Gps waas class 5 nov10

Global Positioning Systems (GPS/WAAS)

Terminal Learning Objective

Action: Identify capabilities and functions of a Flight Management System (FMS) with the Global Positioning System (GPS/WAAS).

Condition: In a classroom or in the aircraft and without reference for the written exam.

Standard: IAW the Guardrail student evaluation plan.

SAFETY REQUIREMENTS: NONE

RISK ASSESSMENT LEVEL: IV/E – Low

ENVIRONMENTAL CONSIDERATIONS: No Impact.

Evaluation: This material may be evaluated in the Phase II/III Flight Evaluation.

Classification: Unclassified.

Administrative DataAdministrative Data

Agenda

• FMS Terms• FMS Inputs• Global positioning System (GPS)• Wide Area Augmentation System (WAAS)• GPS Instrument Approaches• AR 95-1 Compliance

REFERENCES

• FM 2-04.240 (FM 1-240), Chapter 7

• AIM, Section 1-1-19

• FAA-H-8261-1A, Instrument Procedures Handbook, Chapter 5 and 6

• AR-95-1, Chapter 5

• SEMA Hand - Out, GPS RNAV And Approach Charts

• SEMA Hand – Out, RC-12X Flight Management System Universal SCN 1100 Operator’s Manual

Flight Management System(FMS)

Automates a wide variety of in-flight tasks:• Aircraft performance and flight plan

management.• Computes aircraft position using multiple aircraft

sensors (VOR,GPS, INS).• Contains navigation database.• Provides performance and flight path guidance

information to pilot navigation displays and automatic flight control systems

FMS INPUTS

Navigation Inputs from each "active" sensor are blended or deselected then summed up to provide

the best possible position data.

FMS Sensor Inputs

• ADC (Air Data Computer) • DME/DME • VOR • GPS / WAAS• IRU / INS (Inertial Reference System)• Fuel Flow• Barometric Altitude

Common GPS/FMS Terms ADC – Air Data Computer GPS - Global Positioning System IRU – Inertial reference Unit INS – Inertial Navigation System EGI - LN-100 Inertial Navigation System with embedded Global Positioning System (GPS) RNAV - Area Navigation GNSS - Global Navigation Satellite System SBAS - Satellite Based Augmentation System. A general term for WASS navigation

GLS - GNSS Landing System ( LPV and LAAS Approaches) WAAS - Wide Area Augmentation System LNAV - Lateral Navigation (GPS/WAAS) LNAV+V - LNAV approach where an advisory only descent angle is provided APV - Approach with Vertical Guidance LNAV / VNAV– GPS/WAAS Lateral Navigation with WAAS or Barometric Vertical Guidance LPV - GPS/WAAS Localizer Performance with GPS Vertical Guidance GLS - GNSS Landing System ( LPV and LAAS Approaches) RAIM - Receiver Autonomous Integrity Monitoring ANP – Actual navigation Performance RNP – Required Navigation Performance

Inertial Navigation System (INS)

• INS uses a computer and motion sensors (accelerometers) mounted on gyro-stabilized, gimbaled platforms to continuously calculate velocity and dead reckoning position without the need for external references.

• INS gyros can also provide aircraft attitude (pitch, roll, and heading).

• Once aligned with a known position, INS continuously calculate position and velocity.

• INS position accuracy decays with time.

Air Data Computer (ADC) The Air Data Computer (ADC) provides the FMS with:• True Air Speed (TAS)• Barometric Altitude• Pressure Altitude (PA) • Indicated Airspeed (IAS) • MACH Airspeed• Static and Total Air Temperature

All this is translated into useful information and displayed to the pilot as basic flight instruments and used by the FMS.

Student Check

Q: An Inertial Navigation System (INS) requires external navigational aids to operate.

True or False?

• A: FALSE, INS uses a computer and motion sensors (accelerometers) mounted on gyro-stabilized, gimbaled platforms to continuously calculate velocity and dead reckoning position without the need for external references.

Embedded Global positioning system / Inertial Navigation System

(EGI)• LN 100 is an INS system incorporating an imbedded GPS that

is a component of the RC-12X’s mission equipment. • INS alone without up-dating, errors are cumulative and

increase with time (about .6NM per hour error).

• GPS greatly enhances the performance of an INS by providing an in-flight position up-date capability for the INS.

• When GPS is not available because of mountain shadowing of satellites or jamming, INS provides accurate position information until the GPS satellites are in view or the jamming is over.

Area Navigation (RNAV)

• Permits point to point navigation.

• We will see an increased dependence on RNAV

with the FAA’s NextGen evolution.

ADS-B

• Automatic Dependent Surveillance Broadcast (ADS-B) – Evolving system that utilizes aircraft transponders and GPS signals to display an aircraft’s precise position combined with other data and broadcast to other aircraft and air traffic controllers without ground based radar.

• ADS-B may eventually replace ground based ACT radar.

Global Positioning System (GPS)

• GPS is a space-based radio-navigation system consisting of a constellation of satellites and a network of ground stations used for monitoring and control.

• Minimum of 24 GPS satellites orbit the earth of which at least 5 are observable by a user anywhere on earth.

• Minimum of 4 satellites is necessary to establish an accurate three-dimensional position.

24 Satellites, a minimum of 4 is required.

GPS Coverage

Accurate three-dimensional navigation is available to an infinite number of GPS receivers anywhere on or near the Earth within Line of Sight to GPS satellites.

How GPS Works

Global Navigation Satellite Systems GNSS

The generic term for air navigation utilizing GPS for RNAV operations for all phases of flight from departure, enroute, terminal, approach, and surface.

Receiver Autonomous Integrity Monitoring (RAIM)

• The RAIM system monitors the status of GPS satellites and broadcasts the GPS status as part of data message transmitted by GPS satellites.

• GPS status information is available by the Notice to Airmen (NOTAM) system.

• RAIM Prediction

In-Flight (RAIM)

• Continuous fault detection

• Excludes a failed satellites from the FMS position solution.

• RAIM Prediction in flight provides early indications of unscheduled satellite outage that has occurred since takeoff.

• WAAS availability precludes In-Flight RAIM.

RAIM FAILURE

• If a RAIM failure occurs after the Final Approach Way Point (FAWP), the receiver will continue operating without an annunciation for up to 5 minutes allowing completion of the approach (See AR-95-1).

• If a RAIM failure/status annunciation occurs prior to the Final Approach Waypoint (FAWP), the approach should not be completed since GPS may no longer provide the required accuracy.

Standard GPS Accuracy

FAA-H-8083-15A

Pg 7-27

www.faa.gov

Basic GPS signal (worst case scenario) –

• Approximately 100 meters (328 ft) lateral

• Approximately 140 meters (460 ft) vertical

460 ft

328 ft

FMS Navigation Databases

• Navigation databases certified for en route and terminal operations are loaded into the FMS.

• Contain airports, VORs, VORTACs, NDBs, airways and named waypoints (WPs), intersections shown on en route charts, instrument approach charts, SIDs, and STARs.

• There is no specific requirement to check the latitude and longitude of each published database waypoint, type of waypoint and/or altitude constraint. Verify only the general relationship of waypoints in the procedure, or the logic of an individual waypoint's location.

Use of GPS for IFR Oceanic, Domestic En Route, and Terminal

Area Operations • GPS procedures may be restricted outside the United States. Check

for restrictions in FLIP GP and area planning (AP) documents.

• GPS procedures for IFR navigation in the terminal area, equipment must include an updatable navigation database.

• GPS airborne navigation databases may come from the National Geospatial Agency (NGA) or from an approved commercial source such a Jeppessen.

GPS Satellite Jamming and Interference

• GPS as with all navigation aids, interference, whether intentional or unintentional, is a concern. A number of methods for minimizing interference have been identified and tested and others are being investigated.

• The Wide Area Augmentation System (WAAS) helps to detect and mitigate these effects.   

ANTI-SPOOFING

• SELECTIVE AVAILABILITY (SA) - Used to deny hostile use of precise GPS positioning data.

• SA is implemented by DoD to intentionally degrade a non DoD user’s navigation solution resulting in a five-fold increase in positioning error.

• Selective Availability was discontinued in May 2000 but could be re-activated.

Levels of Accuracy Available

• Standard Positioning Service (SPS) – Accuracy is 100 meters lateral and 140 meters vertical and can be received by anyone with a GPS receiver.

• Precise Positioning Service (PPS) - Accuracy

better than 7 meters horizontal. Available to PPS users in possession of proper cryptography.

Actual Navigation Performance(ANP)

• ANP is a measure of the system’s best estimate of error, calculated to allow for flight technical error.

• ANP = 1.00 nm, means a 95% chance that the

FMS position is within 1.00 nm of the actual position.

Required Navigation Performance (RNP)

• RNP is a statement of navigation performance necessary for operation within a defined airspace.

• RNP navigation requires inputs from GPS and/or WAAS to calculate the precision "corridor" or "highway" of an RNP procedure.

• Maintaining a narrow "RNP" corridor of flight space in both vertical and lateral planes allows for increased aircraft operations for any given period of time.

• Flight Management Systems are used to navigate RNP procedures with RNP procedures in their databases.

• Standard GPS approaches require at least .3 nautical mile RNP accuracy on final approach, however, some RNP approaches require greater than .3NM accuracy on final approach.

• FAA requires specialized aircrew training requirements for RNP GPS instrument approaches.

Standard RNP

Radius -TO-Fix leg “RF”

RNP 0.11

GPS Course Deviation Indicator (CDI) Scaling

• Enroute – Greater that 30 miles from destination airport, GPS full scale CDI sensitivity equals +/- 5NM, or each GPS CDI dot equals 1.0NM linear deviation off course.

• Terminal – Within 30 miles from the airport, GPS CDI full scale sensitivity automatically changes to +/- 1NM, or each dot equals .2NM linear deviation mile off course.

• Approach - At two miles from the final approach waypoint (FAWP), GPS CDI full scale sensitivity automatically changes to +/- .3 NM, or each dot represents approximately 365 feet off course.

RNP Navigation

Student Check

Q: Standard GPS Final approaches require accuracy of at least

a. .1 nautical mile accuracy.

b .5 nautical mile accuracy.

c. .3 nautical mile accuracy.

A: c. .3 nautical mile accuracy.

Satellite Based Augmentation Systems (SBAS)

SBAS systems correct and improves the accuracy of GPS receivers.

• North America – WAAS• Asia - Multi-Functional Satellite Augmentation

System (MSAS)• Europe - Euro Geostationary Navigation Overlay

Service (EGNOS)

Eventually, GPS users around the world will have access to precise position data using an SBAS or other compatible system.

Wide Area Augmentation System (WAAS)

• North America’s Satellite Based Augmentation System (SBSA) utilizes an additional two geostationary satellites that work in conjunction with 25 ground stations, providing improved position accuracy and integrity to the base GNSS System.

• WAAS ground stations interpret existing GPS satellite constellation signals and make corrections to any errors that may exist.

• WAAS satellites repeat correction signals down to WAAS capable receivers.

• An additional sensor added to the FMS based on geostationary satellites.

• There are now more published LPV approaches than ILS approaches in the United States.

How WAAS Works

WAAS STATIONS

Benefits of SBAS/WAAS

• ILS-like approach procedures (LPV).

•Higher level of service and accuracy.

•An electronic glide path can be generated independent of ground equipment or barometric aiding. •Key benefit - Vertically-Guided Instrument Approach minimums as low as 200 feet AGL.

WAAS ACCURACYWAAS improves GPS signal accuracy from 100

meters (328 ft) to approximately 7 meters (23ft).

www.faa.gov

WAAS - Safeguards• WAAS system is designed to strictest of safety

standards.

• Users are notified within six seconds of any of hazardous or misleading information that would cause an error in the GPS position estimate.

• Provides indications where system is unusable.

• Precludes In-Flight RAIM Monitoring

LNAV Instrument Approaches

• LNAV is a Non-Precision Approach when Lateral Navigation only is provided by GPS and/or WAAS.

• The pilot flies the final approach with Lateral Navigation provided by GPS, however, the pilot is responsible for vertical navigation.

• The pilot descends to step-down altitudes and to the

Minimum Descent Altitude (MDA) referencing the pilot’s barometric altimeter.

• LNAV+V - When an Advisory Only Descent Angle is provided.

GPS Approaches With Vertical Guidance

• LNAV/VNAV - When Lateral along with Vertical Navigation is provided. The LNAV is provided by GPS and the VNAV is provided by either WAAS or an FMS Barometric Aided VNAV computation (Baro-Aiding).

• Localizer Performance with Vertical Guidance (LPV) -When WAAS is required for both Lateral and Vertical navigation. LPV minimums will usually be lower than LNAV/VNAV or LNAV minimums.

Baro-Aiding VNAV

• Without WAAS or Baro-Aiding, the GPS derived vertical navigation cannot be relied upon since the vertical error can be quite large (± 460 feet) and no integrity is provided.

• Baro-Aiding is a method of augmenting GPS lateral navigation with a vertical navigation solution computed by the FMS using a non satellite input source (Altimeter In-Put).

• To ensure that Baro-Biding is accurate, the current altimeter setting must be entered.

• Pilots must correct the descent path and DA/MDA for colder than standard temperatures.

Baro-Aiding Temperature Compensation

LPV Approach - Localizer Performance with Vertical Guidance

• Localizer performance with GPS vertical guidance.

