INTRODUCTION ABOUT TAALPart of the Pune based Indian Seamless group. TAAL was established in 1994 as the first private sector company in the country to manufacture general aviation i.e. non-military aircraft. The company's vision at the time was to create a nucleus facility for the development of an aeronautical industry in India and in particular to promote affordable general aviation in the country. To kick-off this process, TAAL entered into collaboration with Partenavia of Italy to manufacture the six-seat twin piston-engine P68C aircraft and the eleven-seal twin turbo-prop Viator aircraft. While manufacture of Light Transport and Trainer Aircraft continues to be in TAAL's capability, the company has since diversified its activities and has established a significant presence in many segments of the aviation and aeronautical industries in India. TAAL is into all Aviation related business activities namely. Aircraft Manufacturing & Maintenance Centre and Aviation Infrastructure - Airfield & MRO.GROUP OVERVIEWTAAL is a part of the Pune based Indian Seamless Group. Apart from TAAL the other companies in the Group are ISMT Ltd and TAAL Technologies Pvt. Ltd. ISMT is the leading producer of precision Seamless tubes and carbon and alloy steels, in India. ISMT's Tube Division supplies tubes to the bearing, automotive and energy industries and exports approximately 30% of its production to the U.S. and Europe. ISMTs Steel Division is one of the largest manufacturers of premium grade alloy steel in India and is also a supplier to ISMT. Both companies are TS16949 and AS 9100 B approved. Both companies ISMT and TAAL are independently listed on the Bombay Stock exchange and have combined annual sales in the region of USD 566 Million. TAAL is headquartered at Bangalore, which is the hub of the Indian Aviation Industry (Bangalore is also internationally famous as a software development and engineering design centre).TAAL-Technologies (www.taaltech.com) is a specialized Engineering Design and Development Solutions Company based in Bangalore, India TAAL Tech supports global corporations in their drive to develop winning products / solutions with quicker time-to-market and optimum budget.The team of talented engineers with high skills in contemporarily CAD / CAM / CAE tools and good domain expertise provide innovative solutions to varied Industry needs. The industry Moments to which solutions are offered include Aerospace & Defence. Industrial, Energy and Transportation. TAAL.-Tech has extensive expertise in the area of Concept Design, Detailed Design. Finite Element Analysis. Computation Fluid Dynamics. Motion Analysis / Kinematics, Value Engineering. Cost Optimization. Design and Development of Production Tooling and Jigs & Fixtures. Engineering Change Management Embedded Electronics etc. With the support of TAAL, TAAL.-Tech is uniquely positioned to provide Design-to-Build Solutions.ENVIRONMENTTAAL believes strongly in the need to maintain and improve the quality of the environment. The company shall therefore strive to ensure that its operations comply with all applicable laws and standards, have no adverse impact on the environment and where possible make a positive contribution to improving the quality of the environment.HEALTH AND SAFETYThe Company will comply with all applicable Laws and relevant industry standards of practice concerning protection of health and safely of its employees in the work place and other persons effected by its business activities. Protection of health and safety is of vital importance to the Company and the management of the Company shall take such actions as arc reasonable and necessary to achieve such goal and carry out this policy.ORGANIZATION

TAAL PROJECTS1. Manufacturer of the P68C, a six scat twin piston-engine aircraft. All detailed parts and assemblies including seats, electrical looming, cable assemblies etc. were manufactured at TAAL's facilities.2. TAAL was involved in building up the first three prototypes of the 14 seat. SARAs aircraft for the National Aerospace Laboratories (NAL). TAAL has manufactured the entire air frame of the aircraft (excluding the wings which are manufactured by HAL) including tooling, parts and assembly. The first prototype is now under flight-testing.3. TAAL was associated with the National Aerospace Laboratories (NAL) for the production of the two-seat all composite (glass fibre) trainer aircraft called the "HANS A".4. TAAL is manufacturing the airframes for the full composite (carbon and glass -wet lay-up and room temperature cured) NISHANT, Remote Pilotless Vehicle developed by the Aeronautical Defence Establishment (ADE). 5. TAAL is manufacturing all the composite components (Tail cone. Nose cone and air-intake) for the LAKSHYA, Pilotless Target Aircraft (PTA). This aircraft is now in series production.6. TAAL is manufacturing the Elevator and Stabilizer for the Intermediate Jet Trainer (LIT) manufactured by HAL.7. TAAL is manufacturing a variety of aircraft tooling (Bakelite). Sheet Metal Parts etc., for the Advanced Light Helicopters (ALII); Light Combat Aircraft (LCA) Light Combat Helicopter (LCH); Suk hoi (SU-30) & MIG Series projects of Hindustan Aeronautics Limited (HAL).8. TAAL is manufacturing Auxiliary Fuel tank, stretcher, Armour Panel and interiors for Advanced Light Helicopters of HAL and also interiors for Defence Service Helicopter.9. Parts for Jaguar Drop tanks and Incendiary Containers.10. TAAL is doing space structures for PSLV and C.SLV of Indian Space Research Organization (ISRO).11. Manufacturer of THORP T211 Two Seater aircraft for Domestic and Export Markets.12. In the past TAAL has undertaken certain sub-contract work for the Israel Aircraft Industries (ISI) in India. 13. Number of Modification and Installations on Indian Navy Helicopters and Aircraft. 14. Interiors for Indian Air force Aircraft.

AIRCRAFT MANUFACTURING & MAINTENANCE CENTREThis business has evolved from the initial business of the company, which was to manufacture the Partenavia P68C, six seat, and twin-engine aircraft in India (We are the first and only private sector company in India to have built and certified an aircraft). We currently manufacture aero structures for Hindustan Aeronautics Limited (HAL). Indian Space Research Organization (ISRO). National Aerospace Laboratories (NAL) Aeronautical Development Establishment (ADE). And Number of modifications on Indian Navy and Air force Helicopters and Aircraft. Of these, the largest structures that we manufacture are for ISRO where we build most of the structural assemblies for the Booster rockets of the GSLV program. We have also built major structures of 14 seat Saras aircraft developed by NAL. Once again, we would regard ourselves as the largest dedicated private sector aero structure manufacturer in India.Our core competence in this area is in the manufacture of sheet metal details, machining, composites and assemblies. Facilities are augmented and upgraded to address the domestic and Global Technological requirements on a continuous basis.MAINTENANCE SUPPORTTAAL offers comprehensive Maintenance support for all types of general aviation (business & recreation) aircraft. TAAL has the most modern aircraft maintenance facility in the country located at our own private airfield at Hosur near Bangalore. The airfield can accommodate Airbus A 320 and Boeing 737 type of aircraft. The maintenance facility is located in a brand new 50m x 45m Hangar and has modern amenities for customer services Aviation Infrastructure - Airfield & MRO TAAL has entered into an Aviation Infrastructure - Airfield & MRO facility agreement with Air Works India (Engg) for establishment of commercial Aircraft Maintenance and Operating Aviation Infrastructure - Airfield & MRO Division services at TAAL's private airfield (Licensed) at Hosur near Bangalore. The runway at this airfield is capable of accepting Airbus A 320 and Boeing 737 Series class of aircraft and the hanger is capable of accommodating Narrow Body aircraft. TAAL has DGCA Maintenance approval under CAR 145 for Maintenance of Cessna Jet and other Light Transport Aircraft.

P68C DESCRIPTIONThe P68C is a metal, non-pressurized high wing aircraft of semi-monocoque construction.Frames, bulkheads, stringers and stiffeners on which the skin is riveted form the main fuselage Structure.Windows include a windshield, one crew side window and ten cabin windows, five on each side of the fuselage.An entirely metallic floor fastened to the fuselage bottom structures; is provided with access panels for the inspection and maintenance of the under laying structure, system and controls. Easily removable rails are fastened to the floor for passenger seat installation.Individual passenger seats are provided in a variety of optional seating arrangements.Access to the crew compartment is provided by two doors conveniently located on the RH and LH side of the forward fuselage. The cabin is accessible through an entrance door on the LH side of the centre fuselage.Another door is provided on the RH side of the aft fuselage area through which it is possible to gain access to the passenger cabin and the fuselage baggage compartment. This door is also designated as the emergency exit. A fiberglass radome and tailcone are installed respectively at sta. 1 and sta. 16.The wing is a full cantilever semi-monocoque type construction with removable metallic leading edge and fiberglass tips.LH and RH wing halves are connected at the centre by means of steel splices, bolts and nuts.The entire wing assembly is bolted to the fuselage through attach fittings installed on the front and rear spars.An aileron, flap and power plant attached to each wing half complete the wing assembly.The all metal empennage group is a full cantilever design consisting of a vertical stabilizer (fin), rudder, horizontal stabilizer and elevators. Both the rudder and elevators are provided with mechanically operated trim tabs. All exterior surfaces are coated with AERODEX finish or an equivalent, protective finish.

INTRODUCTIONThis section explains the removal and installation procedures for die structural pans For the removal, installation, rigging and adjustment procedures of the control components of the various structural surfaces is discussed below.WING GROUPGENERALThe wing is a full cantilever, all metal, stressed skin, semi-monocoque box construction design.The wings are classified as wet wings, which means that each form an integral fuel tank. The fuel tank interiors are accessible through gasket sealed doors in the upper skin. The structure of the wing panels consists of 2 front and rear spar, web and baffle type ribs, and riveted skin and stringer assemblies.The front spars are I beam sections built up horn aluminium extruded angle caps, webbing and stiffeners. The rear spars area combination of U shaped channel and stiffeners.The ribs are symmetrical about the fuselage centre line. The stringers provide span wise stiffness to the upper and lower skin panels.The removable metallic leading edges are attached to the front spar and consist of an inboard and an outboard section for e-ach wing panelThe wing tips are made of fiberglass and carry the appropriate position lights.The LH and the RH wing panels arc connected together at the centre, by means of vertically mounted steel splices bolted to the front and the tear spars.The entire wing assembly is bolted to the fuselage through four fittings installed, two each on the front spar and on the rear spar.Each wing panel carries the hinge fittings for the flap and the aileron section, at the rear spars.Flaps and ailerons are similar in construction, a single sheet-metal formed spar, on the rear on which sheet- metal formed ribs are attached.The top and bottom skin panels are riveted to this spar- rib combination.The trailing edge is formed by riveting the two skin panels together with a filler strip between them.To the front of the spar sheet-metal formed nose ribs are attached, forming the base to which the leading edge is riveted.The leading edge, formed of sheet-metal, consists of five sections for the Claps and of three sections for the ailerons. Among these sections the hinge brackets are riveted to the ribs and the spar.In case of emergency, a geared tab, installed on the RH flap, allow s the opening of the rear cabin door with flaps down.The aileron is provided with a trim tab located in the trailing edge near the wing tip.

REMOVAL OF WINGThe wing might be removed from the fuselage as one complete unit or dismantled into its major components i.e. ailerons, flaps, leading edges and wing lips.However, removal of the engines is suggested to avoid difficulties with raising the wing from the fuselage.NoteDo not attempt to separate the two wing halves when the wing is still attached to the fuselage.a. Place all switches to OFF position and disconnect the battery.b. Connect ground wire to the aircraft.c. Drain and purge the fuel tanks.d. Remove the following items: Central seats, rear couch, carpets, rear cold air outlets. Cabin ceiling lining within the area where the wing is attached to the fuselage. Front and wing-fuselage fairings C2 and C3 Central panel above the wing joint. Engines. Inboard leading edges.e. Disconnect fresh and warm air hoses at the wing roots.f. Remove access panel Cll from the cabin floor and disconnect the aileron cables at the turnbuckles.g. Disconnect all electrical wiring at the sockets located on the front spar.NoteTo facilitate reinstallation of control cables, power plant controls and fuel lines, identify cable and line ends in some manner and attach lead lines where applicable to cables and controls before removing them.h. Disconnect fuel control cables from both LH and RH shut-off valves and from cross-feed valve and unthread them at the lubrication flumes.

REMOVAL OF WING TIP a. Remove the position light, and disconnect wiring.b. Disconnect the bonding cable at the point near the aileron mass-balance weight.c. Remove the tip attaching screws.Note Due to the tact that after installation the screw heads are covered with body Tiller, it will be necessary to_remove.it in order to locate the heads of the screws.INSTALLATION OF WING TIPa. Hold tip near the wing and conned the front bonding cable.b. Position the tip on the wing and install the screws.c. Connect wiring and install position light.d. Connect the bonding cable at the point near the aileron mass balance weight.e. Carry out functional test of the position light.REMOVAL OF WING OUTBOARD LEADING EDGEa. Open leading edge access panels.b. Disconnect bonding cables from the front sparc. Disconnect electrical wiring terminals from the stall warning switch, for the RH wing only.d. Remove the engine cowlings.e. Disconnect the cabin air hoses.f. Disconnect and cap the fuel lines between fuel valves and fuel filters.g. Disconnect and cap the de-icer boot hoses, if installed.h. Remove all screws connecting the leading edge to the wing, top and. bottom.i. Remove the girder between front spar and fuselage top from the fuselagej. Disconnect all engine controls at their attaching points on the engine.

Note

In order to prevent contamination and/or damage of fuel, oil and vacuum lines, cap the ends of all disconnected lines, tubes and hoses.k. Disconnect vacuum system tubes. l. Disconnect, if installed, de-icer system tubes.m. Check that no other connections arc present between wing and fuselage.n. Place a suitable padded adjustable cradle under each wing at the wing rib just outboard of the engine nacelle. Note Support the fuselage by placing two profile beam trestles under the appropriate frames.

o. Remove the nuts and washers from the four bolts attaching the wing to the fuselage.p. Raise the cradles until the wing just starts to lift, and then remove the bolts by tapping lightly with a plastic or wooden hammer. If it is difficult to remove, one or more bolts adjust the cradles as required.

Caution Extreme rare has to be taken not to damage the wing or fuselage. Attach fittings during removal of the bolts.q. Lift the wing clear from the fuselage and move it forward by means of the cradles.NoteIn case it is preferable to leave, the engines in place, the wing should be lifted not only by the two cradles, and in addition a hoisting device has to be attached to the lifting lug of each engine

CautionWhen lifting the wing engine assembly, raise carefully the cradles and hoisting devices by equal amounts. Due to the obvious difficulties which will be encountered by removing the attachment bolts, it will be necessary to adjust cradle hoisting device combinations for every single which is difficult to remove.INSTALLATION OF WINGa. Ascertain that the fuselage is correctly supported.b. Support the wing as per step n of previous paragraph.c. Position the wing over the fuselage.d. Lower it carefully until the wing fittings slide into the fuselage brackets.e. Align the holes by adjusting the wing cradles a necessary, and insert, with washers under the heads the two NAS 1108-40 bolts in the front attachment points, and the two NAS 1108-29 bolts in the reattachment points.f. Install washers and nuts and torque the four bolt 515 to 570 inch pounds (6.0 to 6.5 Kgm).g. Install engines.h. If installed, connect the de-icer plumbing.i. Connect vacuum system. Note Ascertain that all fuel oil and vacuum lines, tubes and hoses are free of obstructions and that the protection caps are removed.j. Install the girder between the front spar and the to of the fuselage.k. Connect the fuel selector control cables. Carry out a functional lest of the fuel selector system.l. Connect the electrical wiring at-the front spar.m. Route the aileron cables through the fuselage and connect at the turnbuckles, through access openings ell. Rig aileron control system. Install access panels.n. Install inboard leading edges.o. Install panel above the wing joint.p. Install front and rear wing-fuselage panels.q. Install all items removed at step d. of previous paragraph.r. Connect the battery.s. Check all systems which have been disturbed, for proper operation, leaks etc.t. Remove the ground wire when convenient.u. During the functional check flight, following wing installation, check the correct setting of the station warning detector.NoteAlter the first 100 flight hours of the aircraft: following wing installation, check the wing bolts for proper torque.

INSTALLATION OF WING OUTBOARD LEADING EDGEa. Position the leading edge along the wing span and install the connecting screws, top and bottom.b. Remove caps and connect the de-icer boot hoses, if installed.c. Remove caps and connect the fuel lines between the fuel valves and the fuel fillers.d. Connect the cabin air hoses.e. Connect the electrical wiring terminals to the stall warning switch. RH wing only.f. Connect the bonding cables to the wing front spar.g. Close the leading edge access panels.h. Install the engine cowlings.i. Carry out functional tests of all the systems which have been disturbed during leading edge removal.REMOVAL OF WING INBOARD LEADING EDGEa. Remove the wing-fuselage fairings.b. Remove the engine cowlings.c. Disconnect the cabin air hose from the hot air valve located outside the leading edge, near the engine mount. d. Disconnect the cabin air hose at the fuselage.e. Disconnect the control cable from the hot air valve.f. Disconnect the bonding cables from the front spar. g. Remove all screws, top and bottom, connecting the leading edge to the wing.h. Remove the leading edge.INSTALLATION OF WING INBOARD LEADING EDGEa. Position the leading edge along the wing span and install the connecting screws, top bottom.b. Connect the bonding cables to the front spar.c. Connect the control cable to the hot air valve.d. Connect the cabin air hose to the fuselage.e. Connect the cabin air hose to the hot nil valve located outside the leading edge, near the engine mount.f. Install the wing-fuselage fairings.g. Install the engine cowlings:h. Carry out functional tests for all the systems which have been disturbed during leading edge removal. REMOVAL OF AILERONa. Disconnect the aileron push-pull rod at the centre hinge by removing nut, washer and bolt.b. Disconnect the aileron trim push-pull rod by removing cotter pin. Washer and pin.c. Disconnect the centre hinge by removing nut, washer and bolt. Leave the bonding cable connected to the assembly.d. Support the, aileron and remove the inboard and outboard nuts, washers and disconnect hinge bracket.e. Remove aileron from wing and place on a suitable cradle INSTALLATION OF AILERONNote Any repair, modification or painting of the aileron needs rebalancing.a. Check all hinge bearings for damage and freedom of rotation. Replace if necessary.b. Align the inboard, centre and outboard aileron hinge brackets with the hinge brackets on the wing. Install the bolts, washers and nut securing the in board and outboard hinges. Tighten nuts to the required torque value.c. Install the bolt, bonding cable, washer and nut securing the centre hinge to the wing. Tighten the nut to the required torque value.d. Connect the aileron push-pull rod to the aileron centre hinge bracket with bolt, washer and nut. Tighten the nut to a torque value of 43 inch pounds (0.5 Kgm).e. Check the aileron for free and full travel.f. Rig aileron control systems as described in Section 7.

REMOVAL OF FLAPSa. Fully extend the Haps and disconnect the push-pull rod from the flap bracket by removing nut, washer and bolt. b. Disconnect the tab control rod on the RH flap (inboard) by removing nut, washer, bushing and screw from the wing-flap hinge fitting.c. Support the flap and remove the four hinge- bolts, complete with nut1', and washers. d. Remove the flap from the aircraft and place on a suitable cradle. Note To preclude rigging problems upon installation of the flaps, do not disturb the adjustment of the rod end on the push-pull rod.INSTALLATION OF FLAPSa. Check all hinge bearings for damage and freedom of rotation. Replace if necessary. b. Position the flap at the hinge points and align the hinge bolt holes.c. Install the bolls, washers and nuts securing the hinges to the wing bracket assemblies, install the terminal of the bonding cable under the head of the inboard hinge boll. Tighten the nuts to the required torque value.d. With the flaps fully extended, connect the push-pull rod to the flap bracket with bolt, washer and nut. Tighten the nut to a torque value of 70 inch pounds (0.X Kgm). e. Connect the tab control rod on the RH flap (inboard) by installing the screw, bushing washer and nut.f. Rig flap control system as described in Section 7

MANUFACTURING PROCESS OF WING HEAT TREATMENTHeat treating is a group of industrial and metalworking processes used in alter the physical, and sometimes chemical, properties of a material. Properties of metals such as hardness, brittleness, ductility, etc. can be modified to the required values. Heal treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of a material.Aluminium and its alloys used in the Aeronautical industry are hard and brittle in its Natural state this hard condition of the metal is not suitable tor sheet metal operations as its brittleness would lead to cracks during bending and forming operations. Hence, to be able to use the metal for sheet metal operations, we must soften it and improve its ductility. This is done by a process called 'Annealing'. The metal is placed in a furnace and healed to 410 C for a period of I hour. After heating, the metal is cooled in the furnace itself. The cooling of the metal in the hot furnace allows it to cool at a very slow rate, allowing the metallic crystals to form and align themselves properly, which gives the metal maximum ductility the metal, in this state, is optimum for sheet metal operation.After the metal has been formed as required in the sheet metal shop, it is still in the soft, ductile state. This slate, though optimum for the funning operations, is not suitable for direct application in aeronautical components. The metal must have high hardness to be used in these applications. This is achieved by a process called 'Solutionizing'. In this process, the metal is heated in the furnace to the required temperature and held for a fixed amount of time, similar to annealing. However, after heating, the metal is quenched (cooled at a very rapid rate) by dropping it into a quenching solution of Mucon polymer, the rapid cooling causes the crystals 10 be imperfectly (formed and crossed and interlinked with each other. Tins interlinked structure gives the metal its hardness the quenching time must be less than 10 seconds to achieve the required hardness. After Solutionizing, the metal must undergo another process called Aging. When n precipitation hardening alloy is quenched, its alloying elements will be trapped in solution, resulting in a soft metal. Aging a solutionized metal will allow the alloying elements to diffuse through the micro-structure and form inter-metallic particles. These inter- metallic particles will nucleate and fall out of solution and act as a reinforcing phase, thereby increasing the strength of the alloy. Alloys may age naturally" meaning that the precipitate form at room temperature, or they may age "artificially" when precipitates only form at elevated temperatures. In aerospace applications, naturally aping alloys arc stored in a cold chamber W prevent hardening until after further operations - assembly of rivets, for example, may be easier with a softer part. Three furnaces are used in the plant: A muffle furnace (1000 x 500 x 500 mm), used for steel components. The furnace has a temperature range of 0 - 1000 C. A convection-type air circulation oven (2000 x 1000 s 1000 mm), used for aluminium and its alloys. This furnace has a temperature range 0 600o C. A drop-bottom furnace, which is a type of air circulation oven. This furnace is places directly above the quenching solution and its bottom can be opened For the Solutionizing application, the bottom is opened after heating is completed and she metal pans are dropped directly into the quenching solution.SHEET METALSheet metal operations are earned out on pans made of aluminium and aluminium alloys, whose thickness is generally less than 4mm. Sheet metal components are only used when the component has to only transfer the stresses from the one component to the other. Whenever, a component has to bear high stresses, machined components are used. Aluminium sheet metal component preferred in most aeronautical applications due to their low specific weight.The aluminium sheets are first cur into the desired shapes using a vertical milling machine (drill) by a process called 'Routing'. A route card and engineering drawing of the part is provided to the machinist. The routing may be done manually or by a CNC machine. For manual routing, a drill routing template (DRT) is first prepared out of steel, in the shape of the required pan. The Template is then placed over to a wooden block, which is attached to the work-table. The block has a guide cylinder directly under the drill of the machine. The work-piece is then fastened to the DRT using screws. The machine is started and the template is moved around the guide cylinder, causing the work-piece to be cut as required. For CNC routing, a 3-D model of the pan is first create using a geometric modelling software like CATIA or SolidWorks. The model is exported as an ICS file, which is then converted into a CNC program. After the sheet is cut to the desired shape, it is sent to the heat treatment shop for annealing. The annealed metal is sent back to the sheet metal shop, where the following machines are present to perform the required operations: Rolling MachineTwo multi-roller type rolling machines are present in the shop. The small-scale machine is more regularly used. It is used for roiling for thinner pans { 5mm). The larger machine is used for thicker parts. (> 5mm). Hydraulic PressTo manufacture open 3-D shapes from 2 metal sheet, presses are used. To manufacture a part in the press, first a loot must be made. The tool is shaped in the form of the required part arid generally made of phylum wood, though metal tools can also be used, if required. The tool is used to give the required shape to the metal.Two hydraulic presses are present in the shop:The rubber press has a capacity of 350 tonnes. The work-piece is placed between two plates the form plate (tool) and the top plate. The form plate is in the shape of the required part while the top plate is flat. When the jaws of the press are closed, the metal is bent and formed into the required shape.The metal press has a much larger capacity of 6500 tonnes. It is an extrusion type*, male-female press. The metal to be formed (work-piece) is placed in/on the female section, and the tool is attached to the male section. The jaws are closed and the metal is drawn out in the required shape

