BAvn Bachelor of Aviation Bachelor of Aviation Theory of Flight 5

Question 1

What is 'P-factor' (asymmetric blade effect) and when is it most pronounced in a single-engine propeller aircraft?

Accepted Answer

The descending blade produces more thrust than the ascending blade; most pronounced at high power and high angle of attack

Answer

P-factor occurs because the descending blade has a higher effective angle of attack than the ascending blade during high AoA flight, creating asymmetric thrust yawing toward the ascending blade side.

Question 2

In transonic flight, what is 'wave drag' and how does it arise?

Accepted Answer

Drag resulting from the formation of shockwaves on the aircraft, converting kinetic energy into heat

Answer

Wave drag arises when shockwaves form on the aircraft surface; the shockwave is a discontinuity that converts organized kinetic energy into thermal energy and entropy, creating drag.

Question 3

How does wing dihedral contribute to lateral-directional static stability?

Accepted Answer

When the aircraft sideslips, the lower wing generates more lift than the upper wing, creating a restoring roll moment

Answer

In a sideslip, the lower dihedral wing meets the airflow at a greater effective angle of attack, generating more lift and rolling the aircraft back toward wings-level.

Question 4

What is 'Dutch roll' and which design feature primarily counteracts it?

Accepted Answer

A coupled roll-yaw oscillation; counteracted by a yaw damper system

Answer

Dutch roll is a coupled lateral-directional oscillation where yaw and roll reinforce each other; it is primarily damped by an electronic yaw damper system.

Question 5

When an aircraft transitions from subsonic to supersonic flight, what happens to the aerodynamic center (neutral point)?

Accepted Answer

Moves from approximately the quarter-chord aft to approximately the mid-chord (50%)

Answer

In supersonic flow, linearized theory places the aerodynamic center at the 50% chord, compared to the 25% chord (quarter-chord) position in subsonic flow.

BAvn Bachelor of Aviation Practice Test

BAvn Bachelor of Aviation Practice Test

BAvn Bachelor of Aviation Bachelor of Aviation Theory of Flight 5