9. Flight Controls Flashcards
FLT CONTROL Switches
STBY RUD:
- Activates Standby Hydraulic Pump,
- Opens Standby Rudder Shutoff Valve to,
- Pressurize Standby Rudder Power Control Unit
OFF:
- Closes Flight Control Shutoff Valve,
- Isolating Ailerons, Elevators and Rudder from associated hydraulic system pressure
Flight Control LOW PRESSURE Lights
- Indicates low hydraulic pressure to ailerons, elevator and rudder,
- Deactivated when related FLT CONTROL switch is positioned to STBY RUD and Standby Rudder SOV opens
YAW DAMPER Switch ON
- Engages Main Yaw Damper to Main Rudder Power Control Unit if the B FLT CONTROL switch is ON,
- Engages Standby Yaw Damper to Standby Rudder Power Control Unit if both FLT CONTROL switches in STBY RUD
STANDBY HYD Lights
LOW QUANTITY:
- Always armed
LOW PRESSURE:
- Armed only when Standby Pump operation selected or automatically activated
STBY RUD ON:
- Indicates the Standby Rudder System is commanded on to,
- Pressurize the Standby Rudder Power Control Unit
ALTERNATE FLAPS Master Switch ARM
- Closes TE Flap Bypass Valve to prevent hydraulic lock of the Flap Drive Unit,
- Activates Standby Pump,
- Arms the ALTERNATE FLAPS position switch
ALTERNATE FLAPS Position Switch
UP:
- Electrically retracts TE Flaps,
- LE devices remain extended and cannot be retracted by Alternate Flap System
DOWN:
- Momentary push fully extends LE Devices using Standby Hydraulic Pressure,
- Holding down electrically extends TE Flaps until released
No Asymmetry or Skew protection is provided
FEEL DIFF PRESS Light
- Armed when the TE Flaps are up or down,
- Indicates excessive differential pressure in the Elevator Feel Computer,
- Excessive pressure difference can be caused by erroneous activation of the Elevator Shift Module or,
- Elevator Feel Pitot System failure
SPEED TRIM FAIL Light
- Indicates failure of the Speed Trim System,
- Indicates failure of a single FCC channel during RECALL and extinguishes after reset
MACH TRIM FAIL Light
- Indicates failure of the Mach Trim System,
- Indicates failure of a single FCC channel during RECALL and extinguishes after reset
AUTO SLAT FAIL Light
- Indicates failure of the Auto Slat System,
- Indicates failure of a single SMYD Computer during RECALL and extinguishes after reset
SPEED BRAKE DO NOT ARMED Light
- Deactivated when SPEED BRAKE Lever is in the DOWN position,
- Indicates abnormal condition or test inputs to the Automatic Speed Brake system or,
- During landing, indicates wheel speed < 60KT and the Speed Brake Lever is not in DOWN
SPEED BRAKES EXTENDED Light
Inflight:
- SPEED BRAKE Lever beyond the ARMED position and,
- TE Flaps 15 or more or,
- RA < 800FT
On the ground:
- SPEED BRAKE Lever is in the DOWN detent and,
- Ground Spoilers are not stowed,
- Not illuminate if Hydraulic System A pressure is < 750psi
FLAP Lever
- Selects position of Flap Control Valve, directing hydraulic pressure for Flap Drive Unit,
- Flap Lever positions 30 and 40 arms the Flap Load Relief System,
- Flap Lever positions 10 or more arms the Flap Load Relief System (SFP)
Flap Gates
Prevents inadvertent Flap Lever movement during go-arounds
LE FLAPS TRANSIT Light
- Any LE Device in transit,
- Any LE Device not in programmed position with respect to TE Flaps,
- A LE uncommanded motion exists (2 or more LE Flaps or Slats have moved away from commanded position),
- During Alternate Flap extension until LE Devices fully extended and TE Flaps reach 10 (15 for SFP),
- Light is inhibited during Autoslat operation
LE FLAPS EXT Light
- All LE Flaps extended and all LE Slats in extended position (TE Flap positions 1,2 and 5 / 1 to 25 for SFP),
- All LE Devices fully extended (TE Flap positions 10 to 40 / 30 and 40 for SFP)
Primary Flight Controls Power Sources
- Either hydraulic system can operate all Primary Flight Controls,
- Ailerons and Elevator may be operated manually,
- Rudder may be operated by Standby Hydraulic System
