Taneja Aerospace and Aviation limied


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Taneja Aerospace and Aviation limied

  2. 2. Acknowledgment It brings me a great pleasure to be the part of Taneja Aerospace and AviationLimited for the training period of twenty one days. It gave me the complete exposure to the outside world within a short period oftime, how acutually the theory is being applied pracitically. My special thanks to Mr. Shikhar Chaturvedi, Technical Executive ManagingDirector of TAAL, for taking a lot of pain to see that I can learn something newwhich would not be possible to get in any books. It is because of him only I have been able to prepare this report. I would also thanks to all the staffs of TAAL for guiding and teaching ussomething new which is practical. I request him to be always there to guide me and show the correct pathwhenever I need. Thank you Sir once again. 2
  3. 3. College letter/ certificate 3
  4. 4. Company’s certificate/ company letter 4
  5. 5. Abstract This is the report which has been made from the exposure which I have gotfrom the TAAL.This includes various topics such as construction of an aerodrome,communication system between ground and aircraft, production of P68C typeaircraft, manufacturing various types of products which has being used by DRDO,HAL, CAE, Indian Army, ISRO, ADE etc. For the manufacturing of these products there are various process andprocedure which has to be carried out are broadly explained with an example invarious units of TAAL. This also include the maintaince procedure which is as per the DGCA normssuch as C-Check, painting of a commercial aircrafts. 5
  6. 6. Contents:1) ATC tower. 72) Runway. 123) Indian airspace. 184) Ground handling. 225) Fuel boucher. 246) Fire tender. 267) Manufacturing of aerospace components and process shops. 288) CNC Profiler shop. 439) Paint shop. 4610) Composite shop. 5011) Avionics laboratory. 5712) Simulator shop. 5913) Aircraft engines and its components. 6014) Pnuematic system. 6615) Presurization system. 7016) Oxygen system. 7517) Air conditioning system. 7718) Aircraft Tyres. 8019) P68C aircraft. 8220) Introduction to UAVs. 9221) Bell 407 helicopter. 9722) Maintaince of A320 aircraft. 98 6
  7. 7. ATCIntroduction: ATC means air traffic control, which plays an important role for the comunnication and navigaion purpose in the field of aviation. ATC was born after the first mid air collision between two planes that had occur on 7th April 1922, over Gatewick airport, Great Britain causing the death of seven people.So the basic function of ATC is to maintain the safe distance between the two aircraft in air as well as on the ground and the safety of passenger and aircraft in air as well as on the ground is the main criteria.Brief description: ATC is important in the field of navigatioin and communiocation. Its main function is to provide sepreesion between the two aircrafts in the air as well as on the ground in order to avoid collision. Air traffic control is divided into three to four units which work in coordination with each other to provide safety of an aircraft. 7
  8. 8. ATS is air traffic surface unit which controls the movement of the aircraft on the ground control tower is the tower which gives clearance to the aircraft for the landing and take off. Approach tower is the tower which assign the higher flight level and ask the pilot to switch over to the destination approach frequency. ACU is area control unit which controls the airspace which comes before the destination of an aircraft. So aircraft must take clearance from each ACU to approch control tower.Position of ATC: The position of ATC in the airport should be in a such a way that a 3600 view of the whole airport should be available from one place.So it is at the maximum elevation from the ground.Area description which is under Hosur ATC:The whole air space of 5 nautical miles of radius is under the Hosur tower which includes air andland of the airport.This area is 3050 feet above the mean sea level.On land, the tower controls the movement of all aircraft and other vehicals such as towing vehicle,fuel tank,fire extinguisher vehicles etc, to and fro movements towards the runway.Apron area is the area where the loading/unloding of the pay loads takes place before and after takeoff and landing of an aircraft..Clearance taken by the pilot before take off: If an aircraft is towed by the towing vehicle than this is known as towing in which aircraft power is not utilized. Aircraft is towed from the hanger to the apron area or to the holding point. If an aircraft uses its own power for the movement on the ground is known as taxing. For both these types of movements the pilot must take clearance from the ATS. From the holding point the pilot must take the clearance from the ATC tower. ATC assign a particular flight level, magnetic bearing of the destination, radial code before giving clearance.Note :For HAL, radial code is BBG that is BRAVO BRAVO GOLF.For Banglore International, radial code is BIA that is BRAVO INDIA ALPHA.For Coimbatore airport, radial code is CCB that is CHARLIE CHARLIE BRAVO.This is known as radio telephony language.Information given by the controller to the pilot before take off/landing: QNH- which is Quadrateral Navigation Height. This is height of the airport from the mean sea level. This is very important for the pilot to adjust his altimeter according to QNH as this will give him his exact altitude from the ground. 1 mb of difference in pressure can cause an error of 30 feet.So controller has to give him exact QNH in terms of millibar. The time of take off and landing is the GMT and not the IST standards. Pressure at ground level. Temperature at ground level. Visibility at ground level. 8
  9. 9. Frequency used for the communication by the Hosur Tower: The frequency assigned to the Hosur tower is 129.8 Mega Hertz. Approach tower frequency of Hosur airport is 127.7 Mega Hertz.. For the communication purpose VHF band is used whose range is from 30 to 300 Mega hertz. For aircraft communication frequency used is from 118 to 136.9 Mega Hertz.Advantages of using VHF: It is used for short range of communication which is line of sight type communication. It is more immune to noise. It can accomodate more number of frequency which can be used for the communicaion.Disadvantage of using VHF: It cannot be used for long range communication.Instruments used by the Hosur tower for the communication : Transmitter: It is a device which is used to transmit the signal from the controller to the pilot Receiver: It is a device which is used to receive the signal from the pilot to the controller. Press/Push To Talk (PTT): It is used for the internal communication, commonly known as walkie talkie. Speakers: It is a device which is used to hear the sound of communication clearly. 9
  10. 10. Various instruments used by the Hosur tower: Alitimeter: It is a device which is used to measure the alitiude from the mean sea level. This instrument sense the pressure difference between the static pressure and the outside pressure and gives the reading in terms of altitude, as pressure decreases with increase in altitude. Wind monitor logger: It is a device which gives the speed and direction of wind flow over the airfield The units used for measuring the wind velocity is knots and the direction of wind with refrence from the magnetic north in terms of degree measuring in anticlockwise. Wind socks are used for the visual approach of wind which can give an approximation of the velocity to the wind flow.Reason for the runway to be in East West direction: Usually, the direction of flow of wind is from east to west or vice-versa throughout the year. Aircraft usually take off and land in the direction opposite to the direction of wind, the purpose is for the minimum usage of runway during landing and high lift co-efficient during take off. If runway is in North South direction, then aircraft will face the cross wind which will deviates the aircraft from its glide path.So pilot has to maintain its logitudinal axis along the runway axis which increase the pilot efforts to maintain the magnetic bearing.Thus to reduce the pilot effort and easy accessibility, runway is mostly in East West direction. For bigger aircraft such as 737, A319, A320 etc cross wind of 60-70 knots only will have its affect on the aircraft, while for the smaller aircraft 40 knots of cross wind is sufficient to deviates the aircraft from its magnetic bearing. But at the larger airports to handle large traffic there are both the runways present, that is main runway and cross runway which are used simultaneously.Rules of take off/landings: VFR known as visual flight rules: In this type take off and landing takes place without any help from the navigational aids. For this type, take off and landing should take place between 20 minutes before and after sunrise and sunset respectively. Minimum visibilty must be 5000 meters.. Cloud height should be above 1500 feet from the ground level. IFR known as instruments flight rules: In this type take off and landing taks place with the help of the navigational aids. For this type, take off and landing can take place at any time provided night landing system is available at the airport. With the help of ILS, take off and landing can take place even in zero visibility.Indication over ATC: It is a light indication which indicates the type of airport it is. If it is a combination of green and white, then it is a civilian airport. 10
