Basic Aircraft Maintenance Training Manual PDF 2024

# GMR Aero School of Aviation ## GMR Air Cargo and Aerospace Engineering Limited * **Hyderabad**, Telangana, India * **Website**: `www.gmrschoolofaviation.com` * **Email**: `[email protected]` ## Basic aircraft maintenance training manual * **Module 3**: ELECTRICAL FUNDAMENTALS * **S...

# GMR Aero School of Aviation ## GMR Air Cargo and Aerospace Engineering Limited * **Hyderabad**, Telangana, India * **Website**: `www.gmrschoolofaviation.com` * **Email**: `[email protected]` ## Basic aircraft maintenance training manual * **Module 3**: ELECTRICAL FUNDAMENTALS * **Submodule 3.4**: GENERATION OF ELECTRICITY * **Issue**: 03 * **Dated**: 01 JUL 2024 * **For training purposes only** # Table of Contents - Foreword - Copyright notice - Basic knowledge requirements - Knowledge levels - Category A, B1, B2, B3 and C Aircraft - Maintenance Licence: Level 1, Level 2, Level 3 - Abbreviations - Sources of electricity - Light sources - Heat sources - Friction - Pressure source - Chemical reaction - Magnetism and motion # Foreword It is important to note that the information in this book is for study/ training purposes only and no revision service will be provided to the holder. When carrying out a procedure/ work on aircraft/ aircraft equipment you must always refer to the relevant aircraft maintenance manual or equipment manufacturer's handbook. For health and safety in the workplace you should follow the regulations/ guidelines as specified by the equipment manufacturer, your company, national safety authorities and national governments. # Copyright Notice Copyright. All worldwide rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form by any other means whatsoever: i.e., photocopy, electronic, mechanical recording or otherwise without the prior written permission of GMR School of Aviation. # Basic Knowledge Requirements These Study Notes comply with the syllabus of DGCA Regulation, CAR-66 (Appendix I) and the associated Knowledge Levels as specified. These Study Notes comply with the syllabus of EASA Regulation (EU) No. 1321/2014 Annex (Part-66) Appendix I and the associated Knowledge Levels as specified below: | Objective | CAR 66 / PART 66 Reference | B1.1 | B2 | | ------------- | ------------------------- | ---- | -- | | Generation Of Electricity | 3.4 | 1 | 1 | ## Production of electricity by the following methods: light, heat, friction, pressure, chemical action, magnetism and motion. # Knowledge Levels - Category A, B1, B2, B3 and C Aircraft Maintenance Licence Basic knowledge for categories A, B1, B2 and B3 are indicated by the allocation of knowledge levels indicators (1, 2 or 3) against each application subject. Category C applicants must meet either the category B1 or the category B2 basic knowledge levels. The knowledge level indicators are defined as follows: ## Level 1 A familiarization with the principal elements of the subject. **Objectives**: The applicant should be familiar with the basic elements of the subject. The applicant should be able to give a simple description of the whole subject, using common words and examples. The applicant should be able to use typical terms. ## Level 2 A general knowledge of the theoretical and practical aspects of the subject. An ability to apply that knowledge. **Objectives**: The applicant should be able to understand the theoretical fundamentals of the subject. The applicant should be able to give a general description of the subject using, as appropriate, typical examples. The applicant should be able to use mathematical formulae in conjunction with physical laws describing the subject. The applicant should be able to read and understand sketches, drawings and schematics describing the subject. The applicant should be able to apply his knowledge in a practical manner using detailed procedures. ## Level 3 A detailed knowledge of the theoretical and practical aspects of the subject. A capacity to combine and apply the separate elements of knowledge in a logical and comprehensive manner. **Objectives**: The applicant should know the theory of the subject and interrelationships with other subjects. The applicant should be able to give a detailed description of the subject using theoretical fundamentals and specific examples. The applicant should understand and be able to use mathematical formulae related to the subject. The applicant should be able to read, understand and prepare sketches, simple drawings and schematics describing the subject. The applicant should be able to apply his knowledge in a practical manner using the manufacturer's instructions. The applicant should be able to interpret results from various sources and measurements and apply corrective action where appropriate. # Abbreviations # Sources of Electricity Electrical energy can be produced in a number of methods. The most common are light, heat, friction, pressure, chemical reaction, magnetism and motion. ## 1.1 Light sources Electricity can be produced directly by light using photovoltaic cells. The photovoltaic effect, which is the conversion of radiant energy into electrical energy, occurs when light falls on a suitable material, releasing electron from the material and thus generating electricity. * **Solar cells / photovoltaic cells**: A solar cell or a photovoltaic cell is a device that converts light energy into electricity. Fundamentally, the device contains certain chemical elements that when exposed to light energy, they release electrons. Photons in sunlight are taken in by the solar panel or cell, where they are then absorbed by semi conducting materials, such as silicon. Electrons in the cell are broken loose from their atoms, allowing them to flow through the material to produce electricity. The complementary positive charges that are also created are called holes (absence of electron) and flow in the direction opposite of the electrons in a silicon solar panel. Solar cells have many applications and have historically been used in earth orbiting satellites or space probes, handheld calculators, and wrist watches. *Note: photovoltaic panels are the only devices (except for accumulators) that supply direct current directly.