Aviation Maintenance Engineering

Aviation Maintenance EngineeringGrade 9

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Aviation Maintenance EngineeringAviation Maintenance Engineering

CoursebookCoursebookTerm 1Term 1

2021 - 20222021 - 2022

Grade 9Grade 9

TABLE OF CONTENTTABLE OF CONTENTUnit 1 : Basic Aerodynamics & Electrical Fundamentals 4

CoreLife Skills 5

Learning outcomes 5

Chapter 1: Introduction to aviation maintenance &

aerodynamics 7

Section 1 : Basic introduction .................................................... 8Overview ...............................................................................................................................8

Key vocabulary ................................................................................................................8

What is aviation maintenance? ...........................................................................9

Types of planes .............................................................................................................12

Aircraft structure .......................................................................................................... 14

Section 2 : Physics of atmosphere .......................................... 16Overview ............................................................................................................................ 16

Key vocabulary ............................................................................................................. 16

Atmosphere .....................................................................................................................17

Section 3 : Aerodynamics ....................................................... 22Overview ............................................................................................................................ 22

Key vocabulary ............................................................................................................. 22

How do aeroplanes fly? .........................................................................................23

Chapter 1. Summary ..................................................................................................33

Chapter 2 : Electrical fundamentals 34

Section 1 : Electron theory and static electricity .................. 35Overview ............................................................................................................................35

Key vocabulary .............................................................................................................35

States of matter ............................................................................................................36

Static electricity ............................................................................................................ 41

Section 2 : Electrical terminology ........................................... 45Overview ............................................................................................................................45

Key vocabulary .............................................................................................................45

Electrical Terminology ............................................................................................46

Resistors ............................................................................................................................53

Section 3 : Electricity generation ............................................ 60Overview ........................................................................................................................... 60

Key vocabulary ............................................................................................................ 60

Sources of electricity ............................................................................................... 61

Chapter 2. Summary ................................................................................................ 68

Unit 1Basic Aerodynamics & Electrical Fundamentals

Unit OverviewThe aviation industry continues to expand. There will be a growing demand for maintenance engineers. Engineers carry out many tasks, that must follow the highest standards. This unit introduces the fundamentals of aviation maintenance. It also introduces the basic concepts of aerodynamics. Aerodynamics is one of the most important concepts in the aviation field that helps in understanding how aircraft fly. As many aircraft systems are electrically operated, this unit will also introduce the electrical fundamentals.

f Identify the concept of basic aerodynamics.

f Demonstrate knowledge of electrical fundamentals.

The following CoreLife Skills are present within the learning and assessment of

this unit:

f Problem-solving

f Critical thinking

f Communication skills

f Collaboration

f Interpersonal skills

f Practical learning

f Analysis and observation

f Using 21st-century skills/technologies

f Peer and self-evaluation

Learning outcomes

CoreLife Skills

CoreLife SkillsThe following CoreLife Skills are present within the learning and assessment of this unit:

Analysis and observation

Critical thinking

Practicallearning

Problem solving

Using 21st-century skills-technologies

Interpersonalskills

Peer and self-evaluation

Communicationskills

Collaboration

Chapter Chapter 11Introduction to aviation maintenance & aerodynamics

Chapter OverviewFor thousands of years, people have been interested in flying. Flying became very common when people understood aerodynamics. This helped engineers to design large aeroplanes that can fly in the air. As a result of this, there was a growing demand for maintenance engineers. This chapter introduces aircraft maintenance engineering. It also introduces the atmosphere layers and parameters, basic aerodynamics, and flight control systems.

Learning outcome f Identify the concept of basic aerodynamics.

CHAPTER 1 Introduction to aviation maintenance & aerodynamics 8

Section 1 : Basic introduction

In this section, you will be introduced to aviation maintenance. Maintenance engineers need to be trained and licensed. Training and certification must Follow international and local regulations. EASA and the GCAA are the two main agencies. They control the regulation in the UAE.

