Raked wing tips – Why Boeing-777 doesn’t have winglets?

Boeing uses a desgin called Raked wingtips. Boeng 787, Boeing 767 and boeing 747- 800 uses the same design. All these aircrafts are capable of flying ultra long distance. This wing tip design is known as Raked wing tips.

Raked wingtips design is where the tip of the wing has a higher degree of sweep than the rest of the wing.

Raked wing tips are more efficient in ULTRA LONG cruise segments. Whereas other wingtip treatments like winglets are more efficient in climb. Winglets do reduce drag, but they actually generate a bit of lift due to the way in which wingtip vortices strike the leading edges of the winglet…but that only happens to a significant degree when the wing is at higher angles of attack….like in climb configurations. Aircraft with winglets are shorter range…like the 737. It makes more sense and saves more fuel to optimize the climb and approach segments than it does to try to optimize the cruise phase of the flight. That might seem counter-intuitive, but Boeing engineers proved the math.

Raked wingtips on the other hand don’t generate lift…what they do is reduce drag in a special way…by redirecting wingtip drag (vortices) farther outboard and aft of the rest of the wing… and it also redistributes the lift across the entire wing (called wing loading). The result is that they work in ultra long cruise segments. They don’t depend on wing angle of attack, and they reduce fuel consumption when engine power is already set to cruise.

For more details read this blog..

Short answer is winglets and raked tips both reduce drag and extend the range of an aircraft. But they do it in different ways…and which way is best depends mostly as a function of cruise flight time.

Propeller

Module 17 – Propeller

17.1 Fundamentals
Blade element theory;
High/low blade angle, reverse angle, angle of attack, rotational speed;
Propeller slip;
Aerodynamic, centrifugal, and thrust forces;
Torque;
Relative airflow on blade angle of attack;
Vibration and resonance.

17.2 Propeller Construction
Construction methods and materials used in wooden, composite and metal propellers;
Blade station, blade face, blade shank, blade back and hub assembly;
Fixed pitch, controllable pitch, constant speeding propeller;
Propeller/spinner installation.

17.3 Propeller Pitch Control
Speed control and pitch change methods, mechanical and electrical/electronic;
Feathering and reverse pitch;
Overspeed protection.

17.4 Propeller Synchronising
Synchronising and synchrophasing equipment.

17.5 Propeller Ice Protection
Fluid and electrical de-icing equipment.

17.6 Propeller Maintenance
Static and dynamic balancing;
Blade tracking;
Assessment of blade damage, erosion, corrosion, impact damage, delamination;
Propeller treatment/repair schemes;
Propeller engine running.

17.7 Propeller Storage and Preservation
Propeller preservation and depreservation.

Gas Turbine Engine

Module 15 – Gas Turbine Engine

15.1 Fundamentals
Potential energy, kinetic energy, Newton’s laws of motion, Brayton cycle;
The relationship between force, work, power, energy, velocity, acceleration;
Constructional arrangement and operation of turbojet, turbofan, turboshaft, turboprop.

15.2 Engine Performance
Gross thrust, net thrust, choked nozzle thrust, thrust distribution, resultant thrust, thrust horsepower, equivalent shaft horsepower,
specific fuel consumption;
Engine efficiencies;
By-pass ratio and engine pressure ratio;
Pressure, temperature and velocity of the gas flow;
Engine ratings, static thrust, influence of speed, altitude and hot climate, flat rating, limitations.

15.3 Inlet
Compressor inlet ducts;
Effects of various inlet configurations;
Ice protection.

15.4 Compressors
Axial and centrifugal types;
Constructional features and operating principles and applications;
Fan balancing;
Operation;
Causes and effects of compressor stall and surge;
Methods of air flow control: bleed valves, variable inlet guide vanes,
variable stator vanes, rotating stator blades;
Compressor ratio.

15.5 Combustion Section
Constructional features and principles of operation.

15.6 Turbine Section
Operation and characteristics of different turbine blade types;
Blade to disk attachment;
Nozzle guide vanes;
Causes and effects of turbine blade stress and creep.

15.7 Exhaust
Constructional features and principles of operation;
Convergent, divergent and variable area nozzles;
Engine noise reduction;
Thrust reversers.

