GNSS including PBN standards Flashcards
What do PBN, GNSS, RNAV, RNP and LNAV stand for?
Q: What do PBN, GNSS, RNAV, RNP and LNAV stand for?
- PBN – Performance Based Navigation
- GNSS – Global Navigation Satellite System
- RNAV – Area Navigation – Navigation specification prefix
- RNP – Required Navigation Performance
- LNAV – Lateral Navigation – Navigation specification prefix
REF: AIP GEN 2.2 – Definitions & Abbreviations
What is PBN (Performance-based Navigation)?
Area navigation based on performance requirements for aircraft operating along an ATS route, on an instrument approach procedure or in a designated airspace.
Note: Performance requirements are expressed in navigation specifications (RNAV specification, RNP specification) in terms of accuracy, integrity, continuity, availability and functionality needed for the proposed operation in the context of a Particular airspace concept.
REF: AIP GEN 2.2, 1 Definitions
What is the difference between RNAV and PBN (RNP)?
Q: What is the difference between RNAV and PBN (RNP)?
PBN requires onboard monitoring and alerting (RAIM), RNAV does not.
What does a Star symbol with NO encompassing circle indicate on an instrument approach chart?
It depicts a FLY-BY WAYPOINT (A waypoint which requires turn anticipation to allow tangential interception of the next segment of a route or procedure).
REF: IAL Legend DAP 0-2
What does a Star symbol with an encompassing circle indicate on an instrument approach chart?
It depicts a FLY-OVER WAYPOINT (A waypoint at which a turn is initiated in order to join the next segment or a route of procedure)
REF: IAL Legend DAP 0-2
What is the method of navigation and tolerance required when using published IFR route segments?
The LSALT specified for a route segment is only valid for RNP 2 operations. For operations other than RNP 2 operations, operators and pilots must use a pilot calculated LSALT or grid LSALT.
REF: Aeronautical Chart User Guide 6.4.2 – LSALT
In Australian what is the PBN requirement for SIDs / STARs?
RNP 1
REF: https://www.casa.gov.au/operations-safety-and-travel/airspace/communications-navigation-and-surveillance/performance-based-navigation#
What does FDE stand for and how many satellites are required?
- FDE – Fault Detection and Exclusion; and
- Six satellites are required.
REF: CAO 20.91 Section 4- Definitions, UNS Training Manual Page 30 Fault Detection and Exclusion.
What are its advantages of FDE over receivers with FD only?
FDE receivers exclude data from a faulty satellite from the calculation process which reduces RAIM alerts, extends availability of time the system can be used for navigation.
For FDE to work it requires six satellites to be in the right place.
REF: CAAP 179A – 1(1) Page 12
During the flight planning stage, what must a pilot do if a continuous loss of GNSS integrity function for more than 5 minutes is predicted for any Part of the approach operation?
The flight plan must be revised, for example, by delaying the departure time or planning a different route to ensure an ETA (when an RNP approach may be required) does not fall within the predicted outage period.
REF: CAO 20.91 – section 14.2 - Operating standards – Flight Planning - GNSS integrity availability
Is there any action that must be taken prior to flight using an FMS (or GNSS unit) for standalone navigation along an air route?
Yes, at system initialisation the following must occur:
1. Confirmation that the navigation database is current;
2. Verification of proper entry of the ATC assigned route immediately after initial clearance from ATC to conduct the relevant RNAV route;
3. Action must be taken to ensure the waypoints sequence, depicted by the navigation system matches the route depicted on the appropriate charts and the assigned route
The following cross checks must be made:
4. A cross check of the flight plan by comparing charts or other applicable resources with the navigation system flight plan and the aircraft map display
Note: Differences of up to 3 degrees or less are operationally acceptable
REF: CAO 20.91 – Appendix 3, section 7.2 - 7.3 - Operating standards – Flight Procedures - general
During flight, when using an FMS (or GPS unit) for standalone navigation along an air route, must navigation reasonableness be checked at any stage of the flight?
Yes, if available, as far as practicable, navigation reasonableness must be periodically confirmed by cross reference to available data from ground-based navigation aids.
REF: CAO 20.91 – Appendix 3, section 7.4 - Operating standards – Flight Procedures - general
When using an FMS (or GPS unit) for standalone navigation in controlled airspace, and you receive a “RAIM unavailable” message from the GPS, is there any requirements to advise ATC?
Q: When using an FMS (or GPS unit) for standalone navigation in controlled airspace, and you receive a “RAIM unavailable” message from the GPS, is there any requirements to advise ATC?
- ATC must be notified immediately if the system performance ceases to meet RNP 2 requirements during an RNP 2 operation in controlled airspace
- ATC must also be advised if any of the following occur:
a. During an en-route phase of flight – there is RAIM loss or loss of GNSS integrity for more than 5 minutes;
b. During a terminal phase of flight – there is a RAIM loss or loss of GNSS integrity;
c. When ATS requests the provision of GNSS-derived information – RAIM or GNSS integrity is not available;
d. When ATS grants a clearance or imposes a requirement based on GNSS-derived information – RAIM or GNSS integrity is not available
e. The GNSS receiver is in dead-reckoning mode, or experiences of its navigation function, for more than 1 minute
f. If the GNSS information is considered unreliable, then another means of navigation should be used until RAIM is restored and the aircraft is re-established on track. Following the re-establishment of RAIM, ATC should be notified of RAIM restoration prior to using GNSS information.
g. The phrases “RAIM FAILURE” or “RAIM RESTORED” must be used
REF: CAO 20.91 – Appendix 3, section 8 – Contingency Procedures for Performance Failure & AIP ENR 1.1 4.8.1.2 - GNSS Operations Without RAIM
Can the FMS be used for overlay approaches?
An area navigation system may also be used to assist in flying a conventional approach. However it is necessary for the navigation system upon which the procedure is based to be monitored (NDB, VOR etc.) to ensure that the obstacle clearance requirements of the approach are met, and that the procedure is flown within the tolerances of the navigation system on which the procedure is based.
REF: CAAP 178-1(2) 4.10 – Can I Fly an Area Navigation Approach
What are the RNP values applied during PBN?
- En route = RNP2
- Terminal (within 30 nm) = RNP1
- Initial / Intermediate Approach = RNP1
- Final Approach = RNP APCH (0.3)
- Missed Approach = RNP1
REF; DAP East Intro DAP1-3
