Flight Controls Flashcards
What do the two ELACs control?
Elevator, Aileron, Stabiliser
What do the three SECs control?
What do they control in standby?
Spoilers
Standby- Elevator and Stabiliser
What do the FACs control?
Rudder
Which computers do the FCDC transmit data to?
Where do they receive data from?
Flight Control Data Concentrators
Transmit to:
Electronic Instrument Sys EIS
Central’d Fault Display Sys CFDS
Receive from
ELAC / SEC
Maximum elevator deflection?
Maximum THS deflection?
Elevator
30ºUP, 17º DN
THS
13.5º UP, 4º DN
Pitch
In normal ops, which ELAC controls elev / THS?
Which hydraulic system drives which elevator?
Which motor drives the THS?
ELAC 2
Green- left elevator
Yellow- right elevator
Motor 1 - THS
Pitch
If ELAC 2 or associated HYD sys fails:
Which computer takes over?
Which hydraulic system drives elevator?
Which motor drives the THS?
ELAC 1
Blue
Motor 2
Pitch
What happens if ELAC 1 + 2 fail?
Computer / Motor
SEC 1 / 2 take over pitch
Motor 2 / 3 drive THS
Three modes of the servo jacks
What happens if one servo jack fails?
Active (electrically controlled)
Damping (follows surface)
Centering (hydraulically centred)
Ailerons do not have centering mode- dampen when fail
The active jack (failed) becomes damping, and the damping jack becomes active.
What happens if neither jack is electrically controlled?
If neither jack is hydraulically driven?
Both jacks centred
Both jacks enter damping mode
What happens to one elevator if the other fails?
Deflection limited to avoid excessive asymmetric loads on tail / aft fuselage
How is the stabiliser controlled and actuated?
A screwjack driven by G / Y hydraulic motors
Controlled by 1 of 3 electric motors or the mechanical trim wheel
ELAC controls pitch in Normal, Alternate and Direct law. Which protections does it provide?
- Pitch attitude
- High speed
- High AoA
In which laws do the SECs control pitch?
Alternate / Direct
No protections
What are the maximum deflections for ailerons and roll spoilers?
Ailerons 25º
Roll spoilers 35º
Roll
What happens to both ailerons if both ELACs fail?
Both ailerons revert to damping mode
Roll
Which SECs control which roll spoilers?
And what happens if a SEC fails?
SEC 1 - spoilers 3 + 4
SEC 2 - spoiler 5
SEC 3 - spoiler 2
Associated spoiler automatically retracts if SEC fails
Under what conditions are speed brakes inhibited / retracted? (6)
When and how can speed brakes be regained?
- SEC1 + 3 fault
- Either elevator faulty
- Flaps FULL
- Thrust levers above MCT
- AoA prot active
- Alpha floor active
Lever must be reset after inhibition condition ends, and 10 sec+ delay thereafter.
Speed brake maximum deflection?
A319 differences?
AP OFF
Spoiler 2- 20º
Spoiler 3+4 - 40º
AP ON
Spoiler 2- 12.5º
Spoiler 3+4 25º
A319
As per AP OFF
except spoiler 2- 17.5º, 12.5ºin config 3
If spoilers are being used for both roll and speed braking, which has priority?
What happens if roll command is more than achievable?
Roll has priority
If summed deflection exceeds roll command, up-going wing will retract its counterpart to achieve roll command
RTO
What is the difference between ground spoiler deployment with spoilers armed / unarmed?
What speed is the arming condition?
Will deploy on thrust IDLE when armed (one engine)
Will deploy on REV IDLE when unarmed (other engine must be IDLE)
Arming speed 72kt, WHEEL speed
Landing
Difference between automatic ground spoiler deployment conditions when:
Lever armed (or deployed)
Lever disarmed (and retracted)
Armed (or deployed)
* Both MLG on ground
* Both engines at IDLE or below
* or one in REV and other below MCT
Disarmed (and retracted)
* Both MLG on ground
* Reverse on one engine (below MCT)
Difference- will only deploy on IDLE if armed. Otherwise REV needed.
Conditions for Aileron Anti-Droop on landing?
