Secondary flight controls

Question 1

What is a secondary flight control?

Answer 1

Anything that does not directly control yaw, pitch or roll.

Examples:
Trailing edge flaps
Trimming devices
Leading Edge devices
Spoilers
Speed Brakes

Question 2

Secondary flight controls are used less frequently so can be controlled by what
eg. THS

Answer 2

screw jack

Question 3

Flap asymmetry is extremely dangerous, what precaution is put in place?

Answer 3

A sensor check for symmetry, if asymmetry is detected a brake will be applied that can’t be retracted in flight

Question 4

A flap has a speed limit, what ensures this is stuck to?

Answer 4

FBW or
a system that means the aerodynamic forces can push it back in if too great

Question 5

Explain the function:
Flaps

Answer 5

Increase the lift available and reduce stalling speed. Usually by increasing the wing camber and/or wing area

Question 6

Explain the function:
Trimming devices

Answer 6

Trimming devices – To allow the pilot to balance the forces acting on the aeroplane

Question 7

Explain the function:
Slats

Answer 7

Slats – To delay the stalling angle during high AoA manoeuvres

Question 8

Explain the function:
Spoilers

Answer 8

Spoilers – Dump lift after touchdown (Ground Mode) – Roll control during high-speed flight (Flight Mode)

Question 9

Explain the function:
Speed brake

Answer 9

Speed Brakes – Control aircraft speed during flight

Question 10

V_F

Answer 10

V_F – Design Flap Speed

Question 11

V_FE

Answer 11

V_FE – Maximum Flap extended speed

Question 12

To prevent damage through aerodynamic loads some aircraft are fitted with a…

Answer 12

Flap load Relief or ‘Blow Back’ device
This is a valve within the hydraulic system that senses an increase in pressure
When a predetermined pressure is reached, the aerodynamic loads are allowed to push the flap/slat to a lower setting – thereby reducing aerodynamic loads.

Question 13

What is the transport aircraft design standard

Answer 13

CS-??

Question 14

3 examples of leading edge device

Answer 14

Droop Nose
Krueger Flap
Leading Edge flap
Slats

Question 15

Explain the function:
Droop Nose

Answer 15

Droop Nose – a movable device that moves downwards to increase wing camber

Question 16

Explain the function:
Krueger Flap

Answer 16

Krueger Flaps – Hinges outwards to increase the leading edge radius

Question 17

Explain the function:
Leading Edge flap

Answer 17

Leading Edge flap – moves downwards from the leading edge to increase wing camber

Question 18

Explain the function:
Slats

Answer 18

Slats – a flap which extends out and down from the leading edge to create a slot through which air flows. The slat increases camber and re-energises the boundary layer over the main part of the wing.

Question 19

Krueger Flap is found where?

Answer 19

Usually fitted to the inboard section of the wing – inboard of the inner most engine

It’s designed to increase the wing camber whilst retaining a very small leading edge radius

Question 20

Ground spoilers require a number of arming conditions:

Answer 20

Lever in the armed indent
Main Wheel Spin-up
Thrust levers at Idle