1/18 Airborne Separation and Self-Separation within the Distributed Air/Ground Traffic Management Concept ASAS Thematic Network - Workshop 2 Malmö, Sweden October 6-8, 2003 Mark G. Ballin NASA Langley Research Center             

2/18 Mark G. Ballin Presentation Overview  Introduction to DAG-TM Airborne Component  Potential for Benefits  En Route Free Maneuvering Operations  Capacity-Constrained Terminal Arrival Operations  Closing Remarks

3/18 Mark G. Ballin Distributed Air/Ground Traffic Management (“DAG-TM”) Concept Premise: Large improvements in system capacity, airspace user flexibility, and user efficiency will be enabled through –Sharing information related to flight intent, traffic, and the airspace environment –Collaborative decision making among all involved system participants –Distributing decision authority to the most appropriate decision maker Aeronautical Operational Control Air Traffic Service Provider Flight Crew Information Decision making Responsibility Distributing decision authority may be a key enabler in multiplying system capacity by minimizing workload bottlenecks

4/18 Mark G. Ballin DAG-TM Airborne Component in Context  Mature-state focus –Complements near-term ASAS applications research –Characterization of mature-state feasibility, benefits potential, and system requirements is important, even for evolutionary modernization  Why must we consider such a challenging solution? No other proposed paradigm has potential to –accommodate expected growth in airspace operations – we must consider system that accommodates a threefold capacity increase  Projected increases in air carriers and air cargo  New class of small aircraft designed for point-to-point operations –adapt to demand in a cost-effective way  Increased traffic within region  increased CNS infrastructure –provide robustness to system failures  Increased number of human decision makers  greater redundancy  Redundant CNS infrastructure

5/18 Mark G. Ballin DAG-TM Airborne Component Benefits Potential  Growth scalability for airspace capacity –More aircraft can be accommodated in a sector if a portion of them are self-managing –Each new autonomous aircraft in the system adds to the surveillance and separation provision infrastructures –Constraints due to controller workload are reduced through change in controller’s job from centralized control to traffic flow management  User flexibility to optimize VFR flexibility with IFR protection leads to reduced direct operating costs –Removal of “flow control” ground-hold restrictions based on en route and destination weather forecasts or ATC “saturation” –Reduction or removal of delays involved in waiting for flight plan approval –Time and fuel use during flight  Safety and reliability –Increased redundancy of traffic control  Economic scalability –Distribution of system modernization costs –For NAS users, more direct relationship between capital/recurring investments and benefits

6/18 Mark G. Ballin En Route Free Maneuvering Operations Overview User-determined optimal trajectory

7/18 Mark G. Ballin En Route Free Maneuvering Roles & Procedures for Air/Ground Interaction  Maintains separation from all aircraft »Extra separation margin given to IFR aircraft to minimize impact on ATS Provider »Ensures no near-term conflicts are created by maneuvering or changing intent  Selects and flies user-preferred trajectory »No clearance required in AFR operations (like VFR) »Trajectories selected to meet flight safety, fuel efficiency, performance limitations, and company preferences »Includes avoiding convective weather and maximizing passenger comfort »Unrestricted route & altitude except SUA’s established by ATS Provider  Conforms to TFM constraints »Adjusts path and speed to meet Required Time of Arrival (RTA) received from ATS Provider »Notifies ATS Provider if unable to meet RTA or crossing restrictions; request new assignment »Conformance required to gain terminal area access Air Traffic Service (ATS) ProviderAutonomous Flight Rules (AFR) Aircraft  Separates IFR aircraft only and monitors IFR conformance to flow/airspace constraints »Uses advanced tools and data link for enhancing IFR operations efficiency and tightening TFM tolerances  Establishes flow & airspace constraints for system-wide & local TFM »Meters AFR and IFR arrivals by assigning RTA’s (AFR) and speeds/vectors or data link trajectories (IFR) »Provides AFR aircraft an IFR clearance to enter terminal area (at which time AFR becomes IFR)  Not responsible for monitoring AFR ops »Exception: Avoids creating near-term conflicts between AFR/IFR aircraft when maneuvering IFR aircraft »AFR aircraft treated much like VFR aircraft; relies on AFR aircraft to separate from IFR aircraft »Not responsible for ensuring AFR aircraft meet RTA  Manages strategic fleet operations Airline Operational Control (AOC)

8/18 Mark G. Ballin En Route Operations – Crew Perspective (1/3) Research Prototype Navigation Display (MD-11) Time to Loss of Separation 10 min 5 min2 min0 min Intent Only Intent and State StrategicStrategic & TacticalTactical Detection => Resolution => Conflicting aircraft Ownship Conflict region Airspace constraint Conflict resolution trajectory Conflict prevention band  AOP: Planning system for autonomous operations –Long-term conflict detection (nominal 20+ min.) –Resolution through modified FMS route –Conflict(s) resolved without creating new conflicts with traffic or airspace  Pilot decision is strategic; resolution provides complete solution. Tactical information is also provided –Aircraft state- and intent-based conflicts –Traffic and area hazards –Intent-based CR algorithm  Iterates with FMS trajectory generation function to achieve “flyable” conflict-free trajectory  Not limited by imposed constraints (e.g., required time of arrival)  Determines optimal trajectory based on user-specified objectives

Research Prototype Navigation Display (B777) Several aircraft trajectories possible, depending on ownship pilot actions. All are probed for conflicts: –Planning (typically the FMS flight plan) –Commanded (current autoflight config - “no button push”) –State vector –Path reconnect (LNAV/VNAV not engaged) Conflict prevention alternatives –Provisional (trial planning) FMS –Provisional MCP –Maneuver restriction bands (intent-based “no-go”) –Collision avoidance bands (state-based “no-go” for RTCA “CAZ”) Conflict resolution alternatives –Fully automatic (full LNAV/VNAV solution) –Semi-automatic (pilot specifies resolution DOFs) –MCP targets –State Automatic Resolution (LNAV/VNAV engaged) En Route Operations – Crew Perspective (2/3)

Movie clip speed: 3x Example of Multi-Trajectory Conflict Probing

11/18 Mark G. Ballin Capacity-Constrained Terminal Arrival Operations Terminal airspace ATSP-defined maneuvering corridor Maneuver within prescribed corridors for optimal spacing Merge with converging traffic streams Adhere to runway assignment and sequence for load balancing, throughput Unequipped Aircraft Metering boundary Fly with precision for optimal spacing Adhere to metering assignment for initial spacing and sequence Phase 1

12/18 Mark G. Ballin Advanced Terminal Area Approach Spacing (“ATAAS”) Algorithm Provides speed commands to obtain a desired runway threshold crossing time (relative to another aircraft) Compensates for dissimilar final approach speeds between aircraft pairs Speeds based on a nominal speed profile Includes wake vortex minima requirements Provides operationally reasonable speed profiles Provides guidance for stable final approach speed Provide for any necessary alerting Phase 1 Crew Decision Support Capability

13/18 Mark G. Ballin Procedures based on an extension of existing charted procedures Speed profile added to existing procedure Phase 1 Terminal Arrival Operations – Crew Perspective (1/3)

14/18 Mark G. Ballin Phase 1 Terminal Arrival Operations – Crew Perspective (2/3) Electronic Attitude Director-Indicator (EADI) Numeric display of ATAAS speed guidance Mode annunciation ATAAS speed coupled to F/S indication B757

15/18 Mark G. Ballin Phase 1 Terminal Arrival Operations – Crew Perspective (3/3) Navigation Display Lead traffic highlighted Lead traffic history trail Spacing position indicator ATAAS data block (commanded speed, mode annunciation and assigned time interval, lead traffic ID and range) { B757

16/18 Mark G. Ballin Phase 1 Terminal Arrival Operations – Crew Perspective (4/4) APPR DATA APPROACH SPEEDS NASA KTS UAL KTS MIN DISTANCE 4 NM APPROACH WINDS 180 /19 < APPR SPACING 1/1 SELECT LEAD <PROF SPEED AAL846> AAL941> COA281 > UAL225> UAL903> APPR DATA> FMC CDU Pages Enter assigned spacing interval Select lead aircraft Enter final approach speeds, minimum separation, airport winds APPR SPACING 1/1 <NEW LEAD LEAD AIRCRAFT UAL903 SPACING INTERVAL CURRENT SPACING 128 SEC CURRENT DISTANCE 7.8 LEAD GROUNDSPEED 271 KTS APPR DATA> ---

17/18 Mark G. Ballin  The DAG-TM Airborne Component is part of a future mature-state airspace system consisting of coexisting non-segregated distributed and centralized networks. These networks provide system-level optimization, individual user flexibility to optimize, and a gradual modernization transition path. –Autonomous Flight Rules (AFR) is introduced as a new option for aircraft flight operations, and produces the distributed network in which aircraft exercise autonomous flight management capabilities to meet TFM constraints, maintain separation from all other aircraft, and to achieve user optimization objectives. –IFR operations are centrally managed by ground systems and controllers, and mature independently from AFR operations through evolutionary enhancements to ground automation. –AFR and IFR operations coexist in the same en-route and terminal- transition airspace, and AFR flights give way to IFR operations. AFR and IFR traffic are merged for terminal arrival using ground-based local TFM. Terminal operations at capacity-limited airports are fully IFR. Closing Remarks (1/2)

18/18 Mark G. Ballin  Terminal area throughput is maximized through integrated enhancements in ground and airborne capabilities –Airborne capability to execute strategic spacing clearances accounting for dynamic wake vortex conditions to help maximize throughput. –Ground automation to enable full integration of spacing and non- spacing aircraft.  AFR operations permit growth scalability of the airspace system by accommodating significant traffic growth without exponential growth in ground infrastructure. Enhanced IFR operations provide access to all users with minimal impact from AFR operations.  Users have incentive to equip for AFR through relief from flow management and planning acceptance restrictions Closing Remarks (2/2)

19/18 Backup Slides

20/18 Mark G. Ballin FMC CDU Pages 3. Crew opts for alternative resolution. List displayed 1. Conflict advisory information displayed 2. Crew opts to resolve all conflicts. Recommended resolution presented on ND En Route Operations – Crew Perspective (3/3) 4. Crew uploads resolution to FMS mod route

21/18 Mark G. Ballin Air Traffic Control Technologies Overview  En route tools and display support for trajectory-based traffic management –Meet time cruise and descent speed advisories –Multi-aircraft trial planning for transition airspace –Multi-aircraft trajectory preview display –Datalink for information exchange and trajectory clearances –Toolbar for clearance input, datalink, and display control  TRACON tools and display support for self-spacing operations –Spacing interval advisory –History circles for conformance monitoring  Human-in-the-loop simulation with pilots and controllers –Dallas-Fort Worth airspace - ~ 8 North West en route & TRACON sectors –Arrival rush problem - ~ 90 aircraft –Multi-fidelity aircraft simulators with advanced avionics

22/18 Mark G. Ballin Air Traffic Control Automation for DAG-TM Need some labels for the items on this slide. TMA timeline “shortcut” window Color coded arrivals & overflights “dwelled” aircraft highlighting CTAS conflict list Route trial planning Trial plan conflict list Speed advisories Data entry & display toolbar FMS route display CPDLC capability

23/18 Mark G. Ballin Strategic and Tactical Airborne Conflict Management Safe achievement of flight operational objectives was not affected by (a) reducing lateral aircraft separation requirements or (b) significantly constraining the available airspace for maneuvering Use of strategic conflict management techniques strongly reduced the propagation of traffic conflicts by accounting for all regional constraints and hazards in the conflict solution FY2002 Piloted Simulation of Autonomous Aircraft Operations, NASA Air Traffic Operations Laboratory Research objective: Investigate strategic and tactical conflict management tools in close proximity to traffic, airspace hazards, and traffic flow management constraints Red bars: number and percentage of pilots that experienced at least one 2 nd generation conflict Constrained En-Route Scenario Waypoint with required time of arrival (b) Varied proximity of “Special Use Airspace” (a) Varied standard for lateral separation Traffic density: a/c per 10K nm nm

24/18 Mark G. Ballin Airborne Spacing Flight Evaluation Flight activity recently completed at Chicago O’Hare –Validation of full-mission simulator study results, which showed large benefits achievable and very low impacts on flight crew workload –Vectoring scenarios (reflection of current day operations)  Aircraft followed ground track of leading aircraft, which was vectored by controller Initial Analysis –Results very comparable to simulation, even in presence of widely varying winds (35+ knot tailwind to headwind changes on final) –Spacing Performance  Most runs accurate to ±3 seconds at threshold crossing; many within 1 second (~200 ft)