Hawker 800 XP, Pilot Training Manual

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PRIMUS 870 WEATHER RADAR
SYSTEM
Description and Operation
The Primus 870 system is an x-band, digital
radar used for weather detection and ground
mapping. Some installations have the optional
LSZ-850 lighting sensor system.
The system uses one receiver/transmitter/an-
tennae and two controllers.
Dual controllers allow both pilots to individ-
ually select radar mode, range, tilt and gain set-
tings. On the right to left antenna scan, the
system switches to what is selected on the left
controller and updates the left HSI diaplay. On
the reverse scan of the antenna, the right con-
troller is selected and displayed on the right
HSI. The radar controller displayed on the
MFD is a function of the MFD controller (Fig-
ure 16A-27).
Radar
A rotary switch used to select one of the fol-
lowing functions:
OFF
Turns the radar system off. WX in amber is dis-
played in the mode field.
TBY (Standby)
The radar system is placed in standby, a ready
state, with the antenna scan stopped, the trans-
mitter inhibited and the display memory
erased. STBY, in blue, is displayed in the
mode field. If SBY is selected prior to the ex-
piration of the initial R/T/A warmup period
(approximately 45 seconds), the blue WAIT
legend is displayed in the mode field. Upon
completion of the WAIT period the system
automatically switches to standby mode.
WX (Weather Radar)
Selecting WX places the radar system in the
weather detection mode. The system is fully
operational and all internal parameters are set
for enroute weather detection.
If WX is selected prior to the expiration of the
initial R/T/A warmup period (approximately
45 seconds), the blue WAIT legend is dis-
played. In WAIT mode, the transmitter and an-
tenna scan are inhibited and the memory is
erased. Upon completion of the warmup pe-
riod, the system automatically switches to
WX mode.The system, in preset gain, is cal-
ibrated as defined in Table 16A-2. Blue WX
is displayed in mode field.
RCT (REACT)
Adds the REACT feature to the WX display.
REACT is an acronym for rain echo attenuation
compensation technique and is a submode of the
WX mode. Selecting RCT forces the system to
Revision 1 16A-40
FOR TRAINING PURPOSES ONLY
HAWKER 800 XP PILOT TRAINING MANUAL
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Figure 16A-27. Radar Controller
Rainfall Rate (mm/hr) Color
1-4 mm/hr Green
4-12 mm/hr Yellow
12-50 ~mm/hr Red
Greater than 50 mm/hr Magenta
TABLE 16A-2. WEATHER DETECTION
CALIBRATION SCHEME