Filters under Module 3.16

Filter is under module 3 16 and the level of knowledge is only at level 1. At level 1 the students are expected to describe the subject using common words and examples. Students are also expected to have the knowledge of the common terms related to the subject.
The stated syllabus are as follows... Operation, application and uses of the following filters: low pass, high pass, band pass, band stop.

A. Introduction
If we relate the word filter to the mechanical application, like the water filter, it function include the removal of unwanted particles or impurities. Depending of the type of filter used, it can prevent small or larger particles to pass through.

In we apply the concept to the electronic application, then filters will have the following characteristics.....
- high pass - allows high frequencies to pass through
- low pass  - allows low frequency to pass through
- band pass - allows norrow band of frequencies to pass through
- band stop - stop the flow of narrow band of frequencies.

Module 12.8 Overview

Module 12 is about the real aircraft. The sub-module 8 is about the electrical system.

It must be made clear that under EASA part 66, there is no separate license for Electrical, unlike that of BCAR section L. For that reason, the B1 licensed persons have to develop the competencies in electrical systems. The expected knowledge level is level 3.

The following is the syllabus...

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

1. The batteries
In module 3, you had done the basic of the batteries and cells. That mean the students should have knowledge on the various aspects of it, such as the chemical reactions, the active materials involved in the reactions of the batteries, its constructions and the maintenance practices.

In this module, it is discussing about the installation.
- I would give the students a simple electrical systems for an aircraft, including..
      - the aircraft with DC as the main system,
      - aircraft with AC as the main system
Then, the students need to know where the batteries fit in.
The operation will include the batteries uses in normal situation and in emergency situation.
The installation will include the physical installation, the protection against corrosive effects and the guard against overheat. The operation also include the check for serviceability. How would you know if the battery is serviceable or not?.

TO BE ADDED >>>

How to Use Oscilloscope

The knowledge on oscilloscope is not included in the syllabus for B1-1. In fact the word oscilloscope is not even mentioned in the syllabus. However, this information is added for those interested to further their knowledge as oscilloscope may be used for works related to transistors and amplifiers in module 4. We can use it also in our investigation of the properties of AC circuits in module 3.

I find it easy to do research and start to learn on my own with the easy access to the internet. I normally start the research by using the video, the reason is simple, video captures the 2 important senses, the sound and sight. It is easier to understand and to follow the tuition.

I included a video that teaches the use of the unit from the conceptual introduction.

Take note of the following basic adjustments..
- vertical position knob -adjustment for each channel - what it does is, it repositions the output to the visible range of display. This is done without changing the scale of the display.
-  horizontal position knob (for all channel) - it moves the images horizontally so that it is visible.
- voltage scale - it changes the volts per division. The adjustment is available for each channel.
- time base - seconds per division. (all channel)
- trigger position.- to adjust so that the wave is stabilized.

Differences in the Modules Between B1.1 and B1.3

If you are planning to become an aircraft mechanic or engineer, you have some choice to make.

First - Decide whether to become mechanical or avionics. Mechanical is the core, as it deals with the structure and the airworthiness of the aircraft. The hanger check and the related certifications are signed by mechanical or B1 personnel. That does not mean that the avionics is not important, as modern aircraft are fitted with advance systems.

If you want to do avionics, then go for B2 license. For mechanical, you have a choice of  separate and related licenses.

These are the choice...

B1-1 - fixed wings with turbine engine - like the modern aircraft B737, B747 A380 etc. Fixed wing because the wings that are producing the lift are fixed and note rotating.

B1 - 3 - This the license for rotary wing. The rotating blades on top of the helicopter are shaped like the wing on aeroplane. The main different, the wings on helicopter rotates.

There are two more choices, the pistons airplane or helicopter. However, they are outside the scope of today's discussion.

Let us contrast the module contents of the two choice (Between B1-1 and B1-3).
a. The modules 1 to 10 are common for both.
b. For those going for B1-1 has to do 3 more modules i.e 11A, 15 and 17
c. For those going for B1-3 has to do modules 12 and 15.
Notes.. module 11A is about fixed wing structure and systems.
                         12 is about rotorcraft structure and systems.
                         15 is module on turbine engine
                          17 is propeller.