- Ground spoilers fully extended
- Flaps not clean
- Pitch below 2.5º
- Manual flight
- Normal law
Phased lift dumping
Deployment conditions when lever armed (or deployed)
and disarmed (and retracted)
Armed / deployed
* One MLG down
* Both thrust at IDLE or below
Disarmed + retracted
* One MLG down
* REV on one engine (other below MCT)
Ground spoiler bounce protection
Reduces spoiler deflection if thrust mismanaged in flare
3 conditions for deployment?
- Spoilers armed
- Both MLG down
- Both levers CLB or below
When will ground spoilers retract?
When lever slammed after Landing or RTO
When one thrust lever above 20º for Touch and Go
Yaw
Which computers calculate yaw for turn coordination and yaw oscillation dampening?
Which computer accomplishes these orders?
ELACs
FACs
Yaw
How many servo jacks on the rudder?
Which system normally controls them?
Is there any pedal feedback?
Three independent servo jacks, operating in parallel
Normally operated by green
Yellow remains synchronised with green and takes over in case of failure
No pedal feedback for YD/turns
Artificial feel unit next to Rudder Travel motors (x2) for manual inputs
What happens if the Rudder Travel Limit System fails?
When is full authority regained?
Does the system provide for full authority when max asymmetric thrust?
Limited at last value reached.
Regained at slat extension
Yes.
Which computer controls rudder trim and travel limiting?
FAC
Also takes over yaw commands if ELACs fail. Normally only accomplishes the commands.
Max/min rudder travel limits?
A321?
25º - 3.4º
A321 2.9º
Which are the four pitch protections and one roll protection?
Which is the only one active in Flare mode?
- Pitch Attitude
- Load Factor
- High Speed
- High AoA
- Bank Angle
High AoA is the only prot active in Flare mode
Are the protections designed to be structural limit protections?
No, only to assist PF in emergencies or stressful situations
- Provide full authority for best possible perf in extreme situations
- Reduce risks of overcontrol, stress
- Provide PF with instinctive and immediate procedure
Landing
How long does it take to go from Flight / Flare / Ground modes in both pitch and roll?
At 50 RA
Pitch : Flight to Flare in 1 sec
On Ground
Roll : Flight to Ground in ½ sec
** Ground + 5 sec **
and pitch under 2.5º
Pitch: Flare to ground in 5 sec
Take Off
How long does it take to go from Ground to Flight mode in both pitch and roll?
What is elevator limited to during take off roll?
Pitch above 8º
Pitch : Ground to Flight in 5 sec
Roll : Ground to Flight in ½ sec
Limited to 20º UP (otherwise 30º)
If the sidestick is neutral, what is the pitch load demand?
How far can you bank before pitch corrections are necessary?
1g
independent of speed
33º (normal turn)
When will the autotrim freeze?
- Wheel is moved
- Below 50 RA (100 RA with AP ON)
- Load factor below 0.5g
- High speed / mach prot active
What is the THS value limited to if:
AoA prot engages?
High load factor / bank?
**AoA prot*
Current value down to 4º nose DN
*Over 1.25 g or 33º bank**
Current value down to 3.5ºnode DN
When will AP disconnect (rudder / THS / side stick)
Side stick: overcome restraining force
THS: moved beyond undefined threshold
Rudder: 10º out of trim
What is the only normal law protection not effective with AP ON?
Pitch attitude protection
What does flare mode do with THS?
50 RA- memorises attitude as an initial reference
30 RA- reduces THS to 2ºnose DN over 8 second period
therefore, gentle nose up required for flare
Load factor protections?
Clean: +2.5g to -1g
Config: +2g to 0g
Pitch attitude prot limits?
When do the FDs disappear?
Clean to Conf 3
30ºUP
progressively to 25ºUP at low speed
Config FULL
25ºUP
20º UP at low speed
All configs
15º DN
FDs disappear at 25º Up and 13ºDN
reappear 22º UP and 10º DN
(3º difference)
Can activate A FLOOR with full backstick
When does High AoA prot activate?
What happens?
Can speed be increased? What is sidestick doing?
When AoA exceeds αProt (shown as VαProt on PFD)
- Freezes THS setting
- Maintains αProt unless intervened
Full back stick maintains just above a 1g stall- gentle turns only.
Sidestick commands an AoA
How long are VαProt and VαMax the same for?
5 sec on take off
When does αFloor activate?
How to cancel?
What happens when exit
Just after αProt (somewhere in the amber poll)
Instinctive disconnect
TOGA LK- disarm and rearm
When does High speed prot activate?