15.8 Bearings and Seals
Constructional features and principles of operation.

15.9 Lubricants and Fuels
Properties and specifications;
Fuel additives;
Safety precautions.

15.10 Lubrication Systems
System operation/lay -out and components.

15.11 Fuel Systems
Operation of engine control and fuel metering systems including electronic engine control (FADEC);
Systems lay -out and components.

15.12 Air Systems
Operation of engine air distribution and anti – ice control systems,
including internal cooling, sealing and external air services.

15.13 Starting and Ignition Systems
Operation of engine start systems and components;
Ignition systems and components;
Maintenance safety requirements.

15.14 Engine Indication Systems
Exhaust Gas Temperature/Interstage Turbine Temperature;
Engine Thrust Indication: Engine Pressure Ratio, engine turbine discharge pressure or jet pipe pressure systems;
Oil pressure and temperature;
Fuel pressure and flow;
Engine speed;
Vibration measurement and indication;
Torque;
Power.

15.15 Power Augmentation Systems
Operation and applications;
Water injection, water methanol;
Afterburner systems.

15.16 Turbo-prop Engines
Gas coupled/free turbine and gear coupled turbines;
Reduction gears;
Integrated engine and propeller controls;
Overspeed safety devices.

15.17 Turbo-shaft engines
Arrangements, drive systems, reduction gearing, couplings, control systems.

15.18 Auxiliary Power Units (APUs)
Purpose, operation, protective systems.

15.19 Powerplant Installation
Configuration of firewalls, cowlings, acoustic panels, engine mounts, anti-vibration mounts, hoses, pipes, feeders, connectors, wiring looms, control cables and rods, lifting points and drains.

15.20 Fire Protection Systems
Operation of detection and extinguishing systems.

15.21 Engine Monitoring and Ground Operation
Procedures for starting and ground run-up;
Interpretation of engine power output and parameters;
Trend (including oil analysis, vibration and boroscope) monitoring;
Inspection of engine and components to criteria, tolerances and data specified by engine manufacturer;
Compressor washing/cleaning;
Foreign object damage.

15.22 Engine Storage and Preservation
Preservation and depreservation for the engine and accessories/systems.

Turbine Aeroplane Aerodynamics, Structure and Systems

Module 11A – Turbine Aeroplane Aerodynamics, Structure and Systems

11.1 Theory of Flight

11.1.1 Aeroplane Aerodynamics and Flight Controls
Operation and effect of:
– roll control: ailerons and spoilers;
– pitch control: elevators, stabilators, variable incidence stabilizers and canards;
– yaw control, rudder limiters;

Control using elevons, ruddervators;
High lift devices, slots, slats, flaps, flaperons;
Drag inducing devices, spoilers, lift dumpers, speed brakes;
Effects of wing fences, saw tooth leading edges;
Boundary layer control using, vortex generators, stall wedges or leading edge devices;
Operation and effect of trim tabs, balance and antibalance (leading) tabs, servo tabs, spring tabs, mass balance, control surface bias,
aerodynamic balance panels;

11.1.2 High Speed Flight
Speed of sound, subsonic flight, transonic flight, supersonic flight, Mach number, critical Mach number, compressibility buffet, shock
wave, aerodynamic heating, area rule;
Factors affecting airflow in engine intakes of high speed aircraft;
Effects of sweepback on critical Mach number.

11.2 Airframe Structures – General Concepts
(a) Airworthiness requirements for structural strength;
Structural classification, primary, secondary and tertiary;
Fail safe, safe life, damage tolerance concepts;
Zonal and station identification systems;
Stress, strain, bending, compression, shear, torsion, tension, hoop stress, fatigue;
Drains and ventilation provisions;
System installation provisions;
Lightning strike protection provision;
Aircraft bonding.

(b) Construction methods of: stressed skin fuselage, formers, stringers, longerons, bulkheads, frames, doublers, struts, ties, beams, floor
structures, reinforcement, methods of skinning, anti-corrosive protection, wing, empennage and engine attachments;
Structure assembly techniques: riveting, bolting, bonding;
Methods of surface protection, such as chromating, anodising,
painting;
Surface cleaning;
Airframe symmetry: methods of alignment and symmetry checks.

