Flight Controls Flashcards
Name the Powered Flight Control Surfaces (PFCS)
elevators, spoilers, rudder
What is the FCECU?
Flight Control Electronic Control Unit, located under the passenger floor, single electronic unit divided into two channels which send electrical outputs to primary and secondary flight control systems, flight data recording systems, advisory systems, and caution indicating systems
What is the FCECU powered by?
left channel - left essential DC bus
right channel - right essential DC bus
How is the elevator controlled and powered?
mechanically controlled by two fully independent cable and pulley control circuits (left control column controls left elevator, right control column controls right elevator), hydraulically powered by three identical Power Control Units (PCUs)
Which elevator PCUs are powered by which hydraulic system?
outboard - hyd system 1
center - hyd system 2
inboard - hyd system 3
What prevents an elevator PCU runaway?
input bungees
What prevents damage to the elevator control circuit in the event of a PCU jam?
two overload bungees installed in the horizontal stabilizer, one in each elevator circuit
What provides gust lock protection and elevator flutter suppression?
elevator PCU compensator installed in the return line of the No. 3 hydraulic system
What provides elevator artificial feel and pitch trim inputs?
two identical Pitch Feel and Trim Units (PFTUs) located in the upper section of the vertical stabilizer
ELEVATOR PRESS caution light
all 3 hydraulic systems are supplying pressure to elevator
ELEVATOR ASYMMETRY caution light
position mismatch between the left and right elevator control surfaces
ELEVATOR FEEL caution light
one of the FCECU channels is not able to control the pitch trim actuator
PITCH TRIM caution light
one of the FCECU channels is not able to control its related pitch trim actuator or Pilot and Copilot pitch trim input commands are different
How is the rudder controlled and powered?
mechanically controlled by rudder pedals which are connected by an interconnect rod, hydraulically powered by 2 PCUs
How is artificial feel for the rudder provided?
mechanical feel spring unit
What rudder PCUs are powered by which hydraulic system?
lower PCU - hydraulic system 1
upper PCU - hydraulic system 2
Deflection of rudder sections
full deflection, aft section - 36 degrees
full deflection, fore section - 18 degrees
flap 0 limited, aft section - 24 degrees
flap 0 limited, fore section - 12 degrees
What is rudder deflection limited by?
regulated by FCECU in response to airspeed
What does the Rudder Feel/Trim and Summing Unit do?
provides artificial feedback forces on rudder pedals and sums rudder trim and yaw damper inputs and then commands a single input to the rudder PCUs
RUD 1 switchlight
mechanical jam in lower rudder PCU, depressurizes PCU when pushed
RUD 2 switchlight
mechanical jam in upper rudder PCU, depressurizes PCU when pushed
1 RUD HYD caution light
hydraulic pressure to the No. 1 rudder actuator less than 500 psi +/- 50 psi
RUD CTRL caution light
no hydraulic pressure to the rudder actuators
ROLL SPLR OTBD GND caution light
FCECU can’t control the outboard spoiler lift-dump operation or the outboard spoilers do not extend at touchdown or the outboard spoilers extend after the TAXI mode selection after touchdown
SPLR OUTBD caution light
FCECU has failed to inhibit at greater than 170 KIAS or has failed to re-enable below 165 KIAS
ROLL SPLR OUTBD HYD caution light
No. 2 hydraulic system pressure is less than 900 psi
2 RUD HYD caution light
hydraulic pressure to the No. 2 rudder actuator less than 500 psi +/- 50 psi
FLAP DRIVE caution light
flap drive system malfunction
FLAP POWER caution light
low hydraulic pressure in flap power unit during flap extension or retraction
ROLL SPLR INBD GND caution light
FCECU can’t control the inboard spoiler lift-dump operation or the inboard spoilers do not extend at touchdown or the inboard spoilers extend after the TAXI mode selection after touchdown
ROLL SPLR INBD HYD caution light
no hydraulic pressure to the inboard roll spoiler actuators
How are the ailerons controlled and operated?
mechanically via the co-pilot’s control wheel
What do the aileron geared tabs do?
move in the opposite direction of the aileron to reduce control force
Where is the ground adjustable trim tab located?
right aileron
How does the aileron trim work?
an Aileron Trim and Centering Unit (ATCU) transfers trim input commands from the aileron trim actuator to the aileron forward quadrant, the forward quadrant rotates and deflects both aileron control surfaces
What happens during an aileron trim runaway?
a travel limit switch automatically shuts off electrical power to the trim actuator causing it to stop at the maximum trim input, if the limit switch fails a mechanical stop on the trim actuator will stop it at the maximum trim setting
What are the three modes of spoiler operation?
flight mode, ground mode, taxi mode
What hydraulic systems powers which spoilers?
inboard - 1 hydraulic system
outboard - 2 hydraulic system
At what speed are the outboard spoilers deactivated?
above 170 KIAS
SPLR 1 switchlight
PCU linkage jam and spoiler clutch disengagement, pushing button shuts off extension pressure to inboard spoiler PCUs
SPLR 2 switchlight
PCU linkage jam and spoiler clutch disengagement, pushing button shuts off extension pressure to outboard spoiler PCUs
Type of flaps
single-slotted inboard and outboard fowler flaps
How are the flaps operated?
flaps are connected to screw jacks which are operated by a drive shaft, a hydromechanical Flap Power Unit (FPU) is electrically activated by the Flap Control Unit (FCU), the FPU converts hydraulic power to rotary mechanical power
What hydraulic system provides power to the Flap Power Unit?
No. 1
The Stall Protection System operates when these conditions are met:
CAS less than 215 its
altitude more than 200 ft agl
stick pusher SHUT OFF switchlight not OFF
What does the REF SPEEDS INCR switch do?
sets the stall-operating angle for stick shaker activation and stick pusher activation to a relatively lower angle of attack
1 STALL SYST FAIL caution light
no. 1 stall warning system malfunction or no vane heater current is detected
2 STALL SYST FAIL caution light
no. 2 stall warning system malfunction or no vane heater current is detected
PUSHER SYST FAIL caution light
stick pusher malfunction or no vane heater current is detected
How much force is required to override the stick pusher?
80 pounds
