CPL PoF Lift Revision 1

The upward movement of air at the LEADING edge is known as:

• The total reaction

• Upwash

• Downwash

• Leftwash

The point at the leading edge where air comes to a complete stop is know as:

• The stop point

• The stationary point

• The stagnation point

• The zero speed point

For a general purpose aerofoil the AoA for zero lift is:

• 4° AoA

• 0° AoA

• -4° AoA

• -6° AoA

At the zero lift angle:

• No lift is produced

• A small amount of lift is produced

• The aircraft will stall

• No net lift is produced

For a general purpose aerofoil what is the critical angle and what happens if it is exceeded

• 16° the aircraft will stall

• 18° the aircraft will fly backwards

• 16° the amount of life will continue to increase

• 18° the aircraft will stall

Which of the these pressure envelopes represents an aerofoil at the critical angle (16°)

• A

• B

• C

• D

How does downwash effect the generation of lift:

• Downwash increases lift by increasing the effective AoA

• Downwash decreases lift by increasing the effective AoA

• Downwash increases lift by decreasing the effective AoA

• Downwash decreases lift by decreasing the effective AoA

Centre of Pressure:

• Is the point where weight acts through

• Is the point where upwash acts through

• Is the point downwash acts through

• Is the point lift acts through

The approximate movement of the centre of pressure as a % of the chord is:

• 40% of chord at low AoA to 15% at high AoA

• 15% at low AoA to 40% at high AoA

• Stays at approximately 40% at both low and high AoA

• Stays at 15% chord regardless of AoA

What happens to the total reaction with an increase in AoA

• Decreases and tilts forwards

• Increases and tilts forwards

• Decreases and tilts backwards

• Increases and tilts backwards