Control Laws

Question 1

What is pitch ground mode?

Answer 1

Ground mode is direct sidestick to elevator relationship. During Take off, max elevator deflection reduces to 20* at 75kts

Question 2

What is pitch flight mode?

Answer 2

Flight mode blends in about 5s after lift off when pitch exceeds 8*
Sidestick demands load factor

Question 3

I’m normal law, when does auto trim stop functioning?

Answer 3

When manual trim input
Rad alt below 50ft
Load factors below 0.5g

Question 4

What is flare law?

Answer 4

Allows airbus to land like a normal a/c
At 50ft auto trim freezes
At 30ft starts to lower nose to reach -2* over 8s so the pilot has to flare

Question 5

How can you disconnect the AP using flight controls only?

Answer 5

Forcefully moving the flight controls. Pitch attitude protection is inhibited

Question 6

What is lateral ground mode?

Answer 6

Roll is direct relationship to sidestick input

During takeoff max deflection of ailerons and spoilers reduce

Question 7

What is lateral flight mode?

Answer 7

Flight mode blends in after lift off and sidestick commands roll rate. Turns are coordinated automatically using rudder

Question 8

Max bank angle in normal law?

Answer 8

67*

Question 9

Max roll rate in normal law?

Answer 9

15* per second

Question 10

What changes to the control laws and protections in alternate law? Pitch, roll, landing, protections and speed?

Answer 10

Pitch…unchanged
Roll…direct relationship
Landing…no flare law, landing direct law conf 3
Protections…load factor unaffected, high speed and AoA are downgraded to stabilities, all other protections lost
Speed…max speed 320kts, no Alpha Floor

Question 11

What’s the difference between Altn law with/without protections?

Answer 11

Depends on system downgrades

With protections offers high and low speed stabilities

Question 12

What is flare law in alternate law?

Answer 12

It’s direct law, autotrim freezes and direct relationship to pitch and roll

Question 13

Describe high speed stability?

Answer 13

At usual high speed protection activation, a/c pitches up gently but can be overridden by pilot

Question 14

Describe AoA stability?

Answer 14

Approx 10kts above stall warner, a/c produces nose down pitch. Pilot can override this

Question 15

How does PFD appear in alternate law?

Answer 15

The ‘eyebrow’ protections are replaced by amber xx’s. Speed tape is different also

Question 16

How does PFD annunciation direct law?

Answer 16

Annunciates USE MAN PITCH TRIM in amber

Question 17

What is mechanical back up?

Answer 17

Loss of all FBW computers as a result of total electrical failure.
Meant to be temporary condition until electrics restored
Use pitch trim for pitch and rudders for roll