Principles of Flight

Question 1

Why are advanced propeller blades designed broader and swept back at the blade tips

Answer 1

To reduce the adverse effects of high speed tips

Question 2

How can the solidity of a propeller be increased

Answer 2

By increasing the number of propeller blades to help with power absorption

Question 3

What is the effect known as where the thrust produced by the down going propeller blade when the aircraft is at a higher angle of attack

Answer 3

Asymmetric blade effect

Question 4

If air mass is M, intake air low velocity is Vi and exhaust velocity is Ve, what does Mx (Ve - Vi) x TAS express

Answer 4

Gas turbine jet propulsive power

Question 5

What does M x (Ve - Vi) express

Answer 5

Gas turbine jet thrust

Question 6

Why is the propeller tip speed a critical factor in turbo prop efficiency

Answer 6

Because of the rotational drag at the tip due to compressibility at high tip speeds.

Question 7

How can the adverse effects of the loss of an outboard critical engine be minimised on multi engine turbo prop aircraft

Answer 7

The use of counter rotating propellers

Question 8

How does a turbo fan engine generate high levels of thrust at lower speeds, significantly increasing overall mass flow and thrust

Answer 8

Additional turbine stages absorb more of core gas flow to drive a bypass fan stage

Question 9

What is the ratio of power output over the power generated by the chemical energy of fuel consumed defined as?

Answer 9

Gas turbine efficiency

Question 10

What is meant by the term critical engine in propeller powered aircraft

Answer 10

When it fails, the remaining engine produces the most use due to increased asymmetric thrust moment

Question 11

What is the immediate and secondary effects of asymmetric thrust

Answer 11

Yaw then roll towards the dead engine

Question 12

With wings level, which way will the slip indicator move following an engine failure

Answer 12

Towards the live engine

Question 13

What is the preferred method of asymmetric control in flight

Answer 13

Level the wings and then opposing yaw with rudder

Question 14

What is the preferred method of asymmetric control following an engine failure before V1

Answer 14

Reduce power

Question 15

What conditions are used to calculate an aircraft’s VMCA

Answer 15

Landing gear up
Flap 1
Critical engine feather (prop only)
Live engine at TOGA
Full rudder
5 degree bank toward live engine
Rearmost C of G

Question 16

What is the VMCA of the phenom

Answer 16

97 kts

Question 17

What will happen if no corrective action is taken following an asymmetric engine failure

Answer 17

The aircraft will enter a spiral descent towards the dead engine

Question 18

Once control has been established was is dead leg dead engine used to identify

Answer 18

Which engine has failed

Question 19

What will a low thickness/chord ratio and low aspect wing ratio delay the onset of

Answer 19

Compressibility effects

Question 20

What happens when the airflow over the aircraft surfaces reaches the speed of sound

Answer 20

Shockwave start to form 

Question 21

What are the features of a super critical wing profile?

Answer 21

Blunt nose
Flat upper surface
Thick trailing edge
Higher thickness to chord ratio
S shaped camber

Question 22

In aircraft design what insures a smooth change in cross-sectional area from nose to tail?

Answer 22

Area ruling

Question 23

Below, what speed does air behave like an incompressible fluid

Answer 23

250 to 300 knots

Question 24

What is the only variable in calculating the local speed of sound?

Answer 24

Temperature

Question 25

What is the name given to the ratio of TAS to the local speed of sound?

Answer 25

The Mach number

Question 26

What is Mcrit

Answer 26

The speed at which shockwaves first form on an aircraft

Question 27

What is Mfs

Answer 27

The mach number of the airflow past an aircraft that is unaffected by its passage

Question 28

What does Mdet indicate

Answer 28

The end of transonic flight and the beginning of supersonic flight

Question 29

What effect does the formation of shockwaves have on drag?

Answer 29

The coefficient of drag increases

Question 30

What causes aerodynamic heating at high Mach numbers?

Answer 30

Compression of airflow

Question 31

Why did early sweptwing aircraft tend to pitch up at low speeds, leading to a deep stall or sabre dance?

Answer 31

Swept wings tend to stall at the tip, first, moving the lift centre of pressure forwards

Question 32

How does CLMAX Swepson Street wing compare in relation to AOA

Answer 32

A swept wing has a Lower CLmax at a higher AoA

Question 33

What is the term for the point in the flight envelope at which the aerodynamics stall speed is the same as shock stall speed

Answer 33

Coffin corner

Question 34

What are the three functions of spoilers

Answer 34

Speed break
Lift dumping
Roll control

Question 35

What is a leading edge flap called

Answer 35

Krueger flap

Question 36

Other than a flap what other leading edge lift augmentation devices are there

Answer 36

Slotted flap
Droop

Question 37

What kind of training edge flap increases CL, by increasing wind, camber and cord length

Answer 37

Fowler flap

Question 38

What is lateral stability

Answer 38

The tendency for wing to return level when disturbed in the role axis

Question 39

What is spiral stability

Answer 39

The tendency for the wing to return level, when the control forces are released in a balance turn

Question 40

What do slats increase during climb?

Answer 40

Higher AoA

Question 41

What would happen if slats were attracted before flaps to high angle of attack

Answer 41

Stall