Overview Key vocabulary

WORD MEANING PICTURE

maintenance the process done to keep the object in good condition, if possible

inspection a process where all materials and parts are checked

repair to fix the object and return it to a good condition after any damage

airworthy an expression used to show that the aircraft can operate in the air and fly safely


The process of keeping the aeroplane, airworthy or safe to fly includes constant inspections and repairs. They can be either routine checks between flights or scheduled maintenance done on fixed periods depending on the aeroplane age or flying hours. As shown in Figure 1.1.1, there are two types of aviation maintenance:

Figure 1.1.1 a. Technicians doing line maintenance between flights.

b Technicians doing base maintenance for the aeroplane

Figure 1 1 2 Fixed-wing and rotary-wing

What is aviation maintenance?

•line maintenance: replacing parts and complete routine maintenance between

flights.

•base maintenance: carrying out repairs on a more complex and older

aeroplane.

Aviation maintenance technicians must choose the type of aircraft they want to

be trained on. Fixed-wing aircraft and rotary-wing aircraft, shown in Figure 1.1.2,

are different, and they require different maintenance.


Companies cannot manufacture, maintain, and fly aeroplanes on their own. They must follow a set of high standards and regulations by international entities and the national aviation authority in their country. The European Union Aviation Safety Agency (EASA), shown in Figure 1.1.3, is one of the main agencies that regulate and set the standards and regulations for civil aviation safety. In the UAE, the only Authority responsible for the civil aviation regulations is the General Civil Aviation Authority (GCAA), Figure 1.1.4, Based in Abu-Dhabi and was established in 1996.

EASA and GCAA

Figure 1 1 3 The European Union Aviation Safety Agency (EASA)

Figure 1 1 4 The General Civil Aviation Authority (GCAA)


Figure 1 1 5 Aviation maintenance companies in the UAE

The United Arab Emirates has always been developing the aviation industry. This resulted in making UAE airlines one of the leading airlines in the world.There is a constant demand for aircraft maintenance engineers in many organisations in the UAE. This demand will continue to grow, as the UAE will continue to initiate and develop in the aviation sector. Figure 1.1.5 show some of these organisations.

Future Careers

Practical 1 1 1


There are two main types of aeroplanes fixed-wing and rotary-wing, both could be used for military and civil applications. See Table 1.1.1.

Figure 1 1 6 Airbus A380 aeroplane and Boeing 787 aeroplane

Types of planes

type civil aviation military aviation

fixed-wing

rotary-wing

drones

Table 1 1 1 Types of planes

The two leading manufacturing companies for civil aeroplanes are

airbus (France) and Boeing (USA). Figure 1.1.6 below shows the double-

deck Airbus A380 and Boeing 787.


turbofan turboshaft

Big, civil high-speed aeroplanes

Helicopter aircraft

turbojet turboprop

High-speed, military fighter aircraft

Small, low-speed fixed-wing aeroplane

Aircraft engines

Table 1 1 2 Aircraft engines

Each aeroplane has a different type of gas turbine or engine. The four main categories are turbojet, turboprop, turbofan, and turboshaft. See Table 1.1.2.

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To understand how aeroplane operates, it is important to understand the aeroplane structure. Most aircraft structures include fuselage, wing, tail, and landing gear.

Aircraft structure

Figure 1 1 8 Aircraft wing

Aircraft fuselage

The fuselage, shown in Figure 1.1.7, is the main part of the aircraft. In civil

aviation, this part holds the passengers, crew, and cargo.

Aircraft wing

The aircraft wing, shown in Figure 1.1.8, is the part that provides lift force while

moving through air. An aircraft wing is very crucial and contains the flaps,

spoilers, ailerons, and the slats. Their main role is in providing aerodynamic

control to ensure the right operation of the aeroplane.

Figure 1 1 7 Aircraft fuselage


Figure 1 1 10 Landing gear

Aircraft tail

Controlling flight stability is provided by the tail of the aircraft. Figure 1.1.9

shows the tail of the aircraft, which contains the rudders, elevators, and

horizontal stabilisers.

Landing gear

One of the essential components of the aeroplane is the landing gear, shown

in Figure 1.1.10. It helps provide support while the aeroplane takes-off, and

lands. Also, they enable moving the aeroplane on the ground.