Secondary Flight Controls Power Sources
- TE Flaps, LE Flaps and Slats are powered by hydraulic system B,
- If system B fails, TE Flaps can be operated electrically,
- Under certain conditions PTU automatically powers the LE devices,
- LE devices can also be extended using Standby Hydraulic pressure
Aerodynamically Effective Rudder
During T/O, rudder becomes effective between 40-60KT
Ailerons
- Provide roll control around the airplane’s longitudinal axis,
- CPTs Control Wheel is connected by cables to the Aileron Power Control Unit (PCU),
- F/Os Control Wheel is connected by cables to the Spoiler PCUs through Spoiler Mixer,
- 2 Control Wheels are connected by a Cable Drive System which allows:
- Actuation of both ailerons and spoilers by either Control Wheel
Aileron Transfer Mechanism
- If Ailerons or Spoilers are jammed,
- Force applied to CPTs or F/Os Control Wheel will identify which system is usable,
- CPTs or F/Os Control Wheel can provide roll control
Aileron Trim
- Dual AILERON Trim switches must be pushed simultaneously to command trim changes,
- Trim electrically repositions the Aileron Feel and Centering Unit,
- Which causes the Control Wheel to rotate and redefines neutral position,
- If Aileron Trim is used with the Autopilot engaged, the Trim is not reflected in the Control Wheel position
Flight Spoilers
- 4 Flight Spoilers on the upper surface of each wing,
- Each hydraulic system is dedicated to a different set of Spoiler pairs,
- A Spoiler Mixer connected to the Aileron Cable-Drive, controls hydraulic PCUs on each Spoiler panel to,
- Provide Spoiler movement proportional to Aileron movement,
- Spoilers rise on the wing with up ailerons and remain faired on the other wing,
- Spoiler deflection initiates when Control Wheel displaced around 10 degrees
Elevators
- Provide pitch control around the airplane’s lateral axis,
- Cables connect the pilots’ Control Columns to Elevator PCUs which are powered by hydraulic systems,
- The Elevators are connected by a Torque Tube
Elevator Control Column Override Mechanism
- In the event of a Control Column Jam, override mechanism allows Columns to be physically separated,
- Applying force against the jam will breakout either Control Column,
- Although total travel is significantly reduced, there is sufficient elevator travel for landing flare,
- Control Column forces are higher and exceed those experienced during Manual Reversion
Elevator Feel System
- The computer provides simulated aerodynamic forces using:
1-) Airspeed (from the Elevator Pitot System) and,
2-) Stabilizer Trim position, - Feel is transmitted to the Control Columns by the Elevator Feel and Centering Unit,
- Computer uses the higher hydraulic system pressure
Mach Trim System
- Provides speed stability at higher Mach numbers (> .615),
- Adjusting the Elevators with respect to the Stabilizer as speed increases,
- FCCs use Mach information from ADIRU to computate a Mach Trim actuator position,
- Actuator repositions the Elevator Feel and Centering Unit which adjusts the Control Column neutral position
Stabilizer Trim
- Positioned by a Single Electric Trim motor controlled through main or autopilot trim,
- Main and A/P has 2 speed modes: High Speed with Flaps extended, Low Speed with Flaps retracted,
- Main Electric Stabilizer Trim Circuit actuated by Control Wheel,
- Autopilot Stabilizer Trim Circuit actuated by Autopilot,
- Also Manual Stabilizer control is accomplished through cables connected to Trim Wheels
Stabilizer Trim Cutout and Override Mechanism
- STAB TRIM MAIN ELECT / AUTOPILOT switches allows trim inputs disconnected from the motor,
- Control Column actuated Stabilizer Trim Cutout switches stop Main & A/P trim operation when,
- Control Column movement opposes trim direction,
- When STAB TRIM Override switch is positioned to OVERRIDE,
- Electric Trim can be used regardless of Control Column position,
