11.1 - Theory of Flight

Question 1

Which form of drag is reduced by boundary layer control?

Answer 1

Induced Drag

Question 2

which of the statements is true?

Answer 2

Spoiler and speed brakes always reduce lift and increase drag

Question 3

How are the Leading edge devices deployed?

Answer 3

By the same lever as flap deployment.

Question 4

Regarding aerodynamic heating. which material looses 80% of its strength at 250c

Answer 4

Aluminium Alloys

Question 5

What can be said about changes in velocity, pressure and density in a shock wave?

Answer 5

Changes occur suddenly and sharply

Question 6

What happens to the airflow as an aircraft approaches the speed of sound?

Answer 6

Areas of supersonic airflow increases and shockwaves move closer to the trailing edges.

Question 7

What is the increase in lift provided by the slat system?

Answer 7

35%

Question 8

When does the boundary layer loose control with the surface?

Answer 8

When kinetic energy in boundary layer is too low.

Question 9

What is the critical Mach number

Answer 9

The point at which local airflow reaches Mach 1

Question 10

When is a control surface correctly balanced

Answer 10

When the centre of gravity of the surface is located on the hinge line

Question 11

What is done to prevent extreme pressures and temps at the engine compressor during high speed flight

Answer 11

1 normal and 3 oblique shockwaves are formed to slow airflow

Question 12

What is the disadvantage of an antibalance trim tab

Answer 12

The pilot requires more effort to deflect the control surface

Question 13

Which tab system uses a lever

Answer 13

Control tab type

Question 14

How is profile thickness expressed in aerodynamics

Answer 14

as a relationship between actual thickness divided by chord length

Question 15

What is the name of the most effective flaps

Answer 15

Fowler flap

Question 16

What is the main function of the stabilator

Answer 16

Eliminate Mach Tuck caused by a shockwave formation

Question 17

What is the purpose of ailerons

Answer 17

Roll control

Question 18

Which primary flight controls effect the yaw control of the aircraft

Answer 18

Rudder

Question 19

Which type of tab arrangement increases the effectiveness of a control surface

Answer 19

Anti-balance tab

Question 20

Which of the following materials would generally be used to resist aerodynamic heating

Answer 20

Titanium alloy

Question 21

How does supersonic flight effect the air

Answer 21

The air is compressible

Question 22

If a mach indicator shows a number of 0.6. What does it mean

Answer 22

The aircraft is flying at 60% the speed of sound

Question 23

Which of the following statements, regarding transonic flight is correct

Answer 23

Local Mach number is more than the flight Mach number

Question 24

If the right ruddervator goes down and the left goes up.

Answer 24

The aircraft yaws right

Question 25

How much does the fowler flap increase lift by more than other lifting devices

Answer 25

95%

Question 26

What is the Subsonic speed range

Answer 26

Mach numbers less than 0.8

Question 27

What is the transonic speed range

Answer 27

Mach numbers from 0.8 to 1.2

Question 28

What is the supersonic speed range

Answer 28

Mach numbers between 1.2 to 5.0

Question 29

When flying above Mach 1, an oblique shock wave is formed. What happens to air passing through it

Answer 29

As it passes the wave, the velocity is reduced but remains supersonic. Causing slight increase in temperature and pressure

Question 30

When is an expansion wave formed

Answer 30

When supersonic airflow changes direction around a curve or corner, away from the preceding flow direction

Question 31

How does the Center of lift/pressure chord position differ between subsonic and supersonic flight

Answer 31

At supersonic speeds the centre of lift is approximately 50% chord position

At subsonic speeds the centre of lift is approximately 25%

Question 32

What is the portion of total drag due to shockwaves called

Answer 32

Wave drag

Question 33

What is the function of a vortex generator

Answer 33

Transference of energy from the free airstream to the boundary layer to reduce flow separation

Question 34

How does supersonic airflow act in a Venturi

Answer 34

It acts opposite to subsonic flow due to nozzle chokes the air and increases pressure

Question 35

What is the disadvantage of a swept back wing

Answer 35

Increases span wise airflow