What happens to THS?
What happens to bank?
What if you hold full forward?
When does AP disconnect?
When deactivated?
What happens to A/THR?
When is the ECAM overspeed warning activated?
At VMO / MMO.
= symbol at VMO+6
THS limits at current setting, up to 11ºUP
Wings roll level with neutral sidestick, bank limited to 40º from 67º
Full forward- authority reduces to 0 as speed reaches VMO+16 / MMO +0.04
AP disconnects at VMO+15 / +0.04
Deactivates when below VMO MMO
A/THR arms and activates automatically until exits condition
ECAM at VMO+4 / +0.006
What calculates the Low Speed Aural Alert?
FAC
Max roll rate?
15º/sec
7.5º/sec when AoA/Pitch prot active
What is the decrab function?
Limits induced roll when rudders pressed in the flare
What is bank limited to in Normal Law?
In AoA / Pitch protection?
In High Speed protection?
67º, rolls back after 33º
AP/FD disconnects at 45º
FD returns at 40º
disables autotrim
AoA/ Pitch protection: 45º
High speed protection: 20º
rolls back to 0º when side-stick released
What is Load Alleviation Function?
What are the two subfunctions?
Alleviates wing structural loads
when clean and normal law
- Normal manoeuvres
(Aileron deflection only) - Gusts
(aileron + spoiler 4+5)
both may operate independently during continuous turbulence
Which computer generates the sideslip target?
When does it turn blue?
FAC
Turns blue after EFATO or EFAGA
*Normal law commands some rudder deflection to minimise sideslip
What should rudder trim reading be in level cruise
(Both engines, balanced fuel, AP on)
2.3º L and 1° R
Actual position is ±1.5º, but indication is offset
What happens to the PFD in Alternate / Direct Law?
Alternate Law
αProt band disappears
αMax band replaced with Vsw (red/black)
Green = symbols turn to amber cross
* Pitch above / below
* 67º marks
* High speed
Direct Law
Above plus USE MAN PITCH TRIM
Which failures cause Alternate Law (with prot)?
(14)
- BAT ONLY
- EMER GEN
- Yaw is upgraded to alternate after FAC 1 reset*
- ELAC 1 + 2 (or both ailerons)
- ELAC 1 + 2 pitch
- SEC 123
- All spoilers
- 1 elevator
- F/CTL STABILIZER JAM
- 1 sidestick
- ELAC 1 + G HYD
- ELAC 1 + Y HYD
- ELAC 2 + B HYD
- G + Y
- 2 ADR / 2 IR
Which failures cause Alternate Law (Prot Lost)?
- SFCC 12
- G + B
- 2 ADR (if second not self-detected)
- Reduced prot avail if AoA disagree*
- 3 ADR
Which failures cause Direct Law?
- 2 IR (if second not self-detected)
- ALTN W/PROT if Faulty IR OFF and ELAC 1+2 Reset*
- 3 IR
- 2 RA at LG DOWN
Which three protections available in Alternate Law?
Which protection available with prot lost?
Low and High speed stability
Load factor
Load factor only
Alternate Law
When does ground mode become active in pitch?
What is pitch demand based on?
What is roll demand based on?
Is there a flare mode?
What is available in yaw?
Ground mode (pitch) active 5 sec after touch down
Pitch based on load factor
Roll is direct
Flare mode doesn’t exist, direct law on gear down
YD only in yaw- no turn coordination
authority limited to 5º
Alternate Law - reduced prot
Which protections lost?
Which protections available?
Lost:
Pitch Attitude
Bank Angle
shouts bank <45º, AP discon
Avail
Load Factor
Low Speed Stability
High Speed Stability
Alternate Law
How do High and Low Speed stability work?
Low Speed Stability
* Replaces aProt (no aFloor)
* Only availalble not clean
* 5-10 kt above stall, gentle nose down
* Overridable
* Bank angle compensation for constant AoA
High Speed Stability
* Gentle nose up
* Overridable
* AP disco over VMO/MMO
* Overspeed still sounds +4/+0.006
Direct Law
What is elevator deflection limited by?
Any protections?
Max roll rate?
Spoilers in use?
Yaw services?
Direct deflection limited as function of CG
adequate fwd CG authority, but not too sensitive with aft CG
No protections, overspeed and stall warnings only.
