RolesResponsibilities for Surface Domain Controllers under Precision taxiing

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Roles/Responsibilities for Surface Domain
Controllers under Precision taxiing

• Savvy Verma, NASA Ames Research Center
• Thomas Kozon, NASA/Raytheon
• Victor Cheng, Optimal Synthesis Inc.
• Debbi Ballinger, NASA Ames Research Center
• 3rd Surface Management Workshop
• NASA Ames Research Center, California
• Oct 30- Nov 1, 2007

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Agenda

• Background
• Precision Taxiing Concept
• Previous Study
• Objective
• Method
• Controller area of responsibility
• Results /Issues
• Goals/Objective
• Methodology
• Results
• Summary

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Concept- Precision Taxiing
Surface Automation
Flight Deck Automation
Flight-deck Automation for Reliable Ground
Operation
Air Traffic Controller
Cockpit Crew
Communications
Aircraft Control FARGO
STM Automation GoSAFE
Aircraft Dynamics
Navigation
Surveillance
Ground-Operation Situation Awareness and Flow
Efficiency
Other systems
www.optisyn.com
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Concept Precision TaxiingSurface Automation
Prototype Tool
Clearance Text Segmented

• Plan-View Display
• Surveillance
• Route editing
• Clearance alerts
• Conformance alerts

Node-Traffic Time Lines
Node-Traffic Load Graphs
Clearance Status
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Concept Precision TaxiingOperational Procedures
Clearance by voice say segment number
Mixed
Acknowledgement
Clearance via data link
Datalink
Acknowledgement
GoSAFE
FARGO
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Previous Study

• Objective
• To introduce new automation for precision
  taxiing with the purpose of
• studying human factors issues,
• procedures, and
• identifying requirements for the concept and the
  tool.
• Method
• High fidelity tower simulator, air traffic
  simulator and surface prototype tool were used.
• 4 controller participants.
• DFW East Tower.
• 150 traffic levels simulated.

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Previous StudyControllers Areas of
Responsibilities
LE1
17C
17R
GE1
13L
LE2
Local handles traffic on active runways, and
taxiways in between
Ground handles traffic on taxiways
17L
GE2
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Previous StudyIssues with roles of controllers

• Imbalance in workload due to introduction of
  surface automation
• Local-1 controllers experienced higher workload
  than the other three controllers (statistically
  significant)
• Handled practically every aircraft on the surface
• Ground- 2 controllers experienced the lowest
  workload among the four positions due to Surface
  Automation
• Arrivals from 17L were cleared to the gates by
  Local controller
• GE2s task was that of a monitor

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• Current Study

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Current StudyObjectives

• Objective Redesign areas of responsibility to
  balance workload across controller positions,
  while surface automation for precision taxiing is
  deployed.
• Previous Research
• Sharing control for active runways increases
  communication and coordination loads.
• Splitting control for active runways in the north
  south direction works better than the east west
  direction

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Current StudyNew Controller Responsibilities
LE1
17C
17R
GE1
13L
LE2
17L
GE2
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Current StudyMethod

• Three Integrated Simulators at NASA Ames Research
  Center
• (1) Tower Simulator (2) Air Traffic
  Simulator (3) Surface Automation Prototype Tool
• Participants Four controllers
• Airport Simulated
• DFW East ATC Tower, South Flow airport
  configuration
• Mixed Usage of runways to support parallel
  arrivals on 17R and 17C.
• Three Traffic Scenarios arrival rush, departure
  rush, and departure rush followed by arrival
  rush
• Traffic demand set at 150 of current-day levels
• Arrival flights started at 12 nautical miles out
• Departure flights ended at 5 nautical miles after
  takeoff
• Conditions
• Mixed voice and datalink (5 runs)
• Datalink datalink only (5 runs)

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Current StudyData Collection

• Workload
• NASA Task Load Index (TLX) Multi-dimensional
  rating procedure using six sub-scales.
• Workload Assessment Keypad (WAK) Workload
  assessed every 5 minutes during the simulation
  run using electronic key pad.
• Situation Awareness
• Situation Awareness Rating Scale (SART)
  Multi-dimensional rating procedure using ten
  sub-scales.
• Communications
• Number of Controller Issued Voice Clearances.
• Voice Channel Occupancy Percentage of Radio
  Frequency Occupied Relative to the Total Duration
  of the Simulation Run.

