TM 1-1510-223-10 Change 3          8-23 CAUTION Do not operate the weather radar system in a confined space where the nearest metal wall is 50  feet  from  the  antenna  reflector.  Scanning such surfaces within 50 feet of the antenna re- flector may damage receiver crystals. NOTE The weather radar system should be test before each flight on which the system is to be used. 12.   Weather radar — Test and set as required: a.   RADAR mode selector switch — SBY. b.   LSS mode selector switch — SBY. c.   WX push-button selector switch (display controller) — Depress. Observe that EHSI displays partial compass heading arc. WARNING The radar transmitter is radiating X band micro- wave energy when in the test (TST) mode. d.   RADAR mode selector switch — TST.  Observe that WX mode annunciator on EHSI remains in STBY. e.   Range switches (radar control panel) — Depress   both   switches   simultaneously. Observe  that  WX  mode  annunciator  on EHSI changes from STBY to TEST, and that magenta, red, yellow, and green are displayed. A green noise band will appear at the upper arc range marking. f.   RADAR  mode  selector  switch  —  SBY, then as required. g.   Range switches (radar control panel) 50 NM or greater. h.   LSS mode selector switch — CLR TST. i.   EHSI — Verify that a white lightning rate symbol appears at approximately 25 NM at 45 degrees right of center and a magen- ta  lightning  alert  symbol  is  displayed  at maximum selected range at 45 degrees right of center. NOTE While the aircraft’s weight is on the wheels, the weather radar system is forced into the standby mode. This is a safety feature that prevents the radar from transmitting on the ground to elimi- nate the microwave radiation hazard. 8-23.   * BEFORE TAKEOFF. 1.  AUTOFEATHER switch — ARM. 2.  PNEU & ENVIRO BLEED AIR valves (2) — As required. CAUTION Pitot heat should not be used for more than 15 minutes while the aircraft is on the ground. Over- heating may damage the heating elements. 3.  ICE  &  RAIN  switches  —  As  required.  As  a minimum,  PITOT,  STALL  WARN,  and  FUEL VENT switches shall be ON. 4.  Fuel panel — Check fuel quantity and switch positions. 5.   Flight  and  engine  instruments  —  Check  for normal indications and EFIS display controller is set to desired setting. 6.  CABIN CONTROLLER — Set. 7.   Annunciator  panels  —  Check  (note  indica- tions). 8.   Flaps — As required. 9.   Trim — Set. 10.  ASE/ACS — Set. 11.  Avionics — Set. 12.   Flight controls — Check. 13.   Departure briefing — Complete. 8-24.   * LINE UP. 1.  Engine anti-ice — As required. 2.  Engine AUTO IGNITION switches — ARM. 3.   PROP levers — HIGH RPM.