Flight Controls Flashcards
Name the flight control laws
Normal, alternate, direct and mechanical backup
What is the purpose of mechanical backup?
To be able to control the plane whilst trying to recover flight control computers
What is the purpose of Abnormal Attitude law?
It helps you to recover the aircraft when in an abnormal attitude. It comes in when over 125 degrees bank, above 50 degrees and below 39 degrees pitch, below 70kts and above 440 kts/0.91m. Goes into direct law with ‘use man pitch trim’ displayed. Pitch is in alternate law with no load factor protection, roll is in direct law, yaw is in mechanical backup. When recovered, the aircraft remains in alternate law.
In normal law, explain bank angle protections.
Up to 33 degrees with auto trim. Can roll to 67 degree and when you let go of the stick it will return to 33 degree. In high speed protection, it’s limited to 40 degree bank angle and 45 degrees in low speed protection. You lose FD at 45 and the return at 40 degrees bank angle.
What is the maximum bank angle when alpha protection is in force and what is the maximum bank angle when high speed protection is in force?
45 degrees and 40 degrees
When in alpha prot, what happens when you release the side stick?
Returns to above alpha prot
What is the maximum pitch available in clean configuration and in Config full?
30 degrees config 0-3, 25 degrees config full. This reduces by 5 degrees in low speed protection.
What is the maximum G loading in clean and in other configurations?
+2.5G/-1G in clean, +2G/-0G
Can you explain alpha prot, alpha floor and alpha max?
Alpha prot stands for alpha protect. Instead of flying a g loading, you now fly alpha. If you keep pulling back you will get alpha floor (TOGA power kicks in), if you keep pulling back you will get to alpha max. Alpha max is a protection and is not the stall speed but rather the lowest speed in normal law.
Once you are out of the Alpha floor condition, what thrust mode would you expect to see and how would you recover?
TOGA Lock (basically locked into TOGA) press the red A/THR disconnect buttons.
What is VLS and its relationship to the stall speed?
VLS is lowest selectable speed. Actually you can select lower but providing the A/THR is in, it won’t let you go below VLS
1.13VS on takeoff or following a go-around
1.23VS after retraction of one step of flaps
1.28VS when clean
Can high speed protection be over ridden?
Yes - for avoidance for example but it has an ultimate structural speed that it won’t go beyond it in Normal Law and it will command your pitch input to 0, even with full forward stick
Can you draw the speed tape on alternate law and in normal law?
Normal: high speed barber pole, VLS, yellow, alpha prot yellow and black barber pole, alpha max solid red. Alternate: high speed barber pole, VLS yellow box, VSW black and red barber pole
When might you see “Use Man Pitch Trim” and when might you see “Man Pitch Trim Only”?
Use man pitch trim when in direct law, man pitch trim only when in mechanical backup
What is alpha lock and when might you see it?
It inhibits slat retraction at high angles of attack (when selecting config 0, Alpha lock activates when AOA above 8.5 degrees or the speed is less than 148kts)