CNC Shearing MachineThis machine is used to cut of parts of the sheet by shearing operation. The work-piece is placed on the work table and fed into the machine by the amount required to be cut. The jaws of the machine move downwards and shear of the excess part of the sheet. The machine is operated by feeding it with a CNC program. CNC Bending MachineThe CNC bending machine is an automated machine which is used to bend the sheet in the required shape. The machine requires the certain input data such as the co-ordinate 2D drawing of the required part, radius of curvature, length of metal work-piece, material used, thickness of sheet, etc. The machine automatically calculates the required position and movement of the press, the strength required, etc. and produces the part. Stretch-forming MachineThe stretch-forming machine is a very important pan of any aeronautical plant. Circular parts having only a single radius of curvature can be manufactured on the rolling machine. But a variety of aeronautical components like aerofoils, fuselages, etc. have multiple radii. To manufacture these components, a stretch-forming machine is used.To manufacture a part with this machine, first a contour tool is created containing the necessary shape of the component. The contour tool may be made of wood or metal. The contour tool is placed on the bed of the machine. The annealed metal sheet is first slightly rolled and then held between the jaws of the machine. One jaw is fixed, while the other is movable. The jaws stretch the metal sheet over the entire contour and hold it there for a fixed period of time, thus giving the sheet its desired shape.

PROCESS ENGINEERINGProcess Engineering is used to modify the surface of metal components using chemicals to improve various chemical properties of the metal.Various chemical processes for aluminium and steel components are carried out in the shop. Between two processes, the components are immersed in still water baths to wash off the chemicals of the previous process. Some of the processes for aluminium and steel are similar; however, they are carried out in separate baths.The processes used for aluminium components are as follows: Chemical Alkaline DegreasingThis process is used to remove any oil, grease, wax or other non-water soluble particles stuck on the surface of the parts during the machining or sheet metal operations. The process cleans and prepares pan surfaces for various finishing processes like painting, welding, etc.The components are immersed in a solution of Trisodium Phosphate (20-30 gm/lit) and SodiumCarbonate (20-30 gm/lit) at 50-70 C for 2-3 minutes. Alkaline PicklingThis process is used to remove dust and other similar impurities from the surface of the components.The components are immersed in a solution of Sodium Hydroxide (20-30 gm/lit) and Sodium Carbonate (20-30 gm/lit) at room temperature. De-oxidationThis process is used to remove metal oxides that may have formed or deposited on the surface of the components.The components are immersed in a solution of Nitric Acid (20% v/v) at room temperature for 3-5 minutes. AnodizingAnodizing is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts. The part to be treated forms the anode electrode of an electrical circuit. Anodizing increases corrosion resistance and wear resistance, and provides belter adhesion for paint primers and glues than does bare metal.Anodizing can be done using two different acids. Chromic AcidThis is more commonly used as it is more economical but is of lower quality.The components are first immersed in a solution of Chromic Acid (30-50 gm/lit) at 38-4z C. This forms the anodized plating over the surface of the component.The plating is then fixed onto the surface by a process called ' Hot Water Sealing'. The components are immersed in a hot water bath (5.5