Usually, there are two main landing gears under the wings and one in the front

under the flight deck (cockpit) which is called nse landing gear.

Figure 1 1 9 Aircraft tail


Section 2 : Physics of atmosphere

In this section, you will study the different atmospheric layers. You will understand the important aerodynamics parameters such as Pressure, Temperature, Density, and Humidity. Also, you will learn about the International Standard Atmosphere (ISA).

Overview


atmosphere gaseous layers that surround the earth

aerodynamics study of the behaviour of air and other gases with moving objects

pressure the force applied to a certain area

altitude the height of an object above sea level

density ratio of the matter mass to the volume it occupies in the space

humidity amount of moisture in the air

Key vocabulary

Density


The atmosphere consists of layers of gases that cover our planet. Invisible changes in their temperature separate those layers. The five layers are shown in Figure 1.2.1.It is important to understand how the atmosphere affects aircraft operations.Earth’s atmosphere is 78% Nitrogen, 21% Oxygen, 1% of other gases and water vapour.

Figure 1 2 1 Atmosphere layers

Atmosphere

Oxygen21%

Nitrogen78%

Other gasses1%


Pressure

As shown in Figure 1.2.3, the higher the altitude, the lower the pressure.

The altimeter shown in Figure 1.2.2 indicates the altitude by measuring the

absolute pressure of the air above the aeroplane. Airspeed indicator shows

the speed of the aircraft relative to the air. The vertical speed indicator is an

instrument that shows if the aeroplane is climbing, descending or in level flight.

Pressure gage helps to measure the pressure on the aeroplane.

The pressure is the total force applied to a specific area. It is measured by the

following equation:

P = Force / Area = weight / Area

There are various types of pressure. One of the most important types of

pressure in the aviation industry is atmospheric pressure. It is an important

factor that helps to lift the aircraft. Also, it activates important flight instruments

such as Altimeter, Airspeed indicator, Vertical speed indicator, and Pressure

gage, as shown in Figure 1.2.2.

Figure 1.2.2 Flight instruments affected by atmospheric pressure

Figure 1 2 3 The change in pressure as the altitude increases

Discuss 1 2 1

Air molecules have mass and are pulled down toward Earth by gravityThe net weight of all molecules aboce certain altitude creates atmospheric pressurs for this altitude.

Pressure is highest at sea level and decreases with increase of altitude.

26 hPa

54 hPa

1013 hPa Earth surface

10 km

5 kmMt. Everest

end of atmosphere


Example

A force of 500.0 N is being applied to a 5 m side-length square, what is the

pressure exerted by force on the area of the square?

Note: 1 N/m2 = 1 Pa

Given

Force= 500.0 N, side length = 5 m

Solution:

Calculate the area of the square:

5 x 5 = 25 m2

Using:

P=Force/Area =20 N/m2 = 20 Pa

The three important units in aviation for measuring pressure are:

International Standard Atmosphere (ISA) is a set of international

standards used in the aviation industry. These standards create a global

reference for atmospheric parameters. The ISA standard Pressure at the

sea level is 1013.2 millibars.

Research 1 2 3Interactive 1 2 2

5 m

500 N

Pressure

units

Bars (Ba)

Pounds per Square Inch (psi)

Pascal (Pa)

N/m2


Temperature

Temperature is the measure of how an object is cold or hot with reference to

standard values.

Temperature decrease as the aeroplane takes-off at a rate of 1.98o C for every

1000 feet of altitude until it reaches -56.5°C at 36,089 feet and remains constant

afterwards up to 65,600 feet.

The ISA standard temperature at the sea level is +15°C.

Density

Density is the measure of material mass to the volume it occupies, Figure 1.2.4.

The Greek letter “ρ ” (rho) is the symbol of density and measured usually in Kg/

m3.

ρ =Mass/Volume = Kg /m3

Air density has a great effect on the aeroplane’s aerodynamics. When the air is

compressed, the temperature, pressure, and density increase.

The ISA standard Density at the sea level is 1.225 Kg/ m3.

