SESSION-7 AT SOAR BY AVEMBSYS

       The SDLC has four phases namely Analysis,Design,Development and testing .After each phase the product under development is sent to the client for approval.The client at this stage can request for change(RFC).These changes should be incorporated and then tested.Once Analysis phase is over,its output is a SRSD(Software Requirement Specification Document) which is sent to the client for approval.
                                   The different software development models use are:

1. Waterfall Model
2. Spiral Model
3. V Model

Waterfall Model
               The waterfall model is so called because of the cascade from one phase to another.In this model the following phase should not start until the previous phase has finished.The problems with the analysis phase are identified in the design phase and problems with design phase are identified in the development phase and so on.
Advantages:

• Provides certainity
• Documentation is provided at each phase

Disadvantages:

• Difficult to respond to changing customer needs.

Spiral Model
              Rather than representing the SLDC phases in a sequence this model allows backtracking from one phase to another.Each spiral represents a single phase.The number of spirals shows the level of development.

V Model
               This model is used for machine critical embedded systems.At each phase of the SDLC the corresponding test cases are identified and noted.After the testing phase each of these test cases are tested.At every stage the client requirements are tested.


Then we discussed about the SRS(software requirements specification) for aircraft landing schedules and high level design document.
Airports and Airspace
The airport consists of:

1. Runways-the path where aircrafts run,to takeoff and land.It may be paved or unpaved.The runways are numbered using the magnetic heading.The default is the North Pole.Nmae of the runway is one-tenth of the magnetic heading.Every runway has two numbers.

Standard traffic pattern:

• Downwind leg
• Base leg
• Final approach
• Departure leg
• Crossing leg

The windsock is used to determine the direction of flow of wind.
     2.Taxiway-These are the links between runways and the airport parking areas.
     3.Airport Signs-There are six basic types of signs

• Mandatory
• Location
• Destination
• Direction
• Information
• Runway distance remaining

    4.Lighting systems

• Approach light systems
• Runway edge systems
• In runway lighting
• Taxiway lighting
• Airport beacon
• Visual Approach Slope Indicator(VASI)
• Precision Approach Path Indicator(PAPI)

     5.Controlled airspace

• Class A
• Class B
• Class C
• Class D
• Class E
• Uncontrolled airspace:Class G

Special Airspace

• Prohibited area
• Restricted area
• Warning area
• Military operations areas
• Alert areas
• Controlled firing area

ILS Categories

• Precision

        Cat 1
        Cat 2
        Cat 3:Cat 3A,Cat 3B,Cat 3C

• Non-precision

SESSION-6 AT SOAR BY AVEMBSYS

                                   The  6th session was on 17th JAN 2011.The session started with discussion on bugs in the programs and also  finding the bugs and correcting bugs.The topic we discussed is software development life cycle (SDLC).It is consist of various steps.It is a  process of developing  a software.

The phases in SDLC are

• Analysis (10%)
• Design   (20%)
• Implementation (20%)
• Testing (50%)

Analysis:

In this phase we try understanding the problem by preparing questioners, eliciting requirements from clients, business analyst  and we understand the requirements,  then check for feasibility both technically  and commercially . The output of this phase is Software Requirement Specification Document (SRSD). SRSD is then sent to client for approval.

Design:

 We choose the software development model that would be suitable for the development of the system  and set design goals.

It is of 2 types

1. High level Design
2. Low level  Design

Output of HLD is HLD Document and output of LLD is LLD Documents which are again sent to client for approval.

Implementation:This phase involves translation of design to programming code.  The code needs to be efficient and reusable.
Testing: The test cases are written and tested with respect to system.

SESSION-5 AT SOAR BY AVEMBSYS

     On 11th January 2011 we had our 5th session.The session began with introduction to operators, its precedences , its associativity and also branching and looping constructs in C were discussed by one of our friend.Then  our Tech-lead started  with the introduction of Avionics.Avionics is basically a combination of all electronics and electromechanical system and subsystems installed in an aircraft or attached to it.Avionics must be integrated in the conceptual design phase in the design of an aircraft. Aircrafts can be further classified as follows

1.Aircraft with ejection 

    Civil Aircraft [probability of catastrophic failure<10-9/flight hour].

