FLAME Weapon System Precis PDF

RESTRICTED FLAME WEAPON SYSTEM GENERAL CHARACTERISTICS 1. FLAME is an acronym for Fagot Launcher Adapted for Milan Equipment. This weapon system is unique in the fact that it encompasses the weapon technology of both the European and Russi...

RESTRICTED FLAME WEAPON SYSTEM GENERAL CHARACTERISTICS 1. FLAME is an acronym for Fagot Launcher Adapted for Milan Equipment. This weapon system is unique in the fact that it encompasses the weapon technology of both the European and Russian weapon manufacturers. Aim 2. To learn about the general characteristics of the FLAME launcher and the MILAN missile. Preview 3. This lesson will be divided into the following parts:- (a) Part I. Main components of the FLAME Weapon System. (b) Part II. General characteristics of the FLAME Weapon System. Part I: Main Components of FLAME Weapon System 4. FLAME Weapon system has been divided into two major components:- (a) FLAME Launcher. (b) MILAN Missile. RESTRICTED  RESTRICTED 2 5. FLAME Launcher. (a) Tasks. (i) The missile is loaded on it and is launched from it. (ii) Guides the missile during flight. (b) Main Components. (i) Mount 9P- 56 M. (aa) Tripod. (ab) Pivot Box. (ac) Ramp Assembly. (ii) Ground Control Equipment. (aa) Electronic Pack. (ab) Sight cum Optical and Mechanical Coordinator. (iii) Trigger Mechanism. MAIN COMPONENTS: FLAME LAUNCHER RESTRICTED  RESTRICTED 3 6. MILAN Missile. (a) Task. (i) Anti Tank Ammunition. (ii) Destruction of pill boxes and bunkers. (b) Main Components. (i) Missile. (ii) Launch Tube. (iii) Junction Unit. MILAN MISSILE Part II : Characteristics of Flame Weapon System 7. The general characteristics of FLAME weapon system are as follows:- (a) Range. (i) Minimum. 25 Mtr. (ii) Maximum. 2000 Mtr. (b) Generation. Second. (c) Guidance. Semi Automatic Command to Line of Sight (SACLOS). (d) Crew. Three. (e) Rate of Fire. Three Missiles/Minute. (f) Hit Probability. 90 to 95% (Range more than 300 m). (g) Operating Temp. -40ºC to +52ºC. RESTRICTED  RESTRICTED 4 (h) Launcher Dip. 8 Min (Approx). (j) Missile Trajectory. 0.5 m above the Line of Sight. (k) Tube Ejection. 2 to 6 m behind. (l) Penetration. 850 mm. (m) Time of Action. (i) Carry to Combat. 1.5 min. (ii) Combat to Carry. 2.5 min. (n) Effect of Rain. No effect. (o) Accuracy. 25m around the Point of Impact. Conclusion 8. After having studied the general characteristics of FLAME Weapon system the Anti Tank Guided Missile detachment can apply their knowledge during battle handling and tactical employment. RESTRICTED  RESTRICTED 5 GENERAL DESCRIPTION AND CHARACTERISTICS OF FLAME LAUNCHER Introduction 1. The FLAME MK-II is the major component of the weapon system. It controls the missile after launch till the time it hits the target. The pilot keeps the target in the centre of the sight reticle pattern with the help of elevating/ traversing mechanisms and the launcher controls the missile by continuously sending correction signals to the missile through a wire. Aim 2. To learn about the general characteristics of FLAME Mk-II launcher. Preview 3. The lesson would be covered in the following parts:- (a) Part-I. Tasks of FLAME Launcher. (b) Part-II. Major Components and their tasks. (c) Part-III. Characteristics of FLAME Launcher. (d) Part-IV. General Information. Part I: Tasks of FLAME Launcher 4. The tasks of the FLAME launcher are: - (a) Employed for observing the area ahead, selecting the target and tracking a mobile target. (b) Missile is loaded and launched from it. (c) Prepares command/ correction signal for the missile. (d) Transmits this command/ correction signal to the missile through a wire. RESTRICTED  RESTRICTED 6 Part II : Main Components of FLAME Launcher 5. The main components of FLAME launcher are: - (a) Mount 9P - 56M. (b) Ground Control Equipment (GCE). (c) Trigger Mechanism. 6. Mount 9P - 56M. The Mount can be further sub divided into the following parts:- (a) Tripod. (b) Pivot Box. (c) Ramp Assembly. 7. Tripod. It supports the pivot box. The components of the tripod are:- (a) Mount Base. It supports the launcher. (b) Legs. Front, rear left and rear right legs. The three legs support the mount. (c) Leg Locking Levers. There are three leg locking levers. They are used to lock the legs when the launcher is in combat position. (d) Notches with Arrow Mark. They are three in number. They assist in making the launcher parallel to the ground. (e) Shoes with Spike. They are also three in number, one on each leg and provide a firm grip to the launcher in combat position. (f) Sling Hooks. Three in number, one each on the front, rear right leg and mount base. They are employed in attaching the carrying pad hooks. (g) Sight Protective guards. Fixed on the front and the rear left leg. They protect the sight during carry position. (h) Mount Base Supports. They are three in number and can be used to support the launcher if the tripod legs get damaged. (j) Carrying Bracket. Attached to the front leg, it is provided for carrying Launcher in combat position. RESTRICTED  RESTRICTED 7 (k) Neck with Studs. It is fixed on the front leg and holds the cradle firmly in carrying position. (l) Free Traversing Handle with Plunger and Spring. It assists to rotate the launcher mount by 360º. TRIPOD 8. Pivot Box. (a) It acts as a pivot and rotates on the mount base. (b) It houses the traversing mechanism gears and supports the handles. (c) It supports the GCE. (d) The sub components are as under: - (i) Sight Locking Stud. Locks the sight and prevent damage in carry position. (ii) Water Draining Screw. It is used to drain out water from the pivot box. (iii) Traversing Mechanism. (aa) Handle with plunger and spring. (ab) Hand Wheel. RESTRICTED  RESTRICTED 8 (ac) Speed knob. The speed knob has two positions. If pulled outside the traversing mechanism moves at high speed. If pushed inside it moves at a lower speed. If the target range is less than 700m then the speed knob position is pulled out for easier tracking. (iv) Elevating Mechanism. (aa) Handle with plunger and spring. (ab) Hand Wheel. (ac) Vertical Shaft. It supports the cradle and moves it up and down. PIVOT BOX 9. Ramp Assembly. It is fixed on top of the pivot box with the help of the axle. The sub parts are:- (a) Axles. They are two in numbers and fix the sight and vertical shaft to the ramp assembly. (b) Sight Locking Stud. Locks the sight in combat position. (c) T & A Elevation Screws. Testing and Adjusting screws are used to adjust the elevation of the sight during maintenance. 9 (d) Sight Bracket. Fixes the sight on the pivot box. (e) Sight Locking Lever. Locks the sight in both carry and combat position. RESTRICTED  RESTRICTED 9 (f) Sight Locking Slot. It engages sight locking stud to lock the sight. (g) Clamp and Sight Locking Bands. Fixes the sight to the sight bracket. (h) T & A Azimuth. Testing and Adjusting screws used to adjust the traverse of the sight. (j) Double Guide Pin. Helps in loading the missile on cradle. (k) Blast Shield. Protects the pilot from the blast and heat during launch. (l) Cradle. Two parallel rails on which the missile is loaded. (m) Missile Locking Pin. Locks the missile in load position and is used to eject the junction unit after firing. (n) 12 Pin Connector. Provides electrical connection between the missile and the launcher. It is provided with water proof gasket to protect it from dust and water. This gasket is automatically pressed while loading the missile. (o) Slot. Locks the junction unit hook while loading the missile. RAMP ASSEMBLY RESTRICTED  RESTRICTED 10 10. Ground Control Equipment. (a) Task. (i) Observes the area ahead, lays on the target and tracks it. (ii) Launches the missile. (iii) Calculates the position of missile with respect to the line of sight. (iv) Prepares a command signal for the missile. (v) Transmits this command signal through wire to the missile. (b) Instrument 9W-119M1 Sight cum OMC. It is supported to the cradle with the help of sight bracket. The sub parts are as under:- (i) Eyepiece Rubber Shield. It provides cushion for pilot’s eye while seeing through the sight. (ii) Eyepiece Lens Assembly. An assembly of four lenses out of which two are fixed and two are movable. The sight is focused using the movable lenses. (iii) Focusing Ring. Used to focus the sight according to the pilot’s eyes. (iv) Desicators. They are two in number and contain silica jelly. It absorbs the moisture in the sight. (v) Sight Tube. Houses the objective lens assembly. (vi) W 1 Socket. Connects the sight cum OMC to the electronic pack. (vii) Brightness Selector Switch. It has three positions. Day, Dusk and Night. It controls the brightness of the luminous cross. (viii) Illuminating Bulb with Cover. The bulb is required to make a luminous cross in the sight. (ix) Optical and Mechanical Coordinator (OMC). It is the part of the sight that receives the Infra Red rays and converts the rays to electrical voltage. RESTRICTED  RESTRICTED 11 (x) Protective Glass. Protects the internal parts of the sight from dust and humidity. (xi) Visor with Hooks and Lock. Protects the sight cum OMC from any physical damage. (xii) Neutral Filter with Catch. It is used in very bright light conditions. The filter has two positions of ON and OFF. (xiii) Canvas Cover with SPTA Pocket. It houses the SPTA kit. INSTRUMENT 9W -119M1 SIGHT CUM OMC (c) Electronic Pack. The electronic pack is an electronic unit that is fixed on the pivot box with the help of nuts and bolts. The electronic pack prepares the command signal for the missile and passes it to the missile. (i) C 1 Connector. Connected to the W1 socket (50 Pin). (ii) C 2 Connector. A 50 Pin