Theory Of Flight

Front 1

Is a gaseous envelop surrounded earth from all side.

Back 1

Atmosphere

Front 2

act as a protector to obstruct ultraviolet rays from the sun.

Back 2

Ozone layer

Front 3

Layers of Earth’s Atmosphere

Back 3

1. Troposphere 2. Stratosphere 3. Mesosphere 4. Thermosphere

Front 4

This is the lowest layer of the atmosphere

Back 4

Troposphere

Front 5

All weather changes take place in this layer these includes cloud formations, rain, snow, hailstorm, lightning, thunder etc.

Back 5

Troposphere

Front 6

The boundary between the troposphere and the stratosphere is called ______ meaning end or stop

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tropopause

Front 7

This is a quiet and safe zone for aircraft to fly as there are no disturbances due to weather conditions

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Stratosphere

Front 8

This is the location of the ozone layer

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Stratosphere

Front 9

Upper most boundary of stratosphere is called _____

Back 9

stratopause

Front 10

This is the middle layer (meso means middle) above the stratosphere.

Back 10

Mesosphere

Front 11

Above the earth surface is called

Back 11

ionosphere

Front 12

The thermosphere is divided into two layer,

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IONOSPHERE & EXOSPHERE

Front 13

It is the force exerted on a surface by the air above it as gravity pulls it to Earth.

Back 13

Pressure

Front 14

The ______ of air is the mass per unit volume of atmospheric gases.

Back 14

density

Front 15

measure of how hot or cold the air is

Back 15

Air Temperature

Front 16

is the tendency of an object to resist a change in its motion.

Back 16

The Law of Inertia

Front 17

An unbalanced force causes an object to accelerate. The acceleration of the object is equal to the net force acting on it divided by the object’s mass.

Back 17

Newton’s Second Law

Front 18

states that for every action, there is an equal but opposite reaction.

Back 18

Newton’s Third Law of Motion

Front 19

Increase in the speed of the fluid occur simultaneously with a decrease in pressure or a decrease in the fluid's potential energy

Back 19

Bernoulli’s Principle

Front 20

is an observable phenomenon that is commonly associated with a spinning object moving through the air or another fluid.

Back 20

The Magnus effect

Front 21

A facility that provides a controllable flow field for investigating various flow phenomena and testing aerodynamic models

Back 21

Wind tunnel

Front 22

are used to predict the amount of forced generated by solid objects

Back 22

Wind tunnels

Front 23

Wind Tunnels are also classified by flow speed:

Back 23

 Subsonic (M<.8)  Transonic (.8<M<1.2)  Supersonic (1.2<M<5.0)  Hypersonic (M>5.0)

Front 24

Elements of Wind Tunnel

Back 24

 Settling chamber  Contraction cone  Test Section  Diffuser  Drive Section

Front 25

Types of Wind Tunnel

Back 25

 Open Type  Closed Type  Blowdown  Shock Tube

Front 26

 Also called Eiffel tunnel  Open on both ends and draws air from the room into the best test section

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Open Type

Front 27

 Also called Prandtl tunnel or Gottingen tunnel  Air is conducted from the exit of the test section back to the fan by series of turning vanes  air is returned to the contraction section and back to the test section  Air is continuously circulated

Back 27

Closed Type

Front 28

Straightens the airflows in the wind tunnel

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The settling chamber

Front 29

take a large volume of low velocity air and reduce it to a small volume of high- velocity air

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Contraction cone

Front 30

As airflow flows is brought to the desired velocity, sensors measure forces, such as lift and drag.

Back 30

Test section

Front 31

where the air coming out of the test section slows down prior to to exhausting or recirculating

Back 31

Diffuser

Front 32

provide pressure increase flow, to overcome the pressure loss in the tunnel circuit.

Back 32

Drive section

Front 33

Has a high pressure vessel upstream of the test section and a low pressure reservoir downstream of the test section

Back 33

Blowdown Wind Tunnel

Front 34

The principle is that a fluid's energy equals the fluid's pressure times it's speed

Back 34

Venturi Tube

Front 35

A structure with curved surfaces designed to give the most favorable ratio of lift to drag in flight, used as the basic form of the wings, fins, and horizontal stabilizer of most aircraft.

Back 35

Airfoil Theory

Front 36

is constructed in such a way that its shape takes advantage of the air’s response to certain physical laws.

Back 36

An aerofoil

Front 37

This develops two actions from the air mass:

Back 37

Positive pressure

Negative pressure

Front 38

lifting action from the air mass below the wing,

Back 38

Positive pressure

Front 39

lifting action from lowered pressure above the wing.

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negative pressure

Front 40

Types of Airfoils

Back 40

Symmetrical airfoil

Non symmetrical airfoil

Front 41

is the line joining the midpoints between the upper and lower surfaces of an airfoil and measured normal to the mean camber line.

Back 41

Mean Camber Line

Front 42

Is the line joining the end points of the mean camber line.