11.3 Airframe Structures – Aeroplanes

11.3.1 Fuselage (ATA 52 / 53 / 56)
Construction and pressurisation sealing;
Wing, stabilizer, pylon and undercarriage attachments;
Seat installation and cargo loading system;
Doors and emergency exits: construction, mechanisms, operation and safety devices;
Windows and windscreen construction and mechanisms.

11.3.2 Wings (ATA 57)
Construction;
Fuel storage;
Landing gear, pylon, control surface and high lift/drag attachments.

11.3.3 Stabilizers (ATA 55)
Construction;
Control surface attachment.

11.3.4 Flight Control Surfaces (ATA 55 / 57)
Construction and attachment;
Balancing – mass and aerodynamic.

11.3.5 Nacelles / Pylons (ATA 54)
Construction;
Firewalls;
Engine mounts.

11.4 Air Conditioning and Cabin Pressurisation (ATA 21)

11.4.1 Air Supply
Sources of air supply including engine bleed, APU and ground cart.

11.4.2 Air Conditioning
Air conditioning systems;
Air cycle and vapour cycle machines;
Distribution systems;
Flow, temperature and humidity control system.

11.4.3 Pressurisation
Pressurisation systems;
Control and indication including control and safety valves;
Cabin pressure controllers.

11.4.4 Safety and Warning Devices
Protection and warning devices.

11.5 Instrument / Avionic Systems

11.5.1 Instrument Systems (ATA 31)
Pitot static: altimeter, air speed indicator, vertical speed indicator;
Gyroscopic: artificial horizon, attitude director, direction indicator,
horizontal situation indicator, turn and slip indicator, turn coordinator;
Compasses: direct reading, remote reading;
Angle of attack indication, stall warning systems;
Other aircraft system indication.

11.5.2 Avionic Systems
Fundamentals of system lay-outs and operation of:
– Auto Flight (ATA 22);
– Communications (ATA 23);
– Navigation Systems (ATA 34).

11.6 Electrical Power (ATA 24)
Batteries Installation and Operation;
DC power generation;
AC power generation;
Emergency power generation;
Voltage regulation;
Power distribution;
Inverters, transformers, rectifiers;
Circuit protection;
External/Ground power.

11.7 Equipment and Furnishings (ATA 25)
(a) Emergency equipment requirements;
Seats, harnesses and belts.

(b) Cabin lay-out;
Equipment lay -out;
Cabin Furnishing Installation;
Cabin entertainment equipment;
Galley installation;
Cargo handling and retention equipment;
Airstairs.

11.8 Fire Protection (ATA 26)
(a) Fire and smoke detection and warning systems;
Fire extinguishing systems;
System tests.

(b) Portable fire extinguisher.

11.9 Flight Controls (ATA 27)
Primary controls: aileron, elevator, rudder, spoiler;
Trim control;
Active load control;
High lift devices;
Lift dump, speed brakes;
System operation: manual, hydraulic, pneumatic, electrical, fly-bywire;
Artificial feel, Yaw damper, Mach trim, rudder limiter, gust locks;
Balancing and rigging;
Stall protection system.

11.10 Fuel Systems (ATA 28)
System lay -out;
Fuel tanks;
Supply systems;
Dumping, venting and draining;
Cross-feed and transfer;
Indications and warnings;
Refuelling and defuelling;
Longitudinal balance fuel systems.

11.11 Hydraulic Power (ATA 29)
System lay -out;
Hydraulic fluids;
Hydraulic reservoirs and accumulators;
Pressure generation: electric, mechanical, pneumatic;
Emergency pressure generation;
Pressure Control;
Power distribution;
Indication and warning systems;
Interface with other systems.

11.12 Ice and Rain Protection (ATA 30)
Ice formation, classification and detection;
Anti-icing systems: electrical, hot air and chemical;
De-icing systems: electrical, pneumatic and chemical;
Rain repellant and removal;
Probe and drain heating;
Wiper systems.

11.13 Landing Gear (ATA 32)
Construction, shock absorbing;
Extension and retraction systems: normal and emergency;
Indications and warning;
Wheels, brakes, antiskid and autobraking;
Tyres;
Steering.