- Manual Trim overrides Autopilot or Main Electric Trim,
- Grasping Trim Wheel will stop Stabilizer motion
Stabilizer Position Indication Trim Authority
- Main Electric Trim Flaps Extended: 0.05 to 14.5 units,
- Main Electric Trim Flaps Retracted: 3.95 to 14.5 units,
- Autopilot Trim: 0.05 to 14.5 units,
- Manual Trim: - 0.20 to 16.9 units
- Green Band shows T/O Trim range
Speed Trim System
- Speed Stability Augmentation system design to improve flight characteristics when,
- Low Gross Weight, Aft CG, High Thrust and A/P not engaged,
- Objective is to return the airplane to a trimmed speed by commanding Stabilizer opposite to speed change,
- Uses Autopilot Stabilizer Trim and this increases Control Column forces
Speed Trim System Activation Conditions
- Fully enabled between 100KT and M 0.60 and fadeout to 0 by M 0.68,
- 10s after T/O,
- 5s following release of trim switches,
- A/P not engaged
Stall Protection
- Enhanced by the Yaw Damper, the Elevator Feel Shift (EFS) module and Speed Trim system,
- During high AoA operations, SMYD reduces Yaw Damper commanded Rudder movement,
- EFS module increases System A pressure to the Elevator Feel and Centering unit during stall,
- This approximately doubles Control Column forces,
- As airspeed decreases towards stall speed, Speed Trim system trims Stabilizer nose down,
- With this trim schedule the pilot must pull more aft column to stall the airplane
EFS and Inhibits
Elevator Feel Shift module inhibited when:
- On the ground or,
- RA < 100FT or,
- A/P engaged,
- However if it’s active when descending through 100FT RA, it remains active until AoA reduced below stick shaker
Rudder
- Provides yaw control around the airplane’s Vertical axis,
- Each set of Rudder Pedals mechanically connected to Input Levers of the Main and Standby Rudder PCUs,
- Main PCU consists: 2 independent Input Rods, 2 Individual Control Valves and 2 seperate actuator (1 for each HYD System),
- Standby PCU: Controlled by seperate Input Rod and Control Valve powered by Standby HYD System,
- All Input Rods have individual Jam Override to allow input commands to be transferred to remaining free rods,
RSEP
Rudder System Enhancement Program
Rudder Hydraulic Pressure Limiting
- Above 135KT,
- Both Hydraulic system pressures reduced within Main PCU by 25% each
FFM
- Main Rudder PCU contains Force Fight Monitor,
- Detects opposing pressure between HYD systems,
- This may occur if either system input is jammed or disconnected and if difference detected,
1-) Automatically turns ON Standby Hydraulic Pump,
2-) Open Standby Rudder Shutoff Valve to pressurize Standby Rudder PCU,
3-) Illuminate STBY RUD ON, Master Caution and FLT CONT lights
Rudder Trim
- Electrically repositions the Rudder Feel and Centering Unit,
- Which adjusts the Rudder Neutral position
Yaw Damper
- Consists of a Main and Standby Yaw Damper,
- Either one is capable of: Dutch Roll prevention, Gust Damping and Turn Coordination,
- Does not result in Rudder Pedal movement,
- Pilot can override either Yaw Damper inputs using either Rudder Pedal or Trim inputs,
- During normal operation uses Hydraulic System B,
- Stall Management Yaw Damper (SMYD) computers provide continuos system monitoring
YAW DAMPER Switch Reset
Switch trips if SMYD senses Yaw Damper system fault or that the Yaw Damper does not respond to commands:
- When only B FLT CONTROL switch is OFF or STBY RUD unable to reset,
- During Manual Reversion both FLT CONTROL switches are STBY RUD, in this case can be reset
Speed Brakes Inflight Operation Caution
- Caution should be exercised when deploying Speed Brakes during a turn,
- They greatly increase roll rate
Speed Brake Lever Stop Feature
- SFP aircrafts has it,
- Prevents movement beyond FLIGHT DETENT when,
- Inflight and Flaps UP,
- In the event of the loss of electrical power, lever stop is removed
Automatic Speed Brake Operation
When SPEED BRAKE Lever is ARMED, it operates when:
- SPEED BRAKE ARMED Light illuminated,
- RA < 10FT,
- Landing Gear Strut compress (any strut Flight, R MLG strut Ground Spoilers),
- Both Thrust Levers IDLE,
- Main Landing Gear Wheels spin up (> 60KT)
When SPEED BRAKE Lever is not ARMED, it operates when:
- Main Landing Gear Wheels spin up (> 60KT),
- Both Thrust Levers IDLE,
- Reverse Thrust Levers positioned for reverse thrust
SFP Automatic Speed Brake Limitation
- Following an All Flaps Up Landing, the SPEED BRAKE Lever will not move beyond FLIGHT DETENT,
- Spoilers will not fully deploy
Speed Brake Retraction After Landing or RTO
- If either Thrust Lever is advanced, the SPEED BRAKE Lever automatically moves DOWN,
- All spoiler panels retract
Flaps and Slats
- LE Devices: 2 Flaps inboard and 4 Slats outboard of each engine,
- Slats extend to form sealed or slotted leading edge depending on the TE Flap setting,
- TE Devices: Double Slotted Flaps inboard and outboard of each engine,
- TE Flap positions 1-15 provide increased lift, 15-40 provide increased lift and drag
Flap and Slat Sequencing
Regular NG:
- Flaps 1, 2, 5: LE Flaps extend to Full Extended and Slats extend to Extended position,
- Flaps beyond 5: LE Flaps remain Full Extended and Slats extend to Full Extended position
SFP:
- Flaps 1, 2, 5, 10, 15, 25: LE Flaps extend to Full Extended and Slats extend to Extended position,
- Flaps beyond 25: LE Flaps remain Full Extended and Slats extend to Full Extended position
Flap Load Relief
- Function of Flap Slat Electronic Unit (FSEU) which receives data from L ADIRU (CPT side),
- If CPT side Speed erroneously high, select next higher Flap setting than the desired one,
- Available for 10, 15, 25, 30, 40 on SFP / 30 and 40 on Regular NG,
- Retracts when Placard Speed + 1KT and extends when Placard Speed - 4KT,
- Not available during Alternate Flap extension
Autoslat
- Powered by Hydraulic System B,
- Alternate power Hydraulic System A via Power Transfer Unit (PTU),
- For Flaps 1, 2, 5 (also 10, 15, 25 for SFP) when aircraft approaches stall, Slats move to Fully Extended position,
- Slats return to Extended position when the pitch angle sufficiently reduced below the stick shaker attitude
Alternate Flaps/Slats Extension
- In the event of Hydraulic System B failure: LE device extension / TE extension and retraction provided,
- LE Devices extend to Fully Extended position by Standby Hydraulic system (cannot be retracted)
Asymmetry and Skew
- Asymmetry: One device on one wing does not align with the symmetrical one on the other wing,
- Skew: Symmetrical TE Flaps do not operate at the same rate causing panels to twist,
Asymmetry/Skew/Uncommanded Motion and Stall Characteristics
- SMYD will enable the Stall Warning at a lower AoA,
- PLI values will be lower on both PFDs,
- Wing asymmetry result in both an increased Minimum Operating and Minimum Maneuver Speed
TE Asymmetry and Skew Protection
- Position indications come from FSEU,
- When TE asymmetry or skew detected FSEU:
1-) Closes TE Flap Bypass Valve,
2-) Displays a needle split
LE Devices Uncommanded Motion
Detected when no TE Flap or Autoslat command is present and,
1-) 2 LE Flaps move on one wing,
2-) 2 or more Slats move on one wing,
- FSEU shuts down the LE Control and illuminates LE FLAPS TRANSIT light,
- In addition FSEU maintains pressure on LE retract line and depressurizes extend lines during cruise
TE Uncommanded Motion
- Detected when no FLAP Lever or Flap Load Relief command is present and TE Flaps:
1-) Move away from the commanded position,
2-) Continue to move after reaching a commanded position,
3-) Move in a direction opposite to that command - FSEU shuts down TE Drive unit by closing the TE Flap Bypass Valve,
- Shutdown cannot be reset by Flight Crew and Alternate Flap system must be used
Speed Trim System Inputs
Monitors inputs of:
- Stabilizer position,
- Thrust Lever position,
- Airspeed and,
- Vertical Speed
