TM 1-1510-223-10 8-20           Change 3 8-20.   BEFORE TAXIING. * 1.   BRAKE  DEICE  switch  —  Check  and  set  as required.  Ensure  both  bleed  air  valves  are open. * 2.   CABIN AIR MODE and TEMP controls — Set as desired. NOTE For maximum cooling on the ground, turn the PNEU & ENVIRO BLEED AIR valve switches to PNEU ONLY position. Verify airflow is present from aft cockpit eyeball outlets to ensure suffi- cient cooling for mission equipment. 3.   AC/DC Power — Check for: a.   AC frequency — 394 to 406 Hz. b.   AC voltage — 104 to 124 VAC. c.   DC voltage — 28 to 28.5 VDC. * 4.   AUTO PLT POWER switch — ON. * 5.   AVIONICS MASTER POWER switch — ON. * 6.   #1 and #2 EFIS POWER switches — ON. * 7.  Mission control panel switches — Set as re- quired. For mission flight, set as follows: a.   MISSION CONTROL switch — AUTO. b.   TDOA SYSTEM switch — ON. c.   DAT LINK HV switch — STBY. d.   ELINT BATTERY switch — ON. e.   ELINT POWER switch — ON. 8.  INS — Perform stored heading alignment, if required. NOTE Perform only if a stored heading shutdown was completed and the aircraft has not been moved. Only one stored heading alignment can be done between full alignments. a.   #1 and #2 3 inverters — RESET/ON. b.   BUS CROSS TIE  switch — AUTO. c.   INS mode switch — NAV. d.   INS   SETUP   page   —   Enter   alignment coordinates. e.   After reaching align state zero select auto- mixing mode. 9.   Weather radar — STDBY. 10.   Flaps — Check. 11.   Altimeters — Set and check. 8-21.   *TAXIING. Taxi speed can be effectively controlled by the use of power application and the use of the variable pitch pro- pellers in the ground fine range with the PROP levers re- tarded to the FEATHER detent. 1.   PROP levers — As required. 2.   Brakes — Check. 3.   Flight instruments — Check for normal opera- tion. 8-22.   ENGINE RUNUP. 1.  Mission control panel switches — After receiv- ing clearance from IPF, set as instructed: a.   ANT SEL switch — As required. b.   ANT STEERING switch — As required. c.   DATA LINK HV switch — ON. d.   ELINT    power    switch    (mission    status panel) — ON. e.   Mission  equipment  caution/advisory  an- nunciator  panel  —  Check  for  no  power fault lights. f.   ANT  SEL  switch  and  ANT  STEERING switches — Set AUTO when cleared by IPF. 2.   Propeller feathering — Check by pulling PROP levers aft past the detent to FEATHER. Check that each propeller feathers, then advance lev- ers to the HIGH RPM position. 3.   Autofeather/auto ignition — Check as follows: a.   AUTO IGNITION switches — ARM. b.   POWER   levers   —   Approximately   25% torque.