Tuesday, July 31, 2012

Module 5 TCAS

One of the system installed on a modern passenger aircraft is the TCAS. It stands for Traffic Alert and Avoidance System. As the name indicates, it consists of at least two functions, to alert of the traffic or another flying aircraft and a system to avoid the disaster.

It has an historic reasons for the introduction of the TCAS. In the earlier period of aviation history, the number of aircraft in a given area were small, so there was lesser chance of mid-air collision. However, aviation had grown by leaps and bounds, nowadays the traffic density is high and the separation between aircraft is a matter of concern to the authority. The history of mid-air collision such as the Saudi Arabian Airlines and Kazakhstan Airlines in 1996 which killed 349 people had convinced the authorities to make the system mandatory.

ICAO annex 10 was modified to make it mandatory for all aircraft above 5700 kg to be fitted with TCAS
TCAS operates like a secondary radar, scanning the area around the aircraft. The system consists of two antennae, TCAS receiver transformer and Indicator. Most of the aircraft will use the existing display such as the EHSI. One of its set back is, the aircraft can only be detected if it is fitted with TCAS, that mean, aircraft below 5700kg are not visible.


Material from the internet Traffic Collision & Avoidance TCAS

Basic Tools for Electricians

The electrician will need a variety tools to work on the aircraft wirings.

Electronic Instrument System Module 5.1

I am transferring all my posting from previously modular blog for part 66 into one integrated blog to get a better online presence. The video was created by a training school to give the pilot the first taste of glass cockpit. It appear that it is a PC simulated software. I was a bit uncomfortable to see that the EADI has a patch of white patches on the 'blue sky'.

Sunday, July 29, 2012

Module 5 ECAM

On of the panels in the modern aircraft using the glass cockpit is the ECAM. The other two are the Primary Flight Display and the Secondary Flight Display. ECAM stands for Electronic Centralised Aircraft Monitoring. Used by airbus to display engines parameters and system status. Boeing use the same concept and called it EICAS. The display consists of 2 electronic panels situated in the middle between the pilot and the co-pilots panel.

One of the better way to understand its operation is to see the panel in action


Saturday, July 28, 2012

Module 4 Electronics Fundamental Resource

EASA part 66 Module 4 is for Electronic Fundamentals. It covers the basic of the electronic elements such as..
- the basic of semi-conductor
- basic electronic components such as diodes, transistors, tryristors etc
- integrated circuits, printed circuit boards, large scale integration etc.

It also include the non-electronic elements of servos and positions transmission devices such as transducer, transmitter.

I had traced some online resources, unfortunately it cannot be downloaded

Electronic Fundamentals Module-4 EASA Part-66

Friday, July 27, 2012

Module 5 Central Management System

An aircraft has so many systems that often interact with each other. As such a centralized system is install to capture the data from various aircraft system, store it and make it available for various usage.  Like many Data Management Systems, You may divide it into 4 subsystems:
1.      Acquisition:  The process where the data are captured.
a.       EICAS/ECAM – where the operation data are processed and displayed
b.      Flight Data Recorder (FDRS) mandatory data are recorded for investigation purpose.
c.       Central Maint System (CMS) – monitor BITE data for record of system failures
d.      Aircraft Condition Monitoring (ACMS) – record operation data to monitor engines and aircraft performance.

2.       Consolidation – 2 or more data to be consolidated.
a.       Normal – ECAM display data, ACMS and FDRS permanently recors
b.      Anomaly – ECAM displays anomaly, CMS records BITE system failure.
3.       Retrieval – How do you retrieve the data.
a.       MCDU – multipurpose Control Display Unit in the cockpit
b.      ECAM/EICAS displays in the centre panel.
c.       Download System
d.      ACARS
e.      FDR


4.       Analysis
a.       Minor trouble shooting with the help of EICAS/ECAM, CMS  (via MCDU and ACARSA)
b.      Major trouble shooting with CMS and ACMS
c.       Long term monitoring through ACMS and FDR.


Built In Test Equipment (BITE)
The LRUs such as computers, sensors, actuators, probes etc  are monitored by computers. These LRUs cab be tested for trouble shooting. Part of the computer is allocatted to do the BITE test. In some multi- computer system, a dedicated computer is allotted for this purpose.

Under normal operation, the system monitors faults.
-          Fault detected – either permanent or intermittent
-          Isolation – The BITE able to detect and capture the moment of failure. The failed LRU is suggested.
-          Memory – non volatile memory
-          Concept – the fault  memory sent to centralized maintenance devices. The test can be done from centralized maintenance panel.
o   Main advantages
§  Single interface (cockpit)
§  Easy fault indentification
§  Simplify documentation
§  Standardize equipment.

