Jimmy R. Snow COMMISSIONING THE WIDE AREA AUGMENTATION SYSTEM

2 OVERVIEW  WAAS System/Procedures  WAAS Commissioning Considerations  Ohio University Study  MITRE Computer Modeling  MITRE/Flight Inspection Validation  WAAS Receiver  WAAS Limitations  Future Challenges

3 GNSS RNAV PROCEDURES LPVTakes Advantage of WAAS Capability Equivalent to Localizer Lateral With Vertical Between ILS and LNAV/VNAV, HAT 250 ft & Up LNAV/VNAVVertically Guided Approach With Decreasing Vertical Obstruction Clearance, HAT 350 ft and Up LNAVNon-Precision Approach With 250 ft ROC, Smaller Protected Area Than VOR, No Vertical Guidance CIRCLING Approach Procedure to a runway and then Maneuver to Land on Another Runway

6 Status Of FAA GPS Procedures (9/22/03) Year GPS Proc Published TOTAL LPV 7 LNAV/VNAV Published 613 LNAV Published3,237 Military/Specials 237 GPS Proc Published 4,094

7 WAAS COMMISSIONING CONSIDERATIONS  WAAS Commissioning Date Established Approximately Two Years in Advance  Scheduled on Procedures Publication Date, July 10, 2003  Estimated Over 600 LNAV/VNAV Approaches Published for FMS Baro VNAV Operations  Over 3,000 LNAV Approaches Published for TSO C-129 Receivers  Very Limited WAAS Flight Inspection Capability (Prototype MMR Receiver in Lear 60)  Technical Center WAAS Coverage Chart and Outage Records Used to Restrict Certain LNAV/VNAV Approaches  Numerous Discussions With Certification and Flight Standards

8 WAAS COMMISSIONING OPTIONS  No Flight Inspection or Evaluation of Procedures  Evaluate Each Procedure on Next Periodic (One and Half Years or Longer to Evaluate All)  Surge Effort After WAAS IOC (up to 1,000 Flight Hours)  Non-Traditional Evaluation of Existing Procedures

9 OHIO UNIVERSITY SUPPORT  Initiated Discussions With Ohio University, Avionics Engineering Center May 2001  Established Procedure Parameters With FAA Working Group  Held Discussions With Ohio University to Evaluate WAAS Requirements  Established a Technical Task Directive With Ohio University July 2001 to Evaluate WAAS Commissioning Requirements  Study Delivery Not Later Than Nine Months After Task Signed

10 FLIGHT INSPECTION COMPARISON  GPS/Baro VNAV o Obstacle Evaluation o Standard Instrument Approach Procedure (Section 214) o Procedure Design (Database, Waypoints, Accuracy) o Electromagnetic Spectrum (RFI)  WAAS LNAV/VNAV o Obstacle Evaluation o Standard Instrument Approach Procedure o Procedure Design o Electromagnetic Spectrum o Geosynchronous Satellite Signal

11 OHIO UNIVERSITY CONCLUSIONS  Result Inspection of GPS/Baro VNAV Procedures Should Accomplish All Anticipated WAAS LNAV/VNAV Requirements EXCEPT Ensuring Adequate GEOSAT Signal Coverage  GEOSAT Provides Integrity Information, and Differential Corrections Without, WAAS Receiver Reverts to LNAV Only Capability Thus, LNAV/VNAV Procedures Can Not Be Conducted

12 OHIO UNIVERSITY STUDY ASSUMPTIONS  Assumptions The inherent WAAS monitoring is capable of detecting system faults within the required time-to-alarm The WAAS receiver reverts to a GPS-only capability in the absence of a GEOSAT signal The FAA has authorized WAAS for supporting LNAV/VNAV approach procedures The SIAP procedure has been previously commissioned for GPS/Baro VNAV The availability of GPS/Baro VNAV and WAAS LNAV/VNAV is at least 95 percent The descent altitude is the same for the WAAS LNAV/VNAV and GPS/Baro VNAV procedures There is a high-correlation between predicted (monitoring) and actual WAAS system performance

13 STUDY CONCLUSIONS  ~ 600 GPS/Baro VNAV Procedures Expected to be Commissioned Before WAAS IOC  Inspection of GPS/Baro VNAV Procedures Should Accomplish All Anticipated WAAS LNAV/VNAV Requirements EXCEPT Ensuring Adequate GEOSAT Signal Coverage  Computer-based GEOSAT Coverage Screening Models May be Used to Streamline Flight Inspection Process ( To determine if GEOSAT is shadowed on final approach segment )

14 STUDY RECOMMENDATIONS (1)  The Comparison of GPS/Baro VNAV and WAAS LNAV/VNAV Flight Inspection Requirements Should Be Repeated Once Formal Criteria Are Available in FAA Order 8200  The Feasibility and Benefit of Developing a Screening Model for Assessing GEOSAT Signal Coverage Should Be Assessed Further  Low Confidence Cases, the WAAS LNAV/VNAV Procedure Should Be Flight Inspected Before Being Authorized for Use, Low Priority

