Software Management Module 5:13

Software Management - The title consists of  two words, software and management. The software can be defined as the program that are used by a computer. We can  basically divided software into 2 groups, operating software and application software. Operating software focus on making the computer and its accessories work. The application software is the program designed to produce the specific job for the user.
Management control is the process planning and other activities to ensure that the software meets the desired results. There more to the application of management, but I always stress on the management of the process, which relate to the software life-cycle.

  

Software Management is under the subtopic 13 in the Module 5 for the EASA part 66 license. Module 5 is about Digital Technique and electronic instruments. In teaching this module, I expect the students to be able to explain and give examples to show their understanding of the modules title.  It 

Software in a necessary components of an aircraft system. Examples of aircraft systems using software are...primary and secondary flight controls, engines controls, electrical generation and distribution, brakes and navigation systems.

Let us take a look at the life cycle of a software. The like of human life cycle, the software has the different phases of life. The authority is interest to monitor and control the quality of the different phases. 

The RTCA and Eurocae are responsible to come up with guidelines to ensure the the software used on the aircraft meets the required specification. The specification was published in the joint documents, DO -178/ED - 2. The current  version of the documents are given in another slides.
The Malaysian Civil Aviation recognized the document through its airworthiness directive AN57.

The document gives the outline for approval of software. The designed of the software must be done by an approved company. The requirements are described by RTCA  and Eurocae.

About RTCA

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Software Testing

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The example of data loading panel is taken from B737-400 manual. This will give the students some idea of where the loading process is being done. There is the 

On the loading is done through the optical disk. This must be clear to the students that the software to be local must be an approved software and the workers that is doing the loading must be an approved person.

Syllabus Module 5

Module 5 is about Digital Techniques and Electronic Instruments. The followings are the syllabus for module extracted from the EASA part 66 module (Malaysia)

5.1 Electronic Instrument Systems
Typical systems arrangements & cockpit layout of electronic 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, limitations of various types.

5.4 Data Buses
Operation of data buses in aircraft systems, including knowledge of ARINC and other specifications; Aircraft network / Ethernet.

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, & various memory devices 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.

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 & 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 & 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 Integrated Modular Avionics Cabin Systems Information Systems
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 QUESTIONS FOR EASA PART 66 EXAMINATION

Subject Module 5 Digital Techniques/Electronic Instrument Systems:

Category A-16 multi-choice and 0 essay questions. Time allowed 20 minutes.
Category B1.1 & B1.3-40 multi-choice and 0 essay questions. Time allowed 50 minutes.
Category B1.2 & B1.4-20 multi-choice and 0 essay questions. Time allowed 25 minutes.
Category B2-70 multi-choice and 0 essay questions.

Time allowed 90 minutes.

How Computer Adds Numbers

One one the subject a student learns for the EASA part66 examination is working of a computer.

 This is a good video with plenty of information. These are the key points you can pick up...

a. Information on the motherboard and the microprocessor.
b. Basic information of MosFet transistor with source, drain and gate.
c. Understanding the OR and the AND gate.
d. Binary numbers and its representation using the lights.
e. The different type of dates, OR, AND and Exclusive OR.
f. The full and half adder.  

MOSFET - Module 4 Extra

Reading Analogue Multimeter

Reading the analogue multimeter is a necessary skill for aircraft engineer. Unfortunately the EASA syllabus is arranged in such a way that the learning about multimeter is covered in module 7. However students are expected to be able to use the meter as the earlier modules, such as module 3 and 4 require the use of meter for testings. Example module 3. 9, test of capacitor and module 4. 1, the test for diode.

I had located the site to learn about multimeter. Please follow the link to:
http://www.tequipment.net/pdf/velleman/velleman_avm360_manual.pdf

The area of knowledge to be covered in the use of the meter.
Although it is not stated that the students need to know the working of the meter, I do cover it in order to bring the understanding of the usage of the meter.
a. Construction of the meter.
b. The changes and connections needed to make it reads current, voltage and resistance.
c. The names of the different parts and scales.
d. How to use it to read DC voltage and Current, AC voltage and resistance.
e. The different between Digital and analogue meter.

Take note: for ampere and voltage readings, 0 is on the left and maximum is on the right. However for resistance (ohms) , 0 is on the right and maximum is on the left. Why?. As a student of aircraft maintenance license, you should be able to explain why.

There are three connecting terminals. Many students are wondering about output terminal. The purpose is to measure AC Voltage, when the AV voltage is superimposed on DC.

Module 3.16 Filters

Filters is cover under the syllabus in module 3.16 at level 1 It covers operation, application and uses of 4 types of filters, low pass, high pass, band pass and band stop. A Low pass. The following video explain the
low pass filter.


F(cutoff) = 1/2(pfi)RC

A. About filters - What is a filter.
In the basic science in school, we learn about filter that was used to separate a liquid and the solid impurities. In electronics, the same concept is used. A filter is to separate different signals of different frequencies. The easiest to visualize is in the music, the filters used to divert different signals to different speakers.

