TM 55-1510-220-10
Figure 2-19. Control Locks
a.
Elevator Trim Tab Control. The elevator trim tab
control wheel placarded ELEVATOR TAB DOWN, UP, is
on the left side of the control pedestal and controls a trim
tab on each elevator (fig. 2-8). The amount of elevator
tab deflection, in degrees from a neutral setting, is
indicated by a position arrow.
b.
Electric Elevator Trim. The electric elevator trim
system is controlled by an ELEV TRIM PUSH ON PUSH
OFF switch located on the pedestal, dual element thumb
switches on the control wheels, a trim disconnect switch
on each control wheel and a circuit breaker on the
overhead circuit breaker panel. The PUSH ON PUSH
OFF switch must be in the ON position to operate the
system. The dual element thumb switch is moved
forward for trimming nose down, aft for nose up, and
when released returns to the center (off) position. Any
activation of the trim system through the copilot's trim
switch can be cancelled by activation of the pilot's switch.
Operating the pilot's and copilot's switches in opposing
directions simultaneously results in no trim action. A
preflight check of the switches should be accomplished
before flight by moving the switches individually on both
control wheels. No one switch alone should operate the
system; operation of elevator trim should occur only by
movement of pairs of switches. The trim system
disconnect is a bi-level, pushbutton, momentary type
switch, located on the outboard grip of each control wheel.
Depressing the switch to the first of two levels disconnects
the autopilot and yaw damp system, and the second level
disconnects the electric trim system. The system can be
reset by pressing the ON OFF switch on the pedestal to
ON again.
c.
Aileron Trim Tab Control. The aileron trim tab
control, placarded AILERON TAB LEFT, RIGHT, is on the
control pedestal and will adjust the left aileron trim tab
only (fig. 2-8). The amount of aileron tab deflection, from
a neutral setting, as indicted by a position arrow, is
relative only and is not in degrees. Full travel of the tab
control moves the trim tab 7-1/2 degrees up and down.
d.
Rudder Trim Tab Control. The rudder trim tab
control knob, placarded RUDDER TAB LEFT, RIGHT, is
on the control pedestal, and controls adjustment of the
rudder trim tab (fig. 2-8). The amount of rudder tab
deflection, in degrees from a neutral setting, is indicated
by a position arrow.
2-42. WING FLAPS.
The all-metal slot-type wing flaps are electrically
operated and consist of two sections for each wing.
These sections extend from the inboard end of each
aileron to the junction of the wing and fuselage. During
extension, or retraction, the flaps are operated as a single
unit, each section being actuated by a separate jackscrew
actuator. The actuators are driven through flexible shafts
by a single, reversible electric motor. Wing flap
movement is indicated in percent of travel by a flap
position indicator on the forward control pedestal. Full
flap extension and retraction time is approximately 11
seconds. The flap control switch is located on the control
pedestal. No emergency wing flap actuation system is
provided. With flaps extended beyond the APPROACH
position, the landing gear warning horn will sound, unless
the landing gear is down
2-38