• LPV approaches can only be accomplished with WAAS GPS receivers.

• LPV minimums may be as low as 200 feet AGL with required approach and runway lights.

• Has the potential to provide precision approach accuracy to almost all runways.

Localizer Performance Approaches (LP)

• LP procedures require WAAS for later guidance only.

• Used at locations where the terrain or obstructions do not allow publication of vertically guided LPV procedures.

• LP approaches take advantage of the angular lateral guidance and smaller position errors. provided by WAAS to provide a lateral only procedure similar to an ILS Localizer.

• LP procedures may provide lower minima than a LNAV procedure due to the narrower obstacle clearance surface.

Level of Service Lights (FMS LOS)

• LOS is based on predicted GPS horizontal and vertical accuracy against required horizontal and vertical approach limits.

• LPV - Highest LOS provided by the FMS, equated with LPV approach minimums. When the FMS determines that LPV LOS is available, the LPV LOS light will be illuminated.

• LNAV + VNAV - Second highest LOS . When the FMS determines LNAV + VNAV level of service is available, the LNAV + VNAV Level of Service light will be illuminated.

• LNAV - Lowest LOS. When the FMS determines that only LNAV level of service is available, the LNAV Level of Service light will be illuminated.

NOTE: LPV approach operations require two operational FMS.

WAAS LPV Approaches Identified by a “W”

Level Of Service

Standard Format for RNAV/GPS Minimums

Approach minima (LPV, LNAV/VNAV, LNAV) is predicated on Level Of Service (LOS) annunciated.

GPS Approach Procedures • Stand-Alone - Procedures are designed for use only by GPS

systems.• GPS overlay – GPS procedure overlaid on conventional VOR,

VOR/DME, etc. procedures. Are titled with the type of Navigational Aid (NAVAID), including "or GPS" (e.g., VOR or GPS RWY 24).

• Approaches that may be flown in the GPS mode will contain “RNAV” or "GPS" in the title (e.g., "VOR or GPS RWY 24," "GPS RWY 24," or "RNAV (GPS) RWY 24").

• When flying overlay GPS approaches, the underlying ground-based NAVAIDs are not required to be operational and associated aircraft avionics need not be installed and/or operational.

• ILS Approaches – The ILS approach transition and published missed approach segments may be flown in the FMS mode, however, the ILS final approach segment must be flown with the LOC navigation source selected.

Flying GPS Approaches

• Fly the full approach from an Initial Approach Waypoint (IAWP) or feeder fix unless specifically cleared otherwise.

• When receiving vectors to final, place the FMS in the no-sequencing mode (Activate Approach) and use Command Heading.

• An "arm" annunciation should occur 30 NM straight line distance from the end of the runway reference point and then it should arm automatically.

• Without arming, the receiver will not change from en route CDI and RAIM sensitivity of ±2 NM either side of centerline to ±1 NM terminal sensitivity.

• Within 2 NM of the FAP with the approach mode armed, the approach mode will switch to active, which results in changing to approach CDI sensitivity of ±0.3 NM at the FAWP.

Standard “I” Standard “T”GPS Approach Formats

Terminal Arrival Area (TAA)

Terminal Arrival

Area (TAA)

Right Base

Left Base

Straight-In

Terminal Arrival

Area (TAA)

Right Base

Left Base

Straight-In

Fly-By Waypoint

Fly-Over Waypoint

GPS Missed Approach

• Pressing the Go-Around button will automatically sequence the FMS to the missed approach segment of the procedure past the Missed Approach Way Point (MAWP).

• Turns should not begin prior to the MAWP.

Local Area Augmentation System (LAAS)

• LAAS provides a GPS corrected navigation signal that is broadcast from a LAAS VHF data broadcast transmitter at or near some airports.

• LAAS avionics must be installed on aircraft.

• LAAS covers approximately a 30-mile radius and

provides up to Category III precision approach minimums (DA 50 feet) with accuracy within 1 Meter.

Local Area Augmentation System (LAAS)

LAAS improves GPS signal accuracy from 100 meters (328ft.) to approximately 1 meter (3ft.).

How LAAS Works

JPALSJoint Precision Approach and Landing

System

• Mobile, LAAS-likeLAAS-like DoD system

• All-weather, all-mission, all-user landing system based on local area Differential Global Positioning System (DGPS).

• Provides accurate and reliable landing guidance for fixed and rotary wing aircraft during all weather conditions.

JPALS

• Features a high GPS anti-jam protectionanti-jam protection to assure mission continuity in a hostile environment

• Compatible with civil and military GPS signals

AR 95-1 Chapter 5Flight Procedures and Rules

GPS is authorized for IFR flight if—• IFR GPS is authorized in the applicable

sovereign airspace- check DOD FLIP Area Planning (AP).

• Installed GPS equipment is certified for IFR operation.

• Precise Positioning Service (PPS) will be operated in the PPS mode.

• Current DOD/US Government FLIP products will be carried and accessible at all times.

AR 95-1

User Defined Waypoints - • IFR RNAV/GPS departure, arrival, en route and

terminal procedures will only be flown using waypoints retrieved from an approved non-corruptible database.

• Manual entry or update of the navigation database other than storing “user defined data” is not authorized (except for approved EMER GPS procedures).

AR 95-1

Approved Databases –• Use of commercial IFR databases (for example,

Jeppessen) in Army aircraft is only authorized in the United States and US territories.

• Use of commercial databases elsewhere in the world is restricted to en route navigation or to US military facilities overseas unless approved by USAASA/USAASD–E.

AR 95-1

IFR Alternate Selection –

An airfield will not be selected as an alternate If the global positioning system (GPS) is required for the approach and descent from en route minimum altitude for IFR operation, approach, and landing cannot be made in VFR conditions..

AR 95-1Prior to IFR GPS Flight Check—

• All required navigation performance (RNP) levels must be met when operating in designated RNP airspace.

• IFR GPS flight will not be conducted with an expired navigational database.

• Appropriate suffix for GPS/RNAV equipment will be entered on the flight plan, e.g.: “G” for DD 175 or “S / ITG /S” for DD 1801.

NOTE: Flight Plans Requesting “Q” or “T” Routes”, RNAV SIDs

and STARs require filing in the ICAO Flight plan format.

AR 95-1

GPS Substitution of Navigation aids–

When operating IFR in the US National Airspace System (NAS), GPS waypoints may be used as substitutes for ADF and/or DME receivers.

Consult DOD FLIP/host nation for authorized substitutions.

AR 95-1

RNAV/GPS Departure Procedures (DP)-

• (DP) must have terminal RAIM availability prior to departure.

• The CDI sensitivity will be set to + or - 1nm sensitivity or as published.

AR 95-1

GPS approach Requirements :

• When using a Digital Aeronautical Flight Information File (DAFIF) database, terminal procedures authorized to be flown are RNAV/GPS procedures and GPS overlay approaches if the title contains “or GPS” and the procedure has a Final Approach Fix (FAF) and the procedure can be retrieved from the database.

• Underlying NAVAIDS on overlay approaches should be tuned and monitored during the approach.

• DAFIF will not be used in Flight Management Systems (FMS) to drive/sequence other conventional NAVAID terminal procedures, for example, NDB, VOR, TACAN.

• Same approach must be reviewed and displayed to the crew from the current DOD FLIP procedure.

• Compare the database retrieved procedure loaded in the GPS to the published procedure to ensure accuracy, If differences are detected, the published product, supplemented by NOTAMs, will take precedence over the database procedure.

AR 95-1

GPS Approach Procedures • Verify the GPS system begins to sequence when

entering the terminal area, that the approach is armed prior to the Initial Approach Fix (IAF) and that course sensitivity on the CDI changes appropriately.

• If a RAIM failure/status annunciation occurs or the GPS does not sequence to the “active approach” mode, the pilot will request an alternate procedure or if already passed the Final Approach Waypoint (FAWP), the pilot will climb to the missed approach altitude and execute the missed approach.

AR 95-1

GPS Approach Minimums • Approach minimums listed as GLS (or LPV), and

LNAV/VNAV, categories will only be flown if the aircraft is appropriately equipped.

• Barometric Vertical Navigation (baro-VNAV) decision altitude (DA) is not authorized with a remote altimeter setting. If local altimeter setting is not available, the MDA becomes the published LNAV MDA, cold temperature restrictions apply.

• Circling from RNAV/GPS approaches may be accomplished if circling minimums are published.

AR 95-1

GPS Missed Approach

Upon missed approach, pilots will ensure the missed approach function has been appropriately activated on the GPS.

Student Check

Q: An IFR alternate airfield may be selected if the global positioning system (GPS) is required for an IFR approach to that airfield and descent from en route minimum altitude for IFR operation, approach, and landing cannot be made in VFR conditions..

True or False?

A: FALSE

Summary

• FMS Terms• FMS Inputs• Global positioning System (GPS)• Wide Area Augmentation System (WAAS) • GPS Approaches• AR 95-1 Compliance

Questions ?