Surveillance and Broadcast Services

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Surveillance and Broadcast Services

• ADS-B In-Trail Procedures

Presented to the ASAS TN 2.5 Workshop November
2008 Kenneth M. Jones FAA Surveillance and
Broadcast Services Program Office
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ADS-B In-Trail Procedures

• The Aviation Rulemaking Committee (ARC)
• ARC encouraged SBS Program to examine how
  operational benefits of ADS-B could be optimized
  before compliance with a nationwide ADS-B mandate
• Objective
• Develop a globally accepted, airborne ADS-B
  application that provides operational benefits
  prior to required compliance with the ADS-B
  mandate
• Approach
• Conduct an operational evaluation of ADS-B ITP
  that delivers more efficient oceanic operations
• Anticipated Outcomes
• Insight into the operational aspects of airborne
  ADS-B
• Catalyst for change to regulatory process
• Validate economic benefits of ADS-B ITP
• Provide a growth path to future applications

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ADS-B In-Trail Procedures Following Climb Example

• ADS-B In-Trail Procedures are airborne ADS-B
  enabled climbs and descents through otherwise
  blocked flight levels

FL360
FL350
FL340
Standard Separation
blue ADS-B transceiver and onboard decision
support system red ADS-B out minimum required

• ADS-B In-Trail Procedures
• ADS-B ITP separation standard relies on airborne
  ADS-B data evaluated by the flight crew which
  permits climb request
• Controller retains separation responsibility and
  approves clearance based on knowledge of complete
  traffic situation
• No airborne monitoring during climb required

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In Trail Procedure (ITP)
ADS-B In-Trail ProceduresStandard Climb vs ITP
Climb
Current Separation
ALLOWED
BLOCKED
FL360
Desired Altitude
FL350
FL340
blue ADS-B transceiver and onboard decision
support system red ADS-B out minimum
required white no ADS-B requirements
Sequence of Events Status
Pilot requests following climb
Unable
ATC verifies std climb criteria
Valid
Pilot verifies ITP climb criteria
Pilot requests ITP climb from ATC
ATC verifies ITP climb criteria
Valid
Approved
ATC grants ITP following climb
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ADS-B In-Trail Procedures Development Activities

• Concept and Standards Development
• RTCA/EUROCAE Requirements Focus Group (RFG)
• Airborne Traffic Situation Awareness ITP
  (ATSA-ITP) Safety, Performance and
  Interoperability Requirements (SPR) Document
• Interoperability requirements, Operational and
  Service Environment Description (OSED),
  Operational Safety Assessment (OSA), Operational
  Performance Assessment (OPA)

Approved Summer 2008!
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ADS-B In-Trail Procedures Concept and Standards
Development

• ICAO Separation and Airspace Safety Panel (SASP)
• Adopted ADS-B ITP as part of their work package
  in November 2006
• Developed ADS-B ITP collision risk analysis
  (approved by SASP October 2008)
• Longitudinal Separation subgroup has proposed an
  amendment to ICAO Doc. 4444 (PANS ATM) for ITP
• Still requires broader ICAO approval

Approved by SASP October 2008!
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ADS-B In-Trail ProceduresRetrofit Display Option

• ADS-B applications require an appropriate crew
  interface
• Options for interface include primary field of
  view (e.g. PFD), forward field of view (e.g.
  EICAS) or other secondary fields of view (e.g.
  EFB)
• EFB chosen as a potentially lower cost retrofit
  option
• Display Development
• Initial display designs conceptualized
• Survey distributed to 1500 oceanic line pilots
  design revised based on the 250 survey responses
  received

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ADS-B In-Trail ProceduresConcept Validation
Study Flight Crew Perspective

• Research Objectives
• Assess the Validity of the ITP
• Assess Pilot Acceptability of the ITP
• Part-Task Human-In-The-Loop Experiment
• Conducted in ATOL September 2006
• 26 pilots over a 4 week period, 16 experiment
  scenarios flown
• Participants were 777 and/or 747-400 pilots with
  current oceanic experience

