Hawker 800 XP, Pilot Training Manual

Page: 215 / 504

6-13
FOR TRAINING PURPOSES ONLY
HAWKER 800 XP PILOT TRAINING MANUAL
FlightSafety
international
APU STARTING
General
The APU should not be started until the prestart
checklist is completed and all discrepancies
are corrected. When ready to start the APU,
push the TURBINE START switch momen-
tarily and then release the switch. Monitor
the APU rpm and EGT until both stabilize at
the termination of the start sequence.
CAUTION
If EGT exceeds the red line value or
if rpm hangs or decreases during the
start sequence, turn off the APU
MASTER switch and do not attempt
another start until 30 seconds after
the APU rpm reaches 0%.
Following a normal start, if the APU genera-
tor ammeter does not show a lead, momentarily
move the GENERATOR switch to ON, then re-
lease the switch and monitor the EGT gage.
NOTE
EGT will increase when the APU
generator is turned on.
A start inhibit facility prevents APU
starting while on external power and
the EXT BATT CHG switch, located
on the pilots’ roof panel, is set to ON.
The APU generator will not connect
to the bus system if the external
power generator is supplying the
bus system.
Before turning the APU BLEED AIR
switch on, the APU rpm will indicate
approximately 102%.
If bleed-air extraction is required for the en-
vironmental system, turn on the APU BLEED
AIR switch. EGT will increase and rpm will
decrease.
NOTE
APU EGT is an indirect function of
the cabin temperature controller. If
the controller is at the maximum heat
position, the APU EGT will be high.
Remember, APU EGT will rise in
proportion to the bleed-air valve
opening and the DC generator lead.
ELECTRICAL POWER
SOURCES
GARRETT AND TURBOMACH
APU
PE bus bar
• APU master switch
• Fire warning system
• Fire extinguisher