T Post-test 3 (Aerodynamics)

1. Which of the following will enable the maximum ground distance to be covered in a glide descent?

A. Headwind

B. Decreased mass

C. Tailwind

D. Increased mass

C. Tailwind

2. The stagnation point on an aerofoil is the point where:

A. The boundary layer changes from laminar to turbulent.

B. The airflow is brought completely to rest.

C. None of the above

D. The suction pressure reaches a maximum.

B. The airflow is brought completely to rest.

3. When an aircraft stalls:

A. Lift and drag increase.

B. Lift increases and drag decreases.

C. Lift decreases and drag increases.

D. All of the above

C. Lift decreases and drag increases.

4. Regarding the gust load of an aeroplane, with every other factor remaining constant, which statements are correct?

(i) The gust load increases when the mass decreases.

(ii) The gust load increases when the altitude increases.

A. (i) correct; (ii) incorrect

B. (i) correct; (ii) correct

C. (i) incorrect; (ii) correct

D. (i) incorrect; (ii) incorrect

A. (i) correct; (ii) incorrect

5. After a change in collective pitch, the rotor RPM will rise and fall. This is called:

A. Static droop

B. None of the above

C. Transient droop

D. Under swing

C. Transient droop

6. At low forward speed:

A. A large sideslip angle could cause the fin to stall.

B. Increased downwash from the wing will cause the elevators to be more responsive.

C. Due to the increased angle of attack of the wing, the air will flow faster over the wing, giving improved aileron control.

D. A swept-back wing will give an increased degree of longitudinal stability.

A. A large sideslip angle could cause the fin to stall.

7. The total pressure is:

A. Measured parallel to the local stream

B. Static pressure minus dynamic pressure

C. Static pressure plus dynamic pressure

D. \(\frac{1}{2}\rho V^2\)

C. Static pressure plus dynamic pressure

8. Climbs with forward speed require less power than vertical climbs because of:

A. Increased inertia

B. Forward momentum

C. Translational lift

D. None of the above

C. Translational lift

9. When power-assisted controls are used for pitch control, this:

A. Makes aerodynamic balancing of the controls difficult

B. Ensures that partial aerodynamic forces are still felt on the control column

C. Can only function as an elevator trim tab

D. Makes trimming unnecessary

B. Ensures that partial aerodynamic forces are still felt on the control column

10. An aircraft in straight and level flight is subject to:

A. Zero load factor

B. A load factor of 1

C. A load factor of ½

D. None of the above

B. A load factor of 1

11. The type of flow separation that occurs at the lowest angle of attack is the:

A. Shockstall

B. High-speed stall

C. Deep stall

D. Low-speed stall

A. Shockstall

12. Ice contamination of the leading portion of the aerofoil has which consequences?

(1) The profile of the leading portion of the surface can be changed, preventing normal acceleration of the airflow and substantially reducing lift.

(2) Form (pressure) drag will increase because of the increased frontal area of the aerofoil section.

(3) Loss of lift will have a greater effect than an increase in form (pressure) drag.

(4) At normal angles of attack, lift can be lost entirely if enough ice accumulates.

A. 1, 2 and 3

B. 1, 3 and 4

C. 3 and 4

D. 1, 2, 3 and 4

D. 1, 2, 3 and 4

13. At a constant IAS, what effect will increasing altitude have on damping in roll?

A. Decreases because the ailerons are less effective.

B. Decreases because the density decreases.

C. Increases because the TAS increases.

D. Remains the same.

B. Decreases because the density decreases.

14. The cockpit indication when the elevator trim tab is moved down is:

A. Nose-up

B. Nose-down

C. Dependent on the position of the elevator

D. Neutral

A. Nose-up

15. The temperature lapse rate below the tropopause is:

A. 3°C per 1,000 ft

B. 2°C per 1,000 ft

C. 1°C per 1,000 ft

D. All of the above

B. 2°C per 1,000 ft

16. Dynamic pressure is equal to:

A. Density times speed squared

B. Half the density times the indicated airspeed squared

C. Half the true airspeed times the density squared

D. Half the density times the true airspeed squared

D. Half the density times the true airspeed squared

17. A helicopter hovering near a tall building will:

A. Be unaffected by it.

B. Drift towards it.

C. All of the above

D. Drift away from it.

B. Drift towards it.

18. At sea level, ISA atmospheric pressure is:

A. 14.7 kPa

B. 14.7 PSI

C. 10 Bar

D. All of the above

B. 14.7 PSI

19. During forward flight, the advancing blade will:

A. Lag

B. Flap down

C. Flap up

D. None of the above

C. Flap up

20. What effect would a light crosswind have on the wingtip vortices generated by a large aeroplane that has just taken off?

