GUS gouge

Question 1

The design of a jet intake should accelerate the air to between

Answer 1

0.4M and 0.7M

Question 2

For aircraft operating beyond approx M1.5, multiple shock intakes are used because

Answer 2

the flow is decelerated through a series of oblique shcokwaves resulting in less pressure loses

Question 3

the purpose of a sharp lip on a supersonic pitot intake is to

Answer 3

lower the speed at which the normal shockwave attaches

Question 4

the immediate effects of an engine failure in a multi engine aircraft is yaw and roll to the live engine??

Answer 4

FALSE

Question 5

the critical engine is the engine which, when failed, gives the greatest yaw??

Answer 5

TRUE

Question 6

what is Vmca?

Answer 6

min speed for maintaining control of aeroplane with critical engine inoperative and maintain straight flight with an AoB not more than 5 degrees

Question 7

to overcome increased control forces at high speeds a typical flight control system would use?

Answer 7

powered controls

Question 8

spoilers are often fitted instead of ailerons because

Answer 8

on long thin wings ailerons can cause twisting and possible control reversal

Question 9

what is “q” feel

Answer 9

artificial feel control system where stick force is proportional to dynamic pressure

Question 10

purpose of area ruling is to

Answer 10

reduce wave drag

Question 11

3 techniques used in applying the area rule

Answer 11

• waisting the fuselage
• combining a flat sided fuselage with highly swept wings
• fitting pods on trailing edge

Question 12

a multiple shock intake has greater Q losses but smoother deceleration than a single shock intake because flow passes through numerous shockwaves?

Answer 12

FALSE

Question 13

3 advantages of swept wings

Answer 13

• increased Mcrit and Mcdr
• reduced wave drag
• decreased thickness to chord ratio

Question 14

in supersonic flight, more “subsonic” aerofoil section can be used at the tips of a swept wing because

Answer 14

of flow deceleration caused by inboard shockwaves

Question 15

the purpose of variable geometry wings is to

Answer 15

improve efficiency of wing through a broader range of speeds (who knew ayy)

Question 16

the main advantage of a canard is

Answer 16

contributes to lift produced by main wing

Question 17

what flight regime can LOCAL mach numbers be greater or less than 1.0

Answer 17

transonic

Question 18

the speed of sound in air is a function of

Answer 18

temperature

Question 19

if increasing altitude at a constant IAS, what happens to TAS and Mach Number?

Answer 19

TAS increases and Mach No increases

Question 20

the formation of a bow wave is dependent on the shape of the leading edge and the speed of the object?

Answer 20

TRUE

Question 21

when SUPERsonic flow passes through a divergent duct, what happens to velocity, density and pressure?

Answer 21

velocity increases whilst pressure and density decrease

Question 22

when SUBsonic flow passes through a convergent duct, what happens to pressure and velocity

Answer 22

velocity increases and pressure decreases

Question 23

supersonic flow around a compressive corner will do what WRT pressure and velocity

Answer 23

decelerate and increase pressure

Question 24

expansion fans form at a compressive corner?

Answer 24

FALSE

Question 25

after passing through a normal shockwave, airflow will be

Answer 25

subsonic and at a higher temp

Question 26

airflow passing through an oblique shockwave will be

Answer 26

subsonic OR supersonic and at a higher temp

Question 27

Do normal shockwaves experience lower energy losses than oblique shockwaves?

Answer 27

NO

Question 28

at a constant AoA, Coeff of Lift variations in the transonic region are due to

Answer 28

changes in up wash and formation of shockwaves

Question 29

At subsonic speed the amplitude of pressure waves remains constant with distance from the source?

Answer 29

FALSE

Question 30

Pressure waves emanating from a source moving at sonic speed are evenly spaced?

Answer 30

FALSE

Question 31

Define Mach number

Answer 31

ratio of the speed of an object or flow to the speed of sound

Question 32

the free stream mach number at which the bow shockwave first attaches to a sharp leading edge best defines?

Answer 32

detachment mach no

Question 33

subsonic flight is defined as range of speeds below?

Answer 33

Mcrit

Question 34

at supersonic soeeds lateral stability is reduced due to the overall reduction of Cl of the wings?

Answer 34

TRUE

Question 35

3 design characteristics of supersonic aerofoils

Answer 35

• low thickness to chord ratio
• little to no camber
• sharp leading edge

Question 36

is supercritical aerofoil section suitable for supersonic flight?

Answer 36

NO

Question 37

at supersonic speeds a symmetrical double wedge aerofoil at an AoA of half the wedge angle creates

Answer 37

two shockwaves and two expansion fans

Question 38

best compromise between supersonic and subsonic aerofoils is a

Answer 38

biconvex aerofoil

Question 39

3 design characteristics of supercritical aerofoil

Answer 39

• flattened upper surface
• reflex camber
• thickness to chord ratio >10%

Question 40

at supersonic speeds, energy drag increases as Mfs increases?

Answer 40

TRUE

Question 41

shockwave induced flow separation is caused by

Answer 41

higher pressure air behind a shockwave trying to move forward through the boundary layer

Question 42

rearward movement of the CoP in the transonic region causes?

Answer 42

tuck

Question 43

in transonic flight wing drop is caused by

Answer 43

uneven shockwave formation between each wing