POF - Four Forces of Flight

Question 1

during flight, the four forces acting on the airplane are:

Answer 1

lift, weight, thrust, and drag

Question 2

the four forces are in ___ during unaccelerated flight

Answer 2

equilibrium

Question 3

is the upward force created by the effect of airflow as it passes over and under the wing

Answer 3

Lift

Question 4

the airplane wing’s shape is designed to take advantage of what two principles?

Answer 4

Newton’s Law of Motion and Bernoulli’s principle

Question 5

The reaction to downwash from the top surface of the wing and the airstream striking the wing’s lower surface causes an upward reaction in positive lift according to what law of motion?

Answer 5

newton’s third law of motion.

Question 6

velocity increases, pressure decreases and vice versa refers to what principle

Answer 6

bernoulli’s principle

Question 7

design factors which affect a wing’s lifting capability

Answer 7

planform, camber, aspect ratio, wing area

Question 8

caused by the separation of airflow above the wing’s upper surface.

Answer 8

stall

Question 9

stall always occur after the critical angle of attack regardless of:

Answer 9

air speed, flight attitude, or weight

Question 10

total lift depends on the combined effects of

Answer 10

air speed and angle of attack

Question 11

true or false: when speed decreases, you need to increase angle of attack to maintain the same amount of lift

Answer 11

true

Question 12

include plain, split, slotted, and fowler

Answer 12

flaps

Question 13

force of gravity which act vertically through the center of the airplane toward the center of the earth. opposite of lift

Answer 13

weight

Question 14

forward acting force that opposes drag and propels the airplane

Answer 14

thrust

Question 15

acts in opposition to the direction of the flight, opposes thrust, and limit the speed of the airplane

Answer 15

drag

Question 16

drag caused by any aircraft surface which deflect or interfere with smooth airflow around the plane

Answer 16

parasite drag

Question 17

true or false: if airspeed is doubled, parasite drag increases fourfold

Answer 17

true

Question 18

drag generated by the airflow circulation around the wing as it creates lift

Answer 18

induced drag

Question 19

phenomenon in which the earth’s surface restricts the downward deflection of the airstream from the wing, decreasing induced drag

Answer 19

ground effect

Question 20

arrow which show the forces acting on an airplane

Answer 20

vectors

Question 21

newtons first law

Answer 21

body at rest remains at rest and a body in motion remains moving at the same speed in the same direction.

Question 22

newtons second law

Answer 22

f=ma

Question 23

newtons third law

Answer 23

for every action there is an equal and opposite reaction

Question 24

any surface which provide aerodynamic force when it interacts with a moving stream of air

Answer 24

airfoil

Question 25

deflection of incoming airstream upward and over the wing

Answer 25

upwash

Question 26

angle formed by the chord line of the wing and relative wind

Answer 26

angle of attack

Question 27

downward deflection of airstream as it passes over the wing and past the trailing edge

Answer 27

downwash

Question 28

part of the airfoil which meet meets airflow first

Answer 28

leading edge

Question 29

portion of airfoil where airflow over the upper surface rejoins the lower surface airflow

Answer 29

trailing edge

Question 30

characteristic curve of the airfoil's upper and lower surfaces

Answer 30

camber

Question 31

imaginary line drawn through the leading edge and trailing edge

Answer 31

chord line

Question 32

airflow parallel to flight path

Answer 32

relative wind

Question 33

airplane stalls when critical angle of attack is exceeded regardless of:

Answer 33

airspeed, flight attitude, weight

Question 34

way to measure lift as it relates to angle of attack

Answer 34

coefficient of lift

Question 35

stall characteristics:

Answer 35

mushy feeling, stall warning device identified, slight buffeting of the airplane

Question 36

to recover from stall you must restore smooth airflow by

Answer 36

decrease angle of attack

Question 37

wing design factors

Answer 37

wing planform, camber, aspect ratio, and total wing area

Question 38

relationship between length and width of wing

Answer 38

aspect ratio

Question 39

total surface area of the wing

Answer 39

wing area

Question 40

refers to the shape of the wing

Answer 40

planform

Question 41

a. shape of wing ideal for slow speeds b. shape of wing that has a tendency to stall first at wing root c. shape of wing combined with rectangular and tapered configurations d. shape of wing which include delta wings

Answer 41

a. elliptical b. rectangular c. tapered d. sweptback

Question 42

angle between chord line and longitudinal axis of plane

Answer 42

angle of incidence

Question 43

consists of two metal strips attached to the leading edge of each wing near the fuselage to ensure positive control during a stall

Answer 43

stall strips

Question 44

true or false: drag is always a bi-product of lift

Answer 44

true

Question 45

pilot controls of lift

Answer 45

changing airspeed, changing angle of attack, usage of high-lift devices

Question 46

allows to steepen the angle of descent on an approach without increasing airspeed

Answer 46

flaps

Question 47

refers to the position of landing gear and flaps

Answer 47

configuration

Question 48

a. flap attached to the wing by a hinge. b. flap hinged only to the lower portion of the wing. c. flap that allows a portion of higher air pressure travel through a slot d. flap attached to the wing by a track and roller system

Answer 48

a. plain flap b. split flap c. slotted flap d. fowler flap

Question 49

a. drag related to the structure of the plane b. drag when currents of air over an airplane meet and interact c. drag caused by roughness of the airplane's surface

Answer 49

a. form drag b. interference drag c. skin friction drag

Question 50

sum of parasite and induced drag

Answer 50

total drag

Question 51

true or false: ground effect is noticeable when height is approximately equal to the wingspan of the aircraft

Answer 51

true

Question 52

true or false: during unaccelerated flight, the four forces of flight are in equilibrium

Answer 52

true

Question 53

true or false: as airspeed increases, angle of attack at which airfoil stalls increases

Answer 53

false

Question 54

what is the aspect ratio of the wing below: ``` ws = 35ft ac = 5ft ```

Answer 54

``` ar = ws/ac ar = 35ft/5ft ar = 7ft ```

Question 55

pilot methods to control lift

Answer 55

change air speed, change angle of attack, use high lift devices