15 STUDY RECOMMENDATIONS (2)  Marginal Confidence Cases, the WAAS LNAV/VNAV Procedure Should Be Flight Inspected Before Being Authorized for Use, High Priority  High Confidence Cases, WAAS LNAV/VNAV Operations Authorized and Inspection Performed During Next Periodic Inspection of GPS/Baro VNAV Procedure  For WAAS Procedures Authorized Prior to Formal Flight Inspection, Authorization Should Be Withdrawn if a “Problem Report” Is Received

16 SECOND PHASE COMPUTER MODELING  FAA Contacted MITRE, Center for Advanced Aviation System Development For Assistance (CAASD)  MITRE Advised They Could Modify an Existing Software Program to Do What Ohio University Recommended  Meetings Were Scheduled to Discuss : Establishing an Agreement Between FAA and MITRE Delivery Schedules Evaluation Requirements Data Requirements

17 FAA-MITRE AGREEMENT  AVN Would Provide MITRE the Following: Airport Identifier Airport Reference Point (latitude/Longitude) Airport Elevation Airport Priority for Screening If Available Airport Name and Location  MITRE Will Evaluate Each Airport Using the Following Criteria: Evaluate a point 250 ft Above the ARP From 090 to 270 Degrees o At Least One WAAS GEO is More Than 10 Degrees Above the Horizon o No Terrain Within 40 nm of the ARP More Than 5-deg Elevation Angle Viewed From 250 ft Above the ARP MITRE Would Use Worst-case WAAS GEO Positions MITRE Would Validate the Computer Model and Peer Review Results

18 Elevation Angles in USA and Canada (POR and AOR-W)

19 TERRAIN MASKING: Forty Nautical Miles 10 nm 30 nm Mount Ranier (14,400 ft) 4.5° ARP (Sea Level) FAF (Sea Level) Geo 10° (minimum)

20  An Airport Passing the Screening Test Will Not Have Geo Masking Due to Terrain and Should Not Require Re-flight Check For Terrain –A detailed look at the airport is not required  Failure of the Screening Does Not Necessarily Imply That GEO Masking Will Occur During an Approach to that Airport –Failure implies that a closer look at the airport is warranted  Availability of LNAV/VNAV Approaches Was Not Addressed TERRAIN MASKING: Results

21  AVN Airport Database Entries Were Compared With Jeppesen and Other Databases  GEO Angles Were Computed by Several Methods With No Significant Differences Between Methods  Terrain Masking Code Was Checked Independently  Terrain Results Were Spot Checked With Sectional Charts  AVN Will Spot Check Some Airports During a Later Validation Check VALIDATION EFFORTS

22 AIRPORT GROUP ONE Summary  223 Total Airports With RNAV (LNAV/VNAV) Approaches Developed by AVN  215 Airports Passed Screening GEO > 10 Degrees Elevation and Terrain to South < 5 Degrees Elevation  8 Airports Failed Screening 3 Failed for Terrain 5 Failed for GEO Elevation o 3 in Northern Alaska

23 AIRPORT GROUP TWO Summary  155 Total Airports With RNAV (LNAV/VNAV) Approaches Planned by AVN  142 Airports Passed Screening GEO > 10 Degrees Elevation and Terrain to South < 5 Degrees Elevation  13 Airports Failed Screening 12 Failed for Terrain 1 Failed for GEO Elevation

24 AVN VALIDATION  MITRE Evaluated 378 Airports/AVN Flight Inspected 65 Airports To Validate MITRE results 11 of the 21 Identified by MITRE Did Not Have GEO Coverage 2 Additional Airports of the 65 Would Not Support VNAV For Geo Coverage  AVN Accepted the Results As Satisfactory

26 WAAS MMR RECEIVER  Have Six Collins MMR Receivers With WAAS and LAAS  Two Lear 60s Have WAAS Capability  Due to No TSO Receiver and No STC, Aircraft in Experimental Status  Currently in a MOPS “Beta” Configuration  With the FMS We Must Change the MMR Into “Delta” Configuration, Estimate 2 Years  LPV and LAAS Have FAS Datablock That the AFIS Reads  Aircraft Flying LNAV/VNAV While AFIS Evaluates LPV  New Contract Let to Complete VFR STC (estimate completion January 05)

27 LPV FLIGHT INSPECTION RESULTS Site HPL Meters VPL Meters XTK Error Feet ATK Error Feet SNRBelow Path SNR Worst SNR KFDR KCHK 16L KTYO KGAI KOKC 17R KOKC 35R KOSH

28 WAAS Approach ILS Glideslope ILS vs WAAS LPV Flight Inspection Comparison

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30 WAAS LIMITATIONS  Inverse W on RNAV Approach Charts/Limitations Indicates WAAS Outages May Occur Daily (32 airports) WAAS NOTAMS Are Not Provided For the Procedure Use LNAV Minima For Flight Planning (Destination or Alternate) If Receiver Indicates LNAV/VNAV or LPV Available Guidance May Be Used If WAAS Is Lost Revert to LNAV Minima If Receiver Allows or LNAV Data Is Available  WAAS VNAV NA on RNAV Charts That Did Not Pass MITRE Modeling and Flight Inspection

31 INMARSAT 3 AOR/W 54  W INMARSAT 3 POR 178  E INMARSAT III COVERAGE

Jimmy Snow NAVIGATION CONSULTANT