Human Factors Role - ATM Seminar

6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

Ground-Side Perspective on Mixed Operations with Self-Separating and Controller-Managed Aircraft Paul U. Lee*, Thomas Prevot*, Joey Mercer*, Nancy Smith, Everett Palmer *San Jose State University NASA Ames Research Center Moffett Field, CA 94035

1

Acknowledgements 6th USA/Europe Air Traffic Management R&D Seminar

At NASA Ames Research Center: – the Airspace Operations Laboratory support staff – the Flight Deck Display Research Laboratory support staff – the MACS development team – the 3D CDTI development team – the staff of the Advanced Concepts Flight Simulator

Baltimore, MD June 2005

At NASA Langley Research Center: – The staff of Air Traffic Operations Laboratory Individuals from following contractor companies: – Booz-Allan Hamilton – Titan Systems – San Jose State University

Sponsors and supporting organizations include: – NASA’s Advanced Air Transportation Technology (AATT) Project Office – Air Line Pilots Association (ALPA) – National Air Traffic Controllers Association (NATCA) – FAA’s Air Traffic Services Office 2

CE-5: En Route Free Maneuvering 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

Problem: •

Air traffic service provider (ATSP) workload constraints may limit National Airspace System (NAS) capacity and efficiency

•

ATSP-issued clearances may cause excessive deviations from user preferred trajectories (UPTs) for separation assurance or are otherwise not optimal for users

Solution: •

Air: Appropriately-equipped aircraft maneuver freely for separation assurance – –

•

Aircraft flying under Autonomous Flight Rules (AFR) may modify their flight path without controller’s approval Separation responsibilities given to the cockpit

Ground: ATSP provides traffic flow management for all aircraft (with ground-based DSTs) and provides separation assurance for non-equipped aircraft (Instrument Flight Rules, or IFR)

Some of the potential benefits are: • Operational scalability • Increased airspace capacity and throughput • Flexibility to choose routes and altitudes for AFR aircraft 3

Ground-side Assessment of En Route Free Maneuvering 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

•

Overall Experimental Goals & Objectives – Assess operational viability of mixed operations and traffic scalability – Assess safety impact of mixed operations and scalability – Evaluate initial procedures, roles, responsibilities, and automation tools

•

Ground-side Assessment – Controller workload – Controller acceptability of overall concept and procedures – Controller perspective on safety – Acceptability/usability of ground-side decision support tools

4

Experimental Design 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

Participants

Autonomous

5 Certified Professional ATCs Managed

22 Commercial Airline Pilots

L3

Test Sectors 3 high + 1 low altitude en route sectors 3 Traffic Levels

Traffic Level

L2 T1 L1

L1

C1

C2

T0

L1: DAG Managed L2: Intermediate DAG CE5 L3: High DAG CE5

C3

C4

Experimental Condition

4 Conditions - (4 runs per condition)

T0: Threshold approximating current day monitor alert parameter.

C1: L1 traffic, all managed C2: L1 traffic, mixed operations

T1: Threshold above which managed-only operations may become unmanageable.

C3: L2 traffic, mixed operations C4: L3 traffic, mixed operations

Traffic Trafficcounts countsto toachieve achievethese theselevels levelswere wereestablished establishedininsimulation. simulation. 5

CE-5 Airspace & Traffic Flows 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

Ghost North Amarillo High 70 270

Wichita Falls High 240

Ghost South

Ardmore High Bowie Low

70

Fort Worth Center (ZFW)

Memphis Center (ZME)

Albuquerque Center (ZAB)

Kansas City Center (ZKC)

240 GREGS

UKW BAMBE

6

NASA Ames Simulation Environment 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

Pilot stations with state-of-the-art FMS and displays advanced CDTI and data link

Standard voice com., CPDLC, Trajectory changes Single Aircraft Stations

Multi Aircraft Stations

Controller stations emulating state-ofthe-art and advanced surveillance, automation, and data link capabilities

En Route Center

Not pictured: NASA Langley Single and Multi Aircraft Stations; NASA Ames Advanced Cockpit Flight Simulator

Standard voice com., ADS-B, CPDLC, Trajectory requests

7

Ames DSR-Emulation Controller Display 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

←Toolbar

ÉCPDLC status list

interactive meter fix Timeline View DC View ËTime-to-conflict CPDLC symbol→

Color coded data blocks Route trial plan with conflict graphics

Datablock Close-up

R-CRD view

Trial plan ETA

8

Display of AFR Aircraft 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

•

Solution – AFR aircraft solves all conflict with all controllermanaged (IFR) aircraft – Limited datablock for AFR aircraft to minimize clutter on controller displays

•

•

Key Assumption – Scalability achievable only if AFR aircraft have little impact on controller workload

Added redundancy to enhance safety – AFR-IFR conflicts not resolved at 3 minutes to LOS shown to the controllers – Controllers could (but not required to) contact the pilot to coordinate a resolution 9

Results: Highlights 6th USA/Europe Air Traffic Management R&D Seminar

Managed operations above current day traffic levels –

Mixed operations above current day traffic levels – – –

•

provided efficient arrival traffic flow to the meter fix did not create significantly more separation violations significantly lowered controller workload with slightly higher pilot workload

Mixed operations at 2x and 3x current day traffic levels – – –

•

Aircraft Count

raised safety concerns with regard to short term AFR-IFR conflicts had little impact on controller workload as long as the additional aircraft were AFR and resolved potential conflicts early enabled flight crews to create conflict-free flight paths by changing route and/or altitude even at the highest traffic levels