* ## 1.2 Heat Sources * **Thermocouples**: The most common source of thermal electricity found in the aviation industry comes from thermocouples. Thermocouples are widely used as temperature sensors. They are cheap and interchangeable, have standard connectors, and can measure a wide range of temperatures. It was also noticed that different metal combinations have a different voltage difference. ### **Seebeck Effect** Thermocouples are pairs of dissimilar metal wires joined at least at one end, which generate a voltage between the two wires that is proportional to the temperature at the junction. This is called the See beck effect, in honour of Thomas See beck who first noticed the phenomena in 1821. ### **Peltier Effect** A temperature difference occurs at the junction of 2 materials of different types when electric current passes through them. ### **Thomson Effect** Thomson showed that the See beck and Peltier effect are related. Material subjected to a thermal gradient with electric current flowing through it exchanges heat with the outside environment. Conversely electric current is generated by a material subjected to a thermal gradient with heat flowing through it. * **Unlike the See beck and Peltier effect, which requires the junction of 2 materials the Thomson effect does not require a junction and only requires one material.** * **Thermocouples are utilized in aviation as ways to measure cylinder head temperatures, inter-turbine temperature and exhaust gas temperature.** ## 1.3 Friction The production of electricity by friction refers to the build-up of static electricity when non-conductive materials are rubbed together. A transfer of electrons occurs resulting in an imbalance of charges between the materials. Static electricity is discussed in Sub-Module 02. * **The creation of electric charges by rubbing is the common phenomenon.** Rubbing 2 material together pulls electrons away from the outer layers of the atoms from one material and transfer them to the other. The imbalance of electrical changes between the 2 material is called the potential difference. * **Electrostatic generators based on the principle have been developed and are used to generate high voltages.** ## 1.4 Pressure Source This form of electrical generation is commonly known as piezoelectric (piezo or piez taken from Greek: to press; pressure; to squeeze) is a result of the application of mechanical pressure on a dielectric or nonconducting crystal. The most common piezoelectric materials used today are crystalline quartz and Rochelle salt. However, Rochelle salt is being superseded by other materials, such as barium titanate. * **The application of a mechanical stress produces an electric polarization, which is proportional to this stress. This polarization establishes a voltage across the crystal. If a circuit is connected across the crystal a flow of current can be observed when the crystal is loaded (pressure is applied). An opposite condition can occur, where an application of a voltage between certain faces of the crystal can produce a mechanical distortion. This effect is commonly referred to as the piezoelectric effect.** * **The pressure exerted by the forces F on the piezo electric material creates a potential difference between the 2 sides of the material.** * **Piezoelectric materials are used extensively in transducers for converting a mechanical strain into an electrical signal.** Such devices include microphones, phonograph pickups and vibration-sensing elements. The opposite effect, in which a mechanical output is derived from an electrical signal input, is also widely used in headphones and loudspeakers. ## 1.5 Chemical Reaction Chemical energy can be converted into electricity; the most common form of this is the battery and fuel cell. ### Battery A primary battery produces electricity using two different metals in a chemical solution like alkaline electrolyte, where a chemical reaction between the metals and the chemicals frees more electrons in one metal than in the other. One terminal of the battery is attached to one of the metals such as zinc; the other terminal is attached to the other metal such as manganese oxide. The end that frees more electrons develops a positive charge and the other end develops a negative charge. If a wire is attached from one end of the battery to the other, electrons flow through the wire to balance the electrical charge. ### Fuel Cell Fuel cell is a conversion device very similar to a battery. * **Both are electrochemical devices for converting chemical energy into electrical energy.** In a battery chemical energy stored inside whereas in a fuel cell, chemical energy fuel and (oxidising agent) is supplied from the outside and can be filed continuously. ## 1.6 Magnetism and Motion When a conductor is moved through the magnetic lines of flux created by a magnet or electromagnet, electromotive force is created, and current flow produced for use by various electrically operated devices and components. This generation of electricity via magnetism and motion is discussed in Sub-Module 10 in this book. ### Induced Current If we move a magnet quickly near a coil, we observe that the galvanometer needle deviates. Although the circuit doesn't have a power source, current flows through the electric circuit. This current is called induced current. As soon as the magnet stops moving the needle returns to zero. * We observe the same phenomena when: * the magnet is replaced by an electromagnet. * The coil is moved closer the magnet being fixed.