11.1.2

Question 1

how may times is the speed of sound in water than air

Answer 1

4.3

Question 2

4 speed ranges

Answer 2

subsonic , transonic , supersonic, hypersonic

Question 3

subsonic speed range

Answer 3

up to 0.8

Question 4

supersonic speed range

Answer 4

1.2-5

Question 5

transonic speed range

Answer 5

0.8-1.2

Question 6

hypersonic speed range

Answer 6

above mach 5

Question 7

what property of air changes with the onset of transonic flight

Answer 7

air becomes compressible

Question 8

what is mach number

Answer 8

aircraft speed / speed of sound

Question 9

what is crit mach number

Answer 9

fastest speed aircraft can go without becoming subject to supersonic airflow

Question 10

what wing design delays onset of crit mach

Answer 10

Swept wing

Question 11

where does supersonic airflow first occur on an aerofoil

Answer 11

upper surface

Question 12

what forms on upper surface when crit mach is reached

Answer 12

shockwave

Question 13

what happens to airflow behind a shockwave

Answer 13

large increase in static pressure & flow separation

Question 14

what do u oblique shockwaves do

Answer 14

slow supersonic airflow before shockwave occurs

Question 15

where are oblique shockwaves employed

Answer 15

in the intakes

Question 16

what happens to air velocity in an expansion wave

Answer 16

It increases

Question 17

why does flow separation occur behind a shockwave

Answer 17

boundary layer does not have enough kinetic energy to withstand the large increase in static pressure

Question 18

when does a bow wave form

Answer 18

flight speed exceeds speed of sound

Question 19

which wing profile is known as wing loaded

Answer 19

Transonic

Question 20

advantages of rear loaded profile

Answer 20

lighter, greater fuel capacity, less drag, less sweepback, smaller wing, better low speed charactericts

Question 21

how is tuck under avoided

Answer 21

mach trim system

Question 22

what drag increases due to vortex generators

Answer 22

Parasitic Drag

Question 23

method of reducing wave drag

Answer 23

area rule

Question 24

where does shockwave first form on wing

Answer 24

wing root

Question 25

two types of shockwaves

Answer 25

normal and oblique

Question 26

what shockwave causes an increase in velocity in airflow

Answer 26

none, only expansion wave causes increase in velocity

Question 27

how does vortex generator re-energise the boundary layer

Answer 27

transfers energy from free airflow to the boundary layer

Question 28

when does the boundary layer separate from aerofoil section

Answer 28

when the normal shockwave forms

Question 29

what effect does aerodynamic heating have on metal

Answer 29

they lose strength

Question 30

what point is airflow over a wing at its maximum but below speed of sound

Answer 30

Critical mach number

Question 31

normal swept wing angle

Answer 31

30 degrees

Question 32

transonic wing profile

Answer 32

flatter upper surface curved leading edge thinner trailing edge than normal

Question 33

how is shock stall corrected

Answer 33

with horizontal stabiliser

Question 34

where is c.o.g located on balance control surface

Answer 34

on hinge line

Question 35

how is high speed turn controlled by flying control surfaces

Answer 35

aileron and roll spoilers

Question 36

what automatic system of the horizontal stabiliser corrects tuck under

Answer 36

Mach trim

Question 37

how many ailerons fitted to large aircraft

Answer 37

4 , 2 outbound, 2 inbound

Question 38

when do inbound ailerons operate

Answer 38

low speed and high speed

Question 39

when do outbound ailerons operate

Answer 39

low speed only

Question 40

aluminium strength lose how much strength at temperatures over 250 degrees

Answer 40

80%

Question 41

On a swept wing where does it stall first

Answer 41

Tip

Question 42

Dutch roll is movement is in which direction

Answer 42

Yaw and roll

Question 43

What are Kruger flaps

Answer 43

Leading edge flap hinges

Question 44

How are peto tubes heated

Answer 44

Electrically

Question 45

What is the artificial feel system used for

Answer 45

Required for power operated systems

Question 46

Where does shockwaves form

Answer 46

Highest point of camber

Question 47

when does a bow wave form

Answer 47

Above speed of sound

Question 48

What does vortex generator do

Answer 48

Re-energises boundary layer

Question 49

Purpose of swept wing

Answer 49

Aerodynamic purposes creating a longer thinner wing with an angle of 30 degrees

Question 50

Why do transonic profiles perform well in transonic reigons

Answer 50

There’s no flow separation behind the shockwave as this flow would generate lift

Question 51

If velocity increases what happens to the centre of pressure

Answer 51

Moves rearwards

Question 52

How is centre of pressure moving rearward offset

Answer 52

By horizontal stabiliser

Question 53

What are the waves formed by supersonic flow

Answer 53

Shock waves and expansion waves

Question 54

How can we increase critical Mach

Answer 54

Decreasing camber and increasing chord

Question 55

What happens during stall shock

Answer 55

Lift increases and drag decrees

Question 56

What happens to crit mach with a thicker camber

Answer 56

Crit Mach lowers

Question 57

How much faster is speed of sound in water than air

Answer 57

4.3 times out of

Question 58

How much faster is speed of sound in air than water

Answer 58

4.3 times slower

Question 59

What’s another name for flight tabs

Answer 59

Servo tab

Question 60

Where is the balance panel effective

Answer 60

High speeds