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Current StudyHypotheses

• The change in responsibilities of the controllers
  will
• Equally distribute the workload among the
  controller positions
• Maintain similar Situation Awareness levels
  across positions
• Equally distribute communication loads among the
  controller positions
• due to the presence of the automation

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• Selected
• Results

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Workload (TLX)
mean response (1 low 7 high)
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Workload (TLX)

• Previous study
• - Significant (p lt 0.05) position effects on
  5 of the 6
• TLX workload measures unbalanced
  workload distribution
• (1) LE1 most overworked
• (2) GE2 most underworked
• Current study New surface areas of controller
  responsibility
• Workload more evenly distributed across the four
  controller positions (LE1, LE2, GE1, GE2) with
  the largest impact on LE1 and GE2
• Significant (p lt 0.05) position effect on only 1
  of the 6 TLX workload measures re-balanced
  workload distribution

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Workload (TLX) LE1 and GE2
LE1 Controller Local East 1
GE2 Controller Ground East 2
Some increase in workload may prevent vigilance
decrement
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Workload (WAK)

• Statistically Significant (F15.83, plt.05)
• Areas of Responsibility by Position
  Interaction Effect
• WAK Results Consistent with TLX Results

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Situation Awareness

• Overall situation awareness improvement indicated
  across all 10 situation awareness variables
• Situation awareness improvement found to be
  statistically significant (plt 0.05) among
  several variables

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Situation Awareness LE1 and GE2

• Areas of responsibility by position interaction
  effects observed on 5 of the situation awareness
  measures (p lt 0.05)

LE1 Controller Local East 1
GE2 Controller Ground East 2
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Voice Communication Activity
Mean number of voice transmissions

• Voice communication activity more equally
  distributed across positions
• ( statistically significant position
  effect plt0.05)
• Overall decrease in number of voice transmissions
• Similar trends were observed with percentage of
  voice channel occupancy analysis results

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Summary / Conclusions

• Areas of controller responsibilities were
  redistributed and evaluated
• The automation aided in splitting the active
  runways without increasing controller workload
  and amount of communication
• Improved distribution of
• (1) workload
• (2) frequency congestion
• (3) situation awareness
• among the controllers was observed
• Areas of responsibility were redistributed in a
  way that balanced workload, while deploying new
  surface automation for precision taxiing

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Future Research

• Examination of different areas of
  responsibilities
• Examination of controllers ability to deal with
  off-nominal events
• Use of test beds other than DFW

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THANK YOU !!
Image provided by the FAA

• Savvy Verma saverma_at_mail.arc.nasa.
  gov
• Thomas Kozon tkozon_at_mail.arc.nasa.gov
  
• Victor Cheng vcheng_at_optisyn.com
• Debbi Ballinger dballinger_at_mail.arc.na
  sa.gov

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• Back up slides

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4D Trajectory Clearances
Complete route broken into segments
Timing constraints
Contingency hold
EFG381 1 TAXI VIA K/Z (L_at_ . . .)(17R_at_ . . .)
HS 17R. 2 TAXI VIA Z (M_at_ . . .)(17C_at_ . . .)
HS 17C. 3 TAXI VIA Z/P (R_at_ . . .)(13L_at_ . .
.) HS 13L. 4 TAXI VIA P CLD 13L.
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Sample Results

• Voice vs. Data-Link Clearances
• Data-link clearances easier to handle
• Possibly artificial effect on voice clearances
  due to pseudo-pilots take longer than needed to
  respond when controlling multiple flights
• Handoffs Voice, Data Link, Published/Automatic
• Preferred published/automatic handoffs
• Replanning for New Clearances
• Graphical route editing too time-consuming
• Replanning timing constraints needed to keep
  traffic moving when controllers missed issuing
  timed clearance
• Controller Roles and Responsibilities
• Option of sharing runway responsibility/jurisdicti
  on
• Acceptable, but only with automation

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Sample Results (contd.)

• Impact on Controller Workload
• Periodically report perceived workload using a
  workload assessment keypad
• NASA Task Load Index (TLX) at end of runs
• Perceived workload significantly reduced under
  advanced automation conditions
• Information Requirements and Presentation
  Research Issues
• What type of information would benefit the
  controllers understanding of the intent of the
  automation system
• How to present the information to the controllers
  so that the controllers can act on the GoSAFE
  events in a timely manner.
• Results to be Presented
• AIAA Modeling and Simulation Technologies
  Conference and Exhibit (MST), Hilton Head, SC,
  August 20-23, 2007.
• Human Factors and Ergonomics Society's 51st
  Annual Meeting (HFES), Baltimore, MD, October
  1-5, 2007.

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Guidance Trajectory Generation

• Convert clearance into time history
• Clearance Processing function converts clearance
  to route of nodes arcs
• Construct trajectory from nodes, etc.?as a
  complete function of time
• Requirements
• Airport geometry Observes conventions in
  Airport Design, FAA Advisory Circular AC
  150/5300-13
• Physical constraints
• Performance characteristics per aircraft type
• Surface conditions
• Operational procedures