8-20 Change 3
8-20. BEFORE TAXIING.
* 1. BRAKE DEICE switch Check and set as
required. Ensure both bleed air valves are
* 2. CABIN AIR MODE and TEMP controls Set
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
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
e. After reaching align state zero select auto-
9. Weather radar STDBY.
10. Flaps Check.
11. Altimeters Set and check.
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-
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
e. Mission equipment caution/advisory an-
nunciator panel Check for no power
f. ANT SEL switch and ANT STEERING
switches Set AUTO when cleared by
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%