Flight Controls Flashcards
Normal Law mode Transitions
Pitch Control:
Ground Mode —> Flight Mode - 5s after liftoff and pitch > 8°
Flight Mode —> Flare Mode - 1s after 50’
Flare Mode —> Ground Mode - 5s after landing and pitch < 2.5°
Lateral Control:
Ground Mode —> Flight Mode - 0.5s after liftoff
Flight Mode —> Ground Mode - 0.5s after landing
Protections in Normal Law
‐ load factor limitation ‐ pitch attitude protection ‐ high-angle-of-attack (AOA) protection ‐ high-speed protection - bank angle protection - side slip target
LOAD FACTOR PROTECTION
load factor is automatically limited to:
+2.5 g to -1 g for clean configuration;
+2 g to 0 for other configurations
PITCH ATTITUDE PROTECTION
limits pitch attitude:
‐ 30 ° nose up in conf 0 to 3 (progressively reduced to 25 ° at low speed)
‐ 25 ° nose up in conf FULL (progressively reduced to 20 ° at low speed)
‐ 15 ° nose down (indicated by green symbols “=” on the PFD’s pitch scale)
- flight director bars disappear from the PFD when the pitch attitude exceeds 25 ° up or 13 ° down*
HIGH ANGLE-OF-ATTACK PROTECTION
-activated when angle-of-attack becomes greater than αPROT
- Without pilot input, the F/CTL computers will maintain the AOA equal to αPROT
- AOA can be further increased by the pilot input, up to a maximum value equal to αMAX
- angle-of-attack will not exceed αMAX
- has priority over all other protections
HIGH SPEED PROTECTION
- activated at/or above VMO/MMO
- THS setting is limited between the setting at the aircraft’s entry into this protection and 11 ° nose-up
- Positive spiral static stability is introduced to 0 ° bank angle (instead of 33 ° in normal law)
- bank angle limit is reduced from 67 °to 40 °
- As the speed increases above VMO/MMO, the sidestick nose-down authority is progressively reduced, and a permanent nose-up order is applied to aid recovery
BANK ANGLE PROTECTION
- maintains positive spiral static stability for bank angles above 33°
- Up to 33° the system holds the roll attitude constant when the sidestick is at neutral
- with full lateral side stick bank angle is limited to 67°
- when active, auto trim is inoperative
- If Angle-of-Attack protection is active bank angle is limited to 45°
- If High Speed Protection is active bank angle is limited to 40° and the system maintains positive spiral static stability from a bank angle of 0°
SIDESLIP TARGET
- If one engine fails, the FAC modifies the sideslip indication slightly to show the pilot how much rudder to use to get the best climb performance
- sideslip index on the PFD changes from yellow to blue
Reduced Protections in Alternate Law
- LOAD FACTOR LIMITATION
- LOW SPEED STABILITY
- HIGH SPEED STABILITY
How are the flight control surfaces controlled?
Flight control surfaces are all :
‐ Electrically-controlled
‐ Hydraulically-activated
- stabilizer and rudder can also be mechanically-controlled
- via side stick computers interpret pilot input and move the flight control surfaces
How many flight control computers?
Seven flight control computers
2 ELACs (Elevator Aileron Computer) For :
- Normal elevator and stabilizer control
- Aileron control
3 SECs (Spoilers Elevator Computer) For :
- Spoilers control
- Standby elevator and stabilizer control
2 FACs (Flight Augmentation Computer) For : *Electrical rudder control.
Which computer controls the elevators and stabilizer in normal operation?
ELAC2
*ELAC1 will takeover if failure With ELAC2 or associated hydraulics
How many servo-jacks for each elevator?
2 servo-jacks for each elevator
Each servojack has three control modes :
• Active : The jack position is electrically-controlled
• Damping : The jack follows surface movement
• Centering : The jack is hydraulically retained in the neutral position
Elevator Control Priorities
- Mechanical Trim
- ELAC2
- ELAC1
- SEC2
- SEC1
How many servo-jacks control each aileron surface?
Two servo-jacks per aileron
Each servojack has two control modes :
Active : Jack position is controlled electrically
Damping : Jack follows surface movement
