WEATHER RADAR (RDR 1400C) SYSTEM : Purpose of the system: • The Primary use of this radar is to aid pilot in avoiding thunderstorms and associated turbulence. • The RDR1400C color vision weather radar system also has the capability for surface mapping and to receive signals from beacon Transponders. • The Primary system components of weather Radar system are • Receiver – Transmitter unit, • Radar Control panel, • Antenna Drive & Antenna Array and • Navigation concentrator. • There are two modes of operation : • 1. Normal mode of operation (Operation via Radar control panel) • 2. Back up mode of operation (Operation via MFD) Function selector: • OFF ---- Removes system power. • SBY ----system is operationally ready, no display (Standby mode). • TST ----Displays a test pattern without transmitting, identified by ‘TEST’ and ‘RT FAULT’. • ON -----Systems transmits in normal operation • 60 Narrows antenna scan from 120 deg to 60 deg. Putting back the switch to ‘ON’ • position widens the antenna scan to 120 deg. Antenna Controls: • TILT Adjusts antenna tilt angle. • STAB OFF System transmits without antenna stabilization; ‘STB OFF’ displayed. This function is used in event of AHRS failure in flight. • Stabilization Range: ± 30 degs combined pitch, roll & tilt. Primary mode selectors: • Wx ----- Selects weather mode, the primary mode of operation. The ‘Wx’ appears at the bottom left of the display. • WxA -----Selects weather alert mode. The ‘ WxA’ appears at the bottom left of the display. • “TGT ALRT” flashes at the top left of the display, if red return exists within 25 miles beyond the display range. • SRCH ---- Activates Search1 mode, sea clutter rejection (20 miles range or less) or Search 2 mode, short range precision mapping (20 mile range or less) or Search3 mode, normal surface mapping. ‘SR1/SR2/SR3’ appears at the bottom left of the display. Gain Controls: • SRCH GAIN : This rotary knob adjusts radar receiver gain when search mode is selected on control panel. Search gain value shall be displayed below the ‘SRCH GAIN’ title.