Flight Controls Flashcards
What are the roles of the Elevator Aileron Computers (ELAC 1 and 2)
1) Provide Control of Elevators, Ailerons and Trimable Horizontal Stabilizer (THS)
2) Determines the requirement for and activates spoiler assist during rolls, and rudder input for yaw
Are both ELACs normally active? What happens if one fails
Both are normally active, should one fail, the remaining ELAC will assume all ELAC related functions
What is the role of the Flight Augmentation Computers (FAC 1 and 2)
Provides control of the Rudder to include:
1) Turn Coordination
2) Yaw Dampening
3) High/ Low Speed Rudder Limiting
4) Rudder Trim
Are both FACs active at the same time?
No, one is active with the other serving as a backup.
What are the roles of the Spoiler Elevator Computers (SEC 1, 2 and 3)
Responsible for a specific pair or pairs of spoiler panels
Specifically, what can SEC 1 and 2 additionally provide?
backup control of the Elevators and THS in the event of a dual ELAC failure
What is normal law? what protections does it provide?
1) Defines the Flight Control Computers logic of aircraft pitch, roll and yaw limits during normal ops
2) All protections are available and prevents the aircraft from exceeding the designed flight envelope.
What is alternate law? What protections does it provide?
1) Defines the Flight Control Computers logic on all axis when multiple failures involving a FC, HYD or ADIRS (Nav System)
2) Maintains a high level of capability, but some flight envelope protections are lost
What is direct law? What protections does it provide
1) Typically occurs as the result of the landing gear being lowered while in Alternate Law, but can also be the result of more significant system failures
2) All protections are lost - airplane feels and responds like a conventional aircraft.
What is mechanical backup law? What flight controls will you have available?
1) Occurs when all flight control computers have failed or total loss of electrical power
2) Side sticks are inop and the aircraft can only be controlled by manual pitch trim, rudder pedals and engine thrust.
What is abnormal Attitude Law? What is it a subset of?
1) Provides sufficient control to recover from unusual attitudes as the result of an extraordinary external event (windshear etc.)
2) Is a subset of Alternate Law
What is load factor demand?
The flight control computers interpret pitch change commands as G Load changes
- Climb Commands (stick aft) - result in pos G load change
- Descent Commands (stick fwd) - result in negative G load change
- Neutral stick results in zero G-load change
In which Law(s) is load factor demand available?
Normal and Alternate
How is Automatic Pitch Trim provided during a roll and in what Law(s)
provided by the ELACs in normal and alternate Law
Up to what bank angles is automatic pitch trim provided?
Up to and including 33 degrees.
What is Maneuver Protection?
Restricts flight control surface movement that would cause the aircraft to exceed designed structural G-load limits
1) Clean (flaps and slats retracted): -1g to +2.5gs
2) Slats Extended, Flaps Up: -1g to +2.5gs
3) Slats and Flaps extended: 0g to +2gs
In which Law(s) is Maneuver Protection available
Normal and Alternate Law
What is pitch protection and how is it provided?
Provided by the ELACs to prevent excessive nose up (no greater than 30 deg) and nose down (no greater than 15 deg). Even if the sidestick is fully aft or fwd.
What is High Speed Protection and how is it provided?
1) Attempts to prevent the aircraft from exceeding VMO/MMO.
2) Autopilot will automatically dis-engage
3) ELACs automatically pitch the aircraft up to limit further acceleration, even if sidestick is fully forward
In which Law(s) is High Speed protection available?
Normal only
What is Alpha Protection (Alpha Prot)
AOA where FCCs intervene to prevent a stall.
In what Law(s) is Alpha Prot available
Normal only
How is Alpha Prot indicated on the airspeed indicator
Top of the amber and black band (tiger tail)
Can Alpha Prot be over-ridden and allow the aircraft to slow further?
Yes, with Aft Sidestick movement
What is Alpha Max
The highest Angle of Attack (AOA) the FC computers will allow.
In which law(s) is Alpha Max available, can it be over-ridden by pilot sidestick and how is it represented on the airspeed indicator
1) Avail in Normal Law only
2) Cannot be over-ridden by sidestick
3) Top of the red band on the airspeed indicator
What max roll rate will Full Sidestick deflection yield in Normal Law
15 deg per second regardless of airspeed or configuration
What happens if you deflect a sidestick halfway in Normal Law
you get a roll rate half of the max allowable rate
What will a Neutral Sidestick do to roll rate in Normal Law
Zero change in roll rate
What is bank angle hold?
At bank angles equal to or less than 33 degrees the bank angle is maintained with automatic pitch trim when sidestick is released
What is Positive Spiral Static Stability
1) When bank angle is greater than 33 degrees, the bank angle will return to 33 deg when the sidestick is released
2) If you want to maintain a bank angle greater than 33 degrees continuous bank and pitch pressure must be maintained.
In which Law(s) is Bank Angle Protection and Positive Static Stability available
Normal Only
What is Automatic Pitch Trim during turns and when is it available?
1) Bank angles less than or equal to 33 deg, the ELACs automatically provide pitch trim for the needed back pressure
2) Above 33 deg the feature is inhibited and aft sidestick will be needed to maintain a level turn
In which Law(s) is Automatic Pitch Trim available?
Normal and Alternate
What is Bank Angle Protection?
ELACs restrict bank angle to a max of 67 deg even if full left or right sidestick is maintained
In which Law(s) is Bank Angle Protection available
Normal only
What are the Indications of Normal Law on the PFD
1) 67 deg bank angle limit
2) +30 deg and -15 deg pitch attitude limit
3) High Speed Protection limits
What is Ground Mode (Normal Law)
1) Active when AC is on the ground
2) Direct relationship between the sidesticks and flight control surfaces
3) Allows flight control check and rotation of aircraft on takeoff
What is Flight Mode (Normal Law)
1) Active shortly after takeoff
2) All flight control computer protections and flight characteristics take effect
What is Flare (Landing) Mode (Normal Law)
1) Active when the AC descends through 50 ft RA at which time the ELACs “memorize” the aircraft pitch attitude
2) At 30 ft RA ELACs add a gentle nose down pitch command
3) Pilot counters this with aft input resulting in flare like a conventional aircraft
4) After landing aircraft returns to ground mode and THS resets to 0
How is roll control maintained while in Alternate Law
1) Direct relationship exists between the sidestick deflection and elevator/ aileron deflection
2) All roll control flight characteristics and protections are lost
Describe High Speed Stability in Alternate Law?
1) Becomes active slightly below Vmo and Mmo
2) ELACs command the elevators to increase the aircraft pitch, attempting to prevent an increase in speed
Describe Low Speed Stability in Alternate Law?
1) Becomes active at airspeed slightly higher than stall speed
2) Flight Control Computers command elevators to decrease aircraft pitch, attempting to increase airspeed.
Can High and Low Speed Stability in Alternate Law be over-ridden?
Yes.
How is the Stall Warning indication on the PFD speed scale shown in Alternate and Direct Law
Top of the black/red barber pole in either Law
What are the indications you are in Alternate Law
1) Green Equal Signs are replaced with Amber Xs
2) F/CTL ALTN LAW (PROT LOST) message in the E/WD memo section
Do you lost all Protections in Alternate Law when the (PROT LOST) ECAM message is shown
No, some remain active
What are the indications you are in Direct Law
1) Amber Xs from Alternate Law remain in view
2) USE MAN PITCH TRIM (Amber) appears above the artificial horizon on the PFD
3) F/CTL DIRECT LAW (PROT LOST) message on the E/WD memo section.
Do you lose all Protections in Direct Law when the (PROT LOST) ECAM message is shown
Yes, all protections are lost
What is Mechanical Backup law, when is it intended to be used?
1) Provides mechanical control of the aircraft in the event all flight control computers have failed or there is total electrical failure
2) Intended to be used only until it takes to restore FC computers or electrical power.
What flight control surfaces are operational when in Mechanical Backup Law
1) Rudder
2) THS
Do you need hydraulic power to the respective servos to the operating flight controls when in Mechanical Backup Law
Yes
What are the PFD indications of Mechanical Backup Law
1) The Amber Xs from Alternate and Direct Law Remain
2) MAN PITCH TRIM ONLY (red) appears above the artificial horizon on the PFD (assuming you have power to the PFD)
What is Abnormal Attitude Law
Ensures flight characteristics and protections with Normal Law don’t interfere with recovery from an abnormal flight attitude (Alternate Law with no automatic pitch trim or yaw damping)
After recovery from an unusual attitude will the aircraft revert back to Normal Law?
No - it will stay in Alternate Law for the remainder of the flight
Once out of Abnormal Attitude Law and in Alternate Law, will the aircraft degrade to Direct Law once the landing gear is extended?
No it will stay in Alternate Law
How is the Rudder and Rudder Trim displayed on the ECAM F/CTL page
1) Rudder is green and represents the actual rudder position
2) Rudder Trim is represented by the Cyan (blue) tick mark.
What is the meaning of a pulsing A-LOCK (blue) on the E/WD
Indicates that a leading edge slat retraction has been inhibited due to excessively low airspeed or high AOA
When will the A-LOCK indication disappear and slats retract?
Once the airspeed and/or AOA corrections have been made, the slats will respond to flap lever commands and retract.
How does the sidestick priority system allow either pilots sidestick to have sole control of the aircraft in the event of an opposing sidestick failure
Pressing and holdin the AP Disconnect/ Priority pb:
1) Disengages the AP if engaged
2) Temporarily deactivates the opposite sidestick
3) Generates the “priority left” or priority right” voice message
4) Red Arrow on the deactivated side indicator points to the active side
5) If the deactivated sidestick is not in neutral, CAPT or F/O (green) will show on the active side only to show who has priority
How long do you need to press the AP Disconnect/ Priority pb before releasing it to temporarily deactivate the other side
40 seconds
Can a deactivated sidestick be reactivated
Yes, by pressing its AP Disconnect/ Priority pb. This is not recommended.
What happens if both Sidesticks are simultainiously moved?” What happens if they are moved in the same/ opposite directions?
1) “Dual Input” is heard over the flight deck loadspeakers
2) Same Direction - ELACS will sum their inputs to the max of one sidesticks full deflection
3) Opposite Direction - ELACs cancels both inputs
What are the indications on the ECAM F/CTL page of the HYD system power sources. How are they indicated if a HYD system fails
1) G, Y, B indicates controls powered by the Green, Yellow and Blue systems respectively
2) If a system fails the letter will appear in Amber instead of Green
Which Flight Control Computers are shown on the ECAM F/CTL page?
Two ELACs and Three SECs. The two FACs are not depicted.
How is a FC computer depicted if functioning normally, what if one fails or is turned off?
1) The FC number is Green if functioning normally
2) The number and half box surrounding it turn amber if it fails or is turned off
How is PITCH TRIM presented on the ECAM F/CTL page
Digitally displays the angle of the THS for nose up or nose down trimming. Eg:
- 0.6 deg UP indicates THS is at -0.6 deg for nose up trimming
- 1.2 deg DOWN indicates THS is at 1.2 deg for nose down trim
What are the references on the ECAM F/CTL page for neutral aileron positions
1) Two White Tick Marks - when flaps are retracted
2) White Square (Aileron Droop) - for extra lift when flaps are extended
What is the indication on the E/WD memo section when speed brakes have been deployed. Is there any change if the engine thrust settings change?
SPEED BRK - green if engines are idle and amber if engines are above idle.
How will the speed brakes deploy if the AP is engaged or if AP fails or disconnected while speed brakes have been deployed
1) AP Engaged - SPD BRKS will be 1/2 the max possible range. Placing lever beyond 1/2 position will not yield further deployment
2) AP Fails with Lever beyond 1/2 position - SPD BRKS will immediately deploy to meet the commanded position.
How and Where are the Speed Brakes and Ground Spoilers monitored
1) Green Vertical arrows on ECAM F/CTL and WHEEL pages
2) On landing, the WHEEL page is automatically displayed with landing gear extension (for Ground Spoiler monitoring)
When will the speed brakes automatically retract if deployed in-flight
1) Flaps Full Selected
2) Airspeed decreases to Alpha Prot
3) TL to TOGA
How does Alpha Protection work?
1) AOA is commanded by side stick
2) Spoilers Auto Stow
3) AP automatically disengages
4) Pitch trim inhibited (nose up)
5) FCC logic changes from load factor demand to direct sidestick pitch control