Figure 1 2 4 The more the particles, the higher the density

Temperature units

Kelvin (K)

Fahrenheit (0F) Celsius (0C)

mass

volumedensity

Low HIGH


Humidity

Humidity is defined as the water vapour or the gaseous water concentration

in the air. The more the water vapour in the air, the lighter the air, as presented

in Figure 1.2.5. This is taken into consideration before flying because the air

density in damp days is less than dry days.

High temperature enables the air to absorb more water vapour.

Cabin humidity

Cabin humidity is relatively lower than normal status. Low humidity is not risky

to health, yet it may present some dryness to the skin, and discomfort to the

eyes, mouth, and nose.

Figure 1 2 5 Humidity adds water vapour particles and increases the

density of the matter

Research 1 2 5

Discuss 1 2 4


Section 3 : Aerodynamics

In this section, you will be introduced to the aerodynamic effect on the aeroplane and how it helps it to fly. Also, you will learn how pilots can control the stability of the aeroplane. You will understand the aeroplane wing design and different characteristics with real-life examples.

Overview


airflow the motion of the air around any moving body

airfoil the cross-sectional shape of the wing

thrust the force that pushes the aircraft forward

lift the upward force that pushes the aircraft up

drag the air resistance on the aircraft and it pulls the aircraft backwards

angle of attack (AOA)

the angle formed between the chord line and the relative airflow

Key vocabulary


To understand how humans were able to fly heavier-than-air machines in the air we must understand aerodynamics and the aeroplane structure.

How do aeroplanes fly?

Aerodynamics is a Greek word that means air force.

Aeroplanes wings and tails are made of multiple parts. They have many pieces

that create an upward force to lift the aeroplane upwards then stabilise it in the

air.

Aerios

Dynamics

Air

Force

If we look at the cross-sectional area of the aeroplane’s wing, as shown in

Figure 1.3.1, the wing has a unique shape. This shape is what enables the

aeroplane to fly, and it is called the aerofoil.

The airflow around the aeroplane wing explains how the wing is being lifted

upwards. The airflow around the aeroplane wing is presented in lines in Figure

1.3.2.

The airflow on top of the wing is much faster than the bottom of the wing. Since

velocity is inversely proportional to pressure, as shown in Figure 1.3.3.

The pressure will be higher on the bottom of the wind, and this creates the lift

force.

Airflow and airfoil

Figure 1 3 1 The cross-sectional area of the wing


Figure 1.3.2 The airflow around the wing

Figure 1 3 3 The relationship between speed and pressure

Foil pushed up.

Flow deflected down.

Airfoil

PressureVelocity

High speedLow pressure

Low speedHigh pressure

The air movement relative to the aircraft is called Relative airflow (RAF),

and usually, it opposes the aircraft movement direction, as shown in

Figure 1.3.4.

Figure 1.3.4 Relative airflow direction

DIRECTION OF AIRFOIL



RELATIVE WIND

RELATIVE WIND

RELATIVE WIND

Relative wind


Four forces of flight

While flying aircraft are affected by four forces that keep it balanced in the air,

these forces are thrust, weight, lift and drag, as shown in Figure 1.3.5.

Figure 1 3 5 Forces on aeroplanes

lift the upward force that pushes the

aircraft upwards

weight the gravity force that pulls the

aircraft downwards

thrust the jet engine force that pushes the

aircraft forward

drag the force that pulls the aircraft

backwards, caused by air resistance

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liftdrag

thrust gravity


Fluids

Matter exists in three main states: solid, liquid, and gas.

Solids’ atoms are packed, and its shape does not deform. However, liquids and

gases constantly deform under any external force; those materials are called

fluids.

