Flight Controls Flashcards
Which hydraulic system(s) can power all primary flight controls?
Either hydraulic system A or B
Standby hydraulics only power
-Rudder
-Standby yaw damper
-LED extension
-Thrust reversers
What are the secondary flight controls?
High lift devices (flaps/slats)
Drag devices (speedbrakes)
Roll augmentation (spoilers)
Flaps and Slats are normally powered by? Alternate power source?
Hydraulic system B
Alternate power sources
TE flaps
–Electric motor
LEDs
–Standby hydraulics (extension), or
–PTU
—-Autoslats
—-LED retraction w/ low HYD sys B pressure
What happens when placing a FLT CONTROL switch to STBY RUD?
Activates standby hydraulic system
–STBY RUD ON illuminates
–Arms LOW QUANTITY (<50%) light
Opens standby rudder shutoff valve
Inhibits respective FLT CONTROL LOW PRESSURE light
Yaw damper disengages if system B
What is Speed Trim? What does it provide?
Speed stability system
Returns aircraft to a trimmed speed (using stabilizer trim)
High AOA stall protection
What are the significant conditions required for Speed Trim to operate?
A/P not engaged
Airborne +10 sec
Electric trim switch release +5 sec
Flaps extended, or gear retracted, or CAS < 226kts
*operates mostly during takeoff, climb, go-around
*low speed, weight, aft CG, high thrust
What are the indications of a Speed Trim System fault/failure?
SPEED TRIM FAIL (amber)
Speed trim has failed
Dual channel system, on RECALL then only a single channel has failed
Which system(s) help in identifying and controlling stalls?
Stall Management Yaw Damper (SMYD) computers
-Stick shaker
-Pitch Limit Indicators (PLIs)
-Yaw damper reduced
Speed Trim
-Trims stabilizer nose down
Elevator Feel Shit
-Increases control column forces
Yaw Damper
-Rudder movement reduced by SMYD
FMC BUFFET ALERT
What does the SMYD computer use to determine a stall warning is necessary?
AOA
ADIRUs
Anti-Ice position
Wing configuration
Thrust
FMC outputs
Mach compensation
Air/ground logic
What is Mach Trim? What does it provide?
Speed stability system
Compensation for nose down (tuck) tendencies at higher Mach
Also, additional nose-up elevator during low-speed maneuvering
What are the indications of a Mach Trim fault/failure?
MACH TRIM FAIL (amber)
Mach trim system has failed
Dual channel system, on RECALL then only a single channel has failed
How can Speed Trim System be overridden? Inhibited?
Overridden by
-Electric trim (5 seconds)
-Manual trim
Inhibited by
-A/P engaged
-Control column cutout switches activated
-A/P STAB TRIM CUTOUT switch to CUTOUT
-Bank > 40*
What is the purpose of the stall warning “stick shaker”?
Alert the pilot before a stall develops
What is required to activate the main yaw damper? Standby yaw damper?
Main Yaw Damper
-Hydraulic system B pressure
-FLT CONTROL switch B is ON (normal, guarded position)
-SMYD(s)
-Yaw Damper switch ON
Standby Yaw Damper
-Both FLT CONTROL switches to STBY RUD
-Standby hydraulic pressure
-Yaw Damper switch recycled to ON
What would cause the speedbrake to automatically stow after deployment on landing or an RTO?
Thrust lever advancement (either)
How are the ailerons, elevators, spoilers, and rudder operated in Manual Reversion?
Ailerons – manually (captain yoke)
Spoilers – manually (F/O yoke)
Elevators – manually (both yokes control respective elevator)
Rudder – Standby Hydraulic system
How is roll controlled with jammed spoilers? Ailerons?
Apply force to yokes
Captain has control of ailerons (jammed spoilers)
F/O has control of spoilers (jammed ailerons)
How is the stabilizer trim normally powered? Alternately?
Electric trim motor (one), or
Manually rotating the stabilizer trim wheel
Through the Alternate Flaps UP/DOWN switch, how are the LEDs and TE Flaps operated?
LEDs
-Standby Hydaulics
-FULL EXT only
-Once extended, cannot be retracted (unless HYD SYS B available)
TE Flaps
-Electric motor
-Slow flap transit (plan Flaps 15 landing)
-TE flaps capable of full extension**
-No asymmetry/skew/uncommanded motion protection
-No flap load relief
What is the purpose of the flap load relief system?
Protects TE flaps from excessive air loads
Available for flaps 10-40 (SFP/900ER/MAX)
–Flaps 30/40 for -700 and -800/-900 non-SFP
Retracts one notch, and only one notch
Re-extension once slowed
What protections are provided during an alternate flap extension?
None.
Protections lost
-Asymmetry
-Skew
-Uncommanded motion
-Flap load relief
-Autoslats/PTU
What does LE FLAPS TRANSIT (amber) light indicate?
Any LE device is in transit, or
Any LE device not in correct position regarding TE flaps, or
LE uncommanded motion (2 or more LEDs)
Reprogrammed to FULL EXT/Flaps 15 for alternate flap extion
Inhibited during autoslat operation
How is the Standby Yaw Damper activated?
Both FLT CONTROL switches position to STBY RUD
Yaw Damper switch recycled to ON
When will the SPEEDBRAKES EXTENDED (amber) light illuminate?
Airborne
-Speed brake lever beyond armed, and
-Flaps > 10 or RA < 800’
Ground
-Speed brake lever DOWN, and
-Ground spoiler pressure >750psi (ground spoilers may be extended) Do not takeoff!
