Free Flight with Airborne Separation Assurance

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• Free Flight with Airborne Separationwill result
  in an uncontrolled, dangerous junglewithout a
  firm central controlling elementsuch as ATC.

• Pilots havent got the time, the training nor
  the mental resources available tofunction as ATC
  on top offlying the aircraft.

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NASA/FAA/RLD/NLRFree Flight study

• Jacco Hoekstra (hoekstra_at_nlr.nl)
• Ronald van Gent
• Rob Ruigrok

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Free Flight goals

• Reduce Costs via user preferred routing
• Horizontally
• direct to destination
• optimum speed
• Vertically
• optimum level
• cruise climb
• More capacity

4
Operational concept

• No ATC
• Probe the limits for HF problems
• All aircraft fully equipped
• Linked via e.g. ADS-B
• EFIS-CDTI
• Full user preferred routing
• Direct routing
• Optimal cruise altitude

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1997 Three sub-studies

• CONCEPTUAL DESIGNTool Traffic Manager Off-line
  simulations
• Find a suitable base-line concept
• SAFETY ANALYSISTool TOPAZ (Traffic Organization
  and Perturbation AnalyZer)
• Compare safety of Airborne Separation with safety
  ATC
• MAN-IN-THE-LOOP EXPERIMENT phase ITool Research
  Flight Simulator
• Validation of concept with Man-in-the-Loop
• Man Machine Interface Validation

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1998 Four sub-studies

• CONFLICT GEOMETRY STUDYTool Traffic Manager
  Off-line simulations
• Check critical geometries wall, etc.
• AVIONICS STUDYLiterature survey
• Check requirements for RNP, ADS-B etc.
• COST-BENEFITS PERFORMANCETool Traffic
  Manager Off-line simulations
• Costs of conflict resolution
• MAN-IN-THE-LOOP EXPERIMENT phase IITool
  Research Flight Simulator
• Validation of PredASAS mixed equipage

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1999 Three activities

• DISSEMINATIONConferences, Web site, Contract
  report, RTCA, ICAO
• Explain results obtained so far
• DATA ANALYSIS phase II trials- Analysing data
  generated in phase II trials
• DEVELOPMENT HUMAN INTERACTION EXPTool Traffic
  Manager, Freesim internet
• Effect of competition

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2000 Current and future activities

• HUMAN INTERACTION EXPERIMENTTraffic Manager,
  FreeSim, internet- High number of participants,
  humans vs models, competition
• PHASE III FLIGHT SIMULATOR TRIALSNLR simulator,
  NASA Langley Simulations, HIE cfg(?)- How low
  can you go? From cruise to final incl. SUA,
  weather, RTA
• Continue dissemination effortsWeb site,
  symposia, conferences, RTCA, SAE, (IF)ALPA

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Traffic Experiment Manager
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Result Traffic Manager simulations

• Resolution advisoriesSeveral concepts studied
• Altitude step
• Cross product of speed vectors
• Extended VFR rules (not implemented)
• Variations of TCAS manoeuvres
• Voltage potential
• Co-operative manoeuvring vs. priority
• Minimal bandwidth/HF no intent in Conflict
  Detection

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Conflict Detection Resolution
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Complex Conflict geometries

• Wall scenarios, super conflict (n
  4,8,10,12,16) and crossing the street

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Man-in-the-loop Simulation Configuration
RFS
AIRSIM
TEM
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Traffic Symbol added to ND

• Symbology on Navigation display based on data
  available via ADS-B
• Track indicated with arrow shaped symbol instead
  of track line to avoid clutter
• Label text selectable with de-clutter switches
• Call sign added to label of traffic symbol for
  inter-trafficand crew communication

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Conflict Detection Resolution

• Symbology based on resolution algorithm
• Provides insight into resolution
• Colour indicates urgencyAmber 3 - 5 minRed
  0 - 3 min(time to loss of separation)

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Navigation Display
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Man-in-the-Loop experimentHypotheses

• First explorative HF experiment, so probably
  using simple Mk 1 system would yield
• Less than acceptable
• Subjectively less safe
• More workload
• Result MMI problem areas

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Man-in-the-Loop experimentResults -
Acceptability
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Man-in-the-Loop experimentResults- Subjective
Safety
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Man-in-the-Loop experimentResults
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Task comparison Controlled vs. Free Flight
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Predictive ASAS

• Calculates which track, vertical speed and speed
  selections will result in a conflict within the
  look ahead time
• Predicts a conflict by the red/amber zone moving
  to the actual values
• Indications do not require pilot actions

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Predictive ASAS

• Dont go indications
• Track
• Vertical speed
• Speed

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Preliminary conclusions PASAS

• With predictive ASAS even conflict alerts could
  be avoided
• Enhances situational awareness
• Might provide solution without use of intent
  information for Free Flight!

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Mixed equipage ATM concepts

• Flight Level divisionAbove FF level only
  equipped aircraft
• Protected AirwaysControlled aircraft should
  stay on airways and have right of way
• Fully MixedATC uses longer look ahead time,
  so equipped aircraft have effectively right of
  way

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1998 NASA / FAA / RLD Results Workload Airborne
Subjective
Objective
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1998 NASA / FAA / RLD Results Workload Ground
F(2,8) 9.7, Plt .008
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1998 Man-in-the-loop Conclusions

• The future ATM design has to be chosen very
  carefully
• Full Mixed ATM condition is best from the pilots
  perspective
• Protected Airways ATM condition is sensitive to
  equipage level (transition in time)
• Flight Level ATC condition is most optimal from
  Air Traffic Controllers perspective (Hilburn,
  Pekela)
• The flight deck crew was able to handle higher
  traffic densities than the ground controller

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Current men-in-the-loop experimenthuman
interaction experiment

• Logging into Traffic Manager via internet using
  downloadable FreeSim flight simulation program

• Goal Test effect of
• humans vs models
• competition

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Airport on FF perspective bad news(?)

• Dramatic airspace capacity increase in FF
  airspace (en-route) gt airports will be
  bottleneck (again)

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Airport perspective on FF good news

• ASAS equipment (especially traffic display) could
  facilitate more efficient use under IMC of
• airspace (curved, merging, station keeping)
• runways (concurrent use of parallel and crossing
  runways)
• taxiways (showing other a/c and ground vehicles)
• gt potential to increase sustained capacity

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More information

• Web site http//www.nlr.nl/public/hosted-sit
  es/freeflight
• Comprehensive report on overall studies
  1997-1999Will soon be published. Check web site
  for downloads!
• Demo sessions of human interaction experiment
  configuration will be announced on the website