17. Area Navigation (RNAV) Flashcards
What is Area Navigation?
RNAV
“A method of navigation which permits aircraft operation on any desired flight path within the coverage of station-referenced navigation aids or within the limits of the capability of self-contained navigation aids, or a combination of both”
How does RNAV work?
Instead of having to overfly ground navigational aids, the aircraft’s FMS will fly to a series of pre-loaded waypoints and position itself on a computed track between the individual waypoints.
FMS utilises LNAV (Lateral) and VNAV (Vertical) functions to ensure accuracy with the WGS-84 system
What is B-RNAV?
Forerunner of the RNAV program. Enables
capacity gains through modifications to the en-
route structure.
Accuracy of B-RNAV?
Requires aircraft track-keeping accuracy of +/- 5NM for at least 95% of flight time to meet the required safety targets.
All IFR aircraft must be B-RNAV compliant.
What is RNP?
Required Navigation Performance (RNP)
Is “a statement of the navigation performance necessary for operation within a defined airspace”.
What this means is that the equipment must be sufficiently capable and accurate as denoted by the
regulatory body.
Part of a broader concept called “Performance-based Navigation” (PBN)
Requirements for RNP?
These have an associated performance specification that an aircraft must meet.
The system must monitor the achieved performance and provide an alert in the event that this fails to meet the specification.
Previously based on INS (Inertial Navigation), now based on GNSS(GPS).
RNP Accuracy
There can be multiple types of RNP accuracy
(dependent on the phase of flight).
RNP 0.3 - +/- 0.3nm
RNP 1 - +/- 1nm
RNP 2 - +/- 2nm
RNP 4 - +/- 4nm
from the desired track respectively, for 95% of the time (TSE – Total System Error).
These are sufficient for en route navigation but are not yet sufficient for approaches
What are fixed RNP routes?
Fixed RNP routes are published ATS routes
which can be flight planned for use by aircraft
approved for a specific RNP type.
Fixed RNP routes should begin and end at
notified reporting points and way-points are
established along them
What are contingency RNP routes?
Contingency RNP routes can be made available to
aircraft approved for a specific RNP type during
limited time periods (hours, days, seasons).
They may also be established to meet unusual,
temporary requirements arising at short notice.
What is P-RNAV?
Precision RNAV (P-RNAV) allows for en-route
and/or TMA operations that are standardised EU
wide, ensuring consistent levels of flight safety.
Aircraft equipped and certified with a PRNAV
system ( +/-1NM accurate track) may operate on
P-RNAV SIDs/STARs.
Note: P-RNAV is specific to Europe only.
What is RNP-RNAV?
No requirement for airborne monitoring of the
achieved RNP type accuracy; instead, greater
accuracy is ensured operationally. Allows for
approaches to +/- 0.3NM accuracy. This can be
used in Terminal areas.
Accuracy of a RNP approach?
RNP APCH requires an accuracy of +/- 1.0NM in
the initial, intermediate and missed segments
and 0.3NM in the final segment.
what is RNP (AR) APCH?
RNP (AR) APCH
RNP instrument approach procedures with
Authorisation Required or RNP AR build upon
the PBN concept.
defined as an RNP approach
procedure that requires a lateral TSE lower than
the standard RNP values on any segment of the
approach procedure, down to 0.10NM and
requires crew training in the same way to ILS Cat
II/III procedures.
What are the 3 components of the PBN concept? (3)
Navigation Specification - quality of equipment
Navaid Infrastructure - navaids to assist
Navigation Application - Airspace concepts
Future navigation
4D - Gate to Gate
- strict timing - 2-5 seconds
- 4D FMS required
Business trajectories
- developing free route airspace
