Flight Control Laws Flashcards
(31 cards)
What protections do you have in normal law?
Pitch AoB High speed High AoA Load Factor
What are the pitch protections and limitations in normal law?
Clean to flap 3
- Max 30 degrees NU (25 low speed prot. active)
- max 15 degrees ND
Config full
- max 25 degrees NU (20 low speed prot. Active)
- max 15 degrees ND
FDs disappear at 25 NU and 13ND
FDs reappear at 22 NU and 10 ND
What is the AoA protection and limitation in normal law?
When AoA is greater than alpha prot:
- sidestick demands AoA (not LF)
- further NU trim is inhibited
- AP disconnects
- max AoB = 45 degrees
With pilot input you can reach V alpha max but it can’t be exceeded.
If you release the stick the aircraft will stabilise at V alpha prot.
Between v alpha prot and v alpha max, alpha floor with activate
What are the high speed protections and limitations in Normal Law?
Vmo/Mmo = 350kts/0.82m
Protection activates at Vmo/Mmo
- Max AoB = 40 degrees (not 67)
- Positive static spiral stability at 0 AoB (not 33) so with neutral stick will roll back and hold 0 degrees
- pitch trim is frozen
- as speed increases above Vmo/Mmo sidestick nose down authority is progressively reduced.
Overspeed warning at Vmo +4/Mmo +0.006
- AP disconnects at Vmo + 15/Mmo + 0.04
- Stick down authority slowly reduces to 0 at Vmo + 16/Mmo + 0.04
= can’t ignore it even with stick input.
What are the roll limitations and protections in normal law?
Stick = rate of roll
Max rate of roll = 15 degrees per second
Max AoB = 67 degrees, neutral stick will hold 33 degrees
Unless high sped protection active (40 degrees) or AoA protection active (45 degrees)
Protection activated when AoB > 45 degrees
- no autotrim, back stick pressure required
- AP and FD disconnects
What protections do you have in Alternate law with protections
High speed and low speed stabilities, and load factor protection
The a/c will give you pitch up/down demands to stabilise speed but you can override them.
What protections do you have in Alternate law without protections?
Load factor protection
What are the load factor limitations and when are they available?
+2.5g to -1g clean
+2g to 0g Config 1,2,3 or full
Available in normal, alternate and abnormal law.
What are the high speed protections and limitations in alternate law?
Alternate Law with Protections
- Vmo/Mmo = 350kts/0.82m
Protection active above Vmo/Mmo
- nose up demand that you CAN override
- AP disconnects
- overspeed warning at Vmo +4/Mmo +0.006
Alternate law Without protections
- no protections
- AP disconnects above Vmo/Mmo
- max speed = 320kts/0.77m
- over speed warning at Vmo +4/Mmo +0.006
What protections do you have in direct law?
None!
What are the roll protections and limitations in alternate law?
Stick = direct input
NO BANK LIMIT
Max rate of turn = 30 degrees per second
AP disconnects when AoB > 45 degrees
What protections do you have in abnormal law?
Load factor
What are the roll protections and limitations in direct law?
Stick = direct input
NO BANK LIMIT
Max rate of turn = 30 degrees per second
Only spoilers 4 and 5 used for roll control, (usually 2,3,4,5)
What is the alternative to AoA protection in Alternate law?
Nose down signal given but it is possible to override
AoB compensated to maintain a constant AoA
Speed tape shows Vls and Vsw only
When are you in Abnormal law?
AoB > 125 degrees
Pitch > 50 degrees NU
Pitch > 30 degrees ND
Speed > 440kts or 0.9m
Speed < 60kts or 0.1m
AoA > 30-40 degrees
AoA < -10 degrees
What is the low energy alert and when is it available?
= ‘speed speed speed’
Only available in normal law and config 2,3 and full between 100ft RA and 2000ft RA.
Requires manual increase in thrust.
When does AoA protection activate?
When AoA is greater than V alpha prot
Which protection is the most important and has priority over all others?
AoA protection
What is alpha floor?
When is is available?
When does it activate?
= automatic TOGA thrust given
= available from lift off to 100ft RA on landing
= activates when alpha goes beyond alpha floor threshold
When do you have load factor protection?
Normal law
Alternate law
Abnormal law
What does the sidestick command in pitch in:
Normal law
Alternate law
Direct law?
Normal law stick = load factor
Alternate law stick = load factor
Direct law stick = direct input
What does the sidestick command in roll in:
Normal law
Alternate law
Direct law?
Normal law stick = rate of roll
Alternate law stick = direct input
Direct law stick = direct input
How do you control the aircraft in Mechanical law?
Pitch with the trim wheel and stabiliser
Roll with the rudder pedals and rudder
In normal law when would the AP drop out?
AoB > 45 degrees
AoA > Alpha prot
Speed > Vmo + 15/Mmo + 0.04
Pitch > 25 NU
Pitch > 13 ND
> 10 degrees rudder deflection out of trim
