aviation maintenance engineering
TRANSCRIPT
Aviation Maintenance EngineeringGrade 9
1 2
3
9GradeGrade
2
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 9
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.
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 10
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)
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 11
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 12
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.
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 13
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.
Interactive 1 1 2
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 14
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 15
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 16
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
WORD MEANING PICTURE
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 17
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%
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 18
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 19
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 20
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 21
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 22
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
WORD MEANING PICTURE
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 23
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 24
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
DIRECTION OF AIRFOIL
DIRECTION OF AIRFOIL
RELATIVE WIND
RELATIVE WIND
RELATIVE WIND
Relative wind
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 25
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
Interactive 1 3 1
liftdrag
thrust gravity
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 26
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 27
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 28
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=
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 29
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 30
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
Interactive 1 3 4
Practical 1 3 3
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 31
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
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 32
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
Interactive 1 3 6
Interactive 1 3 5
Interactive 1 3 7
CHAPTER 1 Introduction to aviation maintenance & aerodynamics 33
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