11.14 Lights (ATA 33)
External: navigation, anti-collision, landing, taxiing, ice;
Internal: cabin, cockpit, cargo;
Emergency.

11.15 Oxygen (ATA 35)
System lay -out: cockpit, cabin;
Sources, storage, charging and distribution;
Supply regulation;
Indications and warnings.

11.16 Pneumatic/Vacuum (ATA 36)
System lay -out;
Sources: engine / APU, compressors, reservoirs, ground supply;
Pressure control;
Distribution;
Indications and warnings;
Interfaces with other systems.

11.17 Water/Waste (ATA 38)
Water system lay -out, supply, distribution, servicing and draining;
Toilet system lay -out, flushing and servicing;
Corrosion aspects.

11.18
On Board Maintenance Systems (ATA 45)
Central maintenance computers;
Data loading system;
Electronic library system;
Printing;
Structure monitoring (damage tolerance monitoring).

Basic Aerodynamics

Module 8 – Basic Aerodynamics

8.1 Physics of the Atmosphere
International Standard Atmosphere (ISA), application to aerodynamics.

2.2 Aerodynamics
Airflow around a body;
Boundary layer, laminar and turbulent flow, free stream flow, relative airflow, upwash and downwash, vortices, stagnation;
The terms: camber, chord, mean aerodynamic chord, profile (parasite) drag, induced drag, centre of pressure, angle of attack,
wash in and wash out, fineness ratio, wing shape and aspect ratio;
Thrust, Weight, Aerodynamic Resultant;
Generation of Lift and Drag: Angle of Attack, Lift coefficient, Drag coefficient, polar curve, stall;
Aerofoil contamination including ice, snow, frost.

8.2 Theory of Flight
Relationship between lift, weight, thrust and drag;
Glide ratio;
Steady state flights, performance;
Theory of the turn;
Influence of load factor: stall, flight envelope and structural limitations;
Lift augmentation.

8.3 Flight Stability and Dynamics
Longitudinal, lateral and directional stability (active and passive).

Maintenance Practices

Module 7 – Maintenance Practices

7.1 Safety Precautions – Aircraft and Workshop
Aspects of safe working practices including precautions to take when working with electricity, gases especially oxygen, oils and
chemicals.
Also, instruction in the remedial action to be taken in the event of a fire or another accident with one or more of these hazards.

7.2 Workshop Practices
Care of tools, control of tools, use of workshop materials;
Dimensions, allowances and tolerances, standards of workmanship;
Calibration of tools and equipment, calibration standards.

7.3 Tools
Common hand tool types;
Common power tool types;
Operation and use of precision measuring tools;
Lubrication equipment and methods;
Operation, function and use of electrical general test equipment.

7.4 Avionic General Test Equipment
Operation, function and use of avionic general test equipment.

7.5 Engineering Drawings, Diagrams and Standards
Drawing types and diagrams, their symbols, dimensions, tolerances and projections;
Identifying title block information;
Microfilm, microfiche and computerised presentations;
Specification 100 of the Air Transport Association (ATA) of America;
Aeronautical and other applicable standards including ISO, AN, MS, NAS and MIL;
Wiring diagrams and schematic diagrams.

7.6 Fits and Clearances
Drill sizes for bolt holes, classes of fits;
Common system of fits and clearances;
Schedule of fits and clearances for aircraft and engines;
Limits for bow, twist and wear;
Standard methods for checking shafts, bearings and other parts.

7.7 Electrical Cables and Connectors
Continuity, insulation and bonding techniques and testing;
Use of crimp tools: hand and hydraulic operated;
Testing of crimp joints;
Connector pin removal and insertion;
Co-axial cables: testing and installation precautions;
Wiring protection techniques : Cable looming and loom support, cable clamps, protective sleeving techniques including heat shrink wrapping, shielding.

7.8 Riveting
Riveted joints, rivet spacing and pitch;
Tools used for riveting and dimpling;
Inspection of riveted joints.

7.9 Pipes and Hoses
Bending and belling/flaring aircraft pipes;
Inspection and testing of aircraft pipes and hoses;
Installation and clamping of pipes.

7.10 Springs
Inspection and testing of springs.

7.11 Bearings
Testing, cleaning and inspection of bearings;
Lubrication requirements of bearings;
Defects in bearings and their causes.

7.12 Transmissions
Inspection of gears, backlash;
Inspection of belts and pulleys, chains and sprockets;
Inspection of screw jacks, lever devices, push-pull rod systems.

7.13 Control Cables
Swaging of end fittings;
Inspection and testing of control cables;
Bowden cables; aircraft flexible control systems.

7.14 Material Handling

7.14.1 Sheet Metal Work
Marking out and calculation of bend allowance;
Sheet metal working, including bending and forming;
Inspection of sheet metal work.

7.14.2 Composite and non-metallic
Bonding practices;
Environmental conditions;
Inspection methods.

7.15 Welding, Brazing, Soldering and Bonding
(a) Soldering methods; inspection of soldered joints.

(b) Welding and brazing methods;
Inspection of welded and brazed joints;
Bonding methods and inspection of bonded joints.

7.16 Aircraft Weight and Balance
(a) Centre of Gravity / Balance limits calculation: use of relevant documents.

(b) Preparation of aircraft for weighing;
Aircraft weighing.

7.17 Aircraft Handling and Storage
Aircraft towing and associated safety precautions;
Aircraft jacking, chocking, securing and associated safety precautions;
Aircraft storage methods;
Refuelling / defuelling procedures;
De-icing/anti-icing procedures;
Electrical, hydraulic and pneumatic ground supplies;
Effects of environmental conditions on aircraft handling and operation.

7.18 Disassembly, Inspection, Repair and Assembly Techniques
(a) Types of defects and visual inspection techniques;
Corrosion removal, assessment and reprotection.

(b) General repair methods, Structural Repair Manual;
Ageing, fatigue and corrosion control programmes.

(c) Non destructive inspection techniques including, penetrant, radiographic, eddy current, ultrasonic and boroscope methods.

(d) Disassembly and re-assembly techniques.

(e) Troubleshooting techniques.

7.19 Abnormal Events
(a) Inspections following lightning strikes and HIRF penetration.

(b) Inspections following abnormal events such as heavy landings and
flight through turbulence.

7.20 Maintenance Procedures
Maintenance planning;
Modification procedures;
Stores procedures;
Certification/release procedures;
Interface with aircraft operation;
Maintenance Inspection/Quality Control/Quality Assurance;
Additional maintenance procedures;
Control of life limited components.

Materials and Hardware – EASA part 66 module 6

Module 6 – Materials and Hardware

6.1 Aircraft Materials – Ferrous
(a) Characteristics, properties and identification of common alloy steels used in aircraft;
Heat treatment and application of alloys steels.

(b) Testing of ferrous materials for hardness, tensile strength, fatigue strength and impact resistance.

6.2 Aircraft Materials – Non-Ferrous
(a) Characteristics, properties and identification of common non-ferrous materials used in aircraft;
Heat treatment and application of non-ferrous materials;

(b) Testing of non-ferrous material for

6.3 Aircraft Materials – Composite and Non-Metallic
6.3.1 Composite and non-metallic other than wood and fabric
(a) Characteristics, properties and identification of common composite and non-metallic materials, other than wood, used in aircraft;
Sealant and bonding agents.

(b) The detection of defects/deterioration in composite and non-metallic material;
Repair of composite and non-metallic material.

6.4 Corrosion
(a) Chemical fundamentals;
Formation by, galvanic action process, microbiological, stress.

(b) Types of corrosion and their identification;
Causes of corrosion;
Material types, susceptibility to corrosion.

6.5 Fasteners
6.5.1 Screw Threads
Screw nomenclature;
Thread forms, dimensions and tolerances for standard threads used in aircraft;
Measuring screw threads.

6.5.2 Bolts, studs and screws
Bolt types: specification, identification and marking of aircraft bolts, international standards;
Nuts: self locking, anchor, standard types;
Machine screws: aircraft specifications;
Studs: types and uses, insertion and removal;
Self tapping screws, dowels.

6.5.3 Locking Devices
Tab and spring washers, locking plates, split pins, pal-nuts, wire locking, quick release fasteners, keys, circlips, cotter pins.