2.Aircraft with ejection 

    Fighter Aircraft [probability of catastrophic failure<10-7/flight hour]

Then we discussed the various requirements of the avionics.The Avionics system requirements are as follows

1.Safety of flight

2.Mission of aircraft

3.Life cycle cost/cost of ownership

4.Certification is a major factor in avionics

Some important Abbreviations in Avionics were discussed and these are :

 1.FAA - Federal Aviation Administration

 2. DGCA - Director General of Civil Aviation 

 3. CEMILAC - Center for Military Airworthiness Certification            

A model of an Aircraft was shown to us  with its important features marked.

1.  GPS : Global Positioning Satellite
2. IFF : Identifying Friend or Foe. 
3. MLS : Microwave Landing System
4. Weather RADAR
5. Glideslope : Part of an ILS system
6. DME: Distance Measuring Equipment for giving the pilot an approx measurement of the slant distance from the runway.
7. Marker beacon: Mostly installed at both the ends of the runway, provides information to the pilot about the height, distance etc during final approach in low visibility (outer marker), during missed approach (middle marker) and during arrival at the runway beginning (inner marker).
8. VHF: Very High Frequency.
9. ATC transponder: A transmitter responder that interacts with RADAR frequency on ground giving the details about the A/C  positions.
10. TCAS
11. Radio altimeter: Tells the height of the plane.
12. Military VHF
13. Line TV

The next discussion in the session was about the Aircraft systems that are common to all the aircrafts.

•  Navigation
• Flight Control
• Engine Control
• Flight Management 
• Subsystem Monitoring and Control.
• Collision Avoidance.                     

The session then continued with more about the Aircraft Systems that are used specifically in the Military Aircrafts.

         1.Radar, Infrared and other target systems.

         2. Weapon Management.

         3.Electronic Counter Measures.

         4.Mission Planning.

         5.Formation Flights.

There was a brief about the Regulatory and Advisory Agencies in the Aviation Industry. These Agencies are:
         ICAO – International Civil Aviation Organization
         FAA – Federal Aviation Administration
         FCC – Federal Communication Commission
         RTCA – Radio Technical Commission for Aeronautics
         DO-178B : Software Considerations in Airborne Systems and Equipments
         DO-254 : Design Assurance Guidance for Airborne Electronic Hardware
         ARINC – Aeronautical Radio Inc
         EORACAE – European Organization for Civil Aviation Equipment

Two types of avionic Systems were discussed.

   Enhanced Ground Proximity Warning System (EGPWS)

   There are seven modes of EGPWS, and these modes are.

1.  Excessive Descent Rate.
2.  Excessive Closure to Terrain.
3. Altitude Loss after Takeoff
4. Unsafe Terrain Clearance
5. Excessive Glide slope Deviation.
6. Advisory Callout/ Bank angle
7. Wind Shear Alerting

     The next system discussed was the TCAS(Traffic Collision Avoidance System).It has two types of alerts:

•        Traffic Advisories(TAs)-assist pilot in the visual search for intruder aircrafts.
•        Resolution Advisories(RAs)-resolve potential mid-air collisions.

SESSION-4 AT SOAR BY AVEMBSYS

                                       The 4^th session on 7^th Jan 2011 was started with an introduction of the 8051 Micro controller.After that we discussed on assignment given to us.After that we started with detailed discussion about aircrafts and their various classifications.The early aircrafts were the Ornithopter(Leornado Da Vinci,1500),Lighter than Air-Craft(Fransesco de Lana,1670),Airplane(George Cayley's Model,1804),Glider(Otto,1896) and the first successful airplane by the famous Wright Brothers.

                                       After that discussions were done about the features over which the  aircrafts are classified  which includes the following
1.Space Of Operation which calssifies the aircraft as Aircraft ,Spacecraft and Space shuttle.
2.Propulsion Mechanism which categorizes the air craft as Proppeled and Unproppeled crafts.
3.Crew which divides the aircraft as Manned and Unmanned flights.
4.Wings  which separate the aircrafts as Fixed wings type and Rotary wings type.
5.Number of Wings which sorts the aircraft as Monoplane , Biplane and Triplane.
6.Landing Mode which includes Land , Sea and Amphibians.
7.Engines which makes the division as Proppeler , Turbofan and Turboprop.
8.Number of Engines which categorizes it as Single , Twin and Multiple.
9.Function which classifies aircraft as Fighter , Bomber and Transport.

