Reference System (IRS) has excellent short term characteristics
while VLF/Omega has excellent long term stability. The internal GPS
sensor has excellent overall characteristics and will usually be the
dominant sensor during blending. However, when RAIM is available,
the GPS sensor is the sole contributor to the composite position.
NOTE: RAIM (Receiver Autonomous Integrity Monitoring) is a quali-
ty factor used to determine the accuracy of the GPS position. It is an
internal function of the GPS receiver and determines the accuracy of
it's navigation solution.
The navigation data base is updated on a 28-day cycle by way of a
memory card. This card is inserted in a Personal Computer Memory
Card International Association (PCMCIA) slot located under the lower
portion of the alpha keyboard. This worldwide database contains
over 50,000 waypoints, navaids and airports. It also contains alti-
tudes at appropriate waypoints, SID, STAR, AIRWAY, and
APPROACH procedures. In addition to this database, the memory
can store up to 999 operator generated waypoints. Individual naviga-
tion points can be organized into 56 different stored flight plans, each
containing up to 50 waypoints.
Due to the way the GNS-X
have unique identifiers. However, some duplicate ICAO identifiers
exist for more than one waypoint. In these cases the waypoint identi-
fiers are renamed in the database. Two naming conventions are
used, one for four character identifiers and one for five character
Four character waypoints keep the first four characters and the last
two characters of the ICAO airport identifier as shown in the following
MA11 at KPRC becomes MA11RC in the database.
Five character waypoints keep the first five characters and add the
last character of the ICAO airport identifier as shown in the following
MA27L at KOAK becomes MA27LK in the database.
Additional capabilities of the GNS-X
present position to any waypoint, and data crossfill capability for dual
installations. Trip Plan and Fuel Plan functions are also available.
There is capability for creating a PSEUDO-VORTAC (selected
course) to any waypoint and establishing an offset parallel course.
NAVs, COMMs, ADFs and transponders can be tuned through the
system or by using the individual control heads.
database is structured, waypoints must
include direct navigation from
Flight Management System