  11. 11. If it is a combination of green and yellow, then it is a water airport such as maldives,vienam. If it is a combination of 1 green and 2 white, then it is a defence airport. If it is a combination of green, yellow and white, then it is a Helliport. These are known as beacons lights. Hosur airport has a combination of green and white light over its ATC. There is a wind direction indicator over ATC. There is a flag which may be red or green colour depending upon the traffic. If there is a red flag means there is movement of aircraft in the airfield and for every movement clearance is mandatory from the ATC. If it is green then there is no movement of aircraft and anyone can move without any clearance from ATC.Working of ATC: After the approval of the flight plan submitted by the pilot, ATC controller will give clearance for the flight with a ATC transponder to every aircraft for its flight which will be unique. The pilot will take clearance from the ATS and will report at holding point and wait for the threshold clearance from the ATC. After Clearance given by ATC, aircraft takes off and control tower controller passes it to the approach controller, who gives him higher flight level, heading, speed in tracon airspace and ask him to switch over to destination approach frequency or ACU frequency. Any controller can divert an aircraft from its actual flight plan depending on various factors such as weather,turbulence, traffic etc. Indian airspace is divided in 23 tracons and each tracon is controlled by several controllers which gets information of an aircraft with their various parameters such as flight level flight speed etc entering their airspace through a computer generated flight strip. Vice-versa happens at the time of landing of an aircraft. If an aircraft enters the indian airspace without any ATC transponder then the pilot of that aircraft will be interogated by the controller and if fails to satisfy him with the right answer then the controller can ask the Indian Air Force to ground that aircraft or shoot down it if it is threat to the Indian part in terms of security. 11
  12. 12. RunwayIntroduction: Runway is the place from where an aircraft takes off and land.It should be constructed in such a way that it can bear the sudden load without any damage.It is smoothly finished so that an aircraft does not get any jerk.Brief discreption: The runway is built with the high grade of concrete and tar with the addition of polybon to the concrete and polyurea. The runway is always free from potholes and for this bituminous material available is a non hardening asphalt/sand mixture commnly known as ―winter mix‖. There are various marking done over the runway according to the international standards. The lighting over the runway for the night landing/take off is als according to the international standards. There are various devices such as PAPI, ILS etc.is placed beside runway for the navigational aid to the pilot.Runway description: The total strip length of the Hosur runway is 2.168 Km or 7111 feet. Width of the runway is 45 meters. 12
  13. 13. This runway is capable of handling the aircraft weighings upto 57,000 kilograms. The runway designation is 09-27. It is in the east-west direction such that west end is inclined at 9 degree to the north. The centre line of the runway is white except in the cold region where it is yellow in order to avoid confusion to the pilot from the snow colour. The distance between the two successive centre strip is 25 meters. Runway is sholdered for an about 20 so that there is no accumulation of water and this is done to avoid the skiding of an aircraft in the rainy season.Runway markings: Taxiway: This is the path taken by an aircraft before and after the take off and landing respectively. Its centre line is yellow in colour. Holding point: This is the point on the taxiway where an aircraft wait for the clearance to the entry to runway provided it is clear without any obstruction. It is the main point where the entry to runway starts. 13
  14. 14. Threshold point: This is the starting point of the take off. Touch down point: This is the point from where an aircraft can touch the runway. The width of the srip is 3 meters while its length is 10 meters. The strips are on both the sides of the centre line. Aiming point: This is the point before which an aircraft must touch the ground for a perfect landing. If an aircraft touch after the aminig point the it can shoot the runway. The width of the strip is 5 meters while its length is 30 meters. The strips are on both the sides of the centre line. Touch down zone: This is an area between aiminig point and the touch down point. For a perfect landing, aircraft must touch the runway only in touch down zone. Apron area: This is the area where loading and unloading of the payloads takes places before evey take off and landing respectively.Designation: Hosur runway designation is 09-27, that is 900 to the magnetic north and it is painted at the start of the runway. The two arrow indicates the direction of take off and landing. These arrows are known as line of take off and landing.Runway and taxiway lights: The blue coloured light on both the sides of the way is the taxiway light which indicates the path for an aircraft for taxing process. There are 20 blue taxi lights at Hosur airport. Taxiway bulb is of 45 watts each and operates on single phase ac generator with constant current regulator, CCR. At first and last one-third of the runway there is a combination of two lights, that is yellow and white. The middle part of the runway has light of white colour on both sides of the runway. If pilot uses the runway 09 then he will see the yellow and white light on both the sides of the runway for the first part and only white light for the second part.At the last part he will see only yellow light which indicates that he has limited length of runway remaining for the take off.and vice -versa for the usage of runway 27 respectively. There are five white lights on both the sides of runway from both the end to indicate threshold point.These lights are known as Runway End Identifing Light System (REILS). There are in all 64 lights on runway. Runway bulbs are hallogen bulbs of 200 watts each and operates on three phase ac generator 14
  15. 15. with constant current regulator, CCR. All the lights are connected in series so that all the bulbs will have same current,so same power such that they will illuminate with the same intensity.Repair and maintanance of the runway: At the busy airport such as Mumbai, Delhi International airport, due to high traffic rate, runway is repaired and maintained after every fifty-two take offs and fifty-two landings. This is because every time the aircraft hit the runway, there are chances of the damage to th runway due to high sudden load which is due to aircraft all up weight.Visual navigational aid avialable at TAAL airport: Tri Colour Vasi: In this type the three colour indications are used to show the correct glide angle for an aircraft. If it is amber in colour, then an aircraft is above the glide path. If it is green in colour, the an aircraft is on the correct glide path with correct glide angle. If it is red in colour, then an aircraft is below the glide path with very low glide angle. VGSI: VGSI stands for Visual Glide Slope Indicator. It is same as PAPI but these four lights are arranged in the square fashion with two lights above and below. PAPI: P A P I s t a n d s f o r t h e 15
  16. 16. precessision approach path indicator.It is placed on the left hand side of the approach runway because the Captain of an aircraft seat is on the left hand side.This is placed at the threshold point. It contains four instruments which contains lenses in it which can be seen of different colour when observed at different angle.When pilot is at the approach then he will see the PAPI and if he sees the innear twored colour and outter two white colour then he is at correct glide angle of 30. If he observes the inear three red colour and outermost as white colour, then he is below glide angle, near about 2.20. If he observes all the four red colour, then he is much below glide angle less then 2.20. If he observes the inear three white colour and outermost as red colour, then he is very little above glide angle. If he observes all four white colour, then he is much above the glide path and above the glide angle.The lenses are adjusted such that they show different colours when observed atdifferent angles. The lenses are made up of concave and convex type. The PAPI has acombination of four instruments namining A,B,C,D from the innear side of therunway. The lens in A is adjust at an angle 3057 The lens in B is adjust at an angle 3037 The lens in C is adjust at an angle 2059. The lens in D is adjust at an angle 20.PASI: PASI stands for Pulsating Approach Slope Indicator. If it is pulse rating is white light, then an aircraft is above the glide path. If it is a steady white light, then an aircraft is on the glide path. If it is pulse rating red light, then an aircraft is slightly below the glide path. If it is a steady red light, then an aircraft is much below the glide path.Tri-VGSI was replaced by VGSI and again VGSI was replaced by PAPI.Now-a-days,ILS system is used inseted of PAPI.The visual navigation aid available at the TAAL airport is PAPISignal Square: It is the sign which are used for the visual approach by the pilot for the various indications for the airport. It contains four indicating symbols, they are T-shaped, dumbelled shape, aerodrome refrence point,cross signal. T-shaped sign is used to indicate the runway which is in use. The tail of T indicates that an aircraft must touch down the runway parallel to the tail part from the base. Dumbelled sign is used to indicate that aircraft should maneveure at the available space only and it should not go in the muddy area of the airport. 16
