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TOW2 WEAPON SYSTEM

Subcourse Number MM4811

EDITION 9

United States Army Ordnance Missile and Munitions

8 Credit Hours

Edition Date: July 1989

SUBCOURSE OVERVIEW

This subcourse is designed to teach you the characteristics, purpose, and functional operation of the major assemblies and subassemblies of the TOW2 Weapon System. Contained within this subcourse are instructions on all assemblies and subassemblies to ensure the student understanding of the overall operation of the TOW2 Weapon System.

There are no prerequisites for this subcourse.

This subcourse reflects the doctrine which was current at the time the subcourse was prepared. In your own work situation, always refer to the latest publications.

The words "he," "him," "his," and "men," when used in this publication, represent both the masculine and feminine genders unless otherwise stated.

TERMINAL LEARNING OBJECTIVE

TASK: You will identify the characteristics and state the purpose of: major assemblies, subassemblies, and associated Training Equipment, and the maintenance concepts used to support and train personnel for the TOW2 Weapon System.

CONDITIONS: You will have the subcourse book, and will work without supervision.

STANDARDS: You will answer 19 of 25 questions correctly for a passing score for this subcourse.

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TABLE OF CONTENTS

Section Page

Subcourse Overview ..................................................i

Lesson 1: Introduction to the TOW2 Weapon System.....................1

Practice Exercise.........................................16

Answer Key and Feedback...................................18

Lesson 2: TOW2 Functional Theory....................................20



Lesson 3: TOW2 Test, Measurement, and Diagnostic Equipment..........32



Lesson 4: TOW2 Training Set ........................................46



Lesson 5: TOW2 Maintenance Concept..................................62



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LESSON ONE

INTRODUCTION TO THE TOW2 WEAPON SYSTEM.

Soldier's Manual Tasks: 093-411-3911093-411-3915

OVERVIEW

TASK DESCRIPTION:

Direct maintenance on the TOW2 Weapon System, test equipment, and provide technical assistance to TOW2 repairers.

LEARNING OBJECTIVE:

ACTIONS: When you have completed this lesson, you should be able to identify the purpose and function of the major assemblies and subassemblies of the TOW2 Weapon System.

CONDITIONS: You will have this subcourse book, and will work without supervision.

STANDARDS: Identify the purpose and function of the major assemblies and subassemblies of the TOW2 Weapon System in accordance with the information contained in this subcourse booklet.

REFERENCES: The material contained in this lesson was derived from the following publications.

TM 9-1425-450-12.FM 23-24.FM 23-24 (Test).TC 23-23.

INTRODUCTION

The TOW2 Weapon System is a crew-portable, heavy anti-tank assault weapon consisting of a launcher with tracking and control capabilities and the TOW (Tube-launched, Optically-tracked, Wire command-link) guided missile. The system is an all terrain, all weather, day or night system that is easily maintained and simple to operate. This lesson will identify the purpose and function of the major assemblies of the TOW2 weapon system.

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Facts about the TOW2 System.

Two important features of the TOW2 weapon system are its mobility and simplicity of operation. The launcher consists of self-contained replaceable units. Assembly and disassembly of the launcher is accomplished readily in the field without the use of tools. The operational condition of the launcher system can be checked at any time it is assembled through the use of built-in self-test circuits (no external test equipment is needed). Units which fail the self-test are replaced at the operating site.

The missile can be launched from a ground implacement or from a vehicle mount and is effective against armored vehicles and targets such as fortified emplacements. The tactical TOW2 weapon system (Figure 1-1) consists of eight major assemblies. These assemblies are the tripod, traversing unit, optical sight, launch tube, missile guidance set, battery assembly (2 ea), power conditioner, and night sight.

Figure 1-1. TOW2 launcher System.

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Tripod.

The tripod (Figure 1-2) is a heavy-duty, lightweight unit which provides ground-mounted capability for the TOW2 weapon system. Each tripod leg is adjustable and is secured with a leg lock. Flat tripod feet are adaptable to various types of terrain, and have anchor claws which allow the tripod unit to be staked when necessary. The tripod has three adjustable legs which allow the weapon system to be leveled and folded for easy transport. Two level vials (bubble level indicators) are used to level the tripod. A quick release coupling clamp provides installation or removal of the traversing unit. Friction locks provide an adjustment to secure the tripod in a level position.

Figure 1-2. Tripod.

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Traversing Unit.

The traversing unit (Figure 1-3) consists of a large main housing and a trunnion device which serves as the mounting base for the launch tube and optical sight. The main housing is capable of revolving 360 degrees in azimuth (horizontal) plane, and the trunnion can elevate through an angle of 50 degrees in the elevation (vertical) plane (30 degrees above horizontal and 20 degrees below). Control knobs for use in tracking the target in azimuth and elevation are mounted on the sides of the main housing. The azimuth and elevation signals develop pitch and yaw position. The trigger is mounted on the right-hand side of the main housing, just above the control knob. The molded cable, which transfers signals between the traversing unit and the guidance set (umbilical connector), is mounted in the cup underneath the main housing. The bridge clamp is mounted at the top of the trunnion device. This clamp secures the missile container in the launch tube, and provides electