-NAV: PRED W/S DET FAULT on the upper ECAM DU,
-PRED W/S DET in the INOP SYS item of the STATUS page on the SD. The system 2 (if installed), has to be selected on the weather radar control unit to display windshear information.
NOTE : The system has to reject echoes due to ground clutter or
____
moving surface.
NOTE : In some cases, the pilot has to deselect windshear mode (PWS/
____
OFF/AUTO switch to OFF) for the following reasons:
-
when the aircraft is at a gate area or in maintenance hangars to avoid radiating danger for persons,
-
when nuisance aural alerts are generated.
NOTE : There is no danger of radiation to persons on the ground if
____ the ATC switch on the ATC/TCAS control unit is set to OFF or STBY after landing, even if the windshear switch on the weather radar control unit is still at AUTO.
NOTE : In order to ensure optimum performance for the predictive
____ windshear function, the radome must be at least equal to class B category 1.
(3) Logic of scanning mode (Ref. Fig. 009A) The antenna scan pattern varies depending on the mode of operation.
(a) Weather radar scan pattern In weather radar mode, the antenna scans a 180 deg. in azimuth and has tilt (pitch) coverage of plus or minus 15 deg. Stabilization limits are plus or minus 25 deg. in the pitch axis and plus or minus 40 deg. in the roll axis. The antenna scans the zone 15 times per minute. Beam opening is 3.6 deg. in elevation and 3.5 deg. in azimuth. An antenna scanning is performed in 4 seconds, this causes the transmission of 720 data words to the data bus lines.
R 1EFF : 051-099, 106-149, 201-299, 301-399, 1 34-41-00Page 48 1401-499, 1Config-3 Aug 01/05 1 1 1CES 1
WR/PWS - Logic of scanning mode
Figure 009A
R 1EFF : 051-099, 106-149, 201-299, 301-399, 1 34-41-00Page 49 1401-499, 1Config-3 Aug 01/05 1 1 1CES 1 When the two ranges selected on both EFIS control panels are identical, the radar images displayed on the NDs are refreshed every 4 seconds. On the contrary, when two different ranges are selected on the EFIS control panels, the images are refreshed every 8 seconds.
(b)
Weather and windshear scan pattern When the system is placed into alternate weather/windshear mode, the weather processing is operating during left-to-right scans and windshear processing is operating during right-to-left scans. In this case, the antenna scans only plus or minus 60 deg. But windshear the targets are displayed only in the area plus or minus 30 deg. from the aircraft centerline. An antenna scanning is performed in 3 seconds three other seconds are used to refresh data inside the CPU. Then, when the two ranges selected on both EFIS control panels are identical, the radar images displayed on the NDs are refreshed every 6 seconds. On the contrary, when two different ranges are selected on the EFIS control panels, the images are refreshed every 12 seconds.
(c)
Windshear scan pattern The windshear processing is operating during right-to-left scans and left-to-right scans. The antenna scans only plus or minus 60 deg. The detected windshear targets are displayed only in the area plus or minus 30 deg. From the aircraft centerline. When the two ranges selected on both EFIs control panels are identical, the radar images displayed on the NDs are refreshed every 6 seconds. On the contrary, when two different ranges are selected on the EFIS control panels the images are refreshed every 12 seconds.
NOTE : For roll angle exceeding 28 deg., the windshear detection
____
is not active.
(d) Not Applicable
R 1EFF : 051-099, 106-149, 201-299, 301-399, 1 34-41-00Page 50 1401-499, 1Config-3 Aug 01/05 1 1 1CES 1
**ON A/C 001-049, 101-105, 151-199,
B. Timing of Transmitted Pulses in WX/MAP Mode and in Doppler Mode (Turbulence) and W/S Mode (Ref. Fig. 010)
-
in the WX and MAP modes, the basic period of pulse transmission-reception is 5.25 ms. This causes an interrogation frequency (PRF) of 190 Hz. As two pulses are transmitted (6 micros and 18 micros), the specified PRF is 380 Hz. Both 6-micros and 18-micros pulses are used to cover all range scales
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：A320飞机维护手册 AMM NAVIGATION 导航3(36)
