11 satellites in each of 6 polar orbits aireon ads-b...
TRANSCRIPT
Reduced Separation in US Oceanic AirspaceBenef i ts Analys is through Fast -Time Model ing
Presented by: Dan Howell, Rob Dean, and Joseph Post
Date: 6/20/2019
This work was supported by FAA Surveillance and Broadcast Services through contract 693KA9-18-D-00010
ASEPS Project Overview
2Reduced Separation in US Oceanic Airspace
• The Surveillance & Broadcast Services Advanced Surveillance Enhanced Procedural Separation (SBS ASEPS) Project has been investigating the use of reduced oceanic separation to enhance operations in US oceanic airspace
➢ Space-based ADS-B (SBA)
➢ Automatic Dependent Surveillance – Contract (ADS-C, more frequent update)
• Goal: Increase the efficiency and capacity of operations in Oceanic Flight Information Regions (FIRs) through surveillance enhancements for reduced oceanic separation standards
• FAA has been conducting a cost-benefit analysis of increased ADS-C reporting and SBA
Iridium NEXT Satellites
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• 66 cross-linked satellites in Low Earth Orbit (LEO) 11 satellites in each of 6 polar orbits
• Aireon ADS-B receiver hosted payload
SpaceX Falcon 9
Oceanic Communications and Surveillance Operational View
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GNSS
Inmarsat/Iridium
ATC Facility Service
Provider
ADS-C
Iridium NEXT
Service
Provider
ADS-B
HF Voice
CPDLC
Comm Nav Surveillance
US Oceanic Airspace
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Benefits of Improved Oceanic Surveillance
• Improved Accommodation of altitude requests
• Improved arrival/departure services at non-radar airports
• Reduced Vertical Collision risk
• Reduced convective weather impact
• Improved accommodation of descents, routing, and speed requests
• Improved controller situational awareness
• Accurate and timely information for search and rescue
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Benefits of Improved Oceanic Surveillance
• Improved Accommodation of altitude requests
• Improved arrival/departure services at non-radar airports
• Reduced Vertical Collision risk
• Reduced convective weather impact
• Improved accommodation of descents, routing, and speed requests
• Improved controller situational awareness
• Accurate and timely information for search and rescue
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Improved Accommodation of Altitude Requests
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Oceanic Entry
Altitude (FL310)
Filed Cruise
Altitude
(FL350)Intermediate Step
Altitude (FL330)
New York Oceanic Boundary
Step climb
blocked (conflict)
Successful
Climb Initiated
Altitude
Profile
• Oceanic flights often long
• Strong desire to minimize fuel
• Higher altitudes generally result in higher fuel efficiency
• Aircraft frequently take off very heavy and cannot reach optimal altitude until some fuel is burned off
• Once aircraft are light enough, they often want to climb to reach a more fuel-efficient altitude
• Competition for optimal altitudes frequently occurs
Reduced Separation in US Oceanic Airspace
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Altitud
e (ft
)
Position Report Number
My Flight to Europe
Step Climbs and
Surveillance Gap
My Flight (PHL-LHR June 15)
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*www.flightaware.com
Simulation Model & Methodology
• Global Oceanic Model (GOM)
➢ Fast-time simulation tool developed in MATLAB for examining fuel burn and flight time in oceanic airspace
➢ Time-based model that simulates individual aircraft from origin to destination along specified paths
➢ Randomness built into model through aircraft takeoff mass and equipage levels
➢ Produced under partnership between FAA and Virginia Tech
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•Representative Days
•Growth Assumptions for future demandFlight Schedules
•ADS-B Out
•FANS (ADS-C + CPDLC)Aircraft Avionics
•Historical Flight Plans
•Existing Route StructureRoutes
•Historical Altitude Request Information
•Magnitude of altitude changesAltitude Request
Information
•BADA Performance Model
•Takeoff weight estimatesAircraft Performance
•Carrier Fleet Forecasts
•Future aircraft typesFleet Evolution
•Current and Future Separation Standards
•Types of resolutions used in oceanSeparation And Conflict
Management Data
Global
Oceanic
Model
Modeled Trajectories
Summary Metrics
Reduced Separation in US Oceanic Airspace
Current Oceanic Environment
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• Advanced Technologies and Oceanic Procedures (ATOP) System
➢ Designed to reduce manual processes controllers have historically used to ensure separation
➢ Processes oceanic aircraft and weather data and calculates separation criteria near instantaneously
➢ Provides efficient track and altitude alternatives through Conflict Prediction and Reporting (CPAR)
• Mixed equipage leads to varying separation minima
➢ Current standards lead to high likelihood of preferred routings and altitudes, but expected increases in traffic in future will impact this
• Procedural Separation and Control
➢ “Control By Exception”: Procedural separation whereby controller notified of possible separation situation when there is an actual or predicted violation. Controller does not continuously monitor aircraft positions and altitudes as with tactical separation in a radar environment