Various special type of aircrafts were also shown to us such as Reconnaissance,Airborne warning and control system (AWACS), Microplane, Aerial Refuelling, Vertical Takeoff, Stealth and Aircraft Carriers.For a break in all these facts, we discussed about lighter topics like the UFO's,science fiction becoming reality and the Bermuda Triangle.The high turbulence in this area and the unusual magnetic anomalies have caused 50 ships and 20 airplanes disappear.

                                      Then we were shown the video of the air crash involving Aviance Flight 52 scheduled from Bogota to New York via Medellin in which eight of the nine crew members and 65 of the 149 passengers on board were killed.The crash happened due to lack of fuel at the end of a misunderstanding of the situation by the ATC at New York and the ATCs that were transferring the flight’s control from its region to another. This case study made us understand the importance of specific words that must be used in Aviation and the unusual lack of efficiency in the manual air traffic scheduling systems in case of emergencies that are unpredictably led to a disaster.

We then discussed on the working of ILS system. In order to land the Aircraft, it must be perfectly aligned to the center of runway.How can this be done? Here comes the ILS antenna! A neat technology which sends two signals of different frequencies where the join of these signals correspond to the center of the run way. This is used for both the lateral and vertical guidance. The lateral guidance aligns the aircraft with the center of runway and vertical guidance aligns the aircraft with the glide slope.

SESSION-3 AT SOAR BY AVEMBSYS

                             After a long  break the AVEMBSYS  session  started  again  on 5th  January 2011. The  session  started with discussion on basics of  C  programming by our friend.After that sir gave  us  idea  about  electronic  warfare  in  that we  came to know how a pulse of  high density  electromagnetic wave is used to destroy the enemies electronic devices. Then we moved to the  basics of aerodynamics which included basic concepts of mass , force momentum, moment ,couple, density, temperature, viscosity  and how viscosity increases  with  increase  in  speed.   After  that  we  got  an  idea  about  the static  stagnation and  gauge pressure. In  that  gauge pressure/absolute  pressure that is pressure at  a point static pressure which refers to measure of purely random motion  of  molecule  in gas, and  total/stagnation   pressure  which points to  pressure  at a point where  the fluid element is slowed down to zero.Then we came to know about PITOT tube  and  its  principle and how it is used for the measurement of the speed of the aircraft. After that we  discussed concepts related  to gas such as gas law, isothermal process , adiabatic process. And  then  we came to  know  about different types of altitude  Pressure ,True or Sea Level altitude  and Absolute. Then  we discussed on  aircraft attitude ,center of gravity,aerodynamic   center,center of pressure.After that we came to know about MACH NUMBER which is a measure of   speed of the aircraft.Which is  the ratio of speed of the body and speed of sound.Then details were given about how an aircraft fly and how it produces the lift ,came to know how the shape of the aircraft helps to produce sufficient lift by creating low pressure at the bottom and high pressure at the top,and also how an aircraft produces  thrust by using a jet engine which emit a fast stream of fluid in opposite direction.Next we learnt about the various parts of the aircraft. How  the  lift  is created, also how rotate, drag, adjust in the lift  and the six degrees of freedom were demonstrated with a diagram  showing the various parts such as flaps, slats, wings, spoilers, rudder, aileron etc.Discussions were done   over  lift  coefficient  and how lift first  increases with angle of attack and after certain angle  it starts decreasing.The different  moments  acting  on the aircraft  were  seen as  Pitching,  Rolling  and  Yawing.
The  Session  ended  with a video about how the VTOL which is Vertical Take-Off and Landing.After that    we discussed about cloud burst , air pockets.The 3rd session winded with a video of the crash of French airbus A320.A discussion of the projects preceded the end of the session.The students  who were  interested  in hardware were given an assignment to work on the Transceiver system using an 8051 Micro-controller and also developing a sensor to detect the crossing in range of it.As for the software students we were given a brief about the Software Development Life Cycle and the V-Model that is being used on to develop Critical Systems.