Chapter 18 - Control

Question 1

Basic requirements are
Forces?

Feel?

Responsive?

Movement and Harmony?

Answer 1

The forces on the controls must not be too heavy or light.

You must be able to sense airspeed through the controls- must be proportional to aerodynamic force.

No delay in response

Controls must not require excessive small or large input, fwd + aft, should be the same as left + right to harmonise.

Question 2

Aileron is changing the aerodynamic force which is a what control?

Answer 2

rate

Question 3

Rudder and elevator are a deflection effect which is a what control

Answer 3

displacement ( which changes the direction of the total reaction)

Question 4

Hinge moments give us feel how

Answer 4

aerodynamic force x distance

Question 5

Which aerodynamic balance gives a heavier feel

Answer 5

Anti balance tab

Question 6

What does inset hinge do?

Answer 6

reduces the moment by reducing the distance. Max 25%

Question 7

Horn balance does what?

Answer 7

Add area to the control surface in front of the hinge line

Question 8

Trim Tab

Answer 8

Holds the control surface in the desired position by deflecting the opposite way

Question 9

Internal Balance

Answer 9

Uses differential pressures to reduce forces

Question 10

Balance Tab

Answer 10

Pilot moves the control surface - the balance tab then moves in the opposite direction to help reduce the forces

Question 11

Servo tab

Answer 11

Pilot deflects the servo tab, not very good at low speeds and loses control authority

Question 12

The spring tab

Answer 12

At low speeds = balance tab

At high speeds = Servo tab

Question 13

Mass balance is for what and is put where

Answer 13

To stop flutter and in front of the hinge line

Question 14

Power assisted controls have natural feedback?

Answer 14

Yes

Question 15

Aerodynamic dampering is a resistance to roll why?

Answer 15

Because the down going wing will have an increased AOA

Question 16

What is the difference between elevator and complete moving tail plane

Answer 16

Elevator is camber changing device

Moving tail plane changes the AOA

Question 17

What are the advantages of THS

Answer 17

Can deal with greater CofG changes
No loss of control authority
More efficient because less drag with no trim tabs

Question 18

When does fin stall come into effect

Answer 18

In cross winds

Question 19

Secondary effect of roll is

Answer 19

yaw

Question 20

Secondary effect of yaw is

Answer 20

roll

Question 21

secondary effect of pitch is

Answer 21

Doesn’t have one

Question 22

Adverse Aileron Yaw is

Answer 22

In a roll When the up going wing produces more lift and more induced drag causing the aircraft to yaw towards the up going wing.