VERTICAL DEVIATION DISPLAY
The vertical deviation scale is displayed on the right side of the ADI when
one of the following conditions exists:
• LOC1(2) is the selected primary navaid; in this instance the scale is the
glideslope; the pointer is displayed when reliable GS deviation signal is
reeived;
• LOC1(2) is the selected primary navaid and the FMS is producing
reliable vertical deviation or preview vertical deviation.
One the following annunciators is displayed inside the pointer to indicate the
type of vertical deviation being presented:
• I (ILS) for GlideSplope deviation
• P (Path) for FMS VGP deviation
• V (VPATH) for FMS VPATH deviation
The pointer displayed on the right side of the vertical deviation scale
indicates the deviation associated to the primary navaid.
The pointer displayed on the left side of the vertical deviation scale indicates
the previewed navaid.
GLOBAL POSITIONING SYSTEM – GENERAL
The Global Positioning System (GPS) supplies data for flight guidance and
other information during flight. The GPS installed on the AW139 helicopter is
a 12-channel GPS receiver that receives from the NAVSTAR GPS satellite
constellation.
The GPS interface the Air Data System (ADS) and the Flight Management
System (FMS). The GPS modules have the primary function of determining
the aircraft position from the signal codes. The output data includes:
• three dimensional aircraft position and velocities
• satellite position
• pseudo range
• delta range data