FLIGHT CONTROLS Flashcards
Explain the function of the STABILIZER TRIM brake switch:
The STABILIZER TRIM brake switch is a guarded switch and has two
positions: OFF and normal.
Normal: OFF light is extinguished and primary stabilizer trim is enabled.
Push - Stops horizontal stabilizer movement. Amber OFF illuminates and
electrical power to the brake is removed..
Recall the function of the STICK PUSHER PUSH TO INHIBIT switchlight
During detection of an imminent stall condition, the glareshield STICK
PUSHER PUSH TO INHIBIT switchlights illuminate and the autopilot, if in
use, disconnects. Abrupt forward movement of both control columns
occurs, followed by stick shaker deactivation.
Forward pressure on the control columns continues until the angle-ofattack is reduced below stick shaker onset, the gravity force is sufficiently
reduced, or a STICK PUSHER PUSH TO INHIBIT switchlight is pushed.
Recall how the stick pusher can be overridden:
The flight crew has the ability to override the stick pusher system by
pushing either switchlight.
Stick pusher is inhibited if a decreasing performance windshear is detected
May be manually overridden by pulling aft on the control column. However,
if stall persists and aft pressure released, the stick pusher will again force
the column forward.
Explain the function of the HYD CONT RUDDER switch
Allows selection of manual rudder operation
When the switch is pushed, OFF illuminates, hydraulic power to the rudder
is shut off, and rudder reverts to manual operation.
If manual mode is selected or if right hydraulic pressure is too low, the
rudder control tab unlocks. In manual mode, the rudder pedals move the
control tab on the rudder, and aerodynamic forces on the control tab move
the rudder.
Recall how slats are positioned:
Five individual slat sections on each wing operate as a single unit. Cables
connected to hydraulically powered drums position the slats.
The slat drum assemblies each have two hydraulic actuators, one powered
by the left hydraulic system and one powered by the right hydraulic system.
Either hydraulic system can operate the slats.
The slats are controlled with the FLAP/SLAT handle. There are two slat
positions, UP/RET and EXT
Recall the meaning of a level 2 alert, SLAT DISAG:
SLAT DISAG (CONFIG) - Left and right slat positions disagree with each other or with commanded position.
Recall how the stabilizer is trimmed using the primary trim switches:
When both primary trim switches on either control wheel are moved
simultaneously, the primary trim brake is released and the primary trim
motor drives the stabilizer in the commanded direction. Separate
movement of either switch does not produce stabilizer movement.
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A warning horn, inhibited on the ground, sounds to alert the crew any
time the stabilizer moves more than one degree, and continues to
sound once for each approximately one degree of stabilizer movement.
The “stabilizer motion” voice warning also sounds.
Explain the difference between the primary and alternate stabilizer trim
systems:
When both ALT LONG TRIM switches on the pedestal are moved
simultaneously, the alternate trim motor moves the stabilizer in the
commanded direction at a rate slower than the primary trim motor.
The autopilot trims the airplane using the alternate trim system.
Recall how stabilizer trim position is displayed:
Stabilizer position is displayed at the top of the SD synoptic secondary
engine page as follows:
1. Horizontal green bar displays the stabilizer range,
2. Position bug displays stabilizer relative position,
3. Digital readout displays the exact stabilizer position,
The stabilizer position is also displayed at the top of the CONFIGURATION
page of the SD synoptic, above the airplane symbol.
Recall how the elevators are normally positioned for pitch control:
The elevators are aerodynamically positioned by control tabs, which are
mechanically connected to the control columns.
A variable load feel mechanism simulates aerodynamic forces and returns
the control columns to an artificial center position when they are released.
Explain how pitch control is maintained if either control column jams
An override mechanism, installed on the torque tube connecting the two
control column, allows each column to operate independently, in the pitch
axis, should either side jam.
A substantial amount of force (about 130 pounds) must be applied to the
operable, free column, for the mechanical disconnect to occur. A single
audible “bang” sound may be heard from the base of the Captain’s control
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column, below the cockpit floor, as the disconnect occurs.
Once disconnected, maintenance is required to re-connects them.
Recall the function of the elevator augmentation system:
The elevator has two hydraulic boost cylinders that augment elevator
control during a deep stall recovery, providing additional nose down
capability.
Powered by the left hydraulic system with an accumulator backup in the
event system pressure is lost.
When the elevator augmentation system is activated by pushing the control
columns full forward, the elevators move to full deflection, trailing edge
down.
This is displayed on the CONFIGURATION synoptic
Explain how roll control is accomplished using ailerons and spoilers:
Ailerons are aerodynamically positioned by control tabs connected to the
control wheels.
Aerodynamic forces on the control tabs position the ailerons. For greater
roll control, with more than 5 degrees of control wheel input, the flight
spoilers extend a proportionate amount on the downward moving wing.
The ailerons are trimmed by a trim tab outboard of the control tab on each
aileron.
The AILERON TRIM switches, located on the pedestal, operate the trim
tabs for LEFT WING DOWN/RIGHT WING DOWN control
Recall how ground spoilers are automatically deployed on landing and
for a rejected takeoff:
When armed, the spoilers operate automatically to increase braking during
landing or a rejected takeoff by reducing lift and increasing drag.
Selecting reverse thrust deploys the spoilers for a rejected takeoff.
When landing, main wheel spin-up or a ground shift signal from the nose
gear deploys the spoilers.
Recall that spoilers will retract as throttles are advanced to a high thrust position:
If the throttles are advanced to high thrust while the speed brakes are
extended, the spoilers automatically retract