➢ ATOP uses 2 hour lookahead for conflicts and controllers are expected to resolve conflicts that will occur 30 minutes or less in the future
FANS Equipage• Future Air Navigation System (FANS)
interfaces with ATOP and includes
avionics to support Performance-Based
Navigation, Data Link, and ADS-C position
reporting
• FANS equipage is primary constraint of
SBA-usage since ADS-B Out (required)
will soon be mandated in US airspace
• Current FANS equipage levels (by aircraft
type) were obtained from an analysis of
flight plans provided by MITRE
• Logistics curve fitted to the percentage of
Datalink equipped aircraft time trend in
each ocean to specify overall equipage
levels for future years
• FANS equipage randomly assigned to
unequipped flights until overall target level
was achieved
• Remaining unequipped flights passing
through Gander, Shanwick, and Santa
Maria were equipped to reflect upcoming
mandate
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Separation Standards and Schedules
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Aircraft Equipage Legacy CaseMore Frequent
ADS-CSBA
FANS via SATCOM
with RNP30/30 NM 23/23 NM 15/15 NM
No FANS 50/80 NM 50/80 NM 50/80 NM
•Separation Standards for US Oceanic Airspace
Reduced Separation in US Oceanic Airspace
•Schedules And Traffic Growth
➢20 representative days from FY16 used
in model
➢2016, 2020, 2025, 2030 and 2035 were modeled
➢Results linearly interpolated for intervening years
➢Using current FAA policy on traffic growth for investment decisions, growth was capped in 2028 based on a 10 year sliding window.
Aircraft Altitude Requests• In controlled airspace, aircraft must
request an ATC clearance to deviate from their assigned altitude
• Historical altitude requests and requests cleared were analyzed in ZAN/ZOA and ZNY
• A regression was used to determine whether pilot requests increased as a result of separation changes in ZNY and ZAN
➢ Two independent variables: monthly trend variable and separation change variable
➢ ZNY: Change was significant, indicated a 15% increase in requests handled over the previous average
➢ ZOA/ZAN: 11% over the previous average
➢ Monthly trend variable was not significant in Atlantic, negative in Pacific
• A similar increase in altitude requests was applied in GOM to approximate possible effect of reduced separation on pilot behavior
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Other Model Considerations
• Aircraft Performance
➢ Base of Aircraft Data (BADA) model used
➢ Assumes nominal take-off weight related to aircraft type and distance to be flown
➢ No consideration of actual flight planning process
• Fleet Evolution
➢ SWAC model incorporates a fleet evolution algorithm that replaces old aircraft types with newer ones as specified by FAA’s Carrier Fleet Forecast for 2016-2037
➢ Some types are not supported in GOM. In these cases, we assumed an increase in fuel efficiency of 40% compared to previous type of the same size/range
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Other Model Considerations• Interaction with neighboring FIRs
➢ Agreements with surrounding international Air Navigation Service Providers (ANSPs) are a major factor in how the US controls flights in oceanic airspace
➢ Example: if neighboring ANSP requires higher longitudinal separation than U.S., U.S. controllers must plan and respond appropriately
➢ FAA must consider this when deciding if and when to approve reduced separation standards
• Model Validation
➢ Number of Altitude Change Requests
➢ Percentage of altitude change requests granted
➢ Distribution of flight times and distances traveled across oceanic regions
➢ Distribution of cruise altitudes upon entry to U.S. oceanic airspace
• Limitations
➢ Only conflicts in oceanic airspace considered
➢ No adjustments of wheels-off times for foreign departures
➢ GOM does not model convective weather or turbulence
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Modeled Airspace and Trajectory Data
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Results• 480 simulations conducted to get a full set of results across years,
representative days, oceans, and alternatives
➢ 4 years
➢ 20 unique days
➢ 2 oceans
➢ 3 alternatives
• Annual Direct Fuel Savings (kg)
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SBA Enhanced ADS-C
FY Atlantic Pacific Atlantic Pacific
2020 16,265,582 18,547,428 13,030,382 16,086,360
2025 21,524,161 24,156,380 16,342,274 18,475,954
2030 25,429,404 25,586,382 18,357,171 19,258,831
2035 25,926,102 24,885,958 18,722,780 18,753,088
Reduced Separation in US Oceanic Airspace
Additional Cost-To-Carry Benefit• Oceanic Flights long in duration, ranging up to 14 hours in the Pacific
and 10 hours in the Atlantic
• To account for reduced fuel loading and a consequent additional reduction in fuel burn, we adjusted the results using a method to quantify the incremental fuel impact of reducing takeoff mass[1]
➢Incremental fuel Savings = Weight Savings × flight hrs × 0.005
• Annual Indirect (Cost-to-Carry) Fuel Savings (kg)
19
SBA Enhanced ADS-C
FY Atlantic Pacific Atlantic Pacific
2020 4,259,587 6,013,700 3,441,648 5,226,565
2025 5,575,130 7,865,542 4,302,496 6,000,308
2030 6,587,617 8,312,610 4,847,205 6,281,038
2035 6,695,970 8,070,657 4,927,289 6,106,602
[1] FAA Office of Policy and Plans, “Economic Values for FAA Investment
and Regulatory Decisions, A Guide,” September 2015.
