Jki - Principles Of Flight

Front 1

When did the Wright brothers make their first flight? What were their names? What was the name of the aircraft?

Back 1

December 17, 1903. Orville and Wilbur.
Wright Flyer 1.

Front 2

How much does 1 foot of cubic air weight?

Back 2

38g

Front 3

Illustrate the flow of air around an airfoil.

Back 3

.

Front 4

According to ____ Principles, an ___ in the speed of fluid occurs simultaneously with a ____ in pressure. Approx _/_ of the lift force generated is due to a pressure ____ ontop, and _/_ from a pressure ____ below.

Back 4

Bernoulli's, increase, decrease. 2/3, decrease, 1/3, increase.

Front 5

Lift force can be increased by _____, or _____.

Back 5

Making the air flow faster, increasing the angle of attack.

Front 6

Illustrate the angle of attack.

Back 6

.

Front 7

Explain lift.

Back 7

The phenomenon generated by an airfoil due to pressure differences above and below the airfoil surface.

Front 8

What is the angle of attack?

Back 8

The angle between the chord line of the airfoil and the relative airflow.

Front 9

What is the chord line?

Back 9

A straight line from the leading edge to the trailing edge of an airfoil.

Front 10

The center of pressure can be seen as a single point acting on the ____ ____ line at a ____ ____ to the _____ airflow, through which the airfoils ____ force is produced.

Back 10

chord line, right angle, relative, lifting.

Front 11

The position of the center of pressure is not ____, it depends on ____ ____ along the ____, which in turn depends on the ____ ____ ____. The ____ the ____ ____ ____, the further ____ the center of pressure is.

Back 11

fixed, pressure distribution, chord, angle of attack. Higher, angle of attack, forward.

Front 12

Illustrate the pressure distribution envelope around and airfoil.

Back 12

.

Front 13

Illustrate an airfoil, including the leading and trailing edges, chord length, chord, upper and lower cambers, angle of attack and relative wind.

Back 13

.

Front 14

What are the three types of drag?

Back 14

Profile drag (including form drag and skin friction) and induced drag.

Front 15

Explain form drag and illustrate.

Back 15

Caused by a body as it disturbs the air through which it passes.

Front 16

The overall shape of a streamlined body is called the ____ ____. This means the ____ of the body to its ____. A ratio of around ___ gives the least resistance.

Back 16

fineness ratio. length, width. 4:1

Front 17

The drag that is incurred as the air passes over and under the surface of the airfoils body is called ____ ____.

Back 17

skin friction

Front 18

____ drag is caused by the change in direction of the airflow. The ____ pressure under the wing flows to the ____ pressure above the wing, causing ____ at the wingtips. Another name for these is ____ ____.

Back 18

Induced. High, low, vorticies. Wake turbulence.

Front 19

Aspect ratio is the ratio of the ____ to the ____, i.e the ____ by the ____.

Back 19

span, chord, length, width.

Front 20

High aspect ratio = ____ lift.
Low aspect ratio = ____ lift.

Back 20

High (i.e gliders)
Lower (but capable of higher speeds)

Front 21

What is a stall.

Back 21

A loss of lift due to the airflow over a wings upper surface breaking away when the wing exceeds the critical angle.

Front 22

What is the critical angle?

Back 22

Around 15'.

Front 23

The stalling angle is the ____ ____ ____ at which the ____ ____ ____ of an airfoil is at a maximum, and beyond which it begins to ____ owing to the airflow becoming ____ instead of ____.

Back 23

angle of attack, coefficient of lift, decrease, separated, streamlined.

Front 24

What are the four forces acting on a aircraft in flight?

Back 24

Lift, weight, drag, thrust.

Front 25

Illustrate the four forces acting on an aircraft in flight.

Back 25

.

Front 26

During ____ ____ ____ flight, all of the forces are in balance.
Lift = ____ , Thrust = ____

Back 26

straight and level, weight, drag.

Front 27

Name the three primary control systems on an aircraft.

Back 27

Elevator, ailerons and rudder.

Front 28

The elevator controls the ____ of an aircraft. Forward movement of the control column moves the elevator ____, ____ the lift on that surface therefore pitching the nose ____.

Back 28

pitch, down, increasing, down.

Front 29

The ailerons control the ____ of an aircraft. They are positioned on the ____ ____ ____ of the mainplanes. When the left hand goes down the ____ aileron goes down, creating more lift on the ____ wing (and vice versa for the left wing) therefore rolling the aircraft to the ____.

Back 29

roll, outboard trailing edge, right, right, left

Front 30

The rudder controls the ____ of an aircraft. It is hinged to the rear of the ____ ____. When left rudder input is made, the rudder moves to the ____, creating a sideways lift and sending the tail to the ____, yawing the aircraft to the ____.

Back 30

yaw, vertical stabiliser, left, right, left.

Front 31

Flats and slats are examples of what?

Back 31

High lift devices.

Front 32

High lift devices reduce ____, ____ and ____ speeds. This ____ takeoff and landing distances.

Back 32

stall, takeoff, landing, reduces.

Front 33

Write the lift formula, and name each component.

Back 33

1/2p V S C

1/2p= half the value of air density
V = airflow velocity squared
S= wing span area
C = coefficient of lift

Front 34

What is the coefficient of lift?

Back 34

The lifting ability of a wing.

Front 35

The coefficient of lift depends on two things. What are they?

Back 35

The shape of the wing section, and the angle of attack.

Front 36

Flaps work by extending ____, therefore increasing the ____ ____ ( _ ), and increasing the ____ of the overall wing section (increasing the ____ value).

Back 36

chordwise, wing area, S, camber, C