PRIMUS
r
880 Digital Weather Radar System
A28--1146--102--03
REV 3
3-5
Operating Controls
D FP (Flight Plan) -- The FP position puts the radar system inthe flight
plan mode, which clears the screen of radar data so ancillary data
can be displayed. Examples of this data are:
— Navigation displays
— Electrical discharge (lightning) data.
NOTE: In the FP mode, the radar RTA is put in standby, the
alphanumerics are changed to cyan, and the FLTPLN
legend is shown in the mode field.
The target (TGT) alert mode can be used in the FP mode. With
target alert on and the FP mode selected, the target alert armed
annunciation (green TGT) is displayed. The RTA searches for a
hazardous target from 5 to 55 miles and ±7.5° of the aircraft heading.
No radar targets are displayed. If a hazardous target is detected,
the target alert armed annunciation switches to the alert
annunciation (yellow TGT). This advises the pilot that a hazardous
target is in his flightpath and the WX mode should be selected to
view it.
NOTE: The TGT function is inoperative when a checklist is
displayed.
D TST (Test) -- The TST position selects the radar test mode. A
special test pattern is displayed to verify system operation. The
TEST legend is shown in the mode field. Refer to Section 4, Normal
Operations, for a description of the test pattern.
WARNING
UNLESS THE SYSTEM IS IN FORCED STANDBY, THE
TRANSMITTER IS ON AND RADIATING X--BAND
MICROWAVE ENERGY IN TEST MODE. REFER TO SECTION 6,
MAXIMUM PERMISSIBLE EXPOSURE LEVEL (MPEL), AND THE
APPENDIX, FEDERAL AV IATION ADMINISTRATION (FAA)
ADVISORY CIRCULARS, TO PREVENT POSSIBLE HUMAN BODY
DAMAGE.
FSBY (Forced Standby)
FSBY is an automatic, nonselectable radar mode. As an installation
option, the indicator can be wired to the weight--on--wheels (WOW)
squat switch. When wired, the RTA is in the FSBY mode when the
aircraft is on the ground. In FSBY mode, the transmitter and antenna
scan are both inhibited, the display memory is erased, and the FSBY
legend is displayed in the mode field. When in the FSBY mode,
pushing the STAB button 4 times within 3 seconds, restores normal
operation.