Learjet 60 - APU Operating Procedures; APU Pre-Start Check

Learjet 60

Pilot's Manual
APU
OPERATING PROCEDURES
APU PRE-START CHECK
This check should be accomplished in addition to the Preflight
Inspection in Section II of the FAA approved Airplane Flight Manual .
1 . APU Oil Level - Check .
2 . Check APU area for indications of oil or fuel leaks .
3 . FUEL, GEN, & POR (Point of Regulation) Circuit Breakers
(APU Relay
Panel}-
Set .
4 . APU Inlet & Exhaust - Clear .
5 . FIRE, APU, & GEN
Circuit
Breakers (APU Control Panel] -- Set .
BATTERY I & BATTERY 2 Switches - On .
U (if desired) - Connect .
Verify 18 volts minimum
are
available bar
starting
the APU .
9 . Aircraft 60-001 thru 60-072, Fuselage Fuel Quantity - Check .
10 . Aircraft 60-073 and Subsequent, Left Wing Fuel
Quantity - Check .
11 . APU MASTER Switch - Press . Verify ON, START, STOP and
AMPS indicator all illuminate .
12 . APU SYSTEM TEST Switch - Press . APU fire horn sounds,
APU FIRE warning switch, all APU annunciator lights illumi-
nate and the digital AMPS indicator displays all 8's .
APU START-UP
To start the APU :
1 . BCN/STROBE Switch - BCN .
I APU START Switch - Press (momentarily) . An automatic start
sequence is initiated and the
following events will
occur :
-
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The APU engine start relay
receives starting power from the
ircraft batteries
or external power .
At 5% RPM the APU fuel shutoff valve opens .
At 65% RPM the starter is de-energized .
At 98% RPM + 20 seconds the green RUNNING annunciator
illuminates indicating the APU is ready to provide electrical
power . If external ground power is no
being used,
me APIJ
generator will automatically go
on-line
and the AMPS indi-
cator
will indicate
the APU
generator
load .
3 . GPU (if applicable) - Disconnect .
PM-123
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2-49
Change 4