Fluids can be divided into two main categories:

compressible density changes

when temperature

and pressure

change

gases

incompressible density is constant liquids

Turbulent and laminar flow

During aeroplane operation, the airflow can be either turbulent or

laminar.

turbulent

flow

irregular paths

of particles of

the fluid

laminar flow smooth and

regular paths

of particles of

the fluid


The main characteristics and parts of the aerofoil are shown in Figure 1.3.6.

aerofoil characteristics description

leading-edge the foremost edge of the airfoil

trailing edge the rear edge of the airfoil

chord line the straight line joining the leading and

trailing edges

camber the curvature of the airfoil above or below

the chord line

maximum camber the maximum distance between the camber

and the chord line

maximum thickness The maximum distance between the

upper and lower surfaces of the airfoil.

angle of attack The angle formed between the chord

line and relative airflow.

fineness ratio The ratio between the maximum

thickness of the airfoil to its chord line

length,

Fineness ratio =

Figure 1 3 6 Airfoil characteristicInteractive 1 3 2

angle of attack chord linecamber line

upper surface

lower surface

trailing edge

leading edge

max. thicnessmax. camber

relative wind


Wing shapes

Wings might have many shapes, shown in Figure 1.3.7, the most commonly

used type for commercial aviation is the swept-back wing.

Figure 1.3.7 Different wing types

Wing geometry definitions

term definition

wingtip the free side of the wing

wing root the connected side of the wing

wingspan the distance from tip to tip, perpendicular to

the chord line. See Figure 1.3.8

aspect ratio the ratio of the wingspan to the cord length

aspect ratio= wingspan

Figure 1 3 7 Wingtip, wingroot and wingspan

RECTANGULAR WING ELLIPTICAL WING

DELTA WINGTAPERED WINGSWEPT BACK WING

Wing span

Wing tipWing rootWing rootWing tip

chord length

span

wing area=

22 b

wing areaaspect ratio=


mean aerodynamic

chord (MAC)

the average length of the chord is the mean

aerodynamic chord

angle of incidence the angle between the chord line of the wing and a

reference axis along the aeroplane fuselage

angle of attack the angle between the chord-line and relative

airflow

washin the reduction in the angle of incidence along

the span from root to tip

washout the increase in the angle of incidence along

the span from root to tip

drag coefficient CD coefficient that indicates how much drag force

will be generated from the aerofoil at a specific

angle of attack and aeroplane velocity


lift coefficient CL a coefficient that indicates how much lift force will

be generated from the aerofoil at a specific angle of

attack and aeroplane velocity

stall stall is when the weight of the aircraft pulls it down

toward the earth. It occurs when the aircraft losses

the lift force due to the angle of attack exceeding a

specific value

Flight control surfaces

Pilots use many aircraft flight control surfaces, shown in Figure

1.3.9, to adjust and control the aircraft’s flight attitude, and

maintain stability and orientation.

Figure 1.3.9 Aircraft flight control surfaces

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Aircraft axes of motion How does the pilot control the aeroplane?

Pilots control the aeroplane at the aeroplane cockpit, as shown in

Figure 1.3.11, is connected to different sensors and control systems

where the pilot can assess the situation and control the aeroplane

accordingly.

Figure 1 3 11 Aeroplane cockpit

Figure 1 3 10 Aeroplane axes

The aircraft has three axes of motion:

longitudinal axis the axis that extends the nose through the tail or

lengthwise

lateral axis the axis that extends the wing tip through wingtip

vertical axis the axis that passes vertically through the centre of

the aeroplane


Primary flight controls

The primary flight controls are:

flight control definition type of rotational movement axis

ailerons the pilot controls one of the ailerons with

a control wheel, and it raises or lowers the

aileron wings if one aileron rises the wing

drops and vice versa

rolling longitudinal axis

rudder flight control surface found on the tail of

the aeroplane. Helps the pilot to Move the

aeroplane right and left, or yaw

yawing vertical axis

elevator control surface found at the rear of the

plane. It helps the pilot to raise or lower the

aeroplane, so it goes up or down depending

on the elevator direction

pitching lateral axis

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In Section 1.1, you learned about these:

f Aviation maintenance

f EASA and GCAA

f Types of planes

f Aircraft engines

f Aeroplane structure

In Section 1.2, you learned about the physics of atmosphere:

f International standard atmosphere

In Section 1.3, you learned about aerodynamics:

f How aeroplanes fly

f Four forces of flight

f Fluids

Chapter 1 Summary

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Aviation Maintenance Engineering