Chapter 3 Section A

Question 1

what happens to the four forces of flight during unaccelerated flight?

Answer 1

the four forces are in equilibrium

Question 2

describe how newton’s law of motion and Bernoulli’s principle explain the generation of lift by an airfoil?

Answer 2

the shape of an airfoil causes air to accelerate over the wing and decelerate as it passes under the wing. the increased speed of the air on top of an airfoil produces a pressure drop and this pressure drop is one component of total lift and the decrease of speed of the air on the lower surface increases pressure. since this air pattern causes a downwash the opposite reaction of this is an upward reaction with is lift.

Question 3

as airspeed increases the angle of attack at which an airfoil stalls also increases

Answer 3

false

Question 4

find the aspect ratio
wingspan= 196ft
average cord= 28ft

wingspan=35ft
average cord=5ft

wingspan=37ft
average cord=11ft

Answer 4

aspect ratio=
wingspan divided by average cord
- 7.5
-7
-3.4

Question 5

identify the three methods to control lift during flight

Answer 5

you can control lift by changing the angle of attack, changing airspeed, and by using a high lift device

Question 6

will the wings angle of attack increase or decrease when lowering trailing edge flaps?

Answer 6

increase

Question 7

is it more desirable for wing root or wingtip to stall first and why?

Answer 7

it is more desirable for the wing root to stall first, because when the wing tip stalls first the ailerons are less affect and it can make it impossible to level the wings

Question 8

list three examples of parasite drag and three things that reduce it

Answer 8

form drag it can be reduced by the shape of the airfoils
interference drag it can be reduced by the design of the aircraft
skin friction drag it can be reduced by the smoothness of the aircraft

Question 9

explain why induced drag increases as airspeed decreases

Answer 9

this happens because induces drag is cause by the wingtip vortices and is the reward component of lift. when you decrease airspeed it is because you are in a high angle of attack causing more lift so induce drag increases.