Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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The Free Flight Deck
Society of Automotive Engineers (SAE)
S-7, “Flight Deck and Handling Qualities Standards for Transport Aircraft”
Amsterdam, 1 May 2000
Rob Ruigrok, Jacco Hoekstra, Ronald van Gent
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Presentation Overview Introduction to Free Flight
Design of the Free Flight Deck– Starting points– Airborne Separation Assurance System
Using the Free Flight Deck:– NLR studies on Free Flight with Airborne
Separation Assurance
Conclusions and Recommendations
Future Plans
Demonstrations
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Introduction to Free FlightRTCA definition: zones
Protected zone:– spatial, according
operational separation standards
– expected to remain free of other aircraft
Alert zone:– spatial or time based
zone around the protected zone
– conflict alerts are issued to the pilot
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Introduction to Free FlightEurocontrol’s definition
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Design of the Free Flight DeckStarting points
Operational Concept (probe the limits)– No Air Traffic Control– Air crew responsible for traffic separation– Focus on Free Flight Airspace– Central Traffic Flow Management active– Managed Airspace near airports (TMA)
Cruise flight only– Direct routing– Optimal cruise altitude
Limited scope– No Special Use Airspace (SUA)– No weather
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Design of the Free Flight DeckWhat do we need ?
Aircrew has to:– “see” other traffic– determine conflicts with other aircraft– resolve conflicts with other aircraft– avoid new conflicts with other aircraft– be alerted
Airborne Separation Assurance System (ASAS)
Investigate minimum standard:– flight deck design based on, and close to current
implementation (EFIS, FMS, TCAS)
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Design of the Free Flight DeckASAS equipment
“See” other traffic– Automatic Dependent Surveillance - Broadcast
(ADS-B), Traffic Information Service - Broadcast (TIS-B)– Cockpit Display of Traffic Information (CDTI)
Determine and resolve conflicts with other aircraft– Conflict Detection and Resolution (CD&R)
Avoid new conflicts with other aircraft– Predictive ASAS (PASAS)
Be alerted– Alerting logic
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Design of the Free Flight DeckConflict definition
A conflict is defined as a potential intrusion of the protected zone in the near future
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Design of the Free Flight DeckConflict Detection & Resolution
ownship
intruder
minimum distance
protected zone intruder
avoidance vector
advised vector
1. heading change
2. speed change
not shown: 3. vertical speed change
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Design of the Free Flight DeckCockpit Display ofTraffic Information
Navigation Display– Traffic Symbology– Conflict Detection– Resolution Advisories– Vertical Navigation
Display– Extra EFIS Control
Panel functionality
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Design of the Free Flight Deck Predictive ASAS
“no-go” bands for– track/heading– vertical speed– speed
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Using the Free Flight DeckNLR studies on Free Flight
Studies on Airborne Separation Assurance, the flight deck perspective:– Conceptual design and off-line validation– Safety analysis– 1997 human-in-the-loop experiment– Cost/benefit analysis– Avionics requirements study– Critical conflict geometry study– 1998 human-in-the-loop experiment
In co-operation with NASA, FAA and RLD
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Using the Free Flight Deck1997 human-in-the-loop experiment Traffic Densities:
– Single– Double– Triple
Level of Automation:– Manual– Execute Combined– Execute Separate
Non-Nominal:– Other aircraft failures/events– Own aircraft failures/events– Delay time increased
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Using the Free Flight Deck1997 human-in-the-loop experiment
Acceptability: – 91.5% (single), 83.0% (double), 78.7% (triple)
Safety: – 88.3% (single), 75.5% (double), 71.3% (triple)
Workload:– ratings less than 40, indicating “costing some effort”
Across all densities, across all sessions, across all subject pilots, including non-nominal events
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Using the Free Flight Deck1998 human-in-the-loop experiment
Goals– study the transition to Free Flight Airspace (in space) – study the transition towards Free Flight in time
Starting points:– equipping aircraft should be immediately beneficial to
the airlines– equipping should be economy driven in stead of
mandatory– benefit the equipped aircraft, without excluding the
unequipped aircraft
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Using the Free Flight Deck1998 human-in-the-loop experiment
Three ATM operational scenarios with Free Flight elements defined, implemented and tested:– Flight Level– Protected Airways– Full Mix
Experiment matrix– Traffic Density - low density versus high density– Equipage - 25% versus 75% ASAS equipped– ATM operational concept - Flight Level, Protected
Airways and Full Mix
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Using the Free Flight Deck1998 human-in-the-loop experiment
> 85% of responses indicate FF acceptable or better
Acceptability, traffic density effect(Airways & Mixed procedure only)
0
20
40
60
80
100
Perfect Favorable Acceptable Undesirable Completelyundesirable
Per
cen
tag
e
Medium
High
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Using the Free Flight Deck1998 human-in-the-loop experiment
> 85% of responses indicate FF as safe or safer than ATC Safety, traffic density effect
(Airways & Mixed procedure only)
0
20
40
60
80
100
FF muchsafer
FF safer Same ATC safer ATC muchsafer
Per
cen
tag
e
Medium
High
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Using the Free Flight Deck1998 human-in-the-loop experiment
Workload measurement: – Subjective by means of
questionnaires with Rating Scale of mental Effort (RSME)
– Objective by means of Eye-Point-Of-Gaze measurements
Scan randomness (entropy) used as objective metric for workload
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Using the Free Flight Deck1998 human-in-the-loop experiment
Workload: sensitive to ATM operational scenario
Pilot objective workloadTwo-way interaction of ATC
procedure and equipage (p<0.048)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Equipage 25% Equipage 75%
Equipage
Entr
opy
(Z-s
core
)
Protected AirwaysFull Mix
Pilot subjective workloadTwo-way interaction of ATC
procedure and equipage (p<0.076)
-1
-0.8
-0.6
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1
Equipage 25% Equipage 75%
Equipage
RSM
E (Z
-sco
re)
Protected AirwaysFull Mix
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Conclusions and Recommendations
The feasibility of Free Flight with Airborne Separation Assurance could not be refuted , based on 7 NLR studies on Free Flight
The future ATM design has to be chosen very carefully, since the design itself affects pilot and controller workload considerably
The flightdeck crew was able to handle much higher traffic densities than the ground controller(distributed versus centrally organised nature)
Free Flight might be a solution for current airspace capacity problems
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Future Plans
Human Interaction Experiment, using Internet gaming facilities (scheduled June 2000)(we need many volunteering pilots for this, to register please contact [email protected] or [email protected])
Flight testing of ASAS equipment, using “real” data– using NLR and possibly NASA laboratory aircraft
Simulation experiments to study:– the effect of real ADS-B characteristics– the use of Free Flight equipment in Managed Airspace– the integration of traffic, weather and terrain information
in the cockpit
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Demonstrations Research Flight Simulator: Free Flight demo
NLR’s ATC Research Simulator NARSIM
NLR’s Research Flight Simulator - Next Generation
Nationaal Lucht- en RuimtevaartlaboratoriumNational Aerospace Laboratory NLR
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Contact / More information
NLR Free Flight web site:http://www.nlr.nl/public/hosted-sites/freeflight
E-mail/phone:Rob Ruigrok: [email protected], +31 20 511 3595Jacco Hoekstra: [email protected], +31 20 511 3775Ronald van Gent: [email protected], +31 20 511 3760
Mail:Nationaal Lucht- en RuimtevaartlaboratoriumAnthony Fokkerweg 21059 CM AmsterdamThe Netherlands