1/18 Airborne Separation and Self-Separation within the Distributed Air/Ground Traffic Management Concept ASAS Thematic Network - Workshop 2 Malmö, Sweden

1/18

Airborne Separation and Self-Separation within the

Distributed Air/Ground Traffic Management Concept

ASAS Thematic Network - Workshop 2Malmö, Sweden

October 6-8, 2003

Mark G. BallinNASA Langley Research Center

2/18Mark G. Ballin [email protected]

Presentation Overview

Introduction to DAG-TM Airborne Component

Potential for Benefits

En Route Free Maneuvering Operations

Capacity-Constrained Terminal Arrival Operations

Closing Remarks


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 A

ir T

raff

ic

Ser

vice

Pro

vide

r

FlightCrew

• Information

• Decision making

• Responsibility

Distributing decision authority may be a key enabler in multiplying system capacity by minimizing workload bottlenecks


DAG-TM Airborne Componentin 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


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


En Route Free ManeuveringOperations Overview

Air Traffic Service Provider

Managed (IFR) Aircraft

AeronauticalOperational Control

Special Use Airspaceavoidance

Hazard avoidance

Concept Integrates:

Mixed operations

User flexibility

Operational constraints

Fleet management

Priorityrules

Maneuver restrictions

IFRpriority Airborne

separation

Terminal area

Crossing restrictions

IFR and AFR traffic flow management

IFR trajectorymanagement

$+Cost management,Passenger comfort

Autonomous (AFR) Aircraft

User-determined optimal trajectoryUser-determined optimal trajectory


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)


En Route Operations – Crew Perspective (1/3)Research Prototype Navigation Display (MD-11)

Time to Loss of Separation10

min

5 m

in

2 m

in

0 m

in

Intent Only Intent and State

Strategic Strategic & Tactical Tactical

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


Capacity-Constrained Terminal Arrival Operations

Terminal airspace

ATSP-definedmaneuvering

corridor

Maneuver within prescribed corridorsfor optimal spacing

Merge with converging

traffic streams

Adhere to runway assignment and

sequence for load balancing, throughput

Unequipped Aircraft

Meteringboundary

Fly with precision for optimal spacing

Adhere to metering assignment for initial

spacing and sequence

Phase 1


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


Procedures based on an extension of existing charted procedures

Speed profile added to existing

procedure

Phase 1 Terminal Arrival Operations – Crew Perspective (1/3)



Electronic Attitude Director-Indicator (EADI)

Numeric display of ATAAS speed guidance

Mode annunciation

ATAAS speed coupled to F/S indication

B757



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



APPR DATA APPROACH SPEEDS NASA557 135 KTS UAL903 130 KTS MIN DISTANCE 4 NM APPROACH WINDS 180 /19 <APPR SPACING

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 AIRCRAFTUAL903

SPACING INTERVAL

CURRENT SPACING128 SEC

CURRENT DISTANCE7.8

LEAD GROUNDSPEED271 KTS

APPR DATA>

---


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)


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


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


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


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


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 2nd generation conflict

Constrained En-Route Scenario

Waypoint withrequired time of arrival

(b) Varied proximity of“Special Use Airspace”(a) Varied

standard forlateralseparation

Traffic density: 15 -18 a/c per 10K nm2

0 100 nm


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)

Documents

1/18 Airborne Separation and Self-Separation within the Distributed Air/Ground Traffic Management Concept ASAS Thematic Network - Workshop 2 Malmö, Sweden