Aerodynamics & Aircraft

Question 1

What will an increase in aspect ratio (high) with constant velocity do to the production of lift?

Answer 1

• Decrease drag, especially at high angles of attack; therefore improving the performance of the wing when in a climbing attitude

Question 2

What is positive static stability?

Answer 2

• The tendency of the a/c to return to the original state of equilibrium after being disturbed

Question 3

What’s neutral static stability?

Answer 3

• The tendency of the a/c to remain in a new condition after its equilibrium has been disturbed

Question 4

What’s negative static stability?

Answer 4

• The tendency of the a/c to continue away from the original state of equilibrium after being disturbed

Question 5

What’s the difference between static and dynamic stability?

Answer 5

• Dynamic: Refers to the a/c response over time after it’s original flight path has been disrupted
  • i.e, the waves of motion the a/c does to get back it’s stability
• Static: Refers to the a/c initial response to a change in flight path
  • i.e, the initial nose up, down, or return to it’s flight path

Question 6

What is positive dynamic stability?

Answer 6

• Over time, the motion of the displaced object decreases in amplitude and, because it’s positive, the objects returns towards the equilibrium state

Question 7

What is neutral dynamic stability?

Answer 7

• Once displaced, the displaced object neither decreases or increases in amplitude
• In theory it would continue oscillations forever

Question 8

What is negative dynamic stability?

Answer 8

• Over time, the motion of the displaced object increases and becomes more divergent
• i.e, the waves of the oscillations gets worse and larger as time moves on

Question 9

What happens to IAS as altitude increases for a plane to stall in a particular configuration?

Answer 9

• It remains the same

Question 10

When the wing is 1/10 the span, he reduction of induced drag is reduced by:

Answer 10

• 50%

Question 11

What and why does the IAS and altimeter indicate when in ground effect?

Answer 11

• Ground effect causes a local increase in static pressure
• The ASI and altimeter will indicate slightly lower, and the VSI will show an initial descent rate

Question 12

What is the difference between a skid and a slipping turn?

Answer 12

• Skid: The tail is outside of the turn
• Slip: The tail is inside of the turn

Question 13

In a climbing right turn, you don’t add enough right rudder, what can occur? and why?

Answer 13

• The nose high attitude results in a strong left yaw due to the increase in P-Factor

Question 15

Explain in detail how a spin is developed?

Answer 15

• The lack of right rudder rotates the plane around it’s vertical axis
• The outboard wing is less stalled than the inboard wing which creates a rolling, yawing, and pitching motion
• Plane descends due to gravity
• Maintaining directional control and not allowing the nose to yaw before stall recovery is initiated is key to averting a spin

Question 16

An aircraft able to change directions along a flight path and withstand the stresses imposed upon it is referred to as its:

Answer 16

• Maneuverability

Question 17

A measure of the response of an aircraft relative to the pilot’s flight control inputs is referred to its:

Answer 17

• Controllability