Theory of flight Qs Flashcards Preview

Module 13 > Theory of flight Qs > Flashcards

Flashcards in Theory of flight Qs Deck (30):
1

Name the secondary flight controls?

Flaps, Slats, THS, Spoilers

2

Which axis does the Rudder act on?

Vertical Axis

3

On which axis does the Elevator act on?

Lateral Axis

4

On which axis does the Aileron act on?

Longitudinal

5

What is a flight control trim system used for?

To maintain an equilibrium of an aircraft during flight without using a steering force

6

Name some types of high lift devices used on a modern jet aircraft?

Slots, Slats, Flaps

7

Separation of the boundary layer causes the wing to stall, name some boundary layer control devices?

Sweeping back wings, Vortex Generators, Fences or Saw tooth/dog tooth

8

What is the function of a servo tab?

A tab on the flight control surface assists to help move the control surface

9

What is the function of a trim tab?

A trim tab will be moved to crease an aerodynamic force that will move the control surface and hold it deflected.

10

How does a balance tab work?

The control rod for a surface is attached to the underside of the tab and the underside of the fixed wing.

11

How does a Spring Tab work?

When control forces are high the spring will compress and this moves a rod connected to the tab to reduce the overall force on the surface.

12

What is the purpose of mass balancing?

To prevent control surface flutter

13

How is flutter prevented?

Using mass balancing where weights are added in front of the hinge line to bring the center of gravity closer to the hinge.

14

Speed of sound is affected by the .................. of the air

Temperature

15

What is the critical Mach number?

This is the number where the first indication of sonic flow (normal shockwave) forms somewhere on the wing

16

The speed range below Mach 0.75 is?

Subsonic

17

The speed range between Mach 0.75 - 1.20 is?

Transonic

18

The speed range between Mach 1.20 - 5 is?

Supersonic

19

The speed range greater than Mach 5 is?

Hypersonic

20

In low speed flight air is considered to be?

Incompressible

21

In high speed flight air is considered to be?

Compressible

22

What are the 3 types of pressure waves?

Normal an Oblique shockwaves and expansion waves

23

An oblique shockwave is?

Supersonic air striking a sharp edged airfoil that is forced to turn.

24

Increasing the critical Mach number by effectively decreasing the thickness ratio of the wing is?

Sweepback on the wings

25

Explain the definition 'rotor blade angle'?

The angle between the rotor blade chord and the reference plane.

26

Explain the definition 'rotor angle of attack'?

The angle between the chord line of the airfoil and the relative wind

27

What is the feathering axis?

The axis on which the pitch is changed

28

What is the collective used for?

To raise or lower ALL the aircraft by changing the pitch

29

What is the cyclic used for?

To raise or lower some blades and used in a turn.

30

What are the foot pedals of a helicopter used for?

To steer the helicopter by counteracting or assisting the torque