Weather Radar and PWS Control Panel is part of A320 pedestal
System Switch #
WEATHER RADAR OPERATION –
The Weather Radar provides normal weather radar operation plus Doppler detection of turbulence by measuring the velocity of rain droplets moving parallel to the airplane flight path. Turbulence may be displayed in light rain or entirely outside the precipitation area. Although Doppler cannot detect clear air turbulence, it can detect turbulence in the presence of rain lighter than that displayed in the weather-only mode. Turbulence returns and Level 4 and higher storms are displayed in magenta. These areas can be very dangerous.
SYSTEM SWITCH –
SYS Switch activates the weather radar for display on the ND in any mode except PLAN whenever the switch is selected to ON
Image Selector #
WX – The WX selection provides 180° display of continuously updated weather radar information on the Navigation Display.
MAP – The MAP selection operates the radar in ground mapping mode:
- Black color indicates water
- Green color, ground; and
- Amber color, cities and mountains
WX/TURB – The WX/TURB selection provides 180° display of turbulence and weather to 40 NM, and weather only beyond 40 NM.
Tilt Selector #
TILT – The TILT Selector controls antenna tilt angle with reference to horizon. Tilt angle is displayed on lower right corner of ND. Clockwise rotation commands tilt up, and counterclockwise commands tilt down.
Gain Selector #
The GAIN Selector adjusts the sensitivity of the receiver. It provides automatic gain adjustment when positioned to AUTO, and manual adjustment up to MAX.
PWS – Predictive Windshear Switch #
OFF – The OFF selection deactivates PWS.
AUTO – The AUTO selection activates the PWS provided:
- One engine is operating
- The airplane is below 2300 feet RA
- The TCAS/XPDR switch is in any position other than STBY (if the weather radar SYS switch is selected ON, the PWS operates regardless of transponder switch position)
Predictive Windshear Alerts – Operates only below 2300 feet RA and provides alerts from approximately 10 seconds in front of the airplane out to a distance of 5 NM within 40° of airplane heading. The type of alert provided depends on the location of the windshear relative to aircraft position, aircraft altitude, and phase of flight (takeoff or landing). During takeoff, new alerts are inhibited from 100 knots until 50 feet RA. During approach, new alerts are inhibited from 50 feet RA until 60 knots. Existing alerts will not be removed.
PWS increases alerting time over that provided by the reactive windshear system. This provides pilots the opportunity to either avoid a windshear, or take action to increase the energy state of the aircraft prior to encountering windshear.
PWS uses Doppler capability of the weather radar to detect the presence of low altitude horizontal wind flow and to predict the presence of one or more windshear occurrences.
