National Aeronautics and Space Administration

www.nasa.gov

Automated Air Traffic Control

Operations with Weather and

Time-Constraints

A First Look at (Simulated) Far-Term Control Room Operations

Thomas Prevot

NASA Ames Research Center

Jeffrey R. Homola, Lynne H. Martin, Joey S. Mercer and Christopher C. Cabrall

San Jose State University/NASA Ames Research Center

Ninth USA/Europe Air Traffic Management Research and Development Seminar (ATM2011)Berlin, Germany, 2011-06-14

Outline

Problem

Ground-Based Automated Separation Assurance

Experiment Design

Results

Conclusions

The Problem

• NextGen is expected to accommodate a significantincrease in air traffic demand

• Cognitive resources of air traffic controllers are limited

• Conventional clearance-based separation assurance (SA) is not possible in the envisioned high density environment

Introduction: Trajectory-Based Operations in the near- to mid-term

•18 (near-term) to 25 (mid-term) aircraft are allowed in Airspace “sectors” at any given time

•Teams of 2 Air Traffic Controllers per sector required for high traffic•Video shows 8 controllers handling ~75 aircraft

The Approach

• Ground-based automated separation assurance

• The ground-based automation manages the separation

• The operatorsmanage the automation, provide additional services and make decisions

Footage: SA3 Shakedown in AOL

• 30, 40, or 50 aircraft are allowed in Airspace “sectors” at any given time

• 1 or 2 Air Traffic Controllers per sector possible

• Video shows 8 controllers handling ~300 aircraft

SA3: Functional AllocationAutomation Controller

•Detect Separation and weather Conflicts

•Resolve trajectory-based conflicts (if within tolerances)

•Resolve all time-critical traffic conflicts

•Alert controller to urgent problems

•Provide trajectory planning assistance

•Use data comm. to communicate

•Supervise the automation

•Resolve trajectory conflicts flagged by the automation

•Monitor and maintain schedule compliance

•Implement weather reroutes with automation support

•Place aircraft back on trajectory following automated tactical maneuvers

Experiments

—Separation Assurance Experiments in the AOL

—Research Question

—Current Experiment Design

—Test Matrix

—Participants

—Airspace

—Apparatus

—Procedure

Beginning in 2007, a series of HITL simulations on ground-based automated SA have been conducted in the AOL

Automated Separation Assurance

2008: SA1 Levels of automation 2009: SA2 Air/ground operations with

off-nominal situations2010: SA3 Coordinated simulation with

NASA Langley to compare ground-based and airborne approach (AIAA-ATIO 2010)

2010: SA3 Automated separation assurance operations in “near full mission” control room environment with weather and time constraints

Research Question for this Study

• Can air traffic control operations with ground-based automated separation assurance be an effective and acceptable means to routinely provide high traffic throughput in the en route airspace?

Experiment Design

Day1 Day2 Day3 Day4traffic Wea-

thertraffic Wea-

thertraffic Wea-

thertraffic Wea-

ther

Phase 1 1:00 PM

Light

Mete-

ring

Heavy

Mete-

ring

Decaying

weatherLight

Mete-

ring

Decaying

weather

Heavy

Phase 2 2:00 PM Mete-

Growing

weather

Growing

weatherPhase 3 3:00 PM ring

•Exploratory Study: 4 afternoons, 3 hour runs, •Participants: 10 test positions, 12 controllers, 3 supervisors (current and ret.)•Two Basic Scenarios: (1) Light Metering (2216 aircraft),

(2) Heavy Metering (3060 aircraft)•Three Within Scenario Manipulations: (1) Airspace demand (2) Metering Demand (3) Weather situation

Airspace

•8 en route test sectors from ZKC and ZID centers•Surrounding airspace controlled by confederates•Flight Level 290 and above•Mixture of overflight and transitioning aircraft to and from area airports•All aircraft fully data comm and ADS-B equipped

Apparatus

•MACS simulation platform

•Advanced controller displays

•28 inch Barco displays

•DSR keyboards and trackballs

•Voice Switching and Communication System (VSCS) emulation

•Wall projections of current and predicted traffic situations

Procedure

• Two week study— Three days training— Four days data collection

• 3 hour runs • Participants work one hour shifts, brief next controller, fill out questionnaire, take a break and work the next shift• Runs conducted simultaneously in two areas (ZKC-east and ZID-west)•FAA test participants on supervisor and radar positions for different perspectives•Retired controllers on remaining positions

Results

—Airspace Throughput

—Workload

—Separation Violations

—Schedule Conformance

—Acceptability

—Functional Allocation

—General Comments

Airspace Throughput

Per Sector:• Current Day Monitor Alert Parameter: 18 aircraft• Average aircraft count during study: 24 aircraft• Peak aircraft count during study: 62 aircraft

Workload (Real-time Ratings)

Workload was more impacted by other factors (e.g. weather) than by aircraft count

Workload (Post-Run NASA TLX)

Weather and metering condition both significantly increased participants’ mental workload ratings

Loss of Separation (LOS) Events

• 1450 LOS events were scripted• 42 LOS events occurred (2.9 %)• 9 level flight, 25 descending, 8 climbing• Handling of short-term conflict situations needs to be improved

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1.0 2.0 3.0 4.0 5.0

Distance bin at Closest Point of Approach (nmi)

Num

ber o

f LO

S Ev

ents

Simulation/Pilot Error

Controller Error

Controller/Automation

Tactical CD&R / Off-Traj

Traj-Based CD&R

Conflict Detection

Cause

Schedule Conformance

Schedule Conformance was very good in all conditions

Efficiency: Flight Path Deviation

• Lateral path changes for traffic, metering and weather were small• Metering had a marginal impact on path length• Weather had a significant impact

Subjective Feedback: AcceptabilityMany good acceptance ratings, but also some ratings of uncontrollable, especially towards the end of each run.

Subjective Feedback: Function Allocation

Function allocation between controller and automation should be fine-tuned

Subjective Feedback: Impressions

• “…it seemed as if controller and automation fought against each other at times to resolve conflicts.”

• “it seems fairly natural, why not do it?”

• “You’re on the right track.”

• “It’s inevitable, I think the concept is strong, it needs work and testing, I think it’s the way we’re going to go.”

Conclusions

• Air traffic control operations with ground-based automated separation assurance can be an effective and acceptable means to routinely provide high traffic throughput in the en route airspace.

• Certain situations not yet manageable and acceptable in all sectors due to very complex weather/metering interactions

• Additional research, technologies and procedures required and underway to address this

• Positive feedback on concept and function allocation from participants