Main Differences between module 12 and 11A.
.... to be inserted...

Getting to Know Helicopter

In preparation for the teaching of module 12 on Electrical subjects, I have to build up some knowledge of helicopter. I will be doing three ATA chapters, 24, 26 and 33. For the purpose of delivery, I will be conducting the topics on electrical power, Lightings and Fire Protection.

As the students will be the Malaysian Trainees, I will have to select the examples from Malaysian operators.

My first search is for Malaysian Helicopter operators ... Google revealed the following operators..
1. MHS - Malaysia Helicopter Services
2. Eurocopter Malaysia
3. Solaire Helicopter Training
4. Augusta Westland.

Then, my next task is to get the types of helicopter operated by the various companies. The following are the result Helicopters operated the of different companies...

A. MHS
- Europter AS 365 N2
- Eurocopter AS332 L2 Super Puma
- Eurocopter AS335 F2
- Sikosky S76C

B Eurocopter Malaysia
- Dauphin AS365 N1
- Ecureuil AS350 BA

C. Augusta Westland Malaysia
- AW119
- AW109
- AW139

To support the teaching, I need to select 2 models as the reference for teaching. Looking from models above, the most suitable helicopter to be used for reference are the Augusta and Eurocopter.-

Module 12.15 External Light for General Reading

I had been searching the internet for suitable resources to introduce module 12.15 Lighting system. I found a youtube video, but unfortunately, it was uploaded by a person who is not from the industry. However the pictures and videos are useful resources.

The external lights are...
- Navigation Light - left wing tip - red, right wing tip - green, viewed from rear lights- white.
- Beacon Light - rotating or flashing red light - one on top of the aircraft and the other at the bottom.
- Strobe Light - while flashing lights at three locations, wing tips, and tail of the aircraft.
- Landing Light - used on landing and take-off, normally at three locations, wings and center.
- Taxi Light - for the pilots to see the taxiway
- runway turn off - useful for turning
- wing lights - illuminate the wings areas for ground safety and checking for the ice.
- logo light. - commercial value for advertisement.

External lights are used for different purposes. Some are legal requirements, others are operation while some are commercial. These are the uses..

1. Aircraft parked at the bay - the navigation lights are on, logo lights and wing light on.

2. Time limiting lights - The landing lights and taxi lights are high power. When the aircraft is inflight, the air help to cool the lights. For maintenance, switch it on for as short a time as possible.

3. Disturbing the eyes - both the strobe lights and beacons are affecting the eyes. Use the beacon light as necessary to show movements of aircraft or engine is running. Strobe lights to be used when the aircraft is moving in poor visibility.

OVERHEAD PANEL
The control of the external lights are from overhead panel as shown below. (B767)

VIDEO - Caution about the comments.

Module 12 Syllabus for B1.1

Module 12 is the final module for non-engine subject. It is about the aircraft's aerodynamics, structure and systems. That mean, the students are expected to have completed Modules 1 to 10.
Module 11 is divided to two groups, 11A if you are doing Category B1-1 and module 11B for category B1.2, which are airplane with turbine engine and pistons respectively.

If you are going for rotocraft license, either turbine or piston engine, then, you will take Module 12.

If you are a student, it may be worth thinking of taking more than 1 module. The different between modules 11A and 11B, and even module 12 are rather small. So it will save your study time if you can take more than 1 of the quoted modules.

The syllabus for module 12 is given below...

12.1 Theory of Flight — Rotary Wing Aerodynamics Level 2
Terminology; Effects of gyroscopic precession; Torque reaction and directional control; Dissymmetry of lift, Blade tip stall; Translating tendency and its correction; Coriolis effect and compensation; Vortex ring state, power settling, overpitching; Auto-rotation; Ground effect.

