# Ch 3A - Four Forces of Flight Flashcards

1
Q

Four forces acting on an airplane

A

Life, weight, thrust, and drag

2
Q

Four forces are in equilibrium

A

During unaccelerated flight

3
Q

Force created by the effects of airflow as it passes over and under the wing

A

Lift

4
Q

The airplanes wing shape is designed to take advantage of

A

Newton’s laws and Bernoulli’s principles

5
Q

Bernoulli’s principle

A

Increase in speed of air on the top of an airfoil produces a drop in pressure and this lowered pressure is a component of total lift. The decrease in speed of air on the bottom of the airfoil produces an increase in pressure, providing the main component of total lift

6
Q

Newton’s third law of motion

A

The reaction to downwash causes an upward reaction

7
Q

Design factors that affect a wings lifting capability

A

Planform, camber, aspect ratio, wing area

8
Q

A stall is caused by

A

The separation of airflow from the wings upper surface, and always occurs at an airplanes critical angle of attack regardless of airspeed, attitude or weight

9
Q

Total lift depends on

A

The combined effects of airspeed and angle of attack

10
Q

When speed decreases

A

ou must increase the angle of attack to maintain the same amount of lift

11
Q

Flaps

A

Increase lift and drag by increasing the wings effective camber and changing the chord line that increases the angle of attack

12
Q

Flap types

A

Plain(hinge), split(only lower hinged), slotted(plane w/gap) and fowler(slide out w/gap)

13
Q

Weight

A

Force of gravity that acts vertically through the center of gravity of the airplane towards the center of the earth

14
Q

Thrust

A

Forward-facing force that opposes drag and propels the airplane

15
Q

Drag

A

Acts in opposition to the direction on flight and opposes thrust, limits the forward speed of an airplane

16
Q

Parasite drag

A

Caused by surface that deflects or interferes with the smooth airflow around the airplane; form, interference, skin friction; airspeed doubled = 4X parasite drag

17
Q

Induced drag

A

Airflow circulation around the wings as it creates lift, increases with slow airspeed

18
Q

Ground effect

A

Surface restricts the downward deflection of the airstream from the wing, decreasing induced drag, airplane takes off before recommended take off speed

19
Q

Straight, level, unaccelerated flight

A

Lift=weight and thrust=drag

20
Q

Angle of attack

A

Formed by wing chord line and relative wind

21
Q

Aspect ratio

A

Span(long)/average chord(short)