Reduced Separation in US Oceanic Airspace
Results (Graphical)
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Model Variability• Additional runs performed to
examine the variability of the results
➢ Random seed affecting take-off weights built into the model
➢ Manually randomized which flights for a particular aircraft type were equipped when equipage was not 100%
• Developed distribution of ratios between variability and default simulations
➢ Considerable variability (up to 25% in inner-quartile range)
➢ Default results near middle of range
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Conclusions• Results from this analysis suggest that reduced separation in oceanic
airspace produces significant benefits through improved accommodation of altitude requests
• Results vary greatly by airspace volume. Factors include:
➢ Route length
➢ Traffic density
➢ Equipage
• Results sensitive to modeling assumptions
➢ Aircraft gross weight
➢ Avionics capability
➢ Climb Request Behavior
• Continuing to explore the potential for SBA to save fuel and provide other benefits to airspace users and the FAA
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ASEPS Going Forward
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Miami Center
Miami Oceanic
Havana
Port au Prince Santo
Domingo
San Juan
63
62
5860
40
New York Oceanic
ZAN
Anchorage
Oakland
New York
ZAN
ZOAZNY
43
LONG-TERM (5+ years)
MID-TERM (3-5 years)NEAR-TERM (1-3 years)
Reduced Separation in US Oceanic Airspace
Acknowledgements
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THANK YOU
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References▪ ICAO FIR viewer available at website http://gis.icao.int/flexviewer
▪ Lockheed Martin, “Advanced Technologies and Oceanic Procedures (ATOP) Operational Concept,” FAA-ATOP-2004-0395, November 2004.
▪ SBS Program Office, “Concept of Operations Document for Advanced Surveillance - Enhanced Procedural Separation (ASEPS),” SBS-071, Rev. 02, September 2016.
▪ Aireon LLC, Global Air Traffic Surveillance, information available at website: https://aireon.com/services/global-air-traffic-surveillance/, viewed January 2019.
▪ FAA, “14 CFR Part 91 Automatic Dependent Surveillance-Broadcast (ADS-B) Out Performance Requirements To Support Air Traffic Control (ATC) Service; Final Rule,” May 28 2010.
▪ FAA, Air Traffic Organization 2012 Safety Report, 2015.
▪ FAA, ATO Top 5 Fact Sheet, 2015.
▪ Skybrary, Use of Selected Altitude by ATC, 2011.
▪ Aireon LLC, ALERT, information available at website: https://aireon.com/services/aireonalert/ viewed January 2019.
▪ Trani, A., Li, T., Spencer, T., Tsikas, N., Hinze, N., and Gunnam, A., “Global Oceanic Model Development,” presentation to IATA, January 2016.
▪ Cheng, F., Gulding, J., Baszczewski, B., Galaviz, R., Chow, A., “Modeling the effect of weather conditions in sample day selection using an optimization method,” 2012 Integrated Communications Navigation and Surveillance conference, April 2012.
▪ FAA Office of Performance Analysis, “FY2016 Sample Day Selection,” February 10 2017.
▪ FAA Office of Policy and Plans, FAA Aerospace Forecast 2016-2036, website: https://www.faa.gov/data_research/aviation/aerospace_forecasts/.
▪ Post, J., Gulding, J., Noonan, K., Murphy, D., Bonn, J. and Graham, M, “The Modernized National Airspace System Performance Analysis Capability,” 8th AIAA Aviation, Technology, Integration, and Operations (ATIO) Conference, Anchorage, Alaska, September 2008.
▪ Post, J., “FAA Employs New Model in Benefits Calculation,” Journal of Air Traffic Control, Air Traffic Control Association, Washington D.C., Summer 2013.
▪ Eurocontrol, Base of Aircraft Data (BADA) website, available at http://www.eurocontrol.int/eec/public/standard_page/proj_BADA.html
▪ US DOT Bureau of Transportation Statistics, Air Carrier Statistics Database, available at website https://www.transtats.bts.gov/Fields.asp?Table_ID=293
▪ Antonio Trani, “BADA Model,” presentation to FAA, April 15 2016.
▪ FAA Office of Policy and Plans, Fleet Forecast, September 2015.
▪ International Air Transport Association, “IATA Technology Roadmap 4th Edition,” June 2013.
▪ FAA Office of Policy and Plans, “Economic Values for FAA Investment and Regulatory Decisions, A Guide,” September 2015.
▪ FAA, “Air Traffic Control,” FAA Order 7110.65, Washington, D.C., December 2015.
26Reduced Separation in US Oceanic Airspace