Overview of FAA Satellite Navigation Transition and Backup Strategies Int’l Loran Association October 28, 2002

Navigation Communications Surveillance The Separation Safety Triad Three Legs of the Safety Stool Safety First and Foremost

Drivers for Transition and Backup Strategy Workload within interference area Sustaining separation Radar Non-radar Assuring safe recovery and landing of aircraft in weather Minimizing disruption of air transportation to reduce threat Minimum investment for users in backup capability

Issues During an Interference Event Response time in detecting size of disruption Will controllers know size of interference area quickly to tactically make adjustments? How do pilots get the information to make route change decisions? Controller workload Pilot workload Response time to find and shut down interference Terrain avoidance in interference area in weather En route low altitude RNAV routes Terminal maneuvering Procedural separation in absence of navigation

General Assumptions DoD needs continued TACAN/DME/ILS Precision landing capability (ILS) at least on one runway at those airports necessary for recovery of aircraft during an interference event All Category II/III ILS systems retained New runway landing capabilities can be served by ILS, GPS(WAAS) or GPS(LAAS) Approach lights retained where Category I ILS’s shut off Sufficient VOR’s retained for VOR-VOR direct navigation and landing with VOR non-precision approach at selected airports (minimum operating network) DME’s retained to support INS/FMS redundancy Nav coverage richer where surveillance is limited

© Mitre CAASD Lack of Surveillance Coverage Greater navigation infrastructure retained where surveillance coverage is lacking for low altitude operations Secondary Surveillance Coverage at 6,000 ft AGL

Instrument Ops Percentages Top 200 Airports: 92% of Instrument Ops Top 250 Airports: 95% of Instrument Ops Top 300 Airports: 97% of Instrument Ops Top 350 Airports: 99% of Instrument Ops

System Disruption Likelihood of Occurrence Threat Where is aviation on the curve? Technology Exists Scenarios publicly known Ground emitter Intermittent emitter Airborne emitter ? ? ? ? How much “insurance” is needed to provide critical Infrastructure protection?

Operational Contingency Backup Capability Redundant Capability Operations Disruption Threat Mitigation Intentional Interference Event Scaled Response Procedures Only VOR Minimum Operating Network Long-Range NDB’s ILS DME-DME IRS/FMS FMS ILS

LORAN as a backup Best theoretical Part 91 backup RNAV backup for RNAV Integrated antenna with GPS One sensor in an integrated avionics package Capable of providing alternative independent path for differential corrections for GPS Coverage in mountainous terrain for navigation and differential correction for GPS Reduced number of VOR’s below minimum operating network But….

LORAN X Updated ground infrastructure must continue Not the LORAN C avionics as flown today Loran C only useful for en route nav Existing avionics declining as GPS overtakes panel space in aircraft Must be able to support non-precision approach Meets availability though all-in-view receiver Each transmitter stick used instead of chains H-field antenna for improved signal-to-noise (p-static) Affordable as card in GPS box, not stand alone receiver Avionics in 5 – 7 years (no MASPS/MOPS or TSO) High market risk even with a DOT decision to continue LORAN C 18,200 remaining LORAN-C VFR receivers 8,735 remaining IFR receivers remaining

VOR Proposal for Minimum Operating Network Victor Airways and Jet Routes begin reduction in 2010 leading to no airways by 2014 Replaced with VOR-VOR direct aids and Airport VOR aids Airport VOR supports either VOR NPA, or VOR radial to ILS Minimum Operational Network of VOR’s attained by 2014 No location in the CONUS further than 75 miles from VOR at 5,000 feet AGL line-of-sight Mountainous locations treated differently due to altitude and icing concerns Replace/relocate MON VOR’s and reduce impact of masking radials from 2007 through 2012

Current VOR Coverage 1008 VOR/VORTAC/VOR-DME 5000 ft AGL > 3 © 2002 The MITRE Corporation. All Rights Reserved. Number Visible

VOR Backup Coverage VOR/ VORTAC/VOR-DME ( Fillers) 5000 ft AGL > 3 © 2002 The MITRE Corporation. All Rights Reserved. Number Visible

Existing DME Coverage 930 FAA DMEs (VORTAC/VOR-DME) 18,000 ft MSL > 3 © 2002 The MITRE Corporation. All Rights Reserved. Number Visible

671 Airports with at Least One ILS © 2002 The MITRE Corporation. All Rights Reserved.

1000’ MSL Ground Level VOR 1 VOR AGL Interference Area 4000’ MSL Airport VOR En Route VOR 4 1.Request Climb or Radar Vector 2.Climb up to 5000’ AGL 3.Proceed Direct to VOR 4.Continue to next VOR 5.Continue to next VOR 6.Free of Interference 7.Request RNAV and Altitude Change Backup Redundancy Continue Through Area As Planned Using RNAV 6000’ MSL

Likely Civil User Equipage (En Route Through Non-precision Approach) Satnav GPS/inertial (or GPS/WAAS) GPS (or GPS/WAAS) GPS/WAAS Ground-based Navigation Backup FMS (DME/DME or inertial) RNP/RNAV FMS (DME/DME) RNP/RNAV (1) VOR or (2) Loran RNAV or FMS No inertial No FMS or inertial FMS with inertial Current Avionics Add Retain (3) Ops Contingency

Satnav GPS/LAAS GPS/WAAS Ground-based Navigation Backup Scheduled Operations Large Airports Current Operations Add Retain ILS Cat I/II/III 200 feet and ½ mile Scheduled Operations Many Airports 250 feet and ½ mile with approach lights 250 feet and ¾ mile without approach lights Unscheduled Operations Many Airports ILS/Cat I 200 feet and ½ mile Likely User Equipage (Precision Approach) (1)ILS/Cat I or (2)Ops Contingency

Retain on at least one runway ILS – CAT I and Localizer Only TACAN (includes DME) DME (VOR/DME and Stand Alone) Minimum Operating Network VOR ILS – CAT II/III Current runways retained for capacity Long Range NDB – Alaska and Coastal GPS III GPS WAAS ft & ¾ mile vis (LPV) 3 rd GEO > LAAS CAT I LAAS CAT II/III R&D Required 6 airports + options for 0 to 40 per year LORAN???Decision on Continued Use In Late > 125 1,168 > 546 1,033 > > WAAS - GLS L5 Usable >

Instrument Approaches and WAAS The intent of WAAS was to provide three levels of service for instrument approaches: –GLS (GPS Landing System) Equivalent of ILS Requires 40 m HAL and 12 m VAL Requires LAAS –LNAV/VNAV(Lateral/Vertical Navigation) Requires 556 m HAL and 50 m VAL Requires WAAS or Baro/VNAV (GPS or DME/DME and Baro) –LNAV (Lateral Navigation) Requires 556 m HAL –No vertical guidance (non-precision approach) Requires GPS, WAAS, or DME/DME LNAV New capability from GPS/WAAS –LPV (Lateral Precision with Vertical Guidance) Realizes a 40 m HAL and 50 m VAL Provides lower minimums at more runway ends Requires WAAS

Horizontal and Vertical Protection Required LNAV/VNAV - RNP.3 (556 m horizontal by 50 m vertical) LPV (40 m horizontal by 50 m vertical) GLS (40 m horizontal by 12 m vertical) Full GPS Landing Systems (GLS) will be available from LAAS and when the new L5 radio frequency is operational from the GPS satellite constellation V H

5073 runway ends at 1534 airports LPV and LNAV/VNAV Height above Touchdown (HAT) More Obstacles Prevent Approach HAT (ft) Number of Runways LNAV/VNAV LPV © 2002 The MITRE Corporation. All Rights Reserved.