AGK Systems - Primary Flight Controls

Question 1

What are the three types of control systems?

Answer 1

Manual, partially powered and fully powered.

Question 2

What are the three types of control systems?

Answer 2

Manual, partially powered and fully powered.

Question 3

What is a manual control system?

Answer 3

Mechanically connected control surfaces.

Question 4

What is a partially powered flight control system?

Answer 4

Controls connected via rods and cables.
Hydraulic pressure via actuators is used to assist in overcoming aerodynamic loads.

Question 5

What is a fully powered flight control system?

Answer 5

Input sends electrics, data to computer which move control surfaces.

Question 6

What is the difference between reversible and irreversible controls?

Answer 6

Reversible - pilot feels aerodynamic loads.
Irreversible- pilot does not naturally feel aerodynamic loads.

Question 7

What is redundancy?

Answer 7

Duplications of vital parts.

Question 8

In a fully powered flight control system, what does the ‘spool valve’ do?

Answer 8

Directs hydraulic fluid to the piston in the actuator which moves the control surfaces.

Question 9

What is the ‘feel system’?

Answer 9

Artificial system replicates aerodynamic feels, allows pilot to have a feel of the plane.

Question 10

What are the two feel methods?

Answer 10

Spring feel and Q feel.

Question 11

What does the spring feel method do?

Answer 11

Attached to the base of the control column, when control column moves the spring is stretched resisting the motion.

Question 12

What does the Q feel method do?

Answer 12

Senes dynamic pressure, usually aft, and directs it to a feel unit. Force feedback. More accurate and modern.

Question 13

What is flight control actuation?

Answer 13

Primary flight controls are attached to the trailing edge of the associated structure.
An actuator is pinned against a spar for strength and leverage.
Primary control stops are fitted to limit range of movement.

Question 14

What does trimming do?

Answer 14

Reduces workload.
Balances forces.
Large aircraft move control surface to a neutral point.

Question 15

What is stab trim?

Answer 15

Mounted in tail.
Comprises of Jack screw, 2 electric motors, position switches.
Operating stab trim commands the motors to drive the THS.

Question 16

What does rudder ratio changer do?

Answer 16

Rescues control authority as TAS increases.

Question 17

What is a blow back device?
What happens during this process?

Answer 17

Basic type of protection.
Pressure relief valve within the actuators allow the fluid in the actuator to return to reservoir as the control surface is pushed back by aerodynamic load.

Question 18

Airbus FBW dedicated computers for control surfaces.

Answer 18

2x ELAC - elevator/aileron/THS computer
3x SEC - spoiler/elevator/THS computer
2x FAC - flight augmentation computer
2x SFCC - slat/flap computer

Question 19

How many airbus laws are there are what are they?

Answer 19

Four laws,
Normal law
Alternate law
Direct law
Mechanical law

Question 20

What is normal law?

Answer 20

Full suite of protection features and normal aircraft operating limits.

Question 21

What is alternate law?

Answer 21

Basic range of stabilities with protections lost.

Question 22

What is direct law?

Answer 22

Any input into the sidekick translates into direct movement of control surface. No stabilities or protections.

Question 23

What is mechanical law?

Answer 23

Sidestick and flight computers lost: pitch via the trim wheel and yaw from ruddders, roll from asymmetric thrust.

Question 24

What is a control lock?

Answer 24

Fitted to all primary control surfaces of aircraft with reversible controls. Prevents damage during high winds.