Back 42

Chord Line

Front 43

Is the height of profile measured normal to the chordline.

Back 43

Thickness

Front 44

Is the maximum distance of the mean camber line from the chordline.

Back 44

Camber

Front 45

The foremost edge of an airfoil, especially a wing or propeller blade.

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Leading Edge

Front 46

the rear edge of a moving body, especially an aircraft wing or propeller blade.

Back 46

Trailing Edge

Front 47

is the distance from one wingtip to the other wingtip.

Back 47

Wing span

Front 48

Is the angle between relative wind and chordline.

Back 48

Angle of attack

Front 49

The speed and direction of the airfoil passing through the air. For airfoils on an airplane, the flightpath velocity is equal to true airspeed (TAS).

Back 49

Flight path

Front 50

the angle between the chord line of a blade and rotor hub. It is usually referred to as blade pitch angle. For fixed airfoils, such as vertical fins or elevators, angle of incidence is the angle between the chord line of the airfoil and a selected reference plane of the helicopter.

Back 50

Angle of incidence (AOI)

Front 51

the point along the chord line of an airfoil through which all aerodynamic forces are considered to act. Since pressures vary on the surface of an airfoil, an average location of pressure variation is needed. As the AOA changes, these pressures change and center of pressure moves along the chord line.

Back 51

Center of pressure

Front 52

Equal chamber on each side

Back 52

Symmetrical airfoil

Front 53

Produces useful lift even at negative angles of attack

Back 53

Non symmetrical airfoil

Front 54

Four forces of an Aircraft

Back 54

1. Thrust 2. Drag 3. Weight 4. Lift

Front 55

the forward force produced by the power plant/ propeller or rotor. It opposes or overcomes the force of drag. As a general rule, it acts parallel to the longitudinal axis.

Back 55

Thrust

Front 56

a rearward force, retarding force caused by disruption of airflow by the wing, rotor, fuselage, and other protruding objects. Drag opposes thrust, and acts rearward parallel to the relative wind.

Back 56

Drag

Front 57

the combined load of the aircraft itself, the crew, the fuel, and the cargo or baggage. Weight pulls the aircraft downward force because of the force of gravity. It opposes lift, and acts vertically downward through the aircraft’s center of gravity (CG).

Back 57

Weight

Front 58

upward force opposes the downward force of weight, is produced by the dynamic effect of the air acting on the airfoil, and acts perpendicular to the flightpath through the center of lift.

Back 58

Lift

Front 59

is the pulling force that tends to draw all bodies to the center of the earth.

Back 59

Gravity

Front 60

What’s it take to create lift?

Back 60

Air and motion

Front 61

is the pressure you have if the fluid isn't moving or if you are moving with the fluid

Back 61

Static pressure

Front 62

is what acts on you as you face into the wind and the air collides with your body.

Back 62

Total pressure

Front 63

is the pressure of a fluid that results from its motion. It is the difference between the total pressure and static pressure

Back 63

Dynamic pressure

Front 64

Air moving over the wing moves faster than the air below.

Back 64

Bernoulli’s Principle

Front 65

is the force of resistance aircraft ‘feels’ as it moves through the air.

Back 65

Drag

Front 66

Two Types of Drag

Back 66

 Parasite Drag  Induce Drag

Front 67

is composed of form drag, skin drag and interference drag.

Back 67

Parasite Drag

Front 68

also known as pressure drag or profile drag, is caused by airflow separation from a surface and the low pressure wake that is created by that separation.

Back 68

Form Drag

Front 69

is created in the boundary layer. Turbulent flow creates more friction drag than laminar flow. Skin drag is usually small per unit area, but since the boundary layer covers the entire surface of the airplane, skin drag can become significant in larger airplanes.

Back 69

Skin Drag

Front 70

is generated by the mixing of streamlines between components.

Back 70

Interference drag

Front 71

Is that portion of total drag associated with the production of lift.

Back 71

Induced Drag

Front 72

typically provide the thrust for aircraft.

Back 72

Engines

Front 73

runs from wingtip to wing tip

Back 73

Lateral Axis

Front 74

The rudder is a moveable control surface attached to the trailing edge of the vertical stabilizer.

Back 74

Rudder

Front 75

extends from the nose to the tail, through the fuselage

Back 75

Longitudinal Axis

Front 76

The ailerons form a part of the wing and are located in the trailing edge of the wing towards the tips.

Back 76

Ailerons

Front 77

passes through the center of the fuselage, from the top to the bottom

Back 77

Vertical Axis

Front 78

are the movable control surfaces hinged to the trailing edge of the horizontal stabilizer.

Back 78

Elevators

Front 79

occurs while the airplane is in a slipping or skidding turn can result in a spin entry and rotation in the direction of rudder application, regardless of which wingtip is raised

Back 79

stall

Front 80

occurs when the airplane’s wings exceed their critical AOA (stall) with a sideslip or yaw acting on the airplane at, or beyond, the actual stall

Back 80

spin

Front 81

is a device that is used for, or is intended tobe used for, flight in the air.