B. Filters - EASA syllabus
Under module 3.6, The topic "Filters" is at level 1 and include its Operation, application and uses of the these  filters: low pass, high pass, band pass, band stop.

- Low pass filter - a filter that allows the signal below a certain frequency to pass through unchanged.The point to start the change is the cut-off point.

- High pass filter - a filter that allows the signal above a certain point to pass through unchanged.

Module 3.8 Power

Under the EASA part 66 syllabus, the module 3.8 is about the following topics (level 2):
- Power, work and energy (kinetic and potential
- dissipation of power using resistor
- Power formula
- calculation involving power, work and energy

The Video gives the formula for power in a dc circuit: power = IV = V squared/ R = I squared/ R

Capacitor Color Code

Reference http://www.tpub.com/neets/book2/3g.htm

Module 7 Electrical Subjects

If you are going for B1.1 license, there are three big module for you to do. They are:
- module 7         - Maintenance Practices
- module 11A    - Aerodynamics, Structure and System
- Module 15      - Turbine engine

To facilitate in the delivery of the lectures, we had divided the module 7 into 4 submodules, one of which is on the electrical subject. It covers the following subjects:
- Topic 7.1 -    electrical safety
- Topic 7.4 -    General Test Equipment
- Topic 7.5 -    Schematic and Wiring Diagram
- Topic 7.7    - EWIS
- Topic 7.15 - Soldering

Electrical System Typical B737NGX

Module 4 does not cover a typical electrical system. This would be covered in module 11A, however it make it easier for student to appreciate what they have learned if a typical aircraft system is given.

I have selected a video by angle of attack, giving a brief overview on the Boeing 737NGX electrical system.
The video is designed for the pilot.It is good for introduction, as it does not go into detail as required for the engineers.

Syllabus Module 3 - Electrical Fundamental

After Mathematics and Physics in modules 1 and 2, the next appropriate module is module 3.

I include the syllabus from Malaysian DCA, which is similar to the EASA syllabus.

3.1 Electron Theory B1 - Level 1,
Structure and distribution of electrical charges within: atoms, molecules, ions, compounds; Molecular structure of conductors, semiconductors and insulators.

3.2 Static Electricity and Conduction (B1 L2)
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 (B1-L1)
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 (B1-L1)
Production of electricity by the following methods: light, heat, friction, pressure, chemical action, magnetism and motion.

3.5 DC Sources of Electricity (B1-L2)
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 (B1-L2)
Ohms Law, Kirchoff's Voltage and Current Laws;
Calculations using the above laws to find resistance, voltage & current;
Significance of the internal resistance of a supply.

3.7 Resistance/Resistor (L2)
(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; (L1)
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 (L2)
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 (L2)
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 (B2)
(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 (L2)
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;
Principle uses of inductors;

3.12 DC Motor/Generator Theory (L2)
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 DC motors;
Series wound, shunt wound and compound motors;
Starter Generator construction.

3.13 AC Theory (L2)
Sinusoidal waveform: phase, period, frequency, cycle;
Instantaneous, average, root mean square, peak, peak to peak current values & calculations of these values, in relation to voltage, current & power;
Triangular/Square waves;
Single/3 phase principles.

3.14 Resistive (R), Capacitive (C) and Inductive (L) Circuits (L2)
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 (L2)
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;
Calculation of line and phase voltages and currents;
Calculation of power in a three phase system;
Primary and Secondary current, voltage, turns ratio,power, efficiency;
Auto transformers.

3.16 Filters (L1)1
Operation, application and uses of the following filters: low pass, high pass, band pass, band stop.

3.17 AC Generators (L2)
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;
Permanent Magnet Generators.

3.18 AC Motors (L2)2
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.

Teaching Module 4 - Electronics

The module 4 is for Fundamental Electronics. It has 2 distinct group of knowledge. The syllabus includes:
- subject of electronics and the second part
-  includes the non electronic subject of syncro.

I presume that EASA realise the importance of subjects of data transmission like syncro and they cannot find a suitable module.As such it is parked in module 5.

In the learning theory, the researches had identified the effectiveness of the teaching medium.
- virtual
- audio
- experiential

It had been found that experiential learning is more effective. That mean, learning by doing will improve the learning and the students memory. We were using this method in the delivery.

We include some of the students activities..

Thrystors are generic term used to describe the semiconductors that have the latching effect. The most commonly used is the SCR, the silicon controlled rectifier. A SCR has 3 connecting wires, the anode, the cathode and the gate.

The + is connected to the anode and (-) connected to the cathode. The gate is the controlling input. With a positive pulse, the current will flow from anode to cathode and it continue to flow until the voltage falls below a certain level.

We covers the half wave and full wave rectifiers. For the full wave rectifier, we study the two types, the center tapped full wave rectifier that uses only two diodes. We also study the bridge type of rectifier which uses 4 diodes.
We did not cover the 3 phase rectifier. That remind me, to include the 3 phase rectifier, as it is the most common type used in the modern aircraft, noticeably for TRUs and the voltage regulators.

We covered rather in detail about the operation amplifiers. Covering the above topics, we cover the operation of 3 types of Op amplifiers, the inverting, the summing and comparator.