A. The upwind vortex will tend to remain on the runway longer than the downwind vortex.

B. A crosswind will rapidly dissipate the strength of both vortices.

C. The downwind vortex will tend to remain on the runway longer than the upwind vortex.

D. A crosswind will move both vortices clear of the runway.

A. The upwind vortex will tend to remain on the runway longer than the downwind vortex.

21. When moving from the hover to forward flight, it is necessary to:

A. Decrease the engine power.

B. Increase the engine power.

C. Maintain constant engine power.

D. All of the above

B. Increase the engine power

22. Mach trimming is initiated by an input signal from the:

A. CADC

B. IRS

C. Vertical gyro

D. None of the above

D. None of the above*

23. The bow wave will first appear at:

A. M = 1.05

B. M = Mcrit

C. M = 1.3

D. M = 0.6

A. M = 1.05

24. Vortex generators:

A. Change the turbulent boundary layer into a laminar boundary layer.

B. Transfer the energy from the free airflow to the boundary layer.

C. Reduce the spanwise flow of a swept wing.

D. Take kinetic energy out of the boundary layer to reduce separation.

B. Transfer the energy from the free airflow to the boundary layer.

25. At low Mach numbers, which of the following can occur?

A. Mach tuck

B. Shockwaves

C. Dutch roll

D. Tuck under

C. Dutch roll

26. Compressibility effect is:

A. The increase in total drag of an aerofoil in transonic flight due to the formation of shock waves.

B. Drag associated with the form of an aircraft.

C. Drag associated with the friction of the air over the surface of the aircraft.

D. All of the above

A. The increase in total drag of an aerofoil in transonic flight due to the formation of shock waves.

27. In a level, coordinated turn, the load factor \(n\) (i) and the stalling speed \(V_s\) (ii) are:

A. (i) More than 1; (ii) lower than in straight and level flight

B. (i) Less than 1; (ii) higher than in straight and level flight

C. (i) More than 1; (ii) higher than in straight and level flight

D. (i) Less than 1; (ii) lower than in straight and level flight

C. (i) More than 1; (ii) higher than in straight and level flight

28. The angle of attack at which an aeroplane stalls:

A. Will occur at smaller angles of attack flying downwind than when flying upwind

B. Will remain constant regardless of gross weight

C. Is a function of speed and density altitude

D. Is dependent upon the speed of the airflow over the wing

B. Will remain constant regardless of gross weight

29. Where are Krueger flaps fitted?

A. Outboard on the wing leading edge

B. Inboard on the wing trailing edge

C. Outboard on the wing trailing edge

D. Inboard on the wing leading edge

D. Inboard on the wing leading edge

30. Lateral stability may be increased with:

A. Increased lateral anhedral

B. Increased lateral dihedral

C. Increased longitudinal dihedral

D. All of the above

B. Increased lateral dihedral

31. A jet transport is flying at a standard altitude of 13,087 ft with a velocity of 307 mi/hr. What is the Mach number?

A. 0.422691548

B. 0.528364435

C. 0.08453831

D. 0.634037322

A. 0.422691548

32. The angle between the chord line of the aerofoil section and the longitudinal axis of the aircraft is known as:

A. Sweep back

B. The angle of attack

C. Dihedral

D. The angle of incidence

D. The angle of incidence

33. As air flows over the upper cambered surface of an aerofoil, what happens to velocity and pressure?

A. Velocity decreases, pressure decreases.

B. Velocity increases, pressure decreases.

C. Velocity increases, pressure increases.

D. All of the above

B. Velocity increases, pressure decreases.

34. At a point in the test section of a supersonic wind tunnel, the air pressure and temperature are 59,669 N/m² and 248 K, respectively. Calculate the specific volume (m³/kg).

A. 0.238635942

B. 1.193179708

C. 1.491474635

D. 1.789769562

B. 1.193179708

35. If an aircraft returns to a position of equilibrium, it is said to be:

A. Negatively stable

B. Neutrally stable

C. Positively stable

D. None of the above

C. Positively stable

36. The effect that winglets have is that they:

A. Reduce induced drag

B. Increase the value of Vmd

C. Increase static longitudinal stability

D. Decrease the stalling speed

A. Reduce induced drag

37. When accelerating from \(C_{L\max}\) to the maximum speed, the total drag:

A. Decreases

B. Increases and then decreases

C. Decreases and then increases

D. Increases

C. Decreases and then increases

38. Which condition is the actual amount of water vapour in a mixture of air and water?

A. Relative humidity

B. Dew point

C. Absolute humidity

D. All of the above

C. Absolute humidity

39. The input data to a stall warning device (e.g., stick shaker) system is:

A. Angle of attack, and in some systems the rate of change of angle of attack

B. Angle of attack only

C. Airspeed only

D. Airspeed and sometimes the rate of change of airspeed

A. Angle of attack, and in some systems the rate of change of angle of attack

40. The Mach trimmer corrects for:

A. Pitch-up

B. Movement of the centre of pressure

C. Movement of the centre of gravity

D. Shockwave drag

B. Movement of the centre of pressure

41. Consider the low-speed flight of the space shuttle as it is nearing a landing. If the air pressure and temperature at the nose of the shuttle are 3.68 atm and 307 K, respectively, what is the density in kg/m³?

A. 0.846161213

B. 5.288507579

C. 4.230806063

D. 6.346209094

C. 4.230806063

42. At a point in the test section of a supersonic wind tunnel, the air pressure and temperature are 59,669 N/m² and 248 K, respectively. Calculate the specific volume (m³/kg).

A. 1.193179708

B. 1.491474635

C. 1.789769562

D. 0.238635942

A. 1.193179708

43. Alcohol (specific gravity = 0.80) is flowing through a horizontal pipe that is 10 in. in diameter, with a velocity of 40 ft/s. At a smaller section of the pipe, the pressure is 6 lb/in² less. Assuming that the flow is smooth, what is the diameter at the smaller section?

A. 0.584 ft

B. 1.095 ft

C. 0.73 ft

D. 1.314 ft

C. 0.73 ft

44. An airplane is flying at sea level. The difference between impact and static pressure is 0.25 lb/in². What is the airspeed in knots?

A. 185.4 kts

B. 103 kts

C. 154.5 kts

D. 82.4 kts

B. 103 kts

45. An airplane weighs 7,000 lb, the wing area is 460 sq ft, the \(C_L\) of the wing is 0.85, and the \(C_D\) is 0.053. What power is required by the wing at sea level?

A. 146.1 hp

B. 175.32 hp

C. 77.92 hp

D. 97.4 hp

D. 97.4 hp

46. A venturi tube is 6 in. in diameter at the entrance, where the pressure is 10 lb/in² (gage). The throat is 4 in. in diameter, where the pressure is 6 lb/in² (gage). What is the flow of water?

A. 60.08 psi

B. 135.18 psi

C. 75.1 psi

D. 112.65 psi

C. 75.1 psi

47. A circular pipe, 100 ft long, gradually tapers from 3 ft in diameter at one end to 2 ft in diameter at the other. Fluid is flowing from the bigger toward the smaller end. What is the rate of increase in velocity at the entrance if the velocity there is 80 ft/s?

A. 0.444 fps/ft

B. 0.321 fps/ft

C. 0.3654 fps/ft

D. 0.65412 fps/ft

A. 0.444 fps/ft

48. If the aircraft is flying nose-heavy, which direction would you move the elevator trim tab?

A. Up to move elevator up.

B. Up to move elevator down.

C. Down to move elevator up.

D. All of the above

C. Down to move elevator up

49. An aeroplane with positive static stability is:

A. Always dynamically neutral

B. Dynamically neutral, stable or unstable

C. Always dynamically unstable

D. Always dynamically stable

B. Dynamically neutral, stable or unstable

50. If the total moments of an aeroplane about an axis are not zero, it will result in:

A. An angular acceleration about that axis

B. Equilibrium

C. Increased stability

D. A continuous rotation about that axis

A. An angular acceleration about that axis