  17. 17. Aerodrome indicator is a sign which indicates the position of the aerodrome in termsof latitude and longitude.So if pilot knows the latitude and longitude of theaerodrome than he can locate and visually identify the aerodrome.Cross sign indicates that the airport is not operational and if there is only onediagonal line indicating that the airport is operational.H-indicator is the indicator which is used at the time of night landing where the bulbspresent are luminated in T-fashion an indicating the runway which is used as T-signindicating during the day time.The bulb used are all halogens bulbs and areconnected in series so that they illuminate in with the same intensity.This is present only at the one end of the runway and that is 09 at TAAL airport. 17
  18. 18. Indian AirspaceIntroduction: Airspace is defined as the space above the ground levvel which is used for the flying purpose with or without it help of the controller present at the ground.This airsapce is divided in tracons which are commonly known as zones. Each tracon is controlled by each controller sitting in ACU using SSR and some zones are controlled using PSR also.Brief description: Airspace forms an important part in the field of aviation.This is the space where an aircraft that has to fly with minimumdistance in between them of 1000 feet.The air route taken by an aircraft should be shuch that it does not intersect the other flight plan as well as it should not cross the country airspace accidently also. In case of an international or cross country flight, there should be proper route and it should not fly into unflying zone which may be used for defence or R&D purpose by that country. Airspace of the world are divided into tracons according to the country wise at an international level with accordance with ICAO. Each tracon is divided into two: Controlled airspace and uncontrolled airspace. Controlled airspace: It is defined as an airspace where flying is carried out with the help of the ground controller.This is the airspace which is under the observation by a ground controller for all the 24 hours.For flying in the controlled airspace, clearance from the ground is mandatory in order to avoid collision between the two aircraft. Uncontrolled airspace: It is defined as an airspace where flying is carried out withot the help of the ground controller.This is the airspace which is not under the observation by a ground controller for all the 24 hours but ground controller can scan this airspace also. For flying in the controlled airspace, clearance from the ground is not mandatory in order to avoid collision between the two aircraft.Indian Airspace: Indian airspace is divided into 23 tracons and each tracon is controlled by each ACU and approach tower near an airport area.In India only controlled airspace is present. So flying in India must be co-ordinated with the ground controller and without his clearance no aircraft can be airborne and has to fly within the permissible limit of an airspace. For the controlled airspace, the necessary equipments and informations which are necessary are mentioned below: PSR and SSR are very much essential in order to have aclear view of all the aircraft which is flying under their airspace. Flight information from the pilots such as quantity of fuel present, flight level, flight speed, people on board etc. Type of an aircraft, that is weather commercial, private, military, aerobatics etc. Communication system between ground controller and an aircraft present on ground and in 18
  19. 19. air. Communication system between the controllers and at the time of emegency, agency which has to be ready for the 24 hours. Communication system between the controller and another approach controller also in case of small airport like TAAL, small flying club. For every flight which takes-off from the TAAL, has to take clearance from the HAL approach and has to inform the destination approach to clear the flight level which has assigned to that aircraft and has to give all the information about that aircraft to the approach tower. Flight information are the computer genrated slips which takes the current data fron the SSR and crates a slip so that by having a look over it, controller can have a good control over the aircraft and can communicate with it at any time. The basic & main purpose of this is that controller does not have to waste time to the pilot for its current position and can be a time saving system and it is used for the safe condition of the flight.For a stable airspace, these are required to be satisfied: Conditions which has to be informed to the pilot: There are various information that has to be transmitted from the controller to the pilots are: Information regarding the weather changes Change of servicebility of facility Condition of an aerodrome Controller has to identify the flight for the monitoring it and co-ordination purpose only Pilot must not be left in doubt that they are not receiving radar services There should be a minimum sepression of 1000 feet between two aircraft according to the ICAO. Alternating service: This is the service which has to be in used in case of emergency that may be an accident or search and rescue operation and to alert the appropriate organisation regarding this. It has to provide the notification to the appropriate organisation depending upon the condition. Radar control service: This has to be provided to an aircraft by the ground controller. This depends upon the aircraft which may be operating IFR or VFR. The aircraft operating at IFR, controller can be used or cannot be used for the landing part. The aircraft operating at VFR, controller has to be used for the landing part.Classification of an airspace: There are seven types of an airspace, they are A,B,C,D,E,F,G. In this type A is more restricted airspace while G being least restricted airspace. 19
  20. 20. Type A: This is an airspace where only aircraft using IFR are allowed to fly. It needs ATC clearance before take off and landing. All the aircraft must be seperated from each other. The aircraft operating VFR are not permitted to fly in A zone. Special permissions are required for VFR for entrance in A zone.Type B: This is an airspace where aircraft using both IFR and VFR are allowed to fly. It needs ATC clearance before take off and landing. All the aircraft must be seperated from each other. The aircraft operating VFR are permitted to fly in B zone.Type C: This is an airspace where aircraft using both IFR and VFR are allowed to fly. It needs ATC clearance before take off and landing. All the IFR flights are seperated from all the VFR flights. All the VFR flights are seperated from all IFR flights. Traffic information is given to an individual aircraft only, that is VFR to VFR and IFR to IFR.Type D: This is an airspace where aircraft using both IFR and VFR are allowed to fly. It needs ATC clearance before take off and landing. All the IFR flights are seperated from all the VFR flights. All the VFR flights can be passed over the IFR flights. Traffic information of VFR is given to IFR and IFR to IFR also. INDIAN AIRSPACE IS OF TYPE D.Type E: This is an airspace where aircraft using both IFR and VFR are allowed to fly. It needs ATC clearance before take off and landing. All the IFR flights are seperated from all the VFR flights. All the VFR flights can be passed over the IFR flights and vice-e-versa. Traffic information of VFR is given to VFR and IFR and also vice-e-versa. VFR has to have clearance from the ATC before every step of flying.Type F: This is an airspace where aircraft using both IFR and VFR are allowed to fly. It needs ATC clearance before take off and landing. All the IFR flights are seperated from all the VFR flights. All the VFR flights can be passed over the IFR flights and vice-e-versa. Traffic information of VFR is given to VFR and IFR and also vice-e-versa. VFR does not have to take clearance from the ATC before every step of flying. 20
  21. 21. Type G: This is an airspace where there is no need of ATC and any one can fly anywhere in this airspace.Instrument Flight Rules: IFR permits an aircraft for the IMC, that is instrumental metrollogical conditions. IFR permits an aircraft to operate in IMC i which the it has to have the minimum weather condition compared with VFR. Procedure and training are more complex in this method and pilot has to demonstrate cross- country flying with IFR only. In this rule, pilot has to fly an aircraft with the help of instruments only and cannot have any visual help as his flight level would be high enough to see anything or to get any refrence help from the ground.Visual flight Rules: VFR permits an aircraft to fly with the help of refrence from the ground and has to solely fly only with the outside clues which permits the navigation, orientation and other aircraft also. Mini weather condition for sealling and visibility for VFR are defined as a differnt types of airspace and it depends upon the day time and night time. Thus the cloud height and visibility is very important in all phases of height In day time: VFR minimum for most airspace is 3 statute milies visibility and cloud distance must be 500 feet below, 1000 feet above and 2000 feet horizontal. The condition equal or greater than this is known as VMC, that is visual metroological condition and can be used for both VFR and IFR. 21