6.5.4 Aircraft Rivets
Types of solid and blind rivets: specifications and identification, heat treatment.

6.6 Pipes and Unions
(a) Identification of, and types of rigid and flexible pipes and their connectors used in aircraft.

(b) Standard unions for aircraft hydraulic, fuel, oil, pneumatic and air system pipes.

6.7 Springs
Types of springs, materials, characteristics and applications.

6.8 Bearings
Purpose of bearings, loads, material, construction;
Types of bearings and their application.

6.9 Transmissions
Gear types and their application;
Gear ratios, reduction and multiplication gear systems, driven and driving gears, idler gears, mesh patterns;
Belts and pulleys, chains and sprockets.

6.10 Control Cables
Types of cables;
End fittings, turnbuckles and compensation devices;
Pulleys and cable system components;
Bowden cables;
Aircraft flexible control systems.

6.11 Electrical Cables and Connectors
Cable types, construction and characteristics;
High tension and co-axial cables;
Crimping;
Connector types, pins, plugs, sockets, insulators, current and voltage rating, coupling, identification codes.

Digital techniques and Electronic instrument systems – EASA part 66 module 5

5.1 Electronic Instrument Systems
Typical systems arrangements and cockpit layout of elec-tronic instrument systems.

5.2 Numbering Systems
Numbering systems: binary, octal and hexadecimal;
Demonstration of conversions between the decimal and binary, octal and hexadecimal systems and vice versa.

5.3 Data Conversion
Analogue Data, Digital Data;
Operation and application of analogue to digital, and digital to analogue converters, inputs and outputs, limita-tions of various types.

5.4 Data Buses
Operation of data buses in aircraft systems, including knowledge of ARINC and other specifications.

5.5 Logic Circuits
(a)Identification of common logic gate symbols, tables and equivalent circuits;
Applications used for aircraft systems, schematic diagrams.
(b) Interpretation of logic diagrams.

5.6 Basic Computer Structure
(a)Computer terminology (including bit, byte, software, hardware, CPU, IC, and various memory device such as RAM, ROM, PROM);
Computer technology (as applied in aircraft systems).
(b)Computer related terminology;
Operation, layout and interface of the major components in a micro computer including their associated bus systems;
Information contained in single and multiaddress instruction words;
Memory associated terms;
Operation of typical memory devices;
Operation, advantages and disadvantages of the various data storage systems. (B2 only)

5.7 Microprocessors (B2 only)
Functions performed and overall operation of a microprocessor;
Basic operation of each of the following microprocessor elements: control and processing unit, clock, register, arithmetic logic unit

5.8 Integrated Circuits (B2 only)
Operation and use of encoders and decoders;
Function of encoder types;
Uses of medium, large and very large scale integration.

5.9 Multiplexing (B2 only)
Operation, application and identification in logic diagrams
of multiplexers and demultiplexers.

5.10 Fibre Optics
Advantages and disadvantages of fibre optic data transmission over electrical wire propagation;
Fibre optic data bus;
Fibre optic related terms;
Terminations;
Couplers, control terminals, remote terminals;
Application of fibre optics in aircraft systems.

5.11 Electronic Displays
Principles of operation of common types of displays used
in modern aircraft, including
Cathode Ray Tubes, Light Emitting Diodes and Liquid
Crystal Display.

5.12 Electrostatic Sensitive Devices
Special handling of components sensitive to electrostatic
discharges;
Awareness of risks and possible damage, component and
personnel anti-static protection devices.

5.13 Software Management Control
Awareness of restrictions, airworthiness requirements and
possible catastrophic effects of unapproved changes to
software programmes.

