AFMS N°D01 FOR GARMIN GFC700 AUTOPILOT INSTALLATION AND
RNAV/RNP NAVIGATION ELIGIBILITY
Section 4 – Normal procedures
ADDITIONAL GUIDANCE FOR RNAV GPS
ADDITIONAL GUIDANCE FOR RNAV GPS 9
Experience of RNAV systems, and Flight FMS in general, has identified the pit-
falls of waypoint entry error at the receiver as well as inaccuracies and errors in
the database itself.
Research and experience have both shown that human error, often the result of a
lack of familiarity with the airborne equipment, represents the major hazard in op-
erations using RNAV systems. Therefore, it is imperative that pilots understand
their system thoroughly and are able to determine whether it is safe to proceed.
This requires robust procedures, which check for possible errors in the computer
database, monitor continued performance of the RNAV systems and enable pilots
to identify and avoid not only their own mistakes but also errors in the infor-
mation presented to them.
Flight planning on RNAV routes should include the following recommendation.
- During the pre-flight planning phase, given a GPS constellation of 23 satellites
or less (22 or less for GPS stand-alone equipment that incorporate pressure alti-
tude aiding), the availability of GPS integrity (RAIM) should be confirmed for the
intended flight (route and time). This should be obtained from a prediction pro-
gram either ground-based, or provided as an equipment function, or from an alter-
native method acceptable to the Authority;
- Where a navigation data base is installed, the data base validity (current AIRAC
cycle) should be checked before flight;
- Traditional navigation equipment (e.g. VOR, DME and ADF) should be selected
to available aids so as to allow immediate cross-checking or reversion in the event
of loss of GPS navigation capability.
(a) Pre-flight Planning
During the pre-flight planning phase, the availability of the navigation infrastruc-
ture, required for the intended operation, including any non-RNAV contingencies,
must be confirmed for the period of intended operation. Availability of the
onboard navigation equipment necessary for the route to be flown must be con-
firmed. The onboard navigation database must be appropriate for the region of in-
tended operation and must include the navigation aids, waypoints, and coded ter-
minal airspace procedures for the departure, arrival and alternate airfields.
Where the responsible airspace authority has specified in the AIP that dual
PRNAV systems are required for specific terminal P-RNAV procedure, the avail-
ability of dual P-RNAV systems must be confirmed. This typically will apply
where procedures are effective below the applicable minimum obstacle clearance
altitude or where radar coverage is inadequate for the purposes of supporting P-
RNAV. This will also take into account the particular hazards of a terminal area
and the feasibility of contingency procedures following loss of P-RNAV capabil-
ity.
RAIM availability must be confirmed with account taken of the latest information.
To Next Page
Loading...