12.2 Flight Control Systems Level 3
Cyclic control; Collective control; Swashplate; Yaw control: Anti-Torque Control, Tail rotor, bleed air;
Main Rotor Head: Design and Operation features; Blade Dampers: Function and construction; Rotor Blades: Main and tail rotor blade construction and attachment; Trim control, fixed and adjustable stabilisers; System operation: manual, hydraulic, electrical and fly-by-wire; Artificial feel; Balancing and Rigging.

12.3 Blade Tracking and Vibration Analysis Level 3
Rotor alignment; Main and tail rotor tracking; Static and dynamic balancing; Vibration types, vibration  eduction methods; Ground resonance.

12.4 Transmissions (Level 3)
Gear boxes, main and tail rotors; Clutches, free wheel units and rotor brake. Tail rotor drive shafts, flexible couplings, bearings, vibration dampers and bearing hangers.

12.5 Airframe Structures (Level 2)
(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.
(b) Construction methods of: stressed skin fuselage, formers, stringers, longerons, bulkheads, frames, doublers, struts, ties, beams, floor structures, reinforcement, methods of skinning and anti-corrosive protection. Pylon, stabiliser and undercarriage.


12.6 Air Conditioning (ATA 21)
12.6.1 Air supply (L2)
Sources of air supply including engine bleed and ground cart;
12.6.2 Air Conditioning (L3)
Air conditioning systems;Distribution systems; Flow and temperature control systems; Protection and warning devices.

12.7 Instruments/Avionic Systems
12.7.1 Instrument Systems (ATA 31) (L2)
Pitot static system: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; Vibration indicating systems — HUMS; Glass Cockpit; Other aircraft system indication.

12.7.2 Avionic Systems (L1)
Fundamentals of system layouts and operation of:
Auto Flight (ATA 22); Communications (ATA 23); Navigation Systems (ATA 34).

12.8 Electrical Power (ATA 24) (L3)
Batteries Installation and Operation; DC power generation, AC power generation; Emergency power generation; Voltage regulation, Circuit protection. Power distribution; Inverters, transformers, rectifiers; External/Ground power.

12.9 Equipment and Furnishings (ATA 25) (L2)
(a) Emergency equipment requirements; Seats, harnesses and belts; Lifting systems.-
(b) Emergency flotation systems; (L1)
Cabin lay-out, cargo retention; Equipment lay-out; Cabin Furnishing Installation.

12.10 Fire Protection (ATA 26) (L3)
Fire and smoke detection and warning systems; Fire extinguishing systems; System tests.

12.11 Fuel Systems (ATA 28) (L3)-
System lay-out; Fuel tanks; Supply systems; Dumping, venting and draining; Cross-feed and transfer; Indications and warnings; Refuelling and defuelling.

12.12 Hydraulic Power (ATA 29) (L3)
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. Filters.

12.13 Ice and Rain Protection (ATA 30) (L3)
Ice formation, classification and detection; Anti-icing and de-icing systems: electrical, hot air and chemical;
Rain repellant and removal; Probe and drain heating. Wiper system.

12.14 Landing Gear (ATA 32) (L3)
Construction, shock absorbing; Extension and retraction systems: normal and emergency; Indications and warning; Wheels, tyres, brakes; Steering; Skids, floats. Air ground sensing.

12.15 Lights (ATA 33) (L3)
External: navigation, landing, taxiing, ice; Internal: cabin, cockpit, cargo; Emergency.

12.16 Pneumatic/Vacuum (ATA 36) (L3)
System lay-out; Sources: engine, compressors, reservoirs, ground supply; Pressure control; Distribution; Indications and warnings; Interfaces with other systems.

12.17 Integrated Modular Avionics (ATA42) (L2)-
Functions that may be typically integrated in the Integrated Modular Avionic (IMA) modules are, among others:
- Bleed Management, Air Pressure Control, Air Ventilation and Control, Avionics and Cockpit Ventilation Control, Temperature Control, Air Traffic Communication, Avionics Communication Router, Electrical Load Management, Circuit Breaker Monitoring, Electrical System BITE, Fuel Management, Braking Control, Steering Control, Landing Gear Extension and Retraction, Tyre Pressure Indication, Oleo Pressure Indication, Brake Temperature Monitoring, etc Core System; Network Components.