30º/sec (25º/sec when slats out)
Spoiler 3 inactive (2+4+5 only)
unless 4 has failed
if aileron fails, all roll spoilers are active
No YD or turn coordination
Abnormal Attitude Law
When does it engage?
What are the effects?
When does it disengage?
What remains?
- 125º bank, 50º up / 30º down
- 40º up / 20º down if ADCs all disagree
- Speed below 70-90, above 440 / 0.91
*AoA over 40º - Pitch alternate (no prot, no Ld fctr)
- Roll direct
- Yaw mechanical
- No autotrim
- F/CTL DIRECT LAW
Disengages in normal flight envelope
* Alternate pitch (+prot)
* Direct roll
* Alternate yaw
* F/CTL ALTN LAW
What is mechanical backup for?
What is shown on PFD?
- Achieve all safety objectives with MMEL dispatch
- 7 FBW computers tempo lost
- Tempo total elec loss
- Loss both elevator
- Total loss ailerons/spoilers
MAN PITCH TRIM ONLY red
Rudder trim moves at 1º/sec, how much when the reset pb pressed?
When does pitch trim automatically reset to 0?
Rudder trim: 1.5º/sec
Pitch trim: resets on touch down when pitch is below 2.5ºfor 5 sec
How hard do you press the sidestick to overcome the AP?
What does the PFD sidestick cross show?
5 decanewtons (pitch)
3.5 decanewtons (roll)
Shows summed position
How long to lock out another sidestick? Is it recoverable?
If both takeover buttons pressed, who gets control?
If a stick is locked out on the ground, what will happen at take off?
When is a red arrow light seen?
When is green CAPT - F/O light seen?
40 sec
Locked out until red pb pressed
Last person to press
CONFIG: L (R) SIDESTICK FAULT appears on TO power
Red Arrow:
On losing authority
Green Capt- F/O
Both lights flash if sidesticks both moved and neither pb pressed
One light stays solid if other has pressed pb and sidestick still deflected
F/CTL ECAM
When is the Δ shown on a spoiler?
When is an elevator/aileron scale amber?
Why would a G / Y / B be boxed in amber?
Why would a rudder symbol be amber?
Why would the pitch trim label be amber?
Why would the pitch trim limiter bracket be amber?
Why would the trim position blue marker turn amber?
Spoiler deflected over 2.5º
Scale amber if neither servo jack avail
Amber box G/Y/B if associated FBW computer failed
Rudder amber if all three systems low press
Pitch trim label amber if jammed
Pitch trim limiter bracket amber if both motors failed
Trim blue marker amber if reset has failed
Flaps and Slats
Power Control Unit- are they independent? Are they coupled?
What brakes the transmission once surfaces reached commanded position?
Independent (one per hydraulic source, i.e. GB for slats, GY for flaps),
coupled by differential gearbox.
Power Off Brake
Flaps and Slats
What is the Flap Disconnect Detection System for?
APPU?
FPPU?
IPPU?
If WTB brakes the flaps, can we still use the slats (+ vice versa)
Detects attachment failure and inhibits flap operation to stop further damage. Measures excessive differential movement between inner and outer flaps.
Asymmetry Position Pick-off Unit detects asymmetry between wings
Feedback PPU → SFCC
Instrumentation PPU → ECAM
Yes, WTB separate for slats and flaps
Flaps and Slats
Speed threshold for Config 1+F?
When retracting from Config 2?
Autoretract speed?
When would flaps autoextend in conf 1?
Conf 0→ 1: 100kt
Conf 2 → 1: 210kt
Autoretract 210kt
Speed 100kt or less
Flaps and Slats
When does Alpha lock engage? Until when?
When will alpha lock not work?
How is Alpha Lock shown?
AoA over 8.5º OR
Speed under 148kt
AoA under 7.5º AND
Speed over 154kt
On the ground under 60kt
On ECAM A-LOCK flashes green
Flaps and Slats
Slat and Flap angles?
Conf 1: 18º / 0º
Conf 1+F 18º / 10º
Conf 2: 22º / 15º
Conf 3: 22º / 20º
Conf Full 27º / 35º (40 a321)
Flaps and Slats
Why would F / S labels or position box turn amber on ECAM page?
- Both HYD fail
- WTB on
- Fail