Back 81

aircraft

Front 82

Major categories of aircraft are

Back 82

airplane, rotorcraft, glider, and lighter- than-airvehicles.

Front 83

The airframe of a fixed-wing aircraft consists of five principal units:

Back 83

the fuselage, wings, stabilizers (empennage/tail section), flight control surfaces, and landing gear.

Front 84

is the main structure or body of the fixed-wing aircraft. It provides space for cargo, controls, accessories, passengers, and other equipment

Back 84

The fuselage

Front 85

a rigid framework made up of members, such as beams, struts, and bars to resist deformation by applied loads. The truss-framed fuselage is generally covered with fabric.

Back 85

Truss Type

Front 86

relies largely on the strength of the skin or covering to carry the primary loads.

Back 86

The monocoque (single shell) fuselage

Front 87

True construction of monocoque type

Back 87

Skin

Frame/former

Bulkhead

Front 88

The outside covering of the aircraft.

Back 88

Skin

Front 89

A circumferential member that opposes hoop stress and provide shape and form to the fuselage.

Back 89

Frame/Former

Front 90

A heavy frame to contain pressures or fluids or to disperse concentrated loads.

Back 90

Bulkhead

Front 91

This construction is a modification to the monocoque type wherein the skin is stiffened by longitudinal elements.

Back 91

Semi monocoque type

Front 92

The principal longitudinal member of the fuselage that helps the skin support primary bending load.

Back 92

Longeron

Front 93

Longitudinal member in the fuselage (or spanwise member in the wing) to transmit skin loads to body frames or wing rib.

Back 93

Stringer

Front 94

are made to stressed skin structures, doublers or backing plates are required around the cut-out.

Back 94

Cutouts

Front 95

fitted to pressurized aircraft must withstand both the loads of pressurization and impact loads from birdstrikes.

Back 95

Flight Deck Windows

Front 96

They are designed to be fail-safe and normally have two panes of acrylic plastic mounted in an airtight rubber seal fitted into a metal window frame.

Back 96

Passenger Cabin Windows

Front 97

are airfoils that, when moved rapidly through the air, create lift.

Back 97

Wings

Front 98

have wires or struts to support the wing.

Back 98

Semicantilever wings

Front 99

wings have no external bracing and are supported internally.

Back 99

Full cantilever

Front 100

are the principal structural members of the wing.

Back 100

Spars

Front 101

gives the wing rigidity by stiffening the skin in compression.

Back 101

Stringers

Front 102

maintain the airfoil shape of the wing and transfer the load to the spar.

Back 102

Ribs

Front 103

carries part of the load imposed during flight and transfers it to the rib.

Back 103

Skin

Front 104

are bracings that carry compressive load

Back 104

Struts

Front 105

is an obvious vertical upturn of the wing’s tip resembling a vertical stabilizer.

Back 105

winglet

Front 106

are small airfoil sections usually attached to the upper surface of a wing. T

Back 106

Vortex generators

Front 107

is used to halt the spanwise flow of air.

Back 107

stall fence

Front 108

promote smooth airflow in the gaps between the trailing edge and control surface.

Back 108

Gap seals

Front 109

(sometimes called “pods”) are streamlined enclosures used primarily to house the engine and its components.

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Nacelles

Front 110

is incorporated to isolate the engine compartment from the rest of the aircraft. This is basically a stainless steel or titanium bulkhead that contains a fire in the confines of the nacelle rather than letting it spread throughout the airframe.

Back 110

firewall

Front 111

are also found in the nacelle. These are the structural assemblies to which the engine is fastened.

Back 111

Engine mounts

Front 112

refersto the detachable panels covering those areas into which access must be gained regularly,such as the engine and its accessories.

Back 112

Cowling

Front 113

of an aircraft is also known as the tail section consist of a tail cone, fixed aerodynamic surfaces or stabilizers, and movable aerodynamic surfaces

Back 113

empennage

Front 114

serves to close and streamline the aft end of most fuselages.

Back 114

tail cone

Front 115

supports the aircraft during landing and while it is on the ground.

Back 115

The landing gear

Front 116

dominated early aviation. When landing, tail wheel aircraft can easily ground loop.

Back 116

Conventional or Tail Wheel

Front 117

In addition to two main wheels, a shock absorbing nose wheel is at the forward end of the fuselage.

Back 117

Tricycle Gear

Front 118

These type of aircraft are used by the armed forces of different countries

Back 118

Military aircraft

Front 119

These type of aircraft are used for the purpose of transportation

Back 119

Civilian aircraft

Front 120

These type of aircraft are used by VIP’S for their traveling purposes.

Back 120

Private aircraft

Front 121

These types of aircraft are for both passengers and cargo.

Back 121

Commercial aircraft

Front 122

Three types of commercial aircraft –

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Passenger, cargo and combi aircraft.