12.18 On Board Maintenance Systems (ATA45)  (L2)
Central Maintenance Computers; Data loading systems; Electronic library system; Printing; Structure monitoring (damage tolerance monitoring)

12.19 Information Systems (ATA46) (L2)
The units and components which furnish a means of storing, updating and retrieving digital information traditionally provide on paper, microfilm or microfiche. Includes units that are dedicated to the information storage and retrieval function such as the electronic library mass storage and controller. Does not include units or components installed for other uses and shared with other systems, such as flight deck printer or general use display
Typical example include Air Traffic and Information Management System and Network Server Systems
Aircraft General Information Systems;
Flight Deck Information System;
Maintenance Information System;
Passenger Cabin Information System;
Miscellaneous Information System;

How Helicopter Flies

Although my focus is on avionics and electrical systems, I do need to have some knowledge on other systems. As one of the module covered in the blog is EASA part 66 module 12, which is about rotorcraft systems, some knowledge of helicopter aerodynamics is necessary.

For my shared learning, I enclose a video on how helicopter flies.



 The concept of directional control
There are only two set control surfaces that dictate the flying direction of the helicopter.
- The main rotor
- the tail rotor.
By changing the effective forces of the main rotors, determines the direction of the helicopter.

The effective forces on the main rotor can be changed by following factors:
1. The speed of the rotor
2. the angle of attack
3. the gyroscopic effect
4. the differential forces between the blades.

If both of the rotor provide equal force, then the helicopter will just move vertically up. This is done by the collective control lever.

Let say the lift is more at 3 o'clock. It appear that the helicopter would lean to the left and bank to the left. But gyroscope property will shift the lift by 90 degrees, thus the helicopter will pitch down.

Module 12 Avionics Topics

As this blog is focusing on electrical and avionics, I have to decide which topics are included. To the students, this is not an issue as they have to do the whole topics of module 12.

A. Electrical Topics -(Level 3)  To be taught by instructors with Electrical License under Section L
a. Module 12.8 -Electrical Power (ATA 24 level 3)
- Batteries installation and operation
- DC Power Generation
- AC Power Generation, voltage regulation
- Ground Power
- Emergency Power, Invertor, rectifier
- Power Distribution, transformer,

b. Module 12.10 - Fire Protection (ATA 26) - Include topics on the detection of fire and smoke, Fire extinguishing system and System Test.

c. Module 12. 15 - Lights (ATA33) External Light - Navigation, Landing, taxi and Ice, Beacon
                              Internal - Cabin, cockpit and cargo.
                              Emergency - Doors and Floor


B.  Instruments and Avionics System
a. Module 12.7.1 Instrument System (level 2)
b. Module 12.7.2 Avionic Systems (level 1)

C. Latest Avionic Sysems
a. Module 12.17 - Integrated Modular Avionics  (ATA 42 Level 2)
b. Module 12.18 - On Board Maintenance Sysem (ATA 45 level 2)
c. Module 12.19 - Information System (ATA 46 level 2)

Induction Motor - How it works

Induction motor is commonly used in the aircraft. It is robust, simple and can last a long time.

Principle of Operation.
It works on the principle of rotation magnetic field, the stator is connected to the 3 phase power supply, and the rotor consist of a caged aluminium bars. Current is induced in the rotor which flows in the cage to form electromagnet. The rotor will follow the rotation of the stators field.

Rotating magnets formed by 3 pairs of stator windings connected to the 3 phase AC power.

The 3 phase supply offers the natural 3 phase rotation field.









Construction

Take note of the 2 major parts of the induction motor, the rotor and the stator. The stator is fitted with 3 pairs of windings, correspond to the the phases, A,B and C. The rotor consists of copper bars joined at both ends.

The Operation
When the star windings are connected to the 3 phase supply, the winding A and A1 will form North and South poles. You can imagine the north pole start at winding A, than it moves to pole B and next to the pole C.


Youtube Video