Flight Controls Flashcards Preview

B757 > Flight Controls > Flashcards

Flashcards in Flight Controls Deck (29):

What causes the MACH/SPEED TRIM light to illuminate?

Mach/Speed trim system has failed.


What condition causes the STAB TRIM light to illuminate?

Stabilizer trim rate is 1/2 the normal control wheel switch rate.


Describe how to override a jammed control column.

Apply significant control column force in either direction on the other column.


How are the stabilizer trim motors powered?



When will the stabilizer trim "OFF" flag appear in the Stabilizer Trim Indicator?

When the trim indicator is inoperative.


What condition causes the "UNSCHED STAB TRIM" light to illuminate.

Uncommanded stabilizer motion or alternate trim is used with the autopilot engaged.


What do the STAB TRIM CUTOUT switches do in the "CUTOUT" position?

Remove all hydraulic power from the stabilizer.


At what rate will the autopilot trim the stabilizer?

1/2 the electric or alternate trim rate.


What type of trim will override the input of Electrical Trim switches on the control wheel?

Alternate Trim


What happens if a control column input is made opposing the direction of stabilizer trim?

The stabilizer trim is interrupted.


Which hydraulic systems supply pressure to the rudder?

All three systems (L, C & R).


What will cause the YAW DAMPER INOP light to illuminate?

Yaw Damper Inoperative.


Describe the function of the Rudder Ratio System.

The control commands from the rudder pedals and trim control are modified by the rudder ratio changer. As airspeed increases the ratio changer desensitizes these commands from the pilot to reduce rudder deflection. The system receives ADC airspeed input and provides commands to an actuator powered by the Left Hydraulic System.


When will the "RUDDER RATIO" light be illuminated?

When the Rudder Ratio System has failed. Rudder structural protection is provided by automatic depressurization of the left hydraulic system actuator which limits rudder displacement at high airspeeds.


Which hydraulic system powers the Rudder Ratio Changer?



What condition will illuminate the "SPOILERS" light?

When one or more spoiler pairs are inoperative.


What two conditions will illuminate the "SPEEDBRAKES" light?

Speedbrakes are extended when:

Flaps are in a landing position

Radio altitude is 800' or below.


When would automatic speedbrake deployment occur?

With the lever in the "ARMED" position, landing gear fully on ground (not tilted) and thrust levers at idle.

On the ground when either reverse thrust lever is moved to the reverse idle detent (lever does not need to be in "ARMED" detent).


When will the speedbrakes deploy if they are not armed prior to landing.

Thrust reverser levers (either) moved to reverse idle detent.


What will cause the "AUTO SPDBRK" light to illuminate?

A fault in the system. Note: the light may momentarily flash when moving the lever to the "DOWN" position after automatic deployment.


What happens to the Slats and Flaps when "Flaps 1" is selected?

Slats move to mid-range and flaps move to 1.


How does stall warning affect the Auto Slat System?

When receiving a signal from the stall warning system, the slats automatically move from the mid-range to the fully extended position. The retract to mid-range again a few seconds after the signal is removed.


When do the slats move to the landing position?

Flaps 25


How does the Flap Load Relief system operate?

If the Flap Placard speed is exceeded with the flaps in the 30 position, the flaps automatically retract to 25. When airspeed is reduced the flaps re-extend automatically.


What illuminates the "TRAILING EDGE" light?

It illuminates when the trailing edge flaps disagree with the commanded position and they are not driving toward the selected position, a flap asymmetry exists or load relief did not function properly. All hydraulic power to both flaps and slats is removed.


What illuminates the "LEADING EDGE" light?

It illuminates when the leading edge slats disagree with the commanded position and they are not driving toward the selected position or a slat asymmetry exists. All hydraulic power to both flaps and slats is removed.


What happens when either ALTN Flaps switch is placed in the ALTN position?

Arms the respective Flap/Slat alternate drive unit and shuts off hydraulic power to both the flap and slat drive systems.


What type of asymmetry and load relief protection is available when using ALTN extension?

Slat Asymmetry Only.


When do the Slats extend to the landing position during ALTN extention?

Flaps 20