5.14 Electromagnetic Environment
Influence of the following phenomena on maintenance
practices for electronic system:
EMC-Electromagnetic Compatibility
EMI-Electromagnetic Interference
HIRF-High Intensity Radiated Field
Lightning/lightning protection

5.15 Typical Electronic/Digital Aircraft Systems
General arrangement of typical electronic/digital aircraft
systems and associated BITE
(Built In Test Equipment) testing such as:
ACARS-ARINC Communication and Addressing and
Reporting System
ECAM-Electronic Centralised Aircraft Monitoring
EFIS-Electronic Flight Instrument System
EICAS-Engine Indication and Crew Alerting System
FBW-Fly by Wire
FMS-Flight Management System
GPS-Global Positioning System
IRS-Inertial Reference System
TCAS-Traffic Alert Collision Avoidance System

Electronic Fundamentals – EASA part 66 module 4

4.1 Semiconductors
4.1.1 Diodes
(a) Diode symbols;
Diode characteristics and properties;
Diodes in series and parallel;
Main characteristics and use of silicon controlled rectifiers (thyristors), light emitting diode, photo conductive diode, varistor, rectifier diodes;
Functional testing of diodes.

(b) Materials, electron configuration, electrical properties;
P and N type materials: effects of impurities on conduction, majority and minority characters;
PN junction in a semiconductor, development of a potential across a PN junction in unbiased, forward biased and reverse biased conditions;
Diode parameters: peak inverse voltage, maximum forward current, temperature, frequency, leakage current, power dissipation;
Operation and function of diodes in the following circuits: clippers, clampers, full and half wave rectifiers, bridge rectifiers, voltage doublers and triplers;
Detailed operation and characteristics of the following devices: silicon controlled rectifier (thyristor), light emitting diode, Shottky diode, photo conductive diode, varactor diode, varistor, rectifier diodes, Zener diode.

4.1.2 Transistors
(a) Transistor symbols;
Component description and orientation;
Transistor characteristics and properties.

(b) Construction and operation of PNP and NPN transistors;
Base, collector and emitter configurations;
Testing of transistors;
Basic appreciation of other transistor types and their uses;
Application of transistors: classes of amplifier (A, B, C);
Simple circuits including: bias, decoupling, feedback and stabilisation;
Multistage circuit principles: cascades, push-pull, oscillators, multivibrators, flip-flop circuits.

4.1.3 Integrated Circuits
(a) Description and operation of logic circuits and linear
circuits/operational amplifiers.

(b) Description and operation of logic circuits and linear circuits;
Introduction to operation and function of an operational amplifier used
as: integrator, differentiator, voltage follower, comparator;
Operation and amplifier stages connecting methods: resistive
capacitive, inductive (transformer), inductive resistive (IR), direct;
Advantages and disadvantages of positive and negative feedback.

4.2 Printed Circuit Board
Description and use of printed circuit boards.

4.3 Servomechanisms
(a) Understanding of the following terms: Open and closed loop systems, feedback, follow up, analogue transducers;
Principles of operation and use of the following synchro system components/features: resolvers, differential, control and torque, transformers,  inductance and capacitance transmitters.

(b) Understanding of the following terms: Open and closed loop, follow up, servomechanism, analogue, transducer, null, damping, feedback, deadband;
Construction operation and use of the following synchro system components: resolvers, differential, control and torque, E and I
transformers, inductance transmitters, capacitance transmitters, synchronous transmitters;
Servomechanism defects, reversal of synchro leads, hunting.

Electrical Fundamentals – EASA part 66 module 3

3.1 Electron Theory
Structure and distribution of electrical charges within: atoms, molecules, ions, compounds;
Molecular structure of conductors, semiconductors and insulators.

3.2 Static Electricity and Conduction
Static electricity and distribution of electrostatic charges;
Electrostatic laws of attraction and repulsion;
Units of charge, Coulomb’s Law;
Conduction of electricity in solids, liquids, gases and a vacuum.

3.3 Electrical Terminology
The following terms, their units and factors affecting them: potential difference, electromotive force, voltage, current, resistance, conductance, charge, conventional current flow, electron flow.

3.4 Generation of Electricity
Production of electricity by the following methods: light, heat, friction, pressure, chemical action, magnetism and motion.

3.5 DC Sources of Electricity
Construction and basic chemical action of: primary cells, secondary cells, lead acid cells, nickel cadmium cells, other alkaline cells;
Cells connected in series and parallel;
Internal resistance and its effect on a battery;
Construction, materials and operation of thermocouples;
Operation of photo-cells.

3.6 DC Circuits
Ohms Law, Kirchoff’s Voltage and Current Laws;
Calculations using the above laws to find resistance, voltage and current;
Significance of the internal resistance of a supply.

