What is the state of equilibrium?

All four forces (lift, thrust, drag, weight) are balanced

What 3 ways an aircraft can travel in equilibrium?

Straight and level flight, constant climb, or constant descend

When does acceleration occur?

All four forces (lift, thrust, drag, weight) are not completely balanced

What happens when thrust is greater than drag?

Aircraft accelerates

What happens when drag is greater than thrust?

Aircraft decelerates

What happens when lift is greater than weight?

Aircraft climbs

What happens when weight is greater than lift?

Aircraft descends

What is the purpose of elevators?

To divide the power of the engine into lift and thrust

Where does the power that produces lift and thrust originate from? How does the pilot control it?

The power originates from the engine, which the pilot controls with the throttle

Describe the two types of boundary layers

The laminar layer occurs when the boundary layer is smooth. When the boundary layer is turbulent, it is called the turbulent layer

Describe what happens when the critical angle of attack is reached

The boundary layer can no longer flow smoothly over the wing and the centre of pressure rapidly moves backward. This causes the wing to stall

What happens to the centre of pressure of the airfoil when the angle of attack is increased?

The centre of pressure moves forward as the stall is approached, and then at the point of stall it rapidly moves backward

What is the relationship between the angle of attack and the turbulent layer?

Increasing the angle of attack increases turbulent airflow over the airfoil

At what point does every aircraft stall regardless of airspeed?

At the critical angle of attack

What happens to the boundary layer in a stall?

Air can no longer flow smoothly over the wing resulting in a turbulent layer

Can you stall at a high speed?

Yes, speed does not matter

Define the following: wing platform, span, area, and chord?

Wing platform - the shape of the wing as seen from above Span - the distance from one wing tip to another Chord - the distance between the leading edge and trailing edge of a wing

Define aspect ratio. What is the benefit of a high aspect ratio?

The relationship between the span and the chord of the wing. Higher aspect ratios have lower induced drag

What is the angle of incidence?

The angle of the chord line relative to the longitudinal axis of the aircraft

Define stability

The ability of an aircraft to correct for conditions that act on it, such as turbulence and flight control inputs

What type of stability is this?

Negative dynamic stability

What type of stability is this?

Neutral dynamic stability

What type of stability is this?

Positive dynamic stability

What type of stability is this?

Negative static stability

What type of stability is this?

Neutral static stability

What type of stability is this?

Positive static stability

Describe the different stabilities along the axes

Longitudinal stability (pitch) works about the lateral axis

Lateral stability (roll) works about the longitudinal axis

Directional stability (yaw) works about the vertical axis

What is inherent stability?

The tendency of an aircraft to return to straight and level flight due to its design

What kind of stability are most wings designed for?

Positive static and dynamic stability

Define dihedral

The upward angle of an aircraft's wings