BOMBARDIER Challenger 601-3A CL-600-2B16 Pilot Training Manual page 399

Operation
Fore or aft movement of either control column
mechanically positions the control valves of
all four elevator PCU's. This directs the No.
1 and No. 3 hydraulic systems' pressures to the
left elevator's PCU's and No. 2 and No. 3 sys-
tems' pressures to the PCU's on the right el-
evator. As the elevators deflect, followup
linkages reposition the control valves to neu-
tral, stopping and holding the elevators in the
selected position. Elevator position is dis-
played at all times on the flight SURFACE
position indicator (Figure 15-5).
If a control valve on any of the elevator PCU's
jams, the amber PITCH light on the servo
monitor panel illuminates (Figure 15-6).
The FLT CONT annunciator also illuminates,
and the MASTER CAUTION lights flash.
STABILIZER TRIM
General
Pitch trim is accomplished by varying the
angle of incidence of the horizontal stabilizer
with an actuator incorporating two electric
motors. Each motor is capable of high-or low-
speed operation, and incorporates a braking
PITCH TRIM
PITCH TRIM
DISC BUTTON
SWITCH
AC
BUS
2
DUAL-
CHANNEL
CONTROL
UNIT
CHANNEL 1
CHANNEL 2
AC
ESS
BUS
Figure 15-10. Stabilizer Trim System
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
CL-600-2B16 PILOT TRAINING MANUAL
device that prevents actuator overspeed and
overtravel. A control unit determines rate and
motor drive direction.
The two channels of operation are powered by
separate buses to prevent loss of trim capability
in the event of failure of one bus. Automatic
as well as pilot transfer of channels is provided.
Trim commands originate at the trim switch
on either the pilot's or copilot's control wheel,
the autopilot, or the Mach trim system.
Operation
To arm the pitch trim system, press the CHAN
1 INOP–CHAN 2 INOP switchlight to engage
Channel 2; then press the OVSP–CHNG CHAN
switchlight to engage Channel 1 (Figure 15-4).
The system is now armed for Channel 1 opera-
tion, with Channel 2 in the standby mode, and
both switchlights will be extinguished.
Movement of the pitch trim switch on either
control wheel (Figure 15-10) causes the No.
1 motor to drive the stabilizer in the selected
direction at the rate of 0.5° per second.
Stabilizer position is shown on the STAB po-
sition indicator. As the stabilizer moves, mo-
tion is imparted to the control valves of the
elevator PCU's.
STABILIZER
SCREWJACK
(FEEDBACK)
ACTUATOR
MOTOR MOTOR
1
TO STABILIZER
TRIM CONTROL
PANEL
(SEE FIGURE 15-4)
TO STABILIZER
TRIM POSITION
INDICATOR
2
PRIORITY
1. PILOT TRIM SWITCH
2. COPILOT TRIM SWITCH
3. AUTOPILOT
4. MACH TRIM
CL 601-3A/R 15-9
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