Session 7 @ SOAR by Avembsys

 

This session was held on 19th January. The topics of discussion for the day was Airports and Airspace which includes Runways, Taxiways, Airport Signs, Lighting Signs, Controlled Airspace, Flight Information, Air Traffic Controller(ATC)  and ILS.

 

Initially the session began with introduction to structures.  The SME then took over the session and discussed different software development models such as Waterfall model, Spiral model and V-model its advantages and disadvantages. Waterfall model can be suited to software projects that are stable, Spiral model suites large projects or products and V-model can be used for mission critical embedded systems.

Runway:  Is an area where the aircraft lands or takes-off. Every runway has two numbers, runway number is generally one tenth of the magnetic heading.  Ex: runway numbered 09 points east(90 degree) and 27 points west (270 degree).  When there is parallel runways, each runway is identified by appending Left(L) or Right(R).  The different traffic patterns are Downwind leg, Base leg, Final approach, Departure leg and Crosswind leg. Wind sock tells the direction of flow of wind. 

Runway types: Visual, Non-Precision and Precision.

Taxiway: Is a path in an airport connecting runways with ramps.

Airport signs:

 

-> Mandaroty

-> Location

-> Direction

-> Destination

-> Information

-> Runway Distance Remaining

Lighting System:

-> Approach Light System

-> Runway Edge Light System

-> In Runway Lighting

-> Taxiway Lighting

-> Airport Beacon

-> Visual Approach Slope Indicator(VASI)

-> Precision Approach Path Indicator(PAPI)

Controlled Airspace: Is an aviation term used to describe airspace in which ATC has the authority to control air traffic, the level of which varies with the different classes of airspace.

Class A, Class B, Class C, Class D, Class E are referred as Controlled Airspace.

Uncontrolled Airspace: Class F and Class G

Special Airspace: Prohibited area, Restricted area, Warning areas, Military Operation areas, Alert and Control Firing areas.

Then moved on to ATC, use of Radar, Automated Radar Terminal System(ARTS), ILS, Different Landing Aids based on Cloud Ceiling and Visibility.

 

In this session we got to know the different avionic terms used, the session was informative and interesting.  Eagerly waiting for the next session.

Session 6 @ SOAR by Avembsys

The sixth session was held on 17th Jan and the session began with discussions on bugs(error on the part of the programmer), debugging  of certain sample codes  and efficient way of programming.  The topic of discussion for the session was software development life cycle(SDLC) which includes various phases in development of a software.  The amount of time spent in each phase differ based on the type of system being developed.

Phases in SDLC:

• 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 ( fills the gap between engineers and client) and we understand the requirements,  then check for feasibility both technically (limitations with current technologies) and commercially ( commercially viable). The output of this phase is Software Requirement Specification Document(SRSD).  SRS is sent to client for clarifications, the client may return request for change(RFC)  if any. 
Design: We choose the software development model that would be suitable for the development of the system  and set design goals. High level design document and Low level design document are also prepared. HDD includes algorithms, flowcharts and block diagrams. LDD includes data structures, logic and functions.  The design should be flexible and  reusable.
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.

This session was very much helpful in understanding how exactly a system or software  is developed in industries.  Eagerly waiting for the next session.

Session 5 @ SOAR by Avembsys

The fifth session began with introduction to operators, their precedences and associativity, branching and looping constructs in C were discussed by one of our friend.  The SME then took over the session and queried about the progress in the projects assigned to us.  The discussion continued, with introduction to avionics, avionic systems, its requirements, regulators and advisory agencies and examples of avionics system.
 
Avionics is the combination of electronic and electromechanical system and sub system installed in an aircraft or attached to it.  Avionics must be integrated in the conceptual design phase.  Avionics system requirements are as follows:

• Safety of flight
• Mission of aircraft
• Life cycle cost/cost of ownership
• Certification is a major factor in avionics

Federal Aviation Administration(FAA) certifies civil aviation in U.S,  Center for Military Airworthiness and Certification(CEMILAC) certifies military aircraft.  Avionics placement on Multipurpose aircraft includes GPS, Military IFF, MLS, DME (distance measuring equipment), ATC transponder, Radio altimeter, VHF, ADF(automatic direction finder), TACAN, UHF SATCOM. 

 Avionics System in all aircraft:

• Navigation System
• Communication
• Flight Control
• Engine Control
• Flight Management
• Sub system monitoring and control
• Collision Avoidance
• Weather Detection
• Emergency Location Transmitter(ELT)

Avionics System in military aircraft:

• Radar,Infrared and other target sensors
• Weapon Management
• Electronic Countermeasures
• Mission Planning
• Formation Flight

Regulatory and Advisory Agencies:

• ICAO   (International Civil Aviation Organization)
• FAA     (Federal Aviation Administration)
• FCC      (Federal Communications Commission)
• RTCA   (Requirements and Technical Concepts in Aviation) 
• ARINC (Aeronautical Radio Incorporated)
• SAE      (Society of Automotive Engineers)
• IEEE    ( Institute of Electrical and Electronics Engineers)
• JAA      (European Joint Aviation Authorities)
• EUROCAE (European Organization of Civil Aviation Equipment)
• DGCA   (Directorate General of Civil Aviation)

Aircraft and Mission drive the avionics system design.  Mission Segment(Taxi, Take off, Climb, Cruise).  Functional decomposition can be as follows:

• Mission
• Mission Segment
• Segment Requirement 
• Aviation Requirement

Avionics system interact with four types of data: Fresh and Valid, Fresh but Invalid, Stale but Valid and Stale and Invalid. Every 50msec data is retrieved from sensors.  We also saw certain professional codes and the standards used for professional coding such as AIRBUS C Coding Standard which is one of the highest standard. 
 

Examples of avionics system: EGPWS and TCAS

EGPWS  (Enhanced Ground Proximity Warning System) is a system designed to alert pilots if their aircraft is in immediate danger of flying into the ground or an obstacle.

7 modes of EGPWS:

• Excessive descent rate
• Excessive Closure to Terrain
• Altitude loss after Take off
• Unsafe Terrain Clearance
• Excessive glides scope deviation
• Advisory call out/bank angle
• Wind shear aircraft

TCAS (Traffic Collision Avoidance System) and the types of alerts in TCAS such as Traffic Advisories(assist the pilot in detecting the intruder) and Resolution Advisories (to resolve mid air collisions) and TCAS symbols were also discussed. The class was over all interesting and informative, eagerly waiting for the next session.

Session 4 at SOAR by Avembsys

The session began with the brief introduction to keypad interfacing and 8051 micro controller by one of our project guide. The actual topic of discussion began with the evolution and classification of aircraft. Evolution involved different attempts to flying by human, the initial techniques used gave rise to ornithopter, glider and many more... and finally, flyer was the first powered,sustained and controlled flight by Orville and Wilbur Wright in 1903.

Classification of aircraft

1. Based on space they operate:

              The commercial planes can fly upto a maximum height of 11km and it is 35km for spy planes. Space crafts usually operate in the mesosphere and its characteristics are it can generate huge thrust, instantaneous high speed, no atmospheric support for lift and fuels like kerosene are used. Space shuttles are reusable launch system which launch like rocket and land like aircraft.

2. Based on Propulsion(the way they move forward):

               -> Propelled

               -> Un-propelled

    Example for propelled is airplanes and for un-propelled is airships and gliders.  Characteristics of un-propelled is they are driven by wind, low cost and used for weather monitoring.

3. Based on Crew:

               -> Manned (airplanes) 

               -> Un-manned (UAV/RPV) 

4. Based on Wings:

               -> Fixed wing

               -> Rotary wing (highly flexible and low speed)

5. Based on type of Wing:  Monoplane, Biplane and Triplane

6. Based on landing mode: Sea, Land and Amphibian

      

7. Based on Engines: Propeller, Turbofan and Turboprop

               

8. Based on number of engines: Single, Twin and Multiple

               

9. Based on function:

               -> Fighter (high maneuverability)

               -> Bomber (usually two or more engines)

               -> Transport (commercial planes)

Special types of planes

1. Reconnaissance(high speed), AWACS (Airborne warning and control system)

2. Microplane, Aerial refueling

3. VTO (land like helicopter), Stealth (difficult to detect by radar)

4. Aircraft carriers

Some special projects like voyager(fly around the world non stop non refueled), NPA (Nuclear Powered Aircraft), Sky car, Solo Trek XFV and talks on Bermuda Triangle was interesting.

We were shown a video of the air crash involving Avianca Flight 52. It had been put in a holding pattern for more than a hour due to fog and congestion, during this it was exhausting its reserve fuel supply. The SME discussed the various reasons that gave rise to the crash such as the usage of words such as priority over emergency or using words like "MAYDAY" thrice, the lack of communication between the ATC's at different stations and due to low fuel, engine flames out and the plane lost height and struck ground.

FMS contains ACARS( aircraft communication addressing and reporting system) which is a digital datalink system for transmission of short simple messages between aircraft and ground station. An ILS (Instrument Landing System) provides a precision guidance for an aircraft approaching and landing on a runway. It contains two independent sub-systems, one providing lateral guidance(localizer) and the other vertical guidance(glide scope) to aircraft approaching a runway. The ILS antennas present near the runway transmit two signals of 90hZ and 150hz. The localizer receiver on the aircraft measures the strength of these signals, if there is any predominance of either 90hz or 150hz it means the aircraft is off the center line and need to move left or right accordingly. Eagerly waiting for next session to learn new things.

              

Session 3 @ SOAR by Avembsys

It was nice to have avembsys classes resume after a long time.  The class began with brushing of C concepts such as tokens, identifiers, data types and pointers.  The topic of discussion for the day was Aerodynamic basics and Classification of aircraft.  We also had a brief introduction to certain interesting topics such as Electronic Warfare( Electronic countermeasures involves the use of electromagnetic energy to equipment with the intent of degrading, neutralizing or destroying it), Electronic Magnetic Pulses (EMP) , Air Pockets, Cloud burst and Flight Management System (It contains waypoints i.e reference point in physical space for navigation which is fed in aircraft).

The SME discussed about  basic aerodynamic concepts such as force, momentum, moment, couple, density, viscosity (viscosity of gas increases with increase in temperature), pressure, types of pressure (absolute pressure, static pressure, total/stagnation pressure), gas laws, isothermal process, adiabatic process and pitot tube( an instrument used to determine differential pressure using which airspeed is calculated).  The session continued with discussions on Altitude(height), Standard sea level conditions, Aircraft Attitude(attitude is the angle of the aircraft reference line to the horizon), Center of gravity, Aerodynamic center and Mach Number(speed of body/speed of sound).

It was interesting to know "How does an Aircraft fly" and the principle behind it. The jet engine sucks the air and ejects it to the back which generates a thrust. The lift to the wing of aircraft is produced by the low pressure-high velocity above and low velocity-high pressure below the wing. To stop aircraft i.e during landing first spoilers are ejected and then thrust reversal takes place. The forces acting on aircraft are thrust(left), lift(top), drag(right) and weight(bottom). Certain keywords like pitching, yawning, rolling, angle of attack and VTOL(vertical take off and landing) were discussed. Some parts of aircraft such as Fuselage, Flaps, Aileron, Elevator, Rudder, Spoiler, Stall were also discussed in detail.

The SME gave two assignments to the hardware-software group. First was wireless communication between two micro-controllers and the second was a motion or line sensors.    V Model is one of the software development model used for mission critical systems. This model was discussed in detail and this model is used for development of our software projects.  Eagerly waiting for the next session to know the project title on which we will work and to learn many new things.

 Awaited 2nd Session

The second session was much more interesting and informative. The session began with the reviews of the blogs. It was unexpected to see the Subject Matter Expert(SME) to point out every minute mistake done by us. Thanks for that Sir, as it helps us to improve our writing skills. The SME distributed the Students Orientation for Aerospace and Embedded System Requirements(SOAR) program handbook. The details provided in the book gave us a brief idea about all topics that will be discussed in the due course of the program.

The session started with discussion on the 3 aspects of human personality i.e think,speak and perform and the 80-20% rule in the industry. The SME discussed about the different standards such as  Six Sigma Standard, Aerospace Software Standard DO-178B. Missile ( Self propelled guided weapon) and its types.  A missile can be categorized based on the technique used to detect the position of the target object namely Heat Sensing missiles and Laser Guided missiles. Based on the type of missile, it absorbs the heat or the laser emitted and calculates the trajectory. Electronic Counter Measures (ECM) and Inter Continental Ballistic Missile (ICBM) were also discussed.

The discussion continued with the history of internet(ARPANET and DARPANET), Computer systems (divided into Stand Alone and Embedded Systems), Real Time Systems(divided into Hard and Soft), Spectrum of real time systems and DSP (Defense Support Program). Embedded systems (a system with computer hardware and embedded software designed for a specific purpose) and its Architecture containing four layers (Application Layer, Real Time Operating System, Embedded Computer Chip and Parent System) were also discussed.

Cruise Missile and the different system help guide for cruise missile such as:
1. IGS - Inertial Guidance System
2. TERCOM - Terrain Contour Matching
3. GPS - Global Positioning System
4. DSMAC - Digital Scene Mapping Area Correlator
was discussed in detail.

We were also taught about the landing of aircraft's based on the head wind, tail wind and cross wind using approaches such as TOGA( Take Of Go Around) and Crab. TCAS (Traffic Collision Avoidance System) , ILS( Instrument Landing System) systems and a computerized display containing four parts Airspeed,Altitude,Attitude and Horizontal Situation Indicator(HSI) were also taught.


We where also showed certain videos such as the top 10 scariest landings, the mid air crashes and many more. But the landing of US airways on the Hudson river and the mid air crash video took me off. There was two videos on mid air crash one aircraft with TCAS and the other without. The aircraft with TCAS had a mid air crash because the pilot had confusion which to follow between the TCAS and the ATC.

So its very important by the developers to build a product  i.e 100% right. Here comes the theme of the day " Almost right is 100% wrong " in aerospace as we are putting human lives  at risk, which is prizeless. So no compromise in the reliability and quality of the system.

The session was provided with lot of food for thought which gave about certain problems in aerospace which can be thought of as our project. Eagerly waiting for the next session to learn many new things.

AVEMBSYS - First Session

 

It was an introductory class where we were asked to tell about our self and what we expected from Avembsys. It was nice to see the CEO of Avembsys to give his views on what we told.

The session continued with brushing up of the basic knowledge on demand paging, SDLC (software development life cycle) and certain technical aspects. The concept that he put forth "Think like Engineers" by taking a small example of 'avoiding a hurt by a stone to a person walking on road' which turned into 'providing an virtual eye to the blind'   was very nice. And some students put forth their ideas about their project, which turned out to be a lot more interactive session.

The session was overall interesting and nice. Hope to gain much more knowledge about new technologies and the subject in the coming sessions.