Other Conclusions – – –

A highly advanced ground system is required Air and ground systems need to be well integrated with reliable state and intent information The integrated air/ground system can increase capacity significantly even in all managed operations

Self-separating Controller-managed Max Aircraft Count

•

were possible with advanced DSTs integrated with CPDLC

50 40 30 20 10 0 C1

C2

C3

C4

En Route Sector (Amarillo)

Controller Workload Ratings

•

Baltimore, MD June 2005

ATC Workload 7 6 5 4 3 2 1 0 C1

C2

C3

C4

En Route Sector (Amarillo)

10

Aircraft Count, ATC Workload, and Complexity 6th USA/Europe Air Traffic Management R&D Seminar

C2

C3

30 20 10

C1 C2 C3 C4

0 Amarillo

Ardmore

Wichita Falls

Bowie

C1

C4

C2

C3

C4

7

7 6 5 4 3 2 1 0

Workload Rating

Traffic Complexity Ratings

C1

40

C1 C2 C3 C4

Traffic complexity ratings by ATC increased with increasing number of self-separating aircraft

50

C1 C2 C3 C4

–

Significant increase in total aircraft count did not adversely affect workload Mixed operations did not adversely affect workload

Free Maneuvering

C1 C2 C3 C4

–

•

Controller Managed

ATC workload ratings correlated with managed aircraft count Maximum Aircraft Count

•

Baltimore, MD June 2005

6 5 4 3 2 1

Amarillo

Ardmore

Wichita Falls

Sector

Bowie

Amarillo

Ardmore

Wichita Falls

Bowie

Sector

11

Controller Acceptability of Concept and Procedures 6th USA/Europe Air Traffic Management R&D Seminar

•

Baltimore, MD June 2005

Positive impression on metering efficiency – Easier to deliver managed aircraft to the meter fix – Just as easy to sequence aircraft in mixed operations – Mixed operations slightly more efficient

•

Somewhat negative impression on situation awareness and safety – – – –

•

Slightly more difficult to detect non-conforming aircraft More difficult to cope with unplanned events Slightly more difficult to maintain and monitor separations Mixed operations rated less safe than managed operations

AFR-IFR conflicts – Burdening AFR aircraft of separation responsibilities marginally acceptable – Procedures and phraseology for resolving AFR-IFR conflicts somewhat unacceptable

12

Controller Perspective on Safety 6th USA/Europe Air Traffic Management R&D Seminar

Baltimore, MD June 2005

• Loss of Separations (LOSs) – 3, 4, 5, and 7 LOSs for conditions C1 – C4, respectively – Many LOSs due to system, support staff, and/or training errors

• Controller Ratings – Managed vs. mixed • 100% managed operations safer than mixed operations

– Different AFR traffic levels of mixed operations • Traffic scenarios with lower AFR aircraft count safer than higher AFR count • Ratings may have been adversely affected by increase number of AFR-IFR conflicts in higher traffic conditions

13

Controller Safety Concerns 6th USA/Europe Air Traffic Management R&D Seminar

•

Baltimore, MD June 2005

Concerns related to AFR aircraft – Automation dependency • If conflict detection automations “miss” an AFR-IFR conflict, controllers may not be able to detect them independently

– Situation awareness of AFR aircraft • Limited datablock for AFR aircraft to minimize controller workload also minimizes situation awareness of these aircraft

– Near-term AFR-IFR conflicts • Presenting AFR-IFR conflicts at 3 minutes prior to LOS was not enough time to coordinate a resolution with the cockpit • Roles and responsibilities between controllers and pilots became less clear for near-term conflicts

•

Concerns about increased traffic density – Current day operations have built-in excess buffers to absorb errors by human operators and systems – Increased traffic density may inadvertently strip away those buffers – “Our reality is people fly planes, people work planes, and people get on planes…”

14

Acceptability of Decision Support Tools and Displays 6th USA/Europe Air Traffic Management R&D Seminar

•

Integrated ground-side tools with CPDLC were critical – – –

•

Baltimore, MD June 2005

To keep aircraft on 4D trajectories (e.g. trial plans, route, altitude, and speed uplinks) To offload tasks to automation to reduce workload (e.g. TOC via CPDLC) To maintain an efficient traffic flow (e.g. timeline)

Controllers gave high usability and usefulness ratings for the tools that supported the critical tasks Usability

Usefulness

Trial-planning tool CPDLC interface for TOC Graphical display of trial plan conflicts Color coding of information

Controller Ratings

CPDLC interface for clearances and requests Arrival timelines DSR emulation of existing functions Speed advisories Graphical display of conflict alerts (i.e. flashing data blocks) Graphical display of active IFR conflicts Graphical display of AFR aircraft (i.e. limited data block) STA assignment/swap functions Datalink status list Conflict list Graphical display of AFR-IFR conflicts 0

1

2

3

4

5

Tool Feature

15

Conclusion 6th USA/Europe Air Traffic Management R&D Seminar

•

Baltimore, MD June 2005

En Route Free Maneuvering concept element (CE-5) shows significant potential for increased traffic capacity – With a large number of self-separating aircraft, total aircraft count far exceeded current day Monitor Alert Parameters – Controller workload correlated with managed aircraft count – However… • At very high traffic density (e.g. ~3x traffic), traffic complexity (but not workload) increased significantly • Mixed operations at higher traffic density raised safety concerns by the controllers

• •

Controllers gave neutral to slightly positive feedback for various aspects of mixed operations, with a notable exception with respect to safety Well-integrated air/ground system was critical for mixed operations – Ground-side decision support tools integrated with CPDLC were well accepted and effectively utilized by the controllers – Integrated tools also increased traffic capacity in all managed operations

16