Alternate Law

Question 1

What are the principles of ALT law with regards Pitch, Roll, Landing, Protections, Speed in Flight Mode?

Answer 1

Pitch: Unchanged, Load Factor demand

Roll: Direct relationship

Landing: Flare mode not avail. When LG down, direct law, config 3.

Protections: Load Factor Prot unaffected. Low/High Speed downgraded to stabilities (AOA {pitch attitude limitation} on some a/c) . Others unavail.

Speed: max 320kts (high speed prot and aFLOOR unavail)

Question 2

What is the difference between ALT law with/without Protections?

Answer 2

With protections = Low Speed Stability, High Speed stability, (some a/c pitch attitude limitation) and Load Factor Limitation.

Without Protections: Only Load Factor Limitation

Question 3

What is FLARE mode in ALT law and when will it activate?

Answer 3

ALT Law when LG down = DIRECT Law
Direct relationship in Pitch and Roll
no autotrim

Question 4

Describe the High Speed Stability?

Answer 4

Above VMO/MMO, nose up demand introduced to avoid excessive inc in speed - crew can override.

Question 5

Describe AOA stability?

Answer 5

Avail in all conf, active from about 5/10kts above stall warning speed.
Nose down signal to prevent speed decay - crew can override.

Question 6

Any protections unaffected by ALT Law?

Answer 6

Load Factor Prot

Question 7

How will PFD appear in ALT law compare to NORM law?

Answer 7

Green eyebrows (equals) replaced with amber crosses.
Amber & black aPROT tape replaced with Red & Black vSTALL tape.

Question 8

How does PFD annunciate DIRECT LAW?

Answer 8

“USE MAN PITCH TRIM” in amber

Question 9

Mechanical Backup, what is it and how is a/c controlled in this condition?

Answer 9

To manage a:
temp and total elec loss,
temp loss of 5 fly-by-wire computers,
loss of both elevators,
or total loss of ailerons and spoilers.

Pitch attitude controlled by THS
Lateral controlled by rudder pedals