allow the crew to select primary or secondary
trim operation or to turn both systems off in
the event of a malfunction (Figure 15-14).
The three switch positions are labeled PRI,
OFF, and SEC. When primary trim is selected,
the crew controls pitch trim through either
Control Wheel Trim Switch (CWTS) on the
outboard horn of the control wheels. When
OFF is selected both trim systems are inop-
erative and a white “PITCH TRIM OFF” CAS
message is displayed. When secondary trim is
selected the crew controls pitch trim through
a two-segment spring-loaded toggle on the
center pedestal and a white “SEC PITCH
TRIM” CAS message is displayed.
The monitor systems in the primary trim ac-
tuator and the #1 IC-600 should detect and
stop an uncommanded trim malfunction, how-
ever, the crew can also disable primary and sec-
ondary trim by depressing and holding either
Control Wheel Master Switch (MSW). Trim
can also be disabled by selecting the pitch
trim selector switch to OFF or by pulling the
PRI PITCH or SEC PITCH circuit breakers.
Primary Pitch Trim
General
Normally the pitch trim selector switch, on the
center pedestal, is positioned to PRI. This po-
s i t i o n e n a b l e s t h e C o n t r o l W h e e l Tr i m
Switches (CWTS) and causes commands from
either of these switches to be processed by
the #1 IC-600. The #1 IC-600 sends trim com-
mands to the primary motor on the stabilizer
actuator (Figure 15-13).
Following is a summary of the different pri-
mary trim modes of operation:
• Manual Operation
- Normal primary pitch trim. Actuated
through either CWTS. The #1 IC-600
controls trim speed and monitors oper-
ation.
- IC-600 bypass. Trim is actuated by ei-
ther CWTS. Trim speed is determined by
flap setting. Configuration trim and
Mach trim are inoperative.
• Automatic Operation
- Configuration trim. Controlled by #1
IC-600 for changes in spoiler or flap
position.
- Mach Trim, controlled by #1 IC-600
in response to changes in Mach number.
Except for IC-600 bypass, all of the primary
pitch trim modes listed above are controlled
and monitored through the #1 IC-600.
Primary Manual Trim
The #1 IC-600 receives trim commands from
either CWTS. A CWTS is located on the out-
15-14
FOR TRAINING PURPOSES ONLY
L E A R J E T 4 5 P I L O T T R A I N I N G M A N U A L
FlightSafety
international
Figure 15-14. Trim Control Panel