  22. 22. Ground handlingIntroduction: This is very important for aviation part as this is the part where aircraft is handled with the safety and the security of passengers and their luggages.In air pilot is incharge of the flight but at ground there are several people which take care of ourself to whom even we dont know.For example, airport security, the comfort level at an aircraft is also part of ground hadling and service to the passengers in all term too.Brief description: The comfort zone which has to be provided to the passengers at groud before he board the plane is the main criteria of the ground handling.This includes the cabin services. This ensures the passengers comfort, cleaning of passengers cabin, cleaning of blanckets etc. Cattering: This includes the unloading of unused foods and drinks and loading of the fresh food and drinks which includes juices, tea, coffee, wine, bear, vodka etc. Ram services: This is the services which includes the guiding of an aircraft into or out of its parking possition. Towing the aircraft with the help of towing vehicle or with the help of push back tractor. Water cart: This is the vehicle which is used to drain the seawage from the lavatory of an aircraft and filling with the frsh water with the help of water carriage. Air conditioninig system: There should be proper air conditioning at airport, bus and aircraft. GPU: This is an external power supply to start the engine and to charge all the batteries which are present in the aircraft. Luggage handling: This is the huge system which takes care of loading and unloading of luggage in and from the aircraft respectively.The luggage should always reach before the passengers arrival at the terminal. Air cargo handling; This includes the loading/unloading of all the cargo and moving it to its destination within the short period of time. Refulling and defulling: This is the system which is used to refule or defule an aircraft before and after take off and landing of an aircraft respectively. Ground power: This includes the maintainance of the passengers stairs, wheel chairs for the physically challenged people, hydraulic mulls etc. 22
  23. 23. De-icing and anti icing system: This include the system which are used for the deicing the ice at the ground surface in cold countries. Services for the passengers: Check in,customer calling, arrival terminal, departure services and information providing system to the passengers at the airport is the main part of the ground handling. Field operation services: This is the service which inclues the dispatch of an aircraft at the scheduled timewitn co- ordination of ATC.Equipments used: Ground support equipments on the ram, such as push and pull back trolleys, ladder, trolleys,catering vehicles, chock which is used to placed at the tyre of an aircraft in parked position. Non powered equipments: Trolleys and bag containers, bags cards etc. Dolly for containers and packets etc. Powered equipments: Refullers, trucks, buses, tractors, GPU etc.Electrical system of an aircraft: All aircraft requires 28 V dc power while 110 V ac, 400 Hz. 3 or 4 phase of insulating wire capable pf handling 200 A.Clearances from an ATC: For an international flight, all the aircraft coming to India must have YKA clearance from DGCA which stands for Young Key Alpha in order to enter the Indian airspace. Flight plan of every flight must be approved AAI. Slot, departure clearance will be treated as a ferry plan. Fuel BoucherIntroduction: 23
  24. 24. Fuel boucher is the container which is used for the storage of fuel which is used for aviation uses.At TAAL, the feul boucher is on lease from Indian Oil Corporation limited (IOCL). It contains Jet A1 type fuel which is used for the propulsion purpose for most of all the types of engines. The cost of this fuel is fifty-two rupees per litre which is cheaper than the petrol.Brief description: Fuel boucher is the container where the air turbine fuel (ATF) is stored and this is used for both re-fuelling and de-fuelling.The aircraft which lands at TAAL airport, is de-fueled and then only maintenance work is carried on. Once the maintenance work is completed, aircraft is again re-fueled and it is allowed to fly.The density of the fuel used for the aviation purpose is less than the density of the water.Specifcation of fuel boucher: The capacity of fuel boucher is 16,000 liters. It is internally coated with synthetic material so that it will not be in direct contact with the container which is made up of the iron. If it comes directly in contact with the iron then there are chances of the fuel to get contaminated due to the reaction of fuel with the metal. There are of two methods of de-fuelling an aircraft. Gravity and pressurize method. Gravity method: In this method the fuel is removed using the gravity force. In this type the fuel is not removed completly. It is used for the general aviation type of aircraft only and cannot be used for the larger type of aircraft. It takes comparatively more time than the pressurize method. Pressurize method: In this method the fuel is removed using the pressure pump which forces the fuel to get out of the fuel tank.This can be used for both the type of aircrafts that is general aviation and large aircraft. It takes less time and can be done quickly.Procedure of refueling/defueling: Before refueling /defueling, an aircraft and the fuel boucher are grounded in order to discharge the static electricity generated because of the circulation of fuel. The fuel can be feed with the help of fuel pressure pump, which creates internal pressure and force the fuel to move from the boucher to the fuel tank placed in the aircraft. There is NRV, non return valve which prevents the flow of fuel in both the direction. The internal pressure created should not exceed 30 kg/cm2, as it can damage the hose which carries the fuel from the boucher to the tank. Refulling/defulling is carried in such a way the static balance of an aircraft is maintained and there is no change in aircrafts centre of gravity. The fuel is stroed in the fuel tank which is placed inside the wings of the aircraft. There is provision for the pilot to move fuel from one wing to other through the cross feed valve. 24
  25. 25. Testing for the contamination: For the contamination some fuel is drained out and checked for the contamination through the naked eyes. There should not be any water molecule present in the fuel. For this, some fuel is drained out and a capusle named as ―Aqua indica‖ is used to check the presence of water molecule. If the colour of capsule changes to pink, indicating the presence of water molecules. Some times the fuel is also sent to IOCL lab for the contamination tests.According to the IOCL: If fuel is not used in a particular period of time then it must be circulated using pressure pump through the whole boucher. This will prevent the contamination of fuel from the biological growth and can be stored for a longer period of time. 25
  26. 26. Fire TenderIntroduction: Fire tender is a device which mainly contains the water in the container which can be used to extinguish the fire with the help of the pressure pump which force out the water from the tank where it is stored.It also carries carbon dioxide, foam which also can be used to extinguish the fire.The existence of the fire tender is a part of security department. The security at TAAL airport is under V5 category according to DGCA of India.This depends upon the size of the airport.At TAAL airport there are two fire tender.Brief description: Fire tender is a device which is used to extinguish the fire which occurs due to any mishap or any accidents.The fire can be extinguished using water, carbon dioxide,foam or a mixture of water and carbon dioxide or a mixture of water and foam.The fire extinguisher has a capacity to contain all these three thing at a time and has a capability to extinguish the fire within short period of time.Specification of fire tender: There are two fire tender available at the TAAL airport. The capacity if first extenguisher is 5000 liters of water it can store at one time while other has the capacity of 2000 liters of water.The small tanker is a foam tender of dry carbon dioxide. Each fire tender carries water, foam,100 kg of dry carbon dioxide. The hose which is used by TAAL fire tender is 100 meter long. As per the DGCA rules and regulations, the fire man should be at a distance of 25 meters away from the sight of accident and has to control the fire from there only. The foam tin which is used has a capacity of 50 kg. Foam is a fire chemical brand which is used to control the fire. It will produce a foam layer which will be at the bottom surface and does not allow the fire to grow any more. This can be used with both water and as well as dry carbon dioxide.Procedure of the fire tender: The fire tender vehichle are placed in a such a way that at the time of accident or any mishap it can reach the sight within a minute from that place. So at TAAl airport the fire tender of 2000 liters capacity is placed at the side of runway while the fire tender of 5000 liters capacity is placed with the ambulance at the taxi way at the time of take off and landing of every aircraft which takes place at the airport. There are two meters at the fire tender: Engine pressure and pump pressure. Engine pressure should be 100 psi and thus the water which is dispatched from the tender upto 20 meter from it. Pump pressure should be upto 15 mm of Hg. The average pump pressure is always between 10 to 15 mm of Hg. This is used to pump out the water from 26
  27. 27. the tender.There is also an input which can suck the water from the ground water source such as well,lake etc and can store this water in the tender and then it can directed to extinguish the fire.There are two gate valve and one main gate value.The two gate valve which are placed onleft and right hand side so that there can be two hose which can be used to extinguish firesimultaneously.The main gate valve is used to refill the tanker from the ground source or to drain thewhole water from the tanker through this valve.According to the rule of the DGCA there should be every tender with foam and water areplaced at a distance of 200 to 300 meters from each other depending upon the size of runwayand the frequency of aircraft landing and take offs when they are placed along the runwayside during the take off and landing.The gun fire is also used which can mix coarbon dioxide or foam with the water and help tohave control overt the fire easily and within the short period of time.One tender with an officer is always on alert at the apron area where the loading andunloading of the payload takes place. 27
  28. 28. Manufacturing of Aerospace componentsIntroduction: This is the most important and the vital section of any aircraft or a spacecraft as it has to take all the desired load as well as it must enough strength to withstand it.So the main creteria for the construction point of view is high strength to weight ratio. There are materials which can provide very high strength but add a lot of dead weight, resulting less capacity to carry the pay load.Brief description: The manufacturing of aircraft parts and its components is very important from the structure point of view.The main criteria of this section is to maintain the dead weight as low as possible and to gain the maximum strength from it.There are variety of materials available but the proper selection from it is more important from economic, manufacturing and the requirement point of view.So it depends upon the manufactures and their descission with the customers regarding the materials which has to be used from various considerations.Commonly used material and alloys are: Aluminum alloy Copper Alloy Stainless Steel Alloy Titanium Composite material Nickel Alloy Magnesium Alloy Common aerospace materials include stainless steel, titanium and copper/brass alloys. They are designed to be strong and resistant to corrosion, as well as maintain their integrity in any temperature. These steel alloys are available in sheets, wire, bars, plate and other standard forms. They can also be custom forged, whereby they are melted and pressed into a specified shape.Manufacturing of aerospace materials: Sheet metal fabrication plays an important role in manufacturing aircraft parts like Bulkheads, stringers, Stiffeners, Ribs, Skins etc. Even the casings & boxes for Avionics, Electrical & Instruments are fabricated from sheet metal. The strength to weight ratio is of prime importance. Aluminum alloy has the best strength to weight ratio due to which more than 75%of the aircraft body is made of aluminum alloy and aluminum alloy sheets & extrusions are generally used for making these parts. The grade of alloy may vary depending on its end use on the assembly. Titanium alloy & stainless steel sheet is also used to form the parts operating in heat zone at high temperatureProcess operation: While making any sheet metal part some or all the following operations are performed depending on size, shape & complicacy of the part. 28
  29. 29. Marking – First of all the size of the material/ sheet required for making the part as per drawing is marked by a marker or scriber. Lead pencils should NEVER be used on aluminum sheets, since it develops corrosion over a period of time.Shearing - The blanks are cut to the marked size with the help of shearNibbling tool – It is a hand operated tool for shearing aluminum sheets up to 1.6 mm thickness. It is good for cutting straight or curved shape as well as for cutting holes, trimming & matching.Aviation Snips – Left hand & right hand cutting snips with 90 deg. handle w.r.t. blade is used for cutting the material in tight space where material can not be turned.Hand operated slitting shear – It has long handle for applying leverage while cutting the steel sheets upto 5mm thickness.CNC shearing machine- The CNC machine is used for shearing the Aluminium sheets upto 6mm thickness, steel sheets upto 5mm thickness & stainless steel sheets upto 2.5 mm thickness.Routing— The blank is routed on routing machine to cut to the exact shape & contour of the part. Two type of routing machines are available in our sheet metal shop.a) Manual router Parts having simple cutouts, contours can be routed on manual router with the help of Drilling Routing Template (DRT) made of steel sheet. DRT is 29
  30. 30. clamped to the sheet to be routed with C clamp. Keeping DRT as reference the operator moves the DRT in the guide way provided on the routing table & cuts the sheet as per DRT b) CNC Routing machine For routing the sheet on CNC machine, the sheet is kept on the wooden bed & is clamped by using stoppers made of hylam wood. The operator cut the sheet as per the program fed in the computer.Parts up to 5mm thickness 7 lengths up to 4meter having intricate shape & contour can be routed on the CNC router.nForming – The parts are formed to achieve the specified shape/ contour as per drawing on a form block. The blank obtained from CNC router or manual router is formed into desired shape by using form block tool (FBT) . These tools are made of Hylam wood or metal. Hylam wood normally preferred over metal due to its light weight as well as easy rework ability. The blank is placed over the FBT with top plate on it & is clamped with locking pins. The blank along with FBT is then pressed either in brake press or hydraulic press or rubber pad press 30
  31. 31. Joggling- Joggling operation is performed to make the space to accommodate the part to be fitted in same level on assembly. A typical joggled part to accommodate another part is shown . The joggle can be formed with wooden tool in Al. sheets up to 1.5mm where as in sheets above 1.5mm & extrusions joggle can be formed in metallic dies with the help of hydraulic press.Rolling— A sheet is rolled between the rollers to the required contour of specified radius. sheets upto 2mm thickness & part width upto 400mm can be rolled in hand roller shown in fig. Steel sheets up to 2.5 mm thickness and Al.sheets up to 5 mm & width upto 3 meter can be rolled in manual rolling machine . This is used for rolling the skins of 1/2U & SBS assembly of VSSC. Steel 7 aluminium sheets upto 10 mm thickness can be rolled in power operated rolling machine available in sheet metal shop. This is mainly used for rolling the skins of SONC assembly. 31
  32. 32. Shrinking – It is the process of thickening of the metal by pulling it into itself mechanically with a hammer & a padded dolly. For example, imagine a car hit by a mile stone or a tree on the road. The dent formed in the body of the car due to this hit causes stretching of metal in the center of the dent by shrinking the metal on the periphery of the dent. Pounding of the metal between hammer & a steel dolly tends to thin the metal, hence a soft wooden block & hammer only should be used for this purpose.Stretching— Stretching the metal is the process opposite to shrinking. It is the process of pulling the metal apart by pulling the metal away from its center point or by pounding on the metal with a hammer on one side while holding a dolly on other side. This flattens the metal in the area being worked, forcing it to move outward in to the surrounding the metal. More stretching the metal will tear it when it becomes too thin to have any strength. The part is stretched to form a smooth groove or curve of specified dimension by flowing the material manually or by a machine. A part formed by stretching & shrinking.Dressing— The part is dressed to remove the wrinkles, waviness, unevenness from a formed part before and after solutionising. It must be noted that after solutionising the part must be hand dressed within 2 hrs. otherwise it will start attaining its original hardness & it becomes difficult to hand dress. Alternately it should be stored in cold storage to form it later. Hand dressing is done by using plastic or wooden mallet & clamping the part on bench vice or otherwise by any other clamping method.Trimming— Trimming is carried out to remove the excess material and finish to exact size as per drawing. Material can be removed using electrically operated dual hacksaw blade & later finished by filing.Deburing— Deburring is carried out to remove sharp edges, corners form a finished part with the help of deburring tools or with polish paper. 32
  33. 33. Tools used for the operations are: Shears- Different type of shears, snippers used in a sheet metal shop is shown in Fig.1. these can be used to cut thin sheets. However the thick sheets and the extrusions can be cut accurately In a manually operated shear or CNC operated shearing machine. Router – For cutting a blank to exact shape and contour , routers are used. These can be manually operated or CNC operated Machine. Bending tools— The blanks from thin sheets can be bend to any angle or shape on wooden or steel blocks or steel mandrels with the help of wooden / plastic mallets. The parts made of thick sheets or extrusions can be accurately bend in bending machine with bending tool of correct size & shape. A CNC bending machine whereas manual bending machine. Blocks— These are the blocks made of wood / hylam in exact shape & contour as per the requirement and a part can be formed on these form blocks with the help of hammer. A typical form block for a leading edge is shown in fig.6. Similarly a form block used on a stretch forming machine. Templates— These are made of steel and are used to check the contour & shape of the part formed on a form block or bend on the bending machine. Hydraulic Press— The parts from thick sheets, extrusions can be formed with the help of metallic dies or forming tools in Hydraulic press or rubber pad press . Joggling tool/ dies— The joggles to accommodate the overlapping parts in same level are formed in thin sheets with joggling tools using wooden/ plastic mallet. The joggle in thick sheet & extrusions are formed in male –female matching metallic joggling dies with the help of bend press or hydraulic press.Scnz. 33
  34. 34. Rolling Machine—The three roller rolling machine is used to roll the sheet to desired shape or radius.These could be manually operated or power operated. Mallets—The wooden/ plastic mallets are used to form / dress the part to accurate shape & contour. Deburring tools—Deburring tools / files are used for removing the sharp edges, corners & finishing the part. Press forming tools – For bending /forming the extrusions of various cross section in hydraulic press, press forming tools are used. English wheel— It is used to form the grooves, curves In the panels. It gets its name from the two steel wheels between which metal is formed. The wheels – one above & one below are rolled against each with a piece of sheet metal in between, under a pre adjusted pressure setting. The wheels roll as the sheet is moved back & forth. Stretching & Shrinking machine— A hand operated stretching & shrinking machine whereas a part being formed on pneumatically operated machine. Fluting Pliers & Hand Seamers— Fluitng pliers are used to straighten ribs, flanges & to form curved stringers. The jaws form the metal in such a way that ―shrinks‖ a small section of a flange.A coordinate measuring machine (CMM): It is a device for measuring the physical geometrical characteristics of an object. This machine may be manually controlled by an operator or it may be computer controlled. Measurements are defined by a probe attached to the third moving axis of this machine. Probes may be mechanical, optical, laser, or white light, among others. 34
  35. 35. Heat treatment & anticorrosive treatment processes: The sheet metal component has to undergo heat treatment process during the process of forming as well as after forming. The heat treatments are carried out mainly for the two metals and their alloys, they are steel and alluminium. Annealing – The blank of sheet should be annealed before forming / bending to make it soft so that it can be formed / bend easily without any defect or cracks. Thick sheets & extrusions should be annealed in between the stages to remove the work hardening otherwise the part may crack during forming / bending. The holding temperature is 4100 C for one hour in air circulation oven.adjhl Solutionising—After forming & dressing the part, it is solutionised to regain its original hardness which was removed during annealing.This is carried at the holding temperature of 5000 C for 30 miniutes, it depends upon the thickness of the sheet. Ageing—The solutionised & finished components are artificially aged to retain its hardness for long time. However materials like D16 , D19 gets aged naturally over the period and does not need any artificial ageing.The holding temperature for this is 1600 Cfor nearly 12 hours to 18 hours which depends upon the customers needs. Protective coating— Fully completed & aged parts are protected with anti corrosive treatment. Aluminium alloy parts are Anodized where as steel parts are Cad plated & stainless steel parts are passivated. Additionally all parts are further coated with etch / epoxy primer or any other primer before painting. 35
  36. 36. For steel: There are two types of hardening process is being carried out. First one is carried out in muffle furnance at 8100 C and in the second type tempering is carried out t 6300 C which depends upon the thickness, duration is decided. After solutionising, Al alloy is placed in a cold storage as between the 6 days agening has to be done. The holding temperature is just below the -150 C for 15 hours just to make it hard.Precepitation: It is an artificial form of hardening.Natural hardening: It is the hardness which has achived by cooling an alloy at the room temperature.After heat treatment it comes to the chemical shop: In this shop there are three process which is carried out for alluminium alloy, they are: Anodizing Alodine Chemical millingAnd for steel: Cadmium plating is done by electro deposition Process shopThere are many operations which are carried upon a single job in order to achive the requirement.There are various process which is done in sequence stated as below.Vapour degreasing: Chemical used: Trichloro etheylene Temperature: 750 to 870 C Duration: 2 to 3 minutes. Uses: For removing oil, grease, dust, forign particles etc.Chemical alkaline defreasing bath: Chemical used: Sodium carbonate and Trisodium phosphate Temperature: Room temperature Duration: 2 to 3 minutes. Uses: For removing oil, grease, dust, forign particles etc.Swill water bath: Chemical used: Pure water, only H+ and O- ions Temperature: Room temperature Duration: 2 to 3 minutes. 36
  37. 37. Total dissolved solids: 1000 ppm Size: 1600 x 600 x 650 mm Uses: For removing all the past chemicals and that should not pass to other bath tubs and should not pollute the chemicals.Alkaline pickling bath: Chemical used: Sodium carbonate- 20 to 30 g/l Temperature: Room temperature Duration: 2 to 3 minutes. Size: 1600 x 600 x 650 mm Uses: For mild etchingSwill water bath: Chemical used: Pure water, only H+ and O- ions Temperature: Room temperature Duration: 2 to 3 minutes. Total dissolved solids: 1000 ppm Size: 1600 x 600 x 650 mm Uses: For removing all the past chemicals and that should not pass to other bath tubs and should not pollute the chemicals.De-oxidation bath: Chemical used: Nitric acid- 20% Temperature: Room temperature Duration: 3 to 5 minutes. Size: 1600 x 600 x 650 mm Uses: To remove the oxide layer which has formed due to various heating process.Swill water bath: Chemical used: Pure water, only H+ and O- ions Temperature: Room temperature Duration: 2 to 3 minutes. Total dissolved solids: 1000 ppm Size: 1600 x 600 x 650 mm Uses: For removing all the past chemicals and that should not pass to other bath tubs and should not pollute the chemicals.Anodising Bath II: Chemical used: Chromic acid-30 to 50 g/l Temperature: 380 to 420 C. Duration: For one hour Size: 1600 x 600 x 650 mm Uses: Electro plating is carried out here. Here cathode is stainless steel while the job is anode. Main purpose is to make anti corrosion and electrical resistance. 37
  38. 38. Swill water bath: Chemical used: Pure water, only H+ and O- ions Temperature: Room temperature Duration: 2 to 3 minutes. Total dissolved solids: 1000 ppm Size: 1600 x 600 x 650 mm Uses: For removing all the past chemicals and that should not pass to other bath tubs and should not pollute the chemicals.Hot water sealing: Due to some process, porous will be created so to just fill up all the porous and make the job porous free, this treatment is carried out.Water bath: Chemical used: Pure water, only H+ and O- ions Temperature: 960 to 1000 C pH level: 5.5 to 6 Duration: 20 to 30 minutes. Size: 2800 x 1600 x 500 mm Uses: For removing all the past chemicals and that should not pass to other bath tubs and should not pollute the chemicals.Common Heat Treatments: Softening: Softening is done to reduce strength or hardness, remove residual stresses, improve toughness, restore ductility, refine grain size or change the electromagnetic properties of the steel.Restoring ductility or removing residual stresses is a necessary operation when a large amount of cold working is to be performed, such as in a cold-rolling operation or wiredrawing.Anneling— full Process, spheroid zing, normalizing and tempering— austempering, martempering are the principal ways by which steel is softened. Hardening: Hardening of steels is done to increase the strength and wear properties. One of the pre-requisites for hardening is sufficient carbon and alloy content. If there is sufficient Carbon content then the steel can be directly hardened. Otherwise the surface of the part has to be Carbon enriched using some diffusion treatment hardening techniques. 38
  39. 39. Material Modification: Heat treatment is used to modify properties of materials in addition to hardening and softening. These processes modify the behavior of the steels in a beneficial manner to maximize service life, e.g., stress relieving, or strength properties, e.g., cryogenic treatment, or some other desirable properties, e.g., spring aging.Welding: There are three types of welding carried out at TAAL factory, they are: Arc welding Gas welding Thermit welding and Resistance welding. Arc welding: In arc welding, a metaalic rod is used as a filler element and an electric current is used as a source of power with the help of transformer. TIG welding: TIG stands for the Tungsten Arc Welding. In this type of welding tungsten rod is used as an electrode and as per the requirement filler rod is selected. A gas sheild is created in this type of welding with the help of argon which helps the contact of the atmoshpheric air to be in direct contact with the job during the operation. This is used for very less thickness material and especially for non-ferrous elements can be welded easily and succesfully using this welding. Al alloys, Mg alloy, Cu alloy and non-ferrous alloys can be welded together with this welding. The filler rods usually ised for this type of weldings are Al alloy 4043 Al alloy 5356 Al alloy 5056 ST steel 347 Carbon CM steel 4130.Gas Tungsten Arc Welding (GTAW) is frequently referred to as TIG welding. TIG welding is acommonly used high quality welding process. TIG welding has become a popular choice of weldingprocesses when high quality, precision welding is required.In TIG welding an arc is formed between a nonconsumable tungsten electrode and the metal beingwelded. Gas is fed through the torch to shield the electrode and molten weld pool. If filler wire isused, it is added to the weld pool separately. 39
  40. 40. TIG Welding Benefitslding GasesArgonArgon + HydrogenArgon/HeliumHelium is generally added to increase heat input (increase welding speed or weld penetration).Hydrogen will result in cleaner looking welds and also increase heat input, however, Hydrogen maypromote porosity or hydrogen cracking.Requires greater welder dexterity than MIG or stick weldingLower deposition ratesMore costly for welding thick sections Resistance welding: In this type of welding, a resistance is created and the materials whcih has to be welded together are heated such that by applying proper amount of pressure, they are welded together. Spot welding: In this type of welding with the help of high electric current, the two materials are welded with each other such that there are spots created. The current supplied is 350 to 1220 Amp. The voltage and frequency applied is 415 and 50 Hz. respectively 40
  41. 41. Seam welding: In this type of welding with the help of high electrical curren, the two materials are welded with each other such that there are no spots can be visible and such type of welding are known as seam welding. The current supplied is 350 to 650 Amp. The voltage and frequency applied is 415 and 50 Hz. respectivelyThe machine which is used for both sopt and seam welding is known as ―Mechelonic Engineers‖Products of TAAL for HAL: TAAl is preparing the bombs which are being heat treated and the spot welded with the help of Mechelonic Engineers machine. This is the bomb wich has a volume capacity of 350 litres which carries the fuel in it and it is droped over the target and that is exploded with the fire. For this TIG welding is done and compressed air is used to check for any leakages and if there are any leakages, then it is again welded. The mock Up helicopter for the next month airshow, representing the HAL is being prepared by the TAAL using composites and the panels which are made up of alluminium and welded together. Jigs which are used as a stand for holding various components are also joined together with various welding processes.NDT Shop: NDT stands for the non destructive test which is carried out for every job after it has been manufactured in order to check the presence of any crack in it. If there is a presence of any crack, then a job is rejected otherwise it is accepted without any distortion present in it.Procedure: For this process, liquid fluorecent paint is painted and then it is dried for some 2 to 3 minutes and it is washed under forced water so that all the paint is removed from its surface. After the washing process, it is dried in the hot oven for near about 15 to 20 minutes and 41
  42. 42. then a chemical known as a developer is spread over the whole body and observed under UV rays. If there is any crack formation in it then that area will glow with the fluorecent colour depending upon the depth of the crack and finally it is sent back to the manufacturing unit for a replacement. Purpose of the washing is to remove the excess penetrant from the part which is under UV lighting (Dark Enclosure and special UV lighting). Intensity of light is 275 micro watt/cm2.Water bath: Size: 3 x 1 x 0.9 m Duration: 90 seconds. Temperature: 100 to 380 C. Maximum pressure: 25 psi.Drying oven: The job is dried in this oven with the help of forced air circulation. For drying the parts, after the water wash and before applying a developer over it. Size: 3 x 1 x 0.9 m Duration: 15 minutes. Temperature: 480 to 580 C.Dry Developer tank: Specifications: ZP4B Developing time: 10 minutes. 42
  43. 43. CNC Profiler ShopIntroduction: CNC profiler shop is the shop where the milling operations are done with the help of CNC machine.CNC stands for ―Computer Numerical Control‖ in which a computer is used to do or perform the operations using programming language.The tolerance for the job done with the help of CNC machine is only 0.3 mm.Brief description: Milling machine is the machine which is used to do various types of operation on a single job using variable tool.In this machine the tool is stationary while the job is rotated with three degree of freedom, that is on X-axis, Y-axis and Z-axis respectively. In CNC milling machine a programing language is used to control the machine which in turns control the operation of the job.There is a programmer which reseta the machine using suitable progrme for a particular operation such as chiping, drilling, boring metal removing, levelling, smooth finishing, curving etc. The base of this machine is the hydraulic base so that each movement of its part is done hydraullics only. The software which is used for this CNC milling machine is the ―Power mill‖ which is generated to operate in three dimenssional.Proceedure: The design for the job is prepared by the designer using catia V5 software, and a job sheet is prepared which gives various types of commands has to use and which tool has to be used for a particular operation with appropriate diagram in 3-D view. Then the operator is given the raw material, which he removes the extra material from it using a rough milling cutter as per the instruction stated in the job sheet. For example: The job has to be done is a bracket which is used for the joining purpose.Format of the each program for a particular operation:Tool type Flat drillTool diameter 16 mmPrograme name S1M1 16 flat RFeed 600 mm/minSpeed 2000 rpmDepth of the cut 1 mmCycle time 0.3 minituesWall stock 0.3Bottom stock 0.5Total length 70 mm 43
  44. 44. The operators which operates this machines must be skilled person and they must be expert in controlling the CNC machines.he must be able to underastand all the terms related to this machine and must satisfies all the condition which are necessary for a good profile job without any error. The chances of the fatal accidents should be minimum and there should be continuous flow of the job production so that the final outcome of the company should be good.Explanation of the job sheet: The tool type indicates the type of tool is eused for the operation. What is the tool dimenssion of the tool used for a particular operation. The name of the programe. Feed indicates how much maximum the tool can remove the excess material from the job. Speed indicates the speed at which the tool is rotating in rpm. Depth of cut indicates how deep the cut for each stroke should be maintain. Wall stock indicates the tolerance at the wall of the job Bottom stock indicates the tolerance at the bottom of the job Total length indicates the full length of the job. This is one part of the operation and depending upon the type of job there may be various types of operation which has to be performed over it and for each operation such type of table is prepared by the programmer and a designer. Step 1: S1M1 R means setting one milling 1, and R stands for the rough finishing. That is using a 16 flat , flat is cutter which is used to remove the excess material from the job using a tool whose diameter is 16 mm and it is a flat tool. Step 2: S2M2 R Bull nose. Bull nose is the name of the tool which is used for small curving operations. Here R also stands for the rough finishing. It will have a corner radius which is used for the curving the edge for the job. This is used for the finishing the edge of the job. Step 3: S3M3 F flat 12 Flat means a flat tool is used whose diameter is of 12 mm. Here F stands for the finishing process where all the surface of the job are finished using the same tool.Machines available at TAAL: There are four CNC milling machine available at TAAL manufacturing unit, that is CNC profiler shop. These machine are BMN 45, BMV 60, BMV 80 and a horizontal milling machines. The first three machines are the same vertical machines only they differ with eachother is in their dimenssion and their power consumption. BMV 45 Consumes the power of 45 KW. The maximum size of job it can accomodate is of width 450 mm and length 800 mm. BMV 60 Consumes the power of 60 KW. The maximum size of job it can accomodate is of width 600 mm and length 1000 mm. BMV 80 Consumes the power of 80 KW. The maximum size of job it can accomodate is of width 800 mm and length 2000 mm. 44
  45. 45. Horizontal milling machine consume more power than every machine so one has to be sure that no other machine is being operated when the horizontal milling machine is being used for the operation. The job size which can be accomodate in it is of 2000 mm in width and 4000 mm in length. Operation are very similar to the vertical milling machine.In this machine job is stationary and tool is in motion.Type of coolents: At the time of any operation coolent is used to reduce the heat which is generated through the friction between the tool and the job. The coolent used is castrol coolent which protects the tool from wear and increase the life of the tool with better finishing of the job.Inspection tools: There are various types of tools which are used for the inspection of a job after its operation . The simple type of equipment is DTI which is nothing but the direct touch indicator. In this type the needle is very sensitive to the uneven dimenssions. The needle is touched at a particular surface of the job and then the job is rotated and moved through out the section. If there is unevenness in the dimenssion, then the needle will not be in preset value and will indicate the deflection. Touch ball is a similar type of tool, where if light glows then it is correct and if it does not then it is under dimenssion.Adapters: These are the used to hold the tool and then they are placed in the milling machine. There are many more types of tools and machineries which are used for various types of operations denpending upon the type of the job and the customers requirements. 45
  46. 46. Paint ShopIntroduction: Aircraft painting is also an important part of aircraft manufacture.This has to be done very carefully so that the dead weight must be maintain within the permissible limit.The thickness of the paint should be not more than 25 microns. If this thickness is increased then the dead load of an aircraft increases so that instead of 6 passenger, an aircraft can carry only 4 passenger in case of P68C type of an aircraft.Brief description: Polyunithene paint is used in aircraft painting.To make piant suitable for painting 100ml primer, 100ml hardner and 25ml thinner has to be mixed in paint which have to be applied on aircraft surface. As primer mixing require half an hour. Two types of primer are usually used 1). Epoxy primer, and 2). Etch primer Primer ratio should be of 1:1.After primer mixing,it should be kept for 10min. for cooling.Then the mixture is brought in viscosity cup.Viscosity cup is a device used to measure viscosity.As the thickness and thin of mixture can be checked through it. If paint comes out from the hole of viscosity cup within 17-23 seconds then the paint or mixture is ok and there is no need to add anything in it.If paint takes 25 sec. in coming down from hole then the amount of thinner is added in it,depending upon the quantity of paint. On iodizing we use Epoxy primer(brown plate) and in anodizing we use Etch primer(white-grey plate). Primer cooling time is 8 hours. And after cooling paint can be done on the required area or surface. Test for primer:- Primer is a layer which is put on surface before doing paint.Usually there are three types of tests carried out on paint,they are:Scribber tape test:In this test small part of surface is to be made in form of grids by the means of scribber. Then alayer of primer is applied on it and after that it should be covered by tape. At the time of removle oftape,If some part sticks on it then it means that the primer has less sticking or gripping capacity.Water tape test:In this test a piece of cotton dipped in water should be kept on small part for 24 hours. Then rub it25 times,if primer removes then it is not good and having less gripping capacity.Amigy test:This test is usually done to check weather the quantity of fuel is good or not. This test is also used tocheck weather the mixing is correct or not. While doing paint, first check the room temperature. It should be 15-35 C. Secondly check humidity which is to be 35-75. If humidity is greater than it then paint flows. Bearing 46
  47. 47. pressure should be 42-45 psi. In every part we have to give 23-25 microns thickness of paint. Procedure that must be followed during an aircraft painting: The paint that has to be used must not be polluted as well as by using the it should not pollute the enviorment. The paint should have enough surface tension so that it is grabed by the surface and does not peel off the surface under extreme conditions. The paint should also be anti corrosive.Before painting an aircraft following should be done: 1).Inspection of aircraft: inspection of aircraft includes following points-  Finding out dents and deants,  Inspect for corrossion parts,  Loose rivets,  Inspected in flight control surfaces,  aircrafts windows,doors,de-iceing boots,propellers,etc. 2).Paint stripping: This is done chemically or by scotch bright. 3).Over spray protection: Before painting, windows should be covered,seams should be covered with alluminium tapes,landing gears are covered with plastics or glass. 4).Primer: 3 layers of primer should be done.Two layers of epoxy primer and one layer of anticorrossion primer. 5).Base coat: After primer go for base coat, three coats of PPG aerospace paint. 6).Design and number application details:  Deicing boots,  Flight control balances.There are 20 steps for painting:- 1).Initial inspection 2).Removal of flight controls as per manufacture specification,removed checked balanced 3).Strip to metal and non-metallic surfaces 4).Inprocess inspection:After airframe stripping,it is done to find out hidden corrossion. 5).Corrossion control:All external surface corrossion from airframe is removed. 6).Metal perfection:Imperfection on airframe is corrected if necessary. 47
  48. 48. 7).Fiber glass and plastic perfection:All fiber glass and plastic are machined sanded,filler prime with epoxy primer and hand sanded. 8).Skin seans: skin seans are cleared and inspected. 9).Resist area of control surfaces are thoroghly cleared. 10).wet sanding; all the surfaces are wet sanded, including landing gears. 11).wet cleaning: airframe is cleand with 12).Final cleaning; airframe is chemically cleand with two seperate 13).All alluminium components are wash prime with acid component. Wash primer to 0.2- 0.3mm thickness and allowed to dry for 1 hour. 14).Chromit prime:All surfaces are primed with low viscous chromit primer with 0.9-6mm. 15).Top coat:All surfaces are painted using state of art berves commercial state equipments and acrylic urithene paint with double coating on all surfaces. 16).Design:Two trim tabs are tempted to essure symmetric and smooth flowing of transition. 17).Registration no. Is coordinating colour are applied with as per customer requirment. 18).Anti-slip compound:A new anti-slip compound are applied to the wing walk and other areas. 19).Ressembling:flight controls, cowling fastners and excess panel used are reinstalled with steel. 20).Final step: Before aircraft leaves final inspection is done in order to check the quality of paint and work done over it.The photo is of the painting work carried out at Airworks CMRO of Boeing 737-400. 48
  49. 49. 49
  50. 50. Composite ShopIntroduction: The aircraft body is made up of an alluminium alloy and the skin is made up of alluminium sheets.But nowadays, there is great demand for the high power to weight ratio or more aerodynamically, high lift to weight ratio. The dead weight of an aircraft must be minimum so steel was replaced by an alluminium and now alluminium has being replaced by the composites.Brief description: For less weight and high strength is the main criteria for an aircraft body so composites are used. The section which are made up of composites have high strength to weight ratio.So the power developed for the same amount of fuel consumtion is much higher for the composite then the alluminium alloy. There are some parts which cannot be made up of alloys even alluminium alloys can be used.Thus the composite are used which give the same strength with less weight. These are the fabric which is made up of fibres which are in thread forms. Then these fibres are club with each other as per the requirement and the various process such as heating, pressurizing, vacuuming etc are being carried out and a tough solid body with high strength and less weight. There are various chemicals are used as such as resiens, tools for various jobs, various types of machine such as an autoclave vacuum pressure etc.Materials used for the composites: There are various types of materials used the composite types which depends upon the job size and its requirement.The most commonly material used are kevlar fibre, carbon fibre, glass fibre, ox-core or honeycomb fibre, peel ply, protective layer etc.Arrangement of these fibres: There are many hybrids are developed using the above stated material. Most commonly used hybrid is the glass fibre and the carbon fibre. These fibres are arranged such a way that there are always perpendicular to each other. If they are arranged parallel to each other than the required strength from the material will not be obtained. When they are joined together to make a complete section, their arrangment also plays an importanat role for the total strength of it. Mostly, the strips of the hybrid fibre are arranged perpendicular to each other, which results in high strength. Layers of glass fibres and carbon fibres are integrated with the help of reseins and the hardners as per the customers needs.Wet lay shop: This is the first part of the composite shop. Wet lay process is a process to make the tools using hardners and reseins and a fabric for the outer covering jobs. 50
  51. 51. Thermo forming and curing: Thermo forming and a curing is a process of making the scale down model which is made for the wind tunnel test and the effect of various factors which can occur at that altitude is studied with the help of wind tunnel test and results obtained from it. This is also used for mock up type. Mock up means a full scale model of an aircraft. For example TAAL is preparing a mock up helicopter for the airshow which is going to be conducted next month is fully made using composite materials. It resemble the original model but it cannot be airborne. If someone likes the mockup then he can place an order and then the whole production of original aircraft takes place. The model is placed at airshow for growing the bussiness with less marketing expenditure as the company cannot spend money for constructing an aircraft to be placed in airshow. These types of mock up are known as LUH, that is Light Utility Helicopter.Dry bagging and cutting: This is the second part of the composite shop. In this shop there is an important machine known as an industrial autoclaves where the job is inserted and depending upon the requirement, various operations are carrided out.Industrial autoclave: Industrial autoclaves are pressur vessels used to process parts and materials which require exposure to elevated pressure and temperature. The manufacture of high-performance components from advanced composites often requires autoclave processing. Industrial autoclaves used in the aerospace industry. The autoclave on left is gas-fired; the machine on right is electrically heated. At full pressure, the force acting against the door of the grey machine is over one thousand tons. Both machines use rotating lockring doors; the larger one is hydraulically turned, the smaller is pneumatic.Dimenssions and its specifications: Maximum diameter is 1500 mm. Maximum length is 3000 mm. Working pressure is upto 10 bars. Working temperatue is upto 25000 C. Thermocouples are 12 J Vacuum connections are 12. 51