispersion of trajectories 2

Merging of arrival flows with Precision Area Navigation � Use of area navigation (RNAV, P-RNAV) to revisit the merging of arrival flows � Definition of new route structures, e.g. “trombones” � Merging achieved through route modification But… 3

Limitations “... at high traffic loads, the controllers inevitably revert to radar vectoring in order to maximise capacity .” EUROCONTROL TMA2010+ Business Case for an Arrival Manager with PRNAV in Terminal Airspace Operations (AMAN-P) “The main disadvantage of RNAV procedures is that they reduce the flexibility that radar vectoring affords the controller and experience has shown that, without the help of a very advanced arrival manager, controllers tend to revert to radar vectoring during the peak periods ”. EUROCONTROL Guidance Material for the Design of Terminal Procedures for Area Navigation, Edition 3.0, March 2003 4

Examples EDDF - 14/06/2007 (7:00-10:00) EDDF - 14/06/2007 (17:00-20:00) Source: stanlytrack.dfs.de/stanlytrack/stanlytrackEDDF.jnlp 5

Motivation � Key points � Maintain flexibility to be able to expedite or delay aircraft � Keep aircraft on Flight Management System trajectory � Maximise runway throughput � When investigating airborne spacing (ASAS), a specific method and route structure was defined to expedite or delay aircraft in the terminal area � Can we now apply this method and the route structure without airborne spacing…? 6

Principles � We created a merge point with legs at a constant distance for path shortening or stretching Merge point Envelope of possible paths � Merging is achieved through “direct-to” instructions to the merge point Sequencing legs (vertically separated) 7

Merge point FL120 FL100 Sequencing legs 10NM 8

Series of experiments � A series of small-scale experiments to perform an initial assessment of feasibility, benefits and limits � Experimental conditions � High traffic load (36 to 40 arrivals per hour with 20% heavy) � Various wind conditions (no, moderate and strong) � Various airspace configurations (two, three and four entry points) � Various configurations of legs (same or opposite direction, parallel or non parallel) � Various geometries of legs (straight segments, segments approximating concentric arcs, with or without intermediate points) � Initial measurement of benefits with today’s method (open loop vectors) as baseline (2 x 3 runs) 9

Airspace (baseline) Two frequencies: approach controller (APC) and final director (FIN) FAF Holding SUDOK: FL100 / 140 1 min / 220 kt TAMOT Holding PONTY: 065° SUDOK FL080 / 140 330° SIMON 1 min / 220 kt PONTY CODYN OKRIX SIMON FL100 PONTY FL080 ILS 4000 10

Airspace (point merge) Two frequencies: approach controller (APC) and final director (FIN) FAF LOMAN Holding SUDOK: FL100 / 140 1 min / 220 kt MOTAR NADOR FL080 TAMOT Holding PONTY: SUDOK FL100 FL080 / 140 TOLAD SIMON 1 min / 220 kt PONTY CODYN OKRIX SIMON/TOLAD FL100 MOTAR/NADOR FL080 ILS 4000 11

Density of instructions 1 16 1 16 Baseline Point merge BOKET BOKET FAF FAF LOMAN NADOR MOTAR TAMOT SIMON TAMOT SIMON TOLAD PONTY PONTY SUDOK SUDOK 12

Geographical distribution of instructions 60 Final director Baseline Approach controller Level Direct Heading 40 Speed Number of instructions 20 0 60 Point merge Final director Approach controller 40 20 0 0 5 10 15 20 25 30 35 40 30 35 40 45 50 55 60 65 70 75 80 Distance to reference point (NM) 13

Number of instructions 120 Final director Approach controller Level Direct 100 Heading Speed 80 Number of instructions 60 40 20 0 Baseline Point merge Baseline Point merge 14

Number of instructions per aircraft Baseline Point merge 10 Number of instructions 5 0 Heading Speed Level All Direct 15

Frequency occupancy 100% Final director Approach controller Baseline 80% Point merge Frequency occupancy 60% 40% 20% 0% 16

Spacing on final 7 Baseline Point merge Spacing at final appraoch fix (NM) 6 5 4 Max Max for 95% Mean+STD Mean Mean-STD 3 Min for 95% Min 2 17

Trajectories M3 TMA Vectors M3 TMA Triangle Baseline Point merge Similar distance and time flown: 70 NM during 18 minutes on average 18

Descent profiles 120 100 Point merge Mean Std dev Altitude in feet (*100) 80 60 40 Baseline Mean Std dev 20 0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 Distance to final approach fix (NM) 19

Configurations tested (1/2) Merge point Segmented sequencing legs Straight sequencing legs Common point Merge point Dissociated sequencing legs 3 flows, with 2 sequencing legs of same direction 20

Configurations tested (2/2) IAF 2 IAF 2 IAF 1 IAF 1 FAF FAF IAF 1 IAF 1 IAF 2 IAF 2 IAF 4 IAF 4 IAF 3 IAF 3 FAF1 FAF1 IAF 1 IAF 1 FAF2 FAF2 IAF 4 IAF 4 IAF 2 IAF 2 IAF 3 IAF 3 FAF FAF IAF 4 IAF 4 IAF 3 IAF 3 21

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Summary � Method found comfortable, safe and accurate, even under high traffic load , although less flexible than open loop vectors � Predictability and anticipation increased, workload and communications reduced � Open loop radar vectors no longer used and aircraft remained on lateral navigation mode � Final approach spacing as accurate as today � Descent profiles improved (potential for continuous descent from FL100) � Flow of traffic more orderly with a contained and predefined dispersion of trajectories � All these elements should contribute to improve safety � No specific airborne functions or ground tools are required initially, except P-RNAV capabilities 24

Conclusion The “point merge” method � Maintains flexibility to be able to expedite or delay aircraft � Keeps aircraft on Flight Management System trajectory � Maximises runway throughput 25

In perspective The “point merge” method is � A transition towards extensive use of P-RNAV � A sound foundation to support further developments such as continuous descent (CDA) and target time of arrival (4D) � A step to the implementation of airborne spacing (ASAS) 26