• Results
• Procedure was rated as both valid and acceptable
• Workload similar to standard level changes (no
  significant increase)
• Pilots found the increased situation awareness
  provided by display very useful
• Results available as NASA TP 2008-215313

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ADS-B In-Trail ProceduresConcept Validation
Study Controller Perspective

• Research Objectives
• Assess whether ITP is valid from the perspective
  of an air traffic controller
• Assess whether ITP is acceptable to air traffic
  controllers
• Experiment conducted in Airservices Australias
  TAAATS simulation facility
• 12 controllers from two different procedural
  sectors
• Each controller dealt with multiple ITP scenarios
  in three 50 minute sessions
• Preliminary results
• Workload is no higher than current day operations
• Most controllers thought they would use it more
  than once per shift
• Recommendations for ITP phraseology were
  suggested
• Would prefer preformatted CPDLC messages to free
  text
• ITP could be acceptably applied using VHF voice

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ADS-B In-Trail Procedures Operational
Evaluation/Trial

• Goal of Operational Evaluation of ITP
• Conduct ITP operations in an oceanic environment
  on revenue flights
• Objectives of Operational Evaluation of ITP
• Validate operational performance of ADS-B ITP
• Assess economic benefits of ADS-B ITP
• Establish framework for global ADS-B ITP
  implementation and follow-on airborne ADS-B
  applications
• Initial operations in the SOPAC
• Favorable business case
• DO-260 signal issues appear manageable
• Migrate to the PACOTS
• Appears to be a significant, compelling benefit
  mechanism
• Significant traffic interactions
• Substantial fuel savings potential
• Variety of aircraft types

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ADS-B In-Trail Procedures SOPAC Business Case

• About 10 of flights remain within 60nmi and
  4,000 ft from other traffic for longer than 1 hr
• Traffic interactions are infrequent and very hard
  to predict
• Consequently, variations in fuel burn can be
  significant
• Flights board contingency fuel to avoid unplanned
  fuel stops

January 2004

• Benefit mechanism assumptions
• Flights operate MTOGW reduction in contingency
  fuel replaced with additional cargo revenue
• Airline policy decision to carry less contingency
  fuel
• Statistical analysis has shown that in the SOPAC,
  an airline could choose to keep the same risk of
  unplanned fuel stops and board 300 lb less fuel
  with ITP
• 300 lb contingency fuel reduction results in a
  benefit per equipped aircraft of approximately
  202K/year potentially more
• Return on Investment for a carrier one year!

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ADS-B In-Trail Procedures Operational
Evaluation/Trial Technical Issues

• Certification and verification of DO-260 signal
• Current business case assumes a certified DO-260
  signal
• Need to verify the signal is coming from an
  approved system or to verify the integrity of the
  signal received

• Electronic Flight Bag (EFB)
• Assumed an EFB installation for retrofit aircraft
• Guidance indicates Class III EFB is the best
  solution

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Enhanced Oceanic OperationsPhased Approach

• Phase 1 ADS-B In-Trail Procedures
• Flight level changes allowed based on cockpit
  derived data
• No delegation of separation authority to the
  flight deck
• Increased situation awareness
• Phase 2 Limited, Delegated Oceanic Separation
  Procedures
• Enhanced ITP (ASEP-ITP)
• Limited delegation of separation authority to the
  cockpit during the maneuver
• Simplified procedure, reduced separation distance
• In-Trail Follow Procedures (ASEP-ITF)
• Reduce co-altitude separation distances
• Pair-wise separation using spacing techniques
• Potential for big payoff in the North Atlantic
• Phase 3 Airborne Self-Separation Corridors
  (SSEP-ITP)
• Aircraft allowed to self-separate on approved
  corridors
• Potential for Significant Fuel Savings in Phases
  2 and 3!

Increased Delegation of Separation to the Flight
Deck
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ADS-B In-Trail Procedures Summary and Next Steps

• Summary
• ITP is cost beneficial to airlines in the Pacific
• ITP using certified DO-260 signal produces an
  early payback in the SOPAC
• An 747-400 with a certified ADS-B ITP system will
  receive immediate benefit in the SOPAC and be
  ready for use in other areas when authorized
• Next Steps
• ANSP and private sector partnership development