CPL Aerodynamics 2

Question 1

Which factor primarily determines the critical angle of attack for a given airfoil?

Accepted Answer

Airfoil shape and camber

Answer

Critical angle of attack is a fixed aerodynamic property of the airfoil's shape and camber, not affected by speed or weight.

Question 2

What happens to induced drag when an aircraft's airspeed is doubled at the same altitude and weight?

Accepted Answer

It is reduced to one-quarter

Answer

Induced drag varies inversely with the square of airspeed, so doubling speed reduces induced drag to one-quarter of its original value.

Question 3

Ground effect reduces induced drag primarily because it:

Accepted Answer

Restricts the formation of wingtip vortices

Answer

Ground effect limits downwash and vortex formation near the ground, reducing induced drag significantly during takeoff and landing.

Question 4

An aircraft experiencing 'Dutch roll' is showing instability about which axes?

Accepted Answer

Lateral and vertical simultaneously

Answer

Dutch roll is an oscillatory coupling of roll and yaw (lateral and vertical axes) common in swept-wing aircraft with high dihedral.

Question 5

What is the effect of increasing aspect ratio on an aircraft's aerodynamic efficiency?

Accepted Answer

Reduces induced drag

Answer

A higher aspect ratio reduces wingtip vortex strength per unit span, decreasing induced drag and improving the lift-to-drag ratio.

(CPL) Commercial Pilot Licence Practice Test