TEST
1.       Power Up Test -  The safety test  executed on ground after long power cut. If in flight the power up test is limited in order not to interfere with the operation.
a.       Typical test
                                                               i.      Test microprocessor
                                                             ii.      Test memories
                                                            iii.      Test ARINC 429
                                                           iv.      Test  I/O circuit

2.       Cyclic Test – Carried out continuously. It does not affect operation.  E.g watchdog test – where it restart the operation of a microprocessors.

3.       System Test -  For ground staff to test the system

4.       Specific Tests – Generate simulated signal to the aircraft systems. E.g move control surfaces.



Central Maintenance System (CMS)
1.       Also known as Centralized Fault Display System. It consists of 1 or 2 CMC computers and a/c BITE system
2.       CMC  interface  with…
-          MCDUs
-          Printer
-          ACARS
-          Data Loader (MDDU)

3.       CFDIU ( centralized fault display interface unit)- Scan the buses for fault, if the BITE fault is detected, the CMC and CFDIU copy and store it.
4.       Printer – Most of the CMS reports can be printed. This is PFR post flight report.
5.       ACARS
6.       MDDU – multipurpose disk drive unit.






Condition Monitoring (aircraft condition monitoring system)
Used to monitor engine and Apu performance and for trouble shooting. Retrieved through MCDUs.
1.       Architecture – consist of…
a.       DMU – Data management unit - collect and process data
b.      FDIU – flight data interface units – part of the DFDR system  that sends some of the DFDR  data to DMU.
c.       DMU functions of SAR - 
d.      DAR – Digital ACMS Recorder
e.      MCDU – online display, list of SAR files and request SAR/ DAR records
f.        Printer –
g.       ACARS


                                                                                                                               



Ground Support Equipment (GSE)

Data Loading
The uploading and download can be done either with MDDU – multipurpose disk drive or portable data loader.
MDDU operate in two modes, auto and manual.
-          Auto – for down and upload.
-          Manual – for down load.

MDDU consists of
-          Power supply, inputs and outputs devices, Disk drives
-          LCD windows
-          Protective door.


DATA LOADING SYSTEM

  Electronic Library
-          Part of the efforts towards paperless operation.
-          Data for flight crews, maintenance and cabin crews, organized in task oriented
-          Linked to the onboard maintenance system for a better trouble shooting.
-          The ground operations have extensive use of information management system.     

Introduction To Basic Instruments

Module 5 is about Digital Technique and Electronic Instruments for the EASA part 66 category B1.1.

I was glancing the syllabus for B1.1, I noted that the Basic Instrument is not included. To understand the Electronic Instruments, it is important to understand the basic instruments.

FAA provides a short note on the introduction to the topic. http://www.faa.gov/library/manuals/aviation/instrument_flying_handbook/media/FAA-H-8083-15A%20-%20Chapter%2003.pdf

The Topics Covered are:
A. The traditional Flight Instruments...
- Pitot Static Instrument - the ASI, altimeter and vertical speed.
- Compass -direct reading and remote reading compass
- gyroscope  instrument - the vacuum driven and electrical driven.
                                     - artificial horizon and the ADI


B. The paper also touches on the modern instruments and the glass cockpit.
- The PFD and Navigation Display.
- The GPWS and TCAS.



.



.
The paper is intended for pilot, but it is detail enough to give the understanding for maintenance staff. Moreover, understanding of how the instruments are used by pilot will give the aircraft engineer or mechanics a clearer understanding, as all these instruments have one thing in common, they are designed for pilots.

I find it odd that the Part 66 Modules for B1 Category of License exclude the topics of basic instrument. I consider the study of the following groups of instruments are necessary:
- pitot static instrument - covering altimeter, IAS and vertical speed indicator.
- gyro instruments - Artifical Horizon and HSI
- Compass - the direct and remote reading compass.  

Another site provides powepoint presentation which can be used for a class. 
Aircraft Instruments

Thursday, July 26, 2012

History of Microprocessor

The microprocessor is the enabler of modern electronics.The man on the street will be amazed on the minute size of the electronic components. Millions of parts can be assembled into an area as small as a 10cent coin. Microprocessor is the basic of making the computer. This short video is about the history of microprocessor..

Subtopics of Module 3

Module 3 is for Basic Electrics. It is one of the 13 modules that a student going for EASA B1-1 license. It is divided into 18 subsection following the system in part 66 under EASA. The topics will as follows:
1. Electron Theory
2. Static Electricity and Conduction
3. Electrical Terminology
4. Generation of Electricity
5. DC sources of electricity
6. DC Circuits
7. Resistance and Resistor
8. Power
9. Capacitance and capacitor
10. Magnetism
11. Inductance and Inductor
12. DC Motor/ Generator Theory
13. AC Theory
14. RCL Circuits
15. Transformers
16. Filters
17. AC Generators
18. AC Motors