connector is used to connect the FLTE to the Launcher. (iii) C 3 Connector. A 19 Pin connector. It is connected to the 12 Pin connector. (iv) Humidity Indicator. It contains silica jelly and indicates the amount of moisture in the electronic pack. RESTRICTED  RESTRICTED 12 ELECTRONIC PACK 11. Trigger Mechanism. It is fitted on to the electronic pack with the help of screws. On pressing the trigger an electric current is produced, which activates the Junction Unit Thermal battery. The sub parts are as follows:- (a) Cocking Handle. Cocks the trigger mechanism. (b) Safety Switch. Provides applied safety to the weapon system. It has two position ‘FIRING’ and ‘TRAVEL’ (SAFE). (c) Trigger Guard. Prevents accidental pressing of the trigger. (d) Trigger. Produces current on being pressed. (e) Plug W. The current produced by pressing the trigger is passed on to the Junction Unit Battery through this plug (10 Pin). TRIGGER MECHANISM RESTRICTED  RESTRICTED 13 Part-III: Characteristics of Flame Launcher 12. The general characteristics of FLAME Launcher are:- (a) Can be easily carried by one soldier. (b) A detachment can easily change position after launching a missile. (c) Presents a small target. (d) Can be fired from Fire Trench and Mounted on a vehicle. (e) Can be changed from carry to combat position in 1.5min. (f) Can be changed from combat to carry position in 2.5 min. Part-IV: General Information 13. The general information of the FLAME Launcher are as under:- (a) Weight. (i) FLAME Launcher. 28 Kg (With carrying pad and canvas cover). (ii) FLAME Launcher with Logistic Container. 60 Kg. (b) Operating Temperature. -40ºC to +52º C. (c) Traverse. (i) High Speed - 1.5°/ 2 revolutions. (ii) Low Speed - 0.5°/ 2 revolutions. (d) Elevation. - 0.5°/ 2 revolutions. (e) Dimension Combat Position Carry Position (i) Length 1110mm 900mm. (ii) Width 795mm 435mm. (iii) Height 755mm 450mm. RESTRICTED  RESTRICTED 14 (f) Instrument 9W 119M 1 Sight Cum OMC. (i) Magnification. 10 times. (ii) Field of view. 5º. (iii) Periscopicity. 300 mm. Conclusion 14. Flame Launcher is a very important component of the FLAME Weapon system. Hence it is important that a student understands the components of this weapon clearly. Which will further help in understanding the mechanical functioning of the FLAME Launcher. RESTRICTED  RESTRICTED 15 PACKING AND UNPACKING OF FLAME LAUNCHER IN THE LOGISTIC CONTAINER Introduction 1. Storage and transportation of any weapon system should be carried out very deliberately so that there are no breakages in the weapon system and the weapon is in serviceable condition when it has to fire. FLAME weapon system is very sensitive equipment and any rough handling of this weapon may result in the weapon system developing faults. To facilitate transportation of this weapon system in rough terrain and ensure good storage conditions the weapon system is provided with a container. Awareness of the parts of container and the method of packing the FLAME Launcher into this container is a must. Aim 2. To learn about packing and unpacking of the FLAME Launcher from the logistic container. Preview 3. The topic is covered in three parts:- (a) Part I. Introduction to the Logistic Container. (b) Part II. Opening of Logistic Container and Unpacking of FLAME Launcher. (c) Part III. Packing FLAME Launcher inside the Logistic Container. Part I : Introduction to the Logistic Container 4. The logistic container is a type of box and is made of Fibre Glass. This container is very durable and can even be air dropped. The provision of pressure valve enables the FLAME launcher to be transported to high altitude areas without affecting the effectiveness of the weapon system. 5. General Data. (a) Weight of empty container. -32 Kg. (b) Weight along with FLAME launcher. -60 Kg. (c) Length. - 1010 mm. RESTRICTED  RESTRICTED 16 (d) Width. - 508 mm. (e) Height. - 535 mm. 6. Major External Parts. (a) Stud and Slot. Four in number they are used for keeping the containers secured during transportation. These are used when more than one container is transported in a vehicle and these containers have to be stacked on top of each other. (b) Carrying Handles. Six in number, they are used for lifting the container. (c) Lifting Handles. Two in numbers, they are located on the cover of the container and used for lifting the container cover. (d) Clamps and Hooks. Ten in number, they are used for closing the top of the container. (e) Pressure Valve. It is used for bringing the pressure inside the container at par with the pressure outside the container. (f) Humidity Indicator. Indicates the humidity inside the container. 7. Major Internal Parts. (a) Locking Bracket with Nut. Three in numbers, they are used for securing the FLAME Launcher. (b) Canvas Pocket. Service documents, User handbook (TM & Service), log book and special tubular spanner are kept in this pocket. (c) Base Support Pad. Keeps the launcher secured inside the container by not letting it move inside the container. (d) Silica Jelly Pockets. There are two such pockets. Silica jelly pouch is kept in it. RESTRICTED  RESTRICTED 17 (e) Rubber Pads. Three in numbers, one located next to the front leg and the balance two located next to the rear legs. 8. Markings. The markings on the outside of the container indicate the following:- (a) Manufactured by. (b) Equipment nomenclature. (c) Cat Part No. (d) Logistic container and Equipment serial no. (e) Operating temperature (- 40°C to +52°C). (f) Storage temperature (-10°C to +35°C). (g) Aligning mark. LOGISTIC CONTAINER RESTRICTED  RESTRICTED 18 Part II: Opening of the Logistic Container and Unpacking the FLAME Launcher 9. Opening the Logistic Container. (a) Open the clamps from the hooks with the help of the Container opening key. (b) Lift the cover of the container with the help of the lifting handles and place it to the right of the container. (c) Take out the carrying pad and the cover canvas. (d) With the help of the Special tubular spanner loosen the nuts of the locking bracket. (e) Unlock all the locking brackets. (f) To take out the FLAME launcher from the container hold the Sight Protective Guard with the left hand and with the right hand hold the Ramp assembly. (g) Place the Special tubular spanner back in the designated pocket. (h) Place the container top on the container in case the launcher is to be made use of. Part III: Packing the FLAME Launcher inside the Logistic Container 10. Packing the FLAME Launcher in the Container. (a) Place the FLAME launcher in the container and place all locking brackets in place. (b) Tighten the nuts of the locking bracket with the help of the Special Tubular Spanner. (c) Ensure that the FLAME launcher is secured inside the container properly. (d) Replace the Special Tubular Spanner inside its pocket. (e) Fold and place the cover canvas inside the container. (f) Place the carrying pads on the canvas cover. (g) Aligning the aligning marks of the container and the top, place the top onto the container. RESTRICTED  RESTRICTED 19 (h) Lock the clamps. (j) In case the FLAME launcher is to be transported over considerable distance then the locking pins to be put over the clamps. Conclusion 11. Safe storage and transportation is a pre requisite for optimal achievement from FLAME Weapon System. As ATGM Platoon Commander, it is imperative to ensure that long distances are traversed with the launcher safely secured in the logistic container. This will ensure long life of such an expensive equipment and serviceability in times of need. RESTRICTED  RESTRICTED 20 GROUND CONTROL EQUIPMENT Introduction 1. FLAME is a hybrid second generation anti tank weapon, which works on the principle of SACLOS. The missile has a hit probability in excess of 90%. Firer after locating the tank target fires the missile and the moving target is continuously tracked by the firer. The missile is guided onto the target by the weapon system by means of a thin wire. Electronic signals are generated in the weapon system and through the wire delivered to the missile. Aim 2. To acquaint the class about the components and the functioning of Ground Control Equipment. Preview 3. The topic is covered in four parts:- (a) Part I. Major components of GCE and its functions. (b) Part II. Sight 9W 119M1. (i) Functions. (ii) Internal Parts. (iii) Sight Reticle Pattern. (iv) Luminous Mark Feed Unit. (c) Part III. Optical and Mechanical Coordinator (OMC). (i) Functions. (ii) Internal Parts. (iii) Operations of Channel. (iv) Frequency Modulation. (v) Stabilisation Circuit. (d) Part IV. Electronic Pack. RESTRICTED  RESTRICTED 21 Part I : Ground Control Equipment 4. Functions of GCE. (a) Observe the target area, lay the launcher mount and track a moving target. (b) Launch the missile. (c) Find the position of the missile in relation to the Line of Sight (LOS). (d) Prepare the command signals for the missile. (e) Send these command signals to the missile through the wire. 5. Parts of GCE. (a) Sight. (b) Optical and Mechanical Coordinator. (c) Electronic Pack. Part II : Sight 9W-119M1 6. Sight 9W-119M1 is a periscopic telescope. Its main functions are listed below:- (a) Observe the target area. (b) Selection of the target. (c) Lay the launcher onto the target. (d) Track a moving target. (e) Receives the Infra Red (IR) rays emitted from the missile. 7. Internal Parts. To understand the working of the sight it is imperative that one understands the various components of the sight. (a) Protective Glass. This glass protects the internal parts of the sight from dust, moisture and breakage. (b) Mirror. An ordinary mirror placed at an angle of 75° to the line of sight (LOS). The angle of the mirror is such that it ensures a turn of 105° to any light that is reflected by this mirror. RESTRICTED  RESTRICTED 22 (c) Objective Lens Assembly. A pair of lenses which are used to achieve convergence of light reflected by mirror as well as shorten the distance of convergence of light. (d) Prism Assembly. It is the property of a prism to turn any light that passes through it by 90°. (e) Sight Reticle Plate. This is a glass plate with the sight reticle pattern ‘etched’ on it. Property of glass is such that it does not allow light to pass through those points which are etched on the glass. (f) Light Emitting Diode (LED). Light Emitting Diode was required by the Fagot Launcher for depicting IR interference in the field of view. FLAME Launcher has been made by making minimum modifications to the Fagot weapon system. This LED has no major task to play in a FLAME Launcher. (g) Eye Piece Lens Assembly. A total of four lenses constitute the eyepiece lens assembly. Two of these lenses are fixed and the balance two are used by the pilot to focus onto the target. INTERNAL PARTS: SIGHT RESTRICTED  RESTRICTED 23 8. Light enters the sight through the protective glass and falls on the mirror which reflects this light by 105° to the line of sight. This reflected light passes through the objective lens assembly and falls onto the prism where it is turned by 90° in such a manner that it passes through the Sight Reticle Plate. Portions which are etched do not allow light to pass through. Finally through the Eye piece lens assembly the light falls onto the Pilots eye. RG FINDING LINES PRE-AIMING MK SIGHT RETICLE PATTERN 9. Sight Reticle Pattern. (a) Field of View. The field of view of the sight is 5°. (i) The smallest circle has a field of view of 6 mins. (ii) The middle circle has 30 mins field of view. (iii) The largest circle covers an area of 2º and 30 mins. (b) Horizontal Zero Line. Two lines one to the left and one to the right each. (i) On the right horizontal line there is a small vertical line, which is called Sign 3. This is used by the workshop to check the alignment of the sight. RESTRICTED  RESTRICTED 24 (ii) The left horizontal line is used for aligning a tank target horizontally astride this line to determine the range. (iii) Both the horizontal zero lines are used by the Workshop for harmonizing the sight and by the pilot to set the launcher parallel to the ground. (c) Dark Portion. On the lower portion of the sight a small portion is painted black. The portion is painted to enhance the LED light onto the reticle plate. This dark portion was useful when the light was used for detecting IR rays in Fagot Launcher. (d) Pre Aiming Mark. When the MILAN missile is loaded onto the launcher the weight of the missile in the rear, presses the cradle down. This raises the sight up by 8 minutes. On firing the missile however, the sight comes down. This will upset the aim of the pilot, if he had put the target in the center of the small circle. To offset this, a pre aiming mark, an inverted ‘V’ mark is etched on the sight reticle plate. The pilot while aiming coincides the apex of the inverted ‘V’ with the target, after the missile has been loaded. On firing the missile, the sight dips and the target automatically comes in the center of the small circle. This dip of the sight is called launcher dip and is approximately 8 min. (e) Vertical Zero Line. One line towards the top which is used by the workshop to align the sight and the launcher. (f) Range Finding Lines. Towards the left on top of the left horizontal line there are six range markings - 5, 10, 15, 20, 30 and 40. There are lines below each range, which along with the horizontal lines are used for determining the range of a tank (whose height is 2.5m). The range line so coinciding is multiplied by 100 to determine the range of the tank target. 10. Luminous Mark Feed Unit. On pressing the trigger an orange coloured cross appears superimposed on the sight reticle. This is called the luminous cross mark and it is 5º anti clockwise to the sight reticle zero lines. (a) Characteristics of the Luminous Cross. (i) The lines of the cross are 5º anti clock wise to the sight horizontal and vertical zero lines so they would not obscure the reticle cross. (ii) It has a central clearance, enabling the target to be visible at longer ranges. (iii) Two ‘+’ signs called Sign 1 and Sign 2. Both used for alignment purposes by the workshop. RESTRICTED  RESTRICTED 25 (iv) Orange colour, so that it is easily visible against any background. SIGHT RETICLE PATTERN WITH LUMINOUS CROSS (b) Internal Parts. (i) Illuminating Bulb. On pressing the trigger, the illuminating bulb produces light. (ii) Orange Filter. The light rays pass through an orange filter which absorbs all other colours less orange and permits only orange rays to pass. (iii) Lens. This converges the rays of orange light. (iv) Prism. The light rays pass through a prism which turns them by 90º. Just ahead of the prism is a plate which is opaque except for a cross left clear and so what emerges is orange light in the shape of a cross (+). (v) Lens. The rays then pass through a lens assembly due to which they get converged and focused. (vi) Double Prism. This turns the orange light by 180º and directs them towards the mirror. (vii) The mirror then directs the light rays into the sight tube so that the cross gets superimposed on the sight reticle plate. RESTRICTED  RESTRICTED 26 LUMINIOUS MARK FEED UNIT Part III : Optical and Mechanical Coordinator 11. The OMC is the upper part of the instrument 9W-119M1. It has two channels i.e. broad channel and narrow channel with respectively broad and narrow fields of view. 12. The broad channel has a field of view of 6º, which ensures reception of IR rays from the missile in the initial phase after launch, at greater angular deflection from the LOS. 13. The narrow channel has a field of view of 30’ designed for reception of IR rays after 4.6 seconds of launch. 14. The switching of channels is done for two reasons. These are:- (a) As sub tension increases with range, a lesser field of view is adequate to catch the incoming IR rays at longer range. (b) A smaller field of view reduces the likelihood of any extra IR rays entering the instrument and interfering with the missile IR. RESTRICTED  RESTRICTED 27 15. Functions of OMC. (a) Receives IR rays in form of Angular Deflection. (b) Converts this IR rays into electric impulse. (c) Sends this signal to the Electronic Pack. 16. Internal Parts. (a) Protective Glass. This glass protects the internal parts of the sight from dust, moisture and breakage. (b) Objective Lens Assembly. A total of eight lenses constitute the objective lens assembly. There are four lenses in each of the channel. (c) Diaphragms. There are two diaphragms, one is meant for the broad channel and the second for the narrow one. The broad channel has a aperture (hole) of 6° and the narrow diaphragm an aperture of 30 mins. Apart from it, both channels have a movable diaphragm each. This movable diaphragm is so placed that it blocks the IR rays entering into the diaphragms. (d) Diaphragms Mechanical. This is an electromagnet, which operates movable diaphragm, which is used for blocking the light from entering the OMC. On receiving an impulse the magnet operates the movable diaphragm, removing it from its position. INTERNAL PARTS : OMC RESTRICTED  RESTRICTED 28 (e) Scanning Frame. There are two identical discs called modulating discs, on this frame. This frame makes a plane parallel rotatory motion at the rate of 4500 rpm. This rotatory motion is carried out by a motor, which is part of the stabilisation circuit. (f) Modulating Discs. There are two identical discs on the scanning frame and they correspond to the two channels - broad and narrow. Each disc is portioned into 600 equivalent radial sectors. 300 of these are transparent and the balance are opaque. These disc rotate along with the scanning frame at a similar rate. (g) Photodiode. Two in number, they produce electricity when light falls on them. (h) Photo Electric Current Amplifier (PCA). The current generated by the photodiode is received by the PCA which am first two seconds and thereafter by 200 times. The current so produced is sent to the Electronic Pack. After 4.6 seconds on receiving an electric impulse from the Electronic Pack the channels are switched - from broad to narrow. STAB UNIT (j) Stabilisation Circuit. The missile is guided by electric impulses which are sent to the missile through the wire. It is imperative that flawless electric voltage is supplied to the various components of the FLAME Weapon System. There is a requirement of rotating the scanning frame at a speed of 4500 rpm and to ensure this, a dedicated circuit is in place called stabilisation circuit. Various components of this circuit are as below:- (i) Stabilisation Unit. This is part of the electronic pack and supplies the requisite power supply to the Output Stabilisation Stage (OSS) and receives an impulse from the Rotation Rate Sensor (RRS). It varies the output of electric supply as per the input from the RRS. RESTRICTED  RESTRICTED 29 (ii) Output Stabilisation Stage (OSS). It provides the motor with the required voltage to operate it. Any surge in the voltage is regulated at this stage. (iii) Motor. A driving shaft is attached to the scanning frame which provides plane parallel rotatory motion to the scanning frame as well as the modulating disc. (iv) Rotation Rate Sensor (RRS). Since the requirement of scanning frame rotating at 4500 rpm or 75 rps is a pre-requisite for the correct guidance of the missile therefore a separate unit is provided to measure the rotation rate. This is a dial with 10 teeth and this is rotated by the scanning frame’s rotatory motion, by a shaft. This dial is placed vertically in a horseshoe shaped electromagnet. Whenever the teeth of the dial cuts the electromagnetic field, a current is produced. In one rotation a current equivalent of one hertz (hz) is produced. In one second when the scanning frame rotates 75 rotations the current produced is 750 hz. This current is fed to the stab unit which manages the flow of current to the motor through the OSS. (v) Reference Voltage Generator (RVG). This is attached to the scanning frame by a driven shaft. The shaft end towards the RVG is horse shoe shaped. The RVG determines the location of the scanning frame at any given time and from that the location of the missile can also be derived. The coil to which the magnet is closer generates more electric impulse due to stronger electromagnetic field and the other three produce relatively lesser impulse. Therefore a sine wave corresponding to each position of the scanning frame is predetermined which in turn assists in determining the location of the missile. 17. Operations of Channel. (a) Before Trigger is Pressed. At this time the channels are both shut, as the moving diaphragm is in front of the aperture of the fixed diaphragm. This is necessary to prevent unnecessary usage or entrance of any other radiations. (b) When Trigger is Pressed. (i) The moving diaphragm is activated by getting a signal from the electronic pack, and the movable diaphragm of both the channels move up. This opens the fields of view of both channels. Initially, the PCA is pre-programmed to accept signals from only the broad channel. (ii) At T=4.6 seconds, the PCA gets another signal from the range unit and it stops accepting the signals through the broad channel and starts accepting signals from the narrow channel. Thus the RESTRICTED  RESTRICTED 30 changeover of channels actually takes place by means of time signals to the PCA. 18. Frequency Modulation. (a) The scanning frame along with the modulating disc moves in a plane parallel motion. During this motion, the IR rays strike the transparent and opaque radials. As the Infra Red rays strike the transparent radial, it passes through the scanning frame and hits the photodiodes, which produces a current. When Infra Red rays strike against an opaque radial, the Infra Red rays are not passed to the photodiode and no current is produced. (b) As the modulating discs move in a plane parallel motion, the center of the modulating disc subtends a circle. The center of this subtended imaginary circle coincides with the center of respective channel and with the LOS. In other words if the missile is on the LOS the Infra Red beam will be in the center of this subtended imaginary circle. (c) Since the centre of the subtended circle is at a constant distance, (radius) say ‘X’ from its circumference (the circumference is made by the center of the modulating disc) it can be said that the Infra Red beam at the centre of the subtended circle is at a constant distance from the center of the modulating disc. Thus if the missile is riding on the LOS, the Infra Red beam from the missile cuts the transparent and opaque radials at the constant distance X from its center. Since the width of the radials increase with their distance from the centre the Infra Red rays will be cutting equal portions of transparent and opaque radials. Thus the Infra Red rays will be passing through the alternate radials for the same amount of time. As a result of this the duration for which current is produced is equal to the duration for which the current is not produced. The resultant wave is of a constant frequency is as shown below. ( d) The frequency of the current produced is calculated by the number of pulses produced in one rotation multiplied by number of rotation per second i.e 300 pulses x 75 Rps = 22500 hz. If the missile is on the LOS the PCA produces a current of 22500 hz. If the missile is not on the LOS the current produced will be different. This variance in the frequency help in inferring the angular deflection of the missile. RESTRICTED  RESTRICTED 31 Part IV : Electronic Pack 19. The Electronic Pack may be termed as the actual brain of the system. It receives the electric voltage from the OMC, generates the required correction to get the missile onto the LOS and then sends the correction to the missile by the wire. 20. Functions of Electronic Pack. (a) Launch missile once junction unit battery has achieved correct voltage. (b) Give a correct voltage to the motor of the OMC to ensure correct speed of the scanning frame. (c) Prepare time signals for change of electrical circuits. (d) Receives angular deflections in the form of electric voltage from the sight cum OMC. (e) Converts the electrical signals into linear coordinates. (f) Prepare a polar command signal for the missile. (g) Sends the command signal to the missile by wire. 21. The Electronic Pack is made up of eleven (11) Printed Circuit Boards (PCB) fitted onto a motherboard. Various components of these PCBs, singly and in conjunction with others, perform various tasks to guide the missile in flight. However, various components, depending upon their functions have been classified together as functional units. The units are as under:- (a) Coordinator Unit. (b) Compensator Unit. (c) Coordinate Converter Unit. (d) Pulse Generator. (e) Filter. (f) Range Unit. (g) Relay. (h) Stabiliser Unit. (j) Power Sup Unit. RESTRICTED  RESTRICTED 32 22. Coordinator Unit. (a) Receives angular deflections from the PCA. (b) Amplifies the signal. (c) Receives input from the RVG. (d) Receives input from the Range Unit. (e) Converts the angular deflection into linear coordinates. (f) Changes the FM signal into AM signal. (g) Sends this signal U2Y and U2P to the Compensator Unit. 23. Compensator Unit. (a) Receives Signal U2Y and U2P and amplifies this signal. (b) Adds the Trajectory Raise Programme. This causes the missile to rise to a height of 1.2 m above the LOS upto a distance of 300 m and then stay at 0.5 m above the LOS. (c) Adds the Mass Balance Programme. This is to compensate for the change in mass and shift in centre of gravity (CG) due to the burning of the propellant. This pre - programmed command adjusts the missile to compensate for the change in CG. (d) Adds the Elevation Limiter Programme. This Programme is added to ensure that any dive command given to the missile in flight is automatically inhibited. No “down” commands are given to the missile and it comes down purely by force of gravity. (e) Sends signal U3Y and U3P to the coordinate converter unit. 24. Coordinate Converter Unit. (a) Receives the signal U3Y and U3P. (b) Amplifies the signal. (c) Prepares Polar Command signal to get the missile onto LOS. This signal is in terms of Location of correction and Duration of correction. (d) Sends signal U4L and U4D to the Pulse Generator Unit. RESTRICTED  RESTRICTED 33 25. Pulse Generator Unit. (a) Receives signal U4L and U4D. (b) Receives the gyro pulse which is a reference of the location of the jet interceptor assembly i.e gyro top reference. (c) Finds out roll rate of missile with reference to the gyro top reference pulse. (d) Prepares a pulse to send polar command signal to the missile. (e) Sends the command signal U5LD to the Filter. 26. Filter. (a) Receives command signal pulse U5LD from the Pulse Generator. (b) Prevents induction of atmospheric noise signals into the wire (WCL). (c) Sends the command signal U6LD to the electromagnets of the jet interceptor assembly. 27. Range Unit. (a) It has electronic time clock which makes time signals for ignition of batteries and completion of circuits. (b) Generates voltage as per range of the missile. This is a time dependent signal since it is based upon TOF (Time of Flight). (c) Along with RVG voltage it helps in changing angular deflection signal into missile linear coordinates. (d) At T=4.6 Seconds it sends out a signal to change the circuit of the PCA. 28. Relay. (a) On receiving a time signal from the range unit, its circuit is completed, due to which the batteries send out the first and second ignition pulse. (b) First ignition pulse is of 0.380 sec duration and ignites the Missile Battery and Gyroscopic assembly. (c) Second ignition pulse is of 0.400 sec duration and it is after 0.660 sec. It ignites the Release Thruster, the Gas Generator and the Tracer. RESTRICTED  RESTRICTED 34 29. Stabiliser Unit. (a) Sends voltage to the motor of the OMC. (b) Provides current to the OSS and steps up or down the current depending upon speed of scanning frame. (c) Provides current to PSU from JUB. 30. Power Supply Unit. (a) Supplies power to various parts of the GCE once junction unit battery has achieved a voltage of 20-26V. (b) Provides current from the JUB to the OMC motor and the coordinator unit. Conclusion 31. As users of the FLAME weapon system, it is necessary to know the functioning of the system so that the principles and mechanics by which the missile is guided onto the target are clear. The GCE is the most important part of the system and knowing about it will enable us to immediately diagnose any faults that may occur as well as in imparting training to others. RESTRICTED  RESTRICTED 35 TECHNICAL MAINTENANCE OF FLAME LAUNCHER Introduction 1. As with other equipment and weapons it is imperative that the maintenance of FLAME Launcher be carried out regularly to ensure long life of the weapon and also to prevent any accidents. Aim 2. To get acquainted about the Technical Maintenance of the FLAME Launcher. Preview 3. The topics covered in four parts:- (a) Part-I. Check Inspection. (b) Part-II. Routine Maintenance. (c) Part-III. Technical Maintenance. (d) Part-IV. Seasonal Maintenance. Part-I : Check Inspection 4. This inspection is carried out by the ATGM crew members. This inspection is done during training, war, firing or when moving the launcher from one place to another. Following things are checked:- (a) Pack, straps and hooks of launcher mount. (b) Tripod and the legs. (c) Fitting of Instrument 9 W-119 M1. (d) Traversing and elevating mechanism. (e) All cables and their connections. (f) Cleanliness and working of all optical parts. RESTRICTED  RESTRICTED 36 Part II : Routine Maintenance 5. This is also done by the crew members. It is done once in every two weeks or whenever the launcher mount is being taken for training or parade. The following are checked:- (a) Preventing launcher mount from coming in contact with water, dust or moisture. (b) Lubricating areas without paint. (c) Preventing the launcher mount from rust. (d) Checking of electrical connections. (e) Checking of SPTA of launcher mount. (f) Cleaning of Sight cum OMC. (g) Cleaning of all glass parts with a flannelette cloth. (h) Checking of the traversing and elevating mechanism by turning the hand wheels. (j) Checking all straps and braces. Part-III : Technical Maintenance 6. There are two types of Technical Maintenance. Technical Maintenance 1 (TM 1) and Technical Maintenance 2 (TM 2). 7. Technical Maintenance 1. This is also done by the numbers of the ATGM detachment. This maintenance is done once in a year or after 100 trigger operations whichever is earlier. The following are checked in Technical Maintenance 1:- (a) Checking the launcher mount during the drills of ‘Carry to Combat position’ and ‘Combat to Carry position’. (b) Checking the free traversing of the launcher. (c) Checking the functioning of traversing and elevating mechanism. (d) Checking the functioning of the Trigger mechanism. RESTRICTED  RESTRICTED 37 8. Technical Maintenance 2. Technical maintenance 2 is carried out by the field workshop and is recorded in the log book of the FLAME launcher. It is carried out once in two years or after 300 trigger operations, whichever is earlier. The following are checked:- (a) Alignment of Sight 9W-119 M1. (b) Functioning of the units of Electronic pack. Part -IV : Seasonal Maintenance 9. This maintenance is carried out twice in a year. (a) During Summer Season. (b) During Winter season. 10. This maintenance can be carried out along with the TM 1 or TM 2. The following are checked :- (a) Lubricate the parts requiring lubrication. (b) The lubricant of the elevating mechanism is changed. Conclusion 11. The FLAME Launcher as such requires very little maintenance and if taken care of regularly the weapon system will perform under all circumstances and battle conditions. It is imperative that the maintenance of the FLAME Weapon is known to all the detachment. RESTRICTED RESTRICTED 38 RESTRICTED  RESTRICTED 39 CHARACTERISTICS AND MAIN PARTS OF MILAN MISSILE Introduction 1. Originally developed and produced in France, MILAN is a very potent ATGM and is used to destroy enemy tanks and Armoured Personnel Carriers (APCs) in battle. It is important for the detachment numbers to know about its main parts and characteristics. Aim 2. To learn about the characteristics, main parts and limitations of MILAN missile. Preview 3. This topic is covered in three parts:- (a) Part I. Characteristics. (b) Part II. Main Parts. (c) Part III. Limitations. Part I : Characteristics 4. MILAN Missile is packed in a launch tube and is mounted on the FLAME Launcher for the purpose of firing. Its mechanical functioning is initiated by electric current, which is produced by pressing the trigger. 5. Characteristics are as under:- (a) Range. (i) Minimum. - 20 m. (ii) Maximum. - 2000 m. (b) Time of flight - 12.5 sec (at max range). (c) Velocity. - 75 - 210 m/sec. (d) Penetration. (i) 90° angle of impact. - 850 mm. RESTRICTED  RESTRICTED 40 (ii) 60° angle of impact. - 650 mm. (e) Control. - Thrust vector. (f) Propellant. - Solid. (g) Roll rate. - 6 -14 RPS. (h) Hit probability. - 90 to 95 %( at ranges more than 300 m). (j) Operating temperature. - -40º to +52º C. (k) Tube recoil. - 2 to 6 m. (l) Wire length. - 2020 m. (m) Missile calibre. - 115 mm. (n) Body diameter. - 133 mm. (o) Missile length. - 769 mm. (p) Launch Tube length. - 1200 mm. (q) Launch tube diameter. - 220 mm. (r) Weight. (i) Missile in tactical packing. - 11.8 Kg. (ii) Missile in tube. - 11.3 Kg. (iii) Missile in flight. - 6.7 Kg. (iv) War head. - 2.71 Kg. (v) Fuze. - 0.3 kg. (vi) Missile in logistics container. - 82 Kg. RESTRICTED  RESTRICTED 41 Part II : Main Parts 6. MILAN Missile is divided into three parts:- (a) Launch Tube. (i) Junction Unit. (ii) Missile. 7. Parts of the Launch tube. (a) Covers and Straps. (i) Front and rear covers protect the missile from dust and moisture and is fastened to the tube with Velcro straps. (ii) Diaphragm prevents the entry of dust and moisture into the tube. (iii) Junction unit Cover protects the Junction Unit during storage. (iv) Strap is used to carry and load the tube. (b) Tube. It is made up of fibre glass and it stores and launches the missile. (i) Rubber pads prevent the front cover misplacement. (ii) Stop Ring stops the Fin Retaining ring inside the tube during launch of the missile. (iii) Latching Unit and Junction Unit are mounted on the bracket. (iv) Studs are four (04) in number and provide rotation to the piston and the missile during launch. (c) Latching Unit. It joins the Missile, Launch Tube and Junction Unit before launch. (d) Gas Generator. It produces gases which provide a speed of 75 m/ sec to the launched missile and reduces the speed of recoil from 25 m/ sec to 8 m/ sec. The parts of Gas Generator are as under:- (i) Igniter and Ignition Tube. There is an ignition tube inside the Gas Generator which is filled with explosive. The igniter is fitted on one end of the Ignition Tube and it burns the explosive. RESTRICTED  RESTRICTED 42 (ii) Cable and Connector. Provides current to the Gas Generator. (iii) Front and Rear Chamber. These are filled with explosives which produce gases to launch missile and reduce the speed of recoil. (iv) Valras Discs. These are discs made of explosives. There are 78 Valras Discs in the Front Chamber and 12 in the Rear Chamber. (v) Supporting Assembly. It supports the Valras Discs. (vi) Partition Assembly. It separates the Front and Rear Chambers. (vii) Envelope. It is made up of Fibre Glass. (viii) Gas Escape Holes. There are 105 gas escape holes in the Front chamber and 09 in Rear chamber. The gas produced in the Gas Generator comes out through these and exerts pressure on the Piston. (ix) Attachment Lugs. These are three in number and join the Gas Generator to the Launch Tube. (x) Ejection Front Nut. It provides a passage for the gases to the Blast Tube. (xi) Filter. It stops the explosive particles from entering the Blast Tube. (e) Piston. It is made up of Macralon and is placed between the Gas Generator and the Missile. The gas produced in the Gas Generator exerts pressure on the Piston in the forward direction. The Piston pushes the missile and the missile is launched. The parts of Piston are:- (i) Crown and Retaining Lugs. They hold the missile inside the tube. (ii) Nozzle. It is a passage for the gas to go into the Blast Tube. (iii) Channel. It strikes the Fin Retaining Ring during launch and folds it. (iv) Rubber O Ring. Prevents leakage of gases. (v) Slots and Helical Ramps. They are four in number and are aligned at an angle of 6º to the longitudinal axis to the right. RESTRICTED  RESTRICTED 43 (vi) Rear Connector. Its one end is connected to the Latching Unit and the other to the Missile. 8. Junction Unit. The Junction Unit performs the following functions:- (a) Provides electrical connection between Launcher and the Missile. (b) Provides electric current to initiate the functioning of the Missile. (c) Provides current to the Launcher. (d) Sends the command signal from the Launcher to the Missile. 9. Missile. The missile can be divided into the following main parts:- (a) Head. (i) War head. It is based on the principle of Hollow Charge. It destroys the armour plate on impact. (ii) Fuze. It initiates the War head on receiving current. (b) Vehicle. (i) Motor. The Booster Sustainer Motor is housed inside it which propels the Missile till the target. Four Fins are fitted on to its body. During flight the Missile rolls on its axis due to the Fins. (ii) Rear Section. It houses the Gyroscopic assembly, Missile Battery, Decoder, Jet Interceptor assembly and the Tracer. Wire Spool is wrapped on its body. Part III: Limitations 10. The limitations are as under:- (a) Long Time of Flight. This is due to the low velocity of the missile. The pilot is vulnerable to enemy action till the time the Missile is in flight. The time of flight at various ranges is given below:- Range (m) 400 500 800 1000 1200 1500 2000 TOF(sec) 3.54 4.25 6.5 7.35 8.42 10 12.5 RESTRICTED  RESTRICTED 44 (b) Back Blast. Back blast can be hidden by the detachment numbers by way of choosing good fire position. Conclusion 11. MILAN Missile is a potent Anti Tank weapon and if used effectively can produce desired results in battle field. RESTRICTED  RESTRICTED 45 HEAD AND MOTOR BODY ASSEMBLY: MILAN MISSILE Introduction 1. To be able to understand the functioning of MILAN missile, it is important to be familiar with its components and their functioning. The motor body assembly propels the missile to its destination and the components fitted in the head assembly destroy the target. Aim 2. To learn about Head and Motor Body assembly of MILAN missile. Preview 3. The topic is covered in two parts: - (a) Part - I. Head Assembly. (i) Nose Cone. (ii) Fuze. (iii) Warhead. (b) Part - II. Motor Body assembly. (i) Booster Sustainer Motor. (ii) Fin Assembly. Part - I: Head Assembly 4. Nose Cone. This is made of fibre glass and has two hemispherical cups at the tip. The electrical circuit between the fuze and the decoder is completed when the nose cups or shoulders come in contact. The initiator of the fuze gets ignited and the warhead explodes. The parts of nose cone are as under:- (a) Outer Cup. It is made of Silver plated copper. An Outer Shoulder Contact, made of silver plated copper, is connected with it. (b) Inner Cup. It is inside the outer cup and is made like outer cup. An Inner Shoulder Contact, made of silver plated copper, is connected with it. RESTRICTED  RESTRICTED 46 HEAD AND MOTOR BODY ASSEMBLY (c) Contacts. Inner nose cone is connected to inner shoulder and outer nose cone is connected to outer shoulder with the help of wires. When nose cones or shoulder contacts come in contact the initiator of fuze receives current and the warhead explodes. 5. Fuze. (a) Functions of Fuze. (i) Initiates the warhead. (ii) Blanks off one end of the BSM chamber. (b) Parts. (i) Body. It is made of Aluminium. The parts of Fuze are housed inside it. (ii) Pressure Connector Holes. Two in number, they are drilled on the body of the Fuze. The gas produced in the BSM enters the upper latch chamber through these holes. (iii) Blanking Discs. Two in number. These seal the pressure connector holes during storage. RESTRICTED  RESTRICTED 47 (iv) Initiator Connector Pin. It receives current from the decoder, when the nose cones come in contact. Initiator produces a spark which explodes the detonator. (v) Detonator Flap. The detonator is housed inside it. When the fuze is in unarmed position the detonator and the initiator are not aligned to each other. In this condition even if the initiator receives current the detonator will not explode. When the flap comes to armed position the detonator and the initiator get aligned and if the initiator is ignited the detonator will explode. (aa) Spring. It remains compressed in the unarmed position. When it expands it pushes the detonator flap and the detonator and the initiator come in one line. (ab) Detonator. When ignited it detonates to produce detonating waves at a velocity of 2000 m/ sec. These detonating waves pass through relay and activate the hollow charge. (ac) Locking Stud and Locking Stud Recess. In the unarmed position the locking stud remains inside its housing located in the detonator flap) and its spring remains compressed. When the flap comes to the armed position the locking stud comes in line with the locking stud recess. The spring expands and the locking stud is pushed inside the recess. The detonator flap now gets locked in the armed position. (vi) Latch. It keeps the detonator flap locked in the unarmed position thus not allowing the detonator and initiator to come in one line. (aa) Cut Portion. When the Latch cut portion comes in front of the detonator flap, the detonator flap spring expands and the flap comes in the armed position. (ab) Shearing Pin. It keeps the latch in the unarmed position. When the latch is pushed with a pressure of 64+15 bars the shearing pin breaks. (ac) Guide Pin. The guide pin ensures smooth movement of the latch. (vii) Upper Latch Chamber. The gases from the pressure connector holes enters upper latch chamber and pushes the latch. RESTRICTED  RESTRICTED 48 (viii) Fuseable Plug. This is a safety device. During storage, if due to accidental fire/extreme heat conditions the temperature crosses 96° C the fuseable plug melts and releases the pressure developed inside the upper latch chamber. Thus it prevents accidental arming of the fuze. PARTS OF FUZE FUZE UNARMED POSITION (c) Arming. (i) Initially the latch keeps the detonator flap in the unarmed position wherein the initiator and detonator are not in one line. In this position the spring is compressed. RESTRICTED  RESTRICTED 49 (ii) In this position the latch also cannot move due to the shearing pin. (iii) Part of the gas produced by the BSM burns the blanking disc and enters the upper latch chamber through the pressure connector hole. (iv) The gas exerts pressure on the latch. When the pressure reaches 64±15 bars the shearing pin breaks and the latch moves forward in its passage. (v) The cut portion of the latch comes in front of the detonator flap and the spring releases its tension and pushes the flap forward. The locking stud gets engaged in its recess and locks the flap in the armed position. (vi) In this position the fuze is armed and the detonator and initiator are in one line. (vii) To prevent the accidental arming of the fuze a fuseable plug has been provided in the upper latch chamber. This plug melts at 96°C. It provides a escape route to the gas through the chamber. It also prevents excessive pressure in the fuze. (viii) Arming of the fuze takes place approximately 20 m from the point of launch. (ix) The fuze dose not get armed till the BSM starts functioning. This is a safety mechanism. 6. Warhead. It works on the principles of hollow charge and destroys the target. The parts of the warhead are as under:- (a) Threaded Securing Ring. The warhead has been secured to the BSM with the help of this. (b) Rear Blanking Element. It blanks off the rear of the warhead and provide mechanical and electrical connections to the warhead. (c) Relay. The detonating waves travel through it and reach point booster. (d) Point Booster. It increases the velocity of the detonating waves to 4000 m/ sec. (e) Wave Shaper. It is an impermeable isomer. It ensures that the detonating waves fall uniformly on the explosive charge at one time. RESTRICTED  RESTRICTED 50 (f) Explosive Charge. It weighs 1.81 Kg and is a mixture of HMX (85%) and TNT (15%). It detonates to produce detonating waves at a velocity of 9000 m/ sec. (g) Copper Cone. The detonating waves melt it and it takes the shape of a metallic jet. The jet penetrates the armour and destroys it. Part - II : Motor Body Assembly 7. The motor body is made of aluminium. It houses the BSM and the Fin assembly is mounted on it. 8. Booster Sustainer Motor. (a) Function. (i) Booster charge burns for 1.3 sec and accelerates the missile from 75 m/ sec to 130 m/sec. (ii) Sustainer charge accelerates the missile from 130 m/ sec to 210 m/sec in 11.2 sec. (iii) Part of the gas produced arms the pyrotechnic fuze of the warhead. (b) Parts. (i) Inhibitor. It is an inhibiting varnish coated on the circumference of the propellant. It ensures frontal combustion of the propellants. (ii) Propellant. It is a mixture of Nitrocellulose and Nitro-glycerine. The propellants are arranged in such a manner that they burn in two stages. The propellants for two stages are glued end to end. These are:- (aa) Booster Stage. It has 175 g of propellant and it burns for 1.3 sec. It accelerates the missile from a speed of 75 m/ sec to a speed of 130 m / sec. (ab) Sustainer Stage. It has 630 g of propellant and it burns for 11.2 sec. It accelerates the missile from a speed of 130 m/ sec to a speed of 210 m / sec. (iii) Mira Primer. The gas from the gas generator enters through the blast tube and burns the Mira primer. Mira primer ensures uniform burning of the propellant. RESTRICTED  RESTRICTED 51 (iv) Arming Tube. It is placed inside the propellant. A part of Gas produced due to the burning of booster stage propellant pass through this and enters the fuze through the pressure connector holes. (v) Spherical Cover. It is made up of Durestos (heat resistant material). It protects the body of missile, made of aluminium, from the heat produced inside the motor body. On the rear side there is a hole drilled on its centre, through which the blast tube is connected. A NC Sheet is placed on this hole, which protects the propellant from humidity during storage. (vi) Circlip. This helps in connecting the fuze to the motor body. (vii) Rubber ‘O’ Ring. It prevents the gases produced in the BSM from going towards the warhead. NC Sheet Booster Booster Phase Spherical Cover Sustainer Phase Fuze Blast tube Mira Primer Arming tube Inhibitor NC Sheet PARTS OF BSM (c) Functioning. (i) The gas produced by the Gas Generator moves through the nozzle of the piston, into the blast tube. The gas burns the nitro cellulose sheet on the spherical cover and burns the Mira Primer. (ii) Mira Primer ensures uniform burning of the booster charge. RESTRICTED  RESTRICTED 52 (iii) The inhibitor ensures that the charge burns from one end like a cigarette. (iv) The propellant of booster phase burns till 1.3 sec and propels the missile from 75 m/ sec to 130 m/ sec. Thereafter the sustainer phase continues till 12.5 secs and the missile is propelled from 130 m/ sec to 210 m/ sec. (v) Gases produced due to the burning of the charge enters via the central hole of the spherical cover, into the blast tube and comes out of the jet deflector assembly. (vi) Some gas passes through the arming tube and arms the fuze. 9. Fins. Four in number, these are made of fiber glass reinforced polyester material. Inside the launch tube they are kept folded with the help of fins retaining ring made of aluminium alloy. During launch the retaining ring is stopped by the steel stop ring and the fins open up due to the tension of the springs. The fins are set at an angle of 2° 30’ with regard to the longitudinal axis to ensure clockwise rotation of the missile. As the velocity of the missile increases the roll rate increases from 6 to 14 RPS. 10. Fin Retaining Ring. Fin retaining ring has the following functions:- (a) It keeps the fins in a folded position inside the launch tube. (b) It guides the missile inside the launch tube. (c) In conjunction with the steel stop ring it stops the piston and ensures correct separation of the piston from the missile. Upon impact it is buckled and hence acts as a damper. Conclusion 11. The head and motor body assembly are two important parts of the MILAN missile. The comprehension of these two parts will be useful in understanding the functioning of MILAN missile. RESTRICTED  RESTRICTED 53 REAR SECTION, LATCHING UNIT AND JUNCTION UNIT Introduction 1. The components fitted in the rear section of the missile generate and send signals to the electronic pack during flight. They also receive and interpret the signal received from the electronic pack. The latching unit keeps the missile, the launch tube and the junction unit together during storage conditions and during launch releases them. Aim 2. To learn about the rear section, latching unit and junction unit. Preview 3. The topic is covered in three parts :- (a) Part - I. Rear Section. (b) Part - II. Latching Unit. (c) Part - III. Junction Unit. Part - I: Rear Section 4. The components in the rear section are:- (a) Wire spool and cover. (b) Gyroscopic assembly. (c) Missile battery. (d) Decoder. (e) Jet interceptor assembly. (f) Tracer Element. 5. Wire Spool and Cover. (a) Wire spool. The wire measures approximately 2020 m and is coiled on the rear section. It consists of two copper wires within the same cover RESTRICTED  RESTRICTED 54 made of polyester and silk. The wire is used to transmit the remote control commands from the launcher to the missile and the reference pulses from the missile to the launcher. (b) Short Circuit Bridge. This is a safety device. The electrical circuit between the decoder and the fuze has been short - circuited by means of a small loop of flexible circuit. The wire has been made to pass through this loop. As the wire uncoils approximately 20m, it breaks this short circuit bridge and the current flows to the initiator of the fuze. Thus the missile is armed only after covering a distance of 20 m. (c) Cover. It is made of plastic. It has two parts Crown and Convergent Nozzle. The cover has been fixed on the rear section with the help of crown. The convergent nozzle secures the wire and ensures its smooth uncoiling. 6. Intermediate Plate. This is a plate made of aluminium alloy secured to the body of rear section by means of four screws. It acts as a mechanical support for the printed circuit board (PCB), the gyroscopic assembly, the decoder and the missile battery. RESTRICTED  RESTRICTED 55 7. Gyroscope Assembly. (a) Functions. (i) It determines a reference for firing, independent of the missile rotation. (ii) It supplies pulse used to detect the position of the jet deflector with regard to the reference. (b) Parts. (i) Main Body. (aa) Rotor. It is made of brass and has 18 vanes on it. It weighs 16.5 gms and attains a speed of 1, 00,000 rpm in 0.2 second. The stored energy allows the gyroscope to operate for 15 sec. (ab) Inner Gimbal. The rotor is mounted on it with the help of two bearings. A hole is drilled on the gimbal. During storage conditions, gas outlet tube rests inside this hole and keeps the gimbal in locked position. (ac) Outer Gimbal. Inner gimbal is mounted on it with the help of two bearings. The outer gimbal is mounted on the body of gyroscope with the help of two bearings. Cup shaped element is fitted on the shaft of this gimbal. A hole is drilled on the gimbal. During storage conditions, gas outlet tube rests inside this hole and keeps the gimbal in locked position. (ad) Cup Shaped Element. It is secured to the shaft of the outer gimbal. It has a cut portion called window. During the rotatory motion of the missile, it remains stationary as the outer gimbal cancels the roll effect of the Missile. (ii) Front Section. The front section houses the electric bulb and the photodiode assembly. The electric bulb and the photodiode assembly rotate along with the missile as the front section is fitted to the gyro body. The assembly is placed on top of the cup shaped element in such a manner that the electric bulb lies inside the cup shaped element while the photodiode lies outside. Thus the light emitted by the bulb is obscured by the wall of the cup shaped element. During one rotation the light falls only once on the photodiode, when the electric bulb and the photodiode come in the line of the window. RESTRICTED  RESTRICTED 56 GYROSCOPE ASSEMBLY (iii) Drive Unit. (aa) Double chamber. (ab) Igniter and Propellant. The igniter receives current from the JUB during first ignition pulse. (ac) Piston. (ad) Gas Outlet Tube. The gas outlet tube performs two important functions. Firstly, before operation of the gyroscopic assembly it keeps the gimbals in locked position. In this condition the spring blade rests on the groove of the piston and holds it in forward position and the coil spring remains compressed. Secondly, when the propellant is ignited, it directs the gases on the rotor and the rotor starts rotating. Due to the pressure of the gases the piston is pushed forward and the leaf spring is released. The piston is now free to move backwards. The piston moves back due to the tension of the coil spring once the pressure on the chamber reduces and frees the gimbals. (ae) Diaphragm. (af) Coil spring. (ag) Spring Blade RESTRICTED  RESTRICTED 57. Piston Spring blade Outer gimbal Upper Chamber Gas outlet tube Diaphragm Lower Chamber Igniter Propellant Rotor Coil spring (c) Operation of Gyroscope Assembly. (i) Gas outlet tube maintain the gyro gimbals in locked position before the operation of the gyroscopic unit. (ii) The igniter receives the current from the JUB and burns the propellant. Gases are produced due to the burning of the propellant. (iii) The gases exert pressure on the piston because of which the gas outlet tube moves forward compressing the coil spring. (iv) The leaf spring gets disengaged from the piston recess and moves back in the drive unit body. (v) The diaphragm burns and some part of the gas enters the gas outlet tube. (vi) These gases fall on the rotor vanes and rotate it at a speed of 1, 00,000 rpm in 0.2 sec in anti clock wise direction. (vii) At the end of the combustion period the pressure drops in the chamber and the piston moves back along with the gas outlet tube, due to the tension of the coil spring, therefore the tube is disengaged from the gyroscope gimbals. (viii) Due to the rotation of the rotor and placing of the gimbals the plane of rotation of the rotor remains stationary. The outer gimbals cancel the roll effect and the inner gimbals cancels the yaw effect. (ix) The cup shaped element attached to the shaft of the outer gimbal also remain stationary. RESTRICTED  RESTRICTED 58 (x) The electric bulb and the photodiode attached to the gyroscopic body rotate with the missile rotation. (xi) The cup shaped element allows the passage of light from the bulb to the photodiode, once the window, bulb and diode are in one straight line. (xii) The photodiode, electric bulb and window come in line with each other after a rotation of 360º, a signal is produced due to the falling of light on the diode. This signal is known as the gyroscope top reference pulse. This signal depicts the position of the missile, when the jet interceptor blade is in the top position. 8. Decoder. The decoder performs the following functions:- (a) It amplifies the command signal received from the launcher and activates the electro magnets of the jet interceptor assembly. (b) It amplifies the voltage received from missile battery to 40 volts and gives it to the photodiode assembly. (c) It amplifies the voltage received from missile battery from 90 to 160 volts and stores it in a capacitor. This current is passed to the initiator of the fuze once the nose cones of the warhead come in contact. 9. Missile Battery. The missile battery gets activated on receiving current from the JUB. It takes 0.3 sec to achieve its operating voltage of 9 ± 2 V. It provides current to the decoder. The decoder charges the capacitors of the fuze, electric bulb and photodiode assembly 0.35 sec after receiving current from the missile battery. 10. Jet Interceptor Assembly. This is used to steer the missile in flight by deflection of the exhaust gas jet. It is achieved by getting the jet deflector lever in the way of the exhaust gases. The parts of jet interceptor assembly and their functions are as under:- (a) Support Plate. The assembly has been mounted on it. (b) Blast Tube. It is made of refractory material (thermo - setting resin impregnated with silica) coated with a winding of glass fibre. The front end of the blast tube is fitted to the BSM and at the rear a nozzle is fitted for the passage of gases. The nozzle is made of molybdenum. The blast tube carries out two important functions:- (i) The gases produced in the gas generator pass through it and activates the BSM. (ii) The exhaust gases produced in the BSM pass through it and come out of the nozzle in the form of a jet. RESTRICTED  RESTRICTED 59 (c) Electromagnets. These are two in number. Depending upon the command received from the launcher the decoder energizes one of the electromagnets. The energized electromagnet attracts the steel flap towards it. (d) Flap. It is made of steel and has been positioned between the two electromagnets. The flap is connected to the jet deflector lever. Hence when the flap moves to one of the electromagnets it also moves the lever. (e) Jet deflector Lever. It is made of molybdenum and it lies on the edge of the nozzle fitted on the blast tube. It is fitted on the support plate with the help of a spring blade. The ‘Flap’ is attached to it. The lever is either placed in or withdrawn from the path of the exhaust gas jet depending upon the movement of the ‘Flap’. Thus the path of the jet is changed and the required correction is given to the missile. JET INTERCEPTOR ASSEMBLY Part - II: Latching Unit 11. Functions of Latching Unit. (a) Separates the missile from the tube. (b) Releases the Junction unit from the latching unit. (c) Completes the electrical circuit of the Gas Generator and Tracer. (d) Breaks the short circuit existing in the firing circuit of Gas Generator and Tracer. RESTRICTED  RESTRICTED 60 (e) Acts as a safety device in ensuring that the Gas Generator is not activated before the missile is released from the tube. 12. Parts of Latching Unit. (a) Body. The parts of latching unit are housed inside it. (b) Release Thruster. It is filled with explosive charge and an igniter is fitted to it. On receiving current from the JUB the igniter ignites the charge due to which gases are produced. (c) Latching Finger. It keeps the missile, launch tube and latching unit together before launch. A shearing pin holds it in position. (d) Chamber. The gases produced in the release thruster enter the chamber and press the piston downwards. (e) Piston. The gas pressure in the chamber presses the piston downwards and the piston breaks the shearing pin. The latching finger also moves down. During this downward movement the piston breaks the short circuit bridge and presses the plunger of the junction unit inside its housing. (f) Conducting Ring and Contacts. During the downward movement of the latching finger, the conducting ring (located on the latching finger) comes in contact with the ‘Contacts’. The electrical circuit between the JUB and Gas Generator now gets completed and the current flows to Gas Generator. RESTRICTED  RESTRICTED 61 (g) Flexible Circuit Tape. It short circuits the circuit between the JUB and the Gas Generator and Tracer. The short circuit is broken by the piston once the release thruster is activated by the JUB. (h) Insulating sheath. It is a coating of insulating material on the piston. During storage (before operation of the latching unit), it remains in contact with the contact blades and prevents electrical connection between JUB and Gas Generator. (j) Shearing Pin. Located inside the chamber. It holds the piston in its position during storage. 13. Operation of Latching Unit. (a) Latching finger keeps the missile, tube and latching unit attached to each other. (b) Shearing pin of the junction unit keeps the junction unit plunger in locked position, thereby keeping the junction unit and latching unit together. (c) The igniter of the release thruster receives current from the JUB which causes an explosion of the pyrotechnic charge. (d) The gas produced puts pressure on the piston, inside the chamber. (e) The piston is forced down. In its downward move its breaks the shearing pin retaining it. (f) The latching finger moves out of the fin mounting boss, frees the missile, tube and latching unit from each other. (g) In its downward move it brings the conducting rings in contact with the contact blades. This completes the circuit of the Gas Generator. (h) The piston in its downward move breaks the short circuit in the firing circuit of the Gas Generator. (j) The piston pushes the plunger of the junction unit downwards, breaking the shearing pin which holds it in locked position. The latching unit and junction unit get separated from each other. Part - III: Junction Unit 14. Functions of Junction Unit. (a) It ensures electrical and mechanical connection between the launcher and the missile. RESTRICTED  RESTRICTED 62 (b) Provides current to Missile battery, Gyroscopic assembly, Release thruster, Gas Generator and Tracer. (c) Provides current to the various components of GCE. 15. Parts of Junction Unit. (a) Forward Pole. Located at the front, it supports a wire guide which protects the remote control wire when the missile leaves the launch tube. (b) Slider. It is a spring blade located at the front end of the pole. It provides better connection of the junction unit with the launcher ramp after launch of the missile. (c) Sliding Block with Stud. The control wire is attached to a Stud and a Sliding Block. The Sliding Block is provided with a coil spring. This arrangement is provided to absorb the jerks on the wire during the launch of the missile and during flight. (d) Female Front Connector. It connects with the 12 pin connector of the ramp adapter. (e) Junction Unit Battery. It is a thermal battery which has the following functions:- (i) Provides current to various components of GCE (voltage supplied is between 20 to 26 V). (ii) Provides current to Missile battery, Gyroscopic assembly, Release thruster, Gas Generator and Tracer (voltage supplied is between 4.5 to 10 V). JUNCTION UNIT RESTRICTED  RESTRICTED 63 (f) Connector. It is connected to the connector of the Latching Unit. (g) Rear Platform. The rear platform is provided with two side ramps leading to two slides. The right ramp has a bulging section and a recess. When the missile is loaded on to the launcher, the two ramps located on either side of the junction unit come in contact with two studs secured to the ramp. (h) Plunger. It joins the latching unit with the junction unit during storage conditions. A shearing pin holds it in this position. When the latching unit is activated the piston of the latching unit pushes it down inside its casing. The shearing pin is broken due to the pressure. Conclusion 16. The Rear section, Latching Unit and Junction unit are the three important parts of the MILAN missile, which incorporates various safety mechanism and guidance elements. RESTRICTED  RESTRICTED 64 MECHANICAL FUNCTIONING OF MILAN MISSILE Introduction 1. The hit probability of MILAN missile is more than 90%. A number of precision- made components are fitted in the Missile to ensure such a high hit probability. To understand this system it is imperative to learn the mechanical functioning of the missile. Aim 2. To learn about the mechanical functioning of the MILAN missile. Preview 3. The topic is been covered in four parts:- (a) Part - I. Construction and function of batteries. (b) Part - II. Pre - Launch operations. (c) Part - III. Operations during flight. (i) Arming of the fuze. (ii) Launch sequence. (iii) Guidance of the missile. (d) Part - IV. Function of the warhead. (i) On Impact. (ii) On missing the target. Part - I: Construction and Functions of Batteries 4. FLAME weapon system consists of a number of electrical and electronic components. These components require a power supply source to function. Thermal batteries are used in MILAN missile as a source of power supply. 5. Parts of a Thermal Battery. (a) It consists of 14 cells connected to each other in series. RESTRICTED  RESTRICTED 65 (b) It has two electrodes:- (i) Anode. Calcium. (ii) Cathode. Zinc. (c) Solid electrolyte made of potassium lithium chloride. (d) Powder charge which is a mixer of zirconium powder, asbestos and water. (e) Electrical Igniter. 6. Functioning of a Thermal Battery. (a) On receiving current the electrical igniter ignites and burns the powder charge. (b) The heat produced by the burning of the powder charge melts the solid electrolyte. (c) The melting of the solid electrolyte causes flow of electrons and current is produced. 7. There are two thermal batteries in MILAN missile. These are as under:- (a) Junction Unit Battery (JUB) - Operating voltage of 20 - 26 V. (b) Missile battery - Operating voltage 9 ± 2 V. 8. Functions. (a) JUB. (i) It gets activated in 0.3 secs after receiving current from the trigger mechanism and provides 30 W output for 16 secs. (ii) Provides first ignition pulse to the Missile Battery and Gyroscope assembly after its voltage is checked. (iii) Provides current to various parts of the GCE through the Power Supply Unit. (iv) Provides second ignition pulse to the Release Thruster. (v) Provides current to the Gas Generator and the Tracer after the latching unit has completed its function. RESTRICTED  RESTRICTED 66 (a) Missile Battery. (i) It gets activated after 0.3 secs. (ii) Operates on receiving current from the JUB. (iii) Provides current to the Decoder. The Decoder charges the Capacitors, which provides current to the Bulb and Photodiode assembly and to the initiator of Fuze. Part II: Pre Launch Operations 9. The operations taking place in the weapon system from the time the trigger is pressed to the time the missile is launched are termed as the pre launch operations. There is a certain time delay between the pressing of the trigger and the launching of the missile, the delay is about 1 to 1.52 sec. During this time various batteries get activated and the circuits are checked. The first step in the pre launch operations is the cocking and pressing of the trigger. 10. Function of Trigger Mechanism. The functioning of the trigger mechanism is covered in the following in two parts:- (a) Action on cocking the launcher. (b) Action on pressing the trigger. 11. The main components of the trigger mechanism are as follows :- (a) Spring loaded shackle. (b) Pusher rod. (c) Trigger. (d) Magnetos. Two in number. (e) Armature rods. Two in number. (f) Discs. Two in number. (g) Long and short arm of the sear. (h) Firing pin:- (i) Head. (ii) Lug. RESTRICTED  RESTRICTED