11.9 Flight Controls

Question 1

What are the primary flight controls?

Answer 1

Ailerons
Elevators
Rudder

Question 2

What do ailerons give?

Answer 2

Longitudinal control

Question 3

What control do elevators give?

Answer 3

Lateral

Question 4

Unlike the other what is the direction of movement of an anti balance/servo trim?

Answer 4

Same direction of movement.

Question 5

Where is lateral trim controlled from?

Answer 5

Switch on the centre console, electrically controlled through the FCU.

Question 6

What are SPMs?

Answer 6

Stabiliser position modules.

Question 7

What two active aeroelastic control techniques are there?

Answer 7

Manoeuvre Load Control
Gust Load Alleviation

Question 8

What can active load alleviation systems be based on?

Answer 8

Feedback loop (wing tip acceleration) or feed-forward channel (angle of attack)

Question 9

What is the aim of Manoeuvre Load Control?

Answer 9

To use wing control surfaces to move the lift inboard during manoeuvres so that wing bending is reduced.

Question 10

What is the aim of Gust load allieviation?

Answer 10

Fly by wire aircraft that reduces the effect of gust loads by deflecting control surfaces.

Question 11

What is the typical flap extension for takeoff?

Answer 11

5 to 15 degrees

Question 12

What is the typical flap extension for landing?

Answer 12

25 to 40 degrees

Question 13

What are the lift dump spoilers?

Answer 13

Flight roll spoilers

Question 14

What cables are commonly used in aviation?

Answer 14

7x7 and 7x19

Question 15

In the UK how are control cables classed?

Answer 15

Minimum breaking load in hundred weight force (cwtf)

Question 16

What are cables often made from?

Answer 16

Linear reinforced phenolic resin or aluminium alloy.

Question 17

When do pulley bearings need lubing?

Answer 17

They don’t after manufacture.

Question 18

How accurate is a tensiometer?

Answer 18

98%

Question 19

Where are bell cranks used?

Answer 19

In conjunction with control rods

Question 20

What do bell cranks allow?

Answer 20

A change of direction.

Question 21

When are torque tubes used?

Answer 21

When an angular or twisting motion is needed.

Question 22

What type of thread do screw jacks have?

Answer 22

Coarse

Question 23

In damping mode what happens to the servo unit in a hydraulic pump?

Answer 23

Depressurised.

Question 24

What is a servo control unit divided into?

Answer 24

Power
Distribution

Question 25

What are the main components in a servos power unit?

Answer 25

Cylinder Piston Rod

Question 26

What are the main components in a servos distribution section?

Answer 26

Control valve Bypass valve

Question 27

What two main operating modes does a servo control unit have?

Answer 27

Control/active Damping

Question 28

In a power assisted flight control system does the pilot have feedback?

Answer 28

Yes

Question 29

In a full power flight control system does the pilot have feedback?

Answer 29

No

Question 30

What are pneumatic control systems used for?

Answer 30

Backup on systems such as landing gear and emergency brake.

Question 31

When three channels on fly by wire are being used what is it known as?

Answer 31

Triplex

Question 32

What is normal law in a fly by wire system?

Answer 32

Pre-set characters for the aircraft depending on the stage of flight.

Question 33

What are the three flight control modes in fbw?

Answer 33

Ground Flight Flare

Question 34

What happens in fbw ground mode?

Answer 34

Auto-trim is turned off and there is direct input into the flight controls. Horizontal stab is 4 degrees up.

Question 35

How long is the transition time between ground to flight mode?

Answer 35

5 seconds

Question 36

What 5 protections does flight mode offer?

Answer 36

Pitch attitude Load factor limits High speed High AOA Bank angle

Question 37

When does flight mode cut out on landing?

Answer 37

100 feet

Question 38

What is ALT1 mode?

Answer 38

Combines normal law lateral mode with the load factor.

Question 39

When may ALT1 be entered?

Answer 39

If there are faults in the horizontal stabiliser, an elevator, yaw-damper actuation, slat or flap sensor, or a single air data reference fault.

Question 40

What is ALT2 mode?

Answer 40

Protection for high angle of attack and speed.

Question 41

When is ALT2 entered?

Answer 41

When two engines flame out faults in two inertial or air-data references, with the autopilot being lost.. This mode may also be entered with an all-spoilers fault, certain aileron’s fault, or pedal transducer’s fault.

Question 42

What happens in direct law?

Answer 42

All protections are lost and all flying controls are manual input.

Question 43

When is direct law entered?

Answer 43

Failure of three inertial reference units or the primary flight computers, faults in two elevators, or flame-out in two engine.

Question 44

What is a feel unit?

Answer 44

Gives the pilot an artificial feeling of the aerodynamic loading.

Question 45

What is a q pot feel system?

Answer 45

A very large simple piston feel unit.

Question 46

When does mach tuck happen?

Answer 46

When aircraft transition through the transonic region.

Question 47

How is mach tuck avoided?

Answer 47

Mach trim, keeps the nose up.

Question 48

What is a gust lock?

Answer 48

Method of locking out flight controls.

Question 49

What is static balancing?

Answer 49

The tendency of an object to stay still when balanced.

Question 50

What are the two ways in which something is statically balanced?

Answer 50

Underbalance (+) Overbalance (-)

Question 51

What indicates overbalance?

Answer 51

Upward movement of the trailing edge.

Question 52

What is dynamic balance?

Answer 52

All the rotating forces are balanced within themselves.

Question 53

How is the neutral position determined before balancing?

Answer 53

Using a bubble protractor.

Question 54

What is the advantage of the calculation method for balancing?

Answer 54

The surface doesn't need removing from the aircraft.

Question 55

What is aircraft rigging?

Answer 55

The adjustment and travel of the moveable flight control surfaces.

Question 56

What is surface throw?

Answer 56

The correct prescribed arc of a flying control.

Question 57

What is a stick nudger?

Answer 57

Designed to avoid stall.

Question 58

What angle of attack gives maximum lift?

Answer 58

14 degrees

Question 59

What is an alpha lock?

Answer 59

Prevents the slats from being retracted at high angles of attack, as when they get retracted the angle of attack is increased leading to flow separation.