3.7 Resistance / Resistor
(a) Resistance and affecting factors;
Specific resistance;
Resistor colour code, values and tolerances, preferred values, wattage ratings;
Resistors in series and parallel;
Calculation of total resistance using series, parallel and series parallel combinations;
Operation and use of potentiometers and rheostats;
Operation of Wheatstone Bridge.

(b) Positive and negative temperature coefficient conductance;
Fixed resistors, stability, tolerance and limitations, methods of construction;
Variable resistors, thermistors, voltage dependent resistors;
Construction of potentiometers and rheostats;
Construction of Wheatstone Bridge.

3.8 Power
Power, work and energy (kinetic and potential);
Dissipation of power by a resistor;
Power formula;
Calculations involving power, work and energy.

3.9 Capacitance / Capacitor
Operation and function of a capacitor;
Factors affecting capacitance area of plates, distance between plates, number of plates, dielectric and dielectric constant, working voltage, voltage rating;
Capacitor types, construction and function;
Capacitor colour coding;
Calculations of capacitance and voltage in series and parallel circuits;
Exponential charge and discharge of a capacitor, time constants;
Testing of capacitors.

3.10 Magnetism
(a) Theory of magnetism;
Properties of a magnet;
Action of a magnet suspended in the Earth’s magnetic field;
Magnetisation and demagnetisation;
Magnetic shielding;
Various types of magnetic material;
Electromagnets construction and principles of operation;
Hand clasp rules to determine: magnetic field around current carrying conductor.

(b) Magnetomotive force, field strength, magnetic flux density, permeability, hysteresis loop, retentivity, coercive force reluctance, saturation point, eddy currents;
Precautions for care and storage of magnets.

3.11 Inductance / Inductor
Faraday’s Law;
Action of inducing a voltage in a conductor moving in a magnetic field;
Induction principles;
Effects of the following on the magnitude of an induced voltage:
magnetic field strength, rate of change of flux, number of conductor turns;
Mutual induction;
The effect the rate of change of primary current and mutual inductance has on induced voltage;
Factors affecting mutual inductance:
number of turns in coil, physical size of coil, permeability of coil, position of coils with respect to each other;
Lenz’s Law and polarity determining rules;
Back emf, self induction;
Saturation point;
Principal uses of inductors.

3.12 DC Motor / Generator Theory
Basic motor and generator theory;
Construction and purpose of components in DC generator;
Operation of, and factors affecting output and direction of current flow in DC generators;
Operation of, and factors affecting output power, torque, speed and direction of rotation of C motors;
Series wound, shunt wound and compound motors;
Starter Generator construction.

3.13 AC Theory
Sinusoidal waveform: phase, period, frequency, cycle;
Instantaneous, average, root mean square, peak, peak to peak current values and calculations of these values, in relation to voltage, current and power; Triangular/Square waves;
Single / 3 phase principles.

3.14 Resistive (R), Capacitive (C) and Inductive (L) Circuits
Phase relationship of voltage and current in L, C and R circuits, parallel, series and series parallel;
Power dissipation in L, C and R circuits;
Impedance, phase angle, power factor and current calculations;
True power, apparent power and reactive power calculations.

3.15 Transformers
Transformer construction principles and operation;
Transformer losses and methods for overcoming them;
Transformer action under load and no-load conditions;
Power transfer, efficiency, polarity markings;
Primary and Secondary current, voltage, turns ratio, power, efficiency;
Auto transformers.

3.16 Filters
Operation, application and uses of the following filters: low pass, high pass, band pass, band stop.

3.17 AC Generators
Rotation of loop in a magnetic field and waveform produced;
Operation and construction of revolving armature and revolving field type AC generators;
Single phase, two phase and three phase alternators;
Three phase star and delta connections advantages and uses;
Calculation of line and phase voltages and currents;
Calculation of power in a three phase system;
Permanent Magnet Generators.

3.18 AC Motors
Construction, principles of operation and characteristics of:

AC synchronous and induction motors both single and polyphase;
Methods of speed control and direction of rotation;
Methods of producing a rotating field: capacitor, inductor, shaded or
split pole.