1/14 Development and Evaluation of Prototype Flight Deck Systems for Distributed Air-Ground Traffic Management ASAS Thematic Network - Workshop 3 Toulouse,

1/14

Development and Evaluation of Prototype Flight Deck Systems for Distributed Air-Ground Traffic Management

ASAS Thematic Network - Workshop 3Toulouse, FranceApril 19-21, 2004

Richard BarhydtNASA Langley Research Center

2/14Richard Barhydt [email protected]

Distributed Air / Ground Traffic ManagementDistributed Air / Ground Traffic Management

Distributed Air/Ground Traffic Management (DAG-TM)

Long range focus designed to significantly improve system capacity while maintaining or improving safety.

Autonomous aircraft flying under “Autonomous Flight Rules” (AFR) responsible for maintaining separation from all other traffic (AFR and IFR), while meeting traffic flow management constraints.

Air traffic service provider continues to provide traffic separation between IFR aircraft and assigns constraints to all aircraft for flow management.– Distributing separation responsibilities to AFR aircraft

enables controllers to focus more on overall traffic flow management.

– Constraints (waypoint speed, altitude, or time) presumed to be assigned at TRACON entry point where all AFR traffic transitions to IFR.



Potential Incentives for DAG-TM Equipage

Removal of “flow control” ground-hold restrictions due to weather or ATC “saturation” (AFR flow control done through arrival time management).

Priority arrival slots at capacity-constrained airports. User flexibility to select desired route and altitude. Capabilities travel with airplane.

– Less dependence on local ground system infrastructure.– Presumes ADS-B out or TIS-B.



En Route Operations Research Platform

Air Traffic Operations Lab at NASA Langley used as research platform for airborne concept, procedures and prototype systems development and evaluation.

Personal Computer (PC)-based aircraft workstations leverage existing systems and projected capabilities.– Simulated ADS-B used to exchange state and intent

information between pilot stations and ground system. Considers real-world limitations (message format, probability of

reception vs. range, update interval). Based heavily on industry standards (ADS-B MASPS,

RTCA/DO-242A).

– Modeled ARINC 429 data buses used for information exchange within aircraft simulation.

– Autonomous Operations Planner (AOP) provides separation assurance services to flight crew - integrates with existing aircraft systems, displays, and controls.



AOP Design Features

Provides conflict detection, prevention, and resolution services.– Considers traffic conflicts and airspace hazards (special use

airspace and hazardous weather areas), aircraft performance limitations, flow management constraints.

AOP incorporates human factors design principles:– Commands linked directly to DAG-TM pilot procedures:

Recognize and resolve conflicts with all other aircraft. Avoid maneuvers that create near-term conflicts.

– Information consistent with existing flight deck systems and aircraft control states:

Color conventions for status information, alerts, and warnings. Resolutions correspond to current aircraft flight mode (Mode

Control Panel or Flight Management Computer).

– Status information on nearby traffic can be turned on/off.



AOP Design Features

Considers real-world complexities associated with trajectory generation and intent information management:– Uses command trajectory as basis for ASAS functions.

Predicted path that aircraft will fly assuming pilot does not change automation modes or settings.

Recommended by various forums (FAA/Eurocontrol Intent TIM, RTCA ADS-B MASPS).

– Considers aircraft dynamics, winds, and integrates target states from multiple aircraft systems: Flight Management Computer (FMC) Control Display Unit (CDU) Mode Control Panel (MCP) Flight Control Computer (FCC)



B-777 Style Navigation Display with Conflict

Resolution Uploaded

to FMC

Loss of Separation

Region

Ownship

Intruder



DAG-TM Concept (Terminal Area)

Concept Goals:– Increase runway throughput while maintaining or improving

safety.– Leverage existing navigational procedures and aircraft

systems, displays, and controls.– Conduct operations without adversely affecting flight crew or

controller workload.– Effectively integrate aircraft with mixed equipage

capabilities.



DAG-TM Terminal Area Operations

Runway throughput improved by reducing threshold crossing delay time between aircraft (consistent with safety).

Airborne Merging and Spacing tool for Terminal Arrivals (AMSTAR) designed to reduce delay time by improving threshold crossing accuracy and precision:– Accuracy: time intervals closer to optimum spacing.– Precision: successive intervals have better consistency.– Provides speed commands needed to achieve desired

threshold crossing time behind preceding aircraft.



• Compensates for dissimilar final approach speeds between aircraft pairs.

• Includes wake vortex minima requirements.

• Compensates for wind changes encountered during approach.

• Speeds based on a nominal speed profile consistent with current day operations.

• Emphasizes low pilot workload and system stability.

–Speed changes given in 5 knot increments.–Speed commands kept within 10% of nominal speed profile.

• Provides smooth transition to desired final approach speed.

• Provides any necessary alerting.

AMSTAR Design Features



Nominal Speed Profile

Existing Procedure with Downwind Extension



Flight Crew Actions

Pilot engages PDS guidance

Pilot selects lead aircraft and enters

spacing data through CDU

90



Airborne Spacing Flight Evaluation

High fidelity simulator study:– Pilots achieved desired spacing

interval (mean values): Within 5 sec when following

speed guidance with MCP or manual throttles.

Within 1 sec when coupled to autothrottle.

Standard deviation within 2 sec. Flight test at Chicago O’Hare

with Langley B-757 research aircraft:– Widely varying winds (35+ knot

tailwind to headwind changes on final).

– Mean spacing performance within 1 sec of desired interval.

– Standard deviation ~ 8 sec.



Upcoming Studies

En Route and Arrival Operations:– Joint Experiment with NASA Ames Research Center.

Air/ground coordination with subject pilots and controllers. Will address concept scalability and mixed operations. Overflight and descent scenarios (with required time of arrival

at TRACON entry point.)

Terminal Area Operations:– Batch studies (effects of ADS-B range, wind prediction

accuracy, different aircraft types in stream).– Human-in-the-loop study (adaptability to different

airports/airspace, pilot workload, controller feedback).

Documents

1/14 Development and Evaluation of Prototype Flight Deck Systems for Distributed Air-Ground Traffic Management ASAS Thematic Network - Workshop 3 Toulouse,