CPL Aerodynamics 4

Question 1

What is the primary purpose of a vortex generator on an aircraft wing?

Accepted Answer

To re-energize the boundary layer and delay flow separation

Answer

To reduce drag at cruise speed

Answer

To increase the critical Mach number

Answer

To reduce stall speed at all flap settings

Question 2

Which statement about the boundary layer is correct?

Accepted Answer

Turbulent boundary layers are more resistant to separation than laminar ones

Answer

Laminar flow produces higher skin friction than turbulent flow

Answer

Boundary layer thickness decreases with distance from the leading edge

Answer

Laminar flow extends further aft on rough surfaces

Question 3

What is the speed at which the induced drag equals the parasite drag known as?

Accepted Answer

All of the above

Answer

Best glide speed (L/Dmax)

Answer

Minimum drag speed

Answer

VMD (velocity of minimum drag)

Question 4

Accelerated stalls are dangerous primarily because they occur at:

Accepted Answer

Higher airspeeds than the published 1-G stall speed

Answer

Lower airspeeds than in level flight

Answer

The same airspeed regardless of bank angle

Answer

Only during instrument meteorological conditions

Question 5

What aerodynamic effect does wing sweep have on stall characteristics?

Accepted Answer

It causes tip stall before root stall, worsening pitch-up tendency

Answer

It ensures root stall occurs first, improving safety

Answer

It has no effect on spanwise flow distribution

Answer

It delays stall only on the inboard sections

Question 6

During a glide, what change increases the glide ratio?

Accepted Answer

Increasing L/D ratio

Answer

Increasing weight

Answer

Lowering flaps

Answer

Reducing altitude

Question 7

What is the aerodynamic significance of the 'propeller slipstream effect' on a single-engine aircraft?

Accepted Answer

It increases dynamic pressure over the tailplane, enhancing elevator effectiveness

Answer

It decreases effective angle of attack on the tail

Answer

It causes asymmetric lift by accelerating air over one wing more than the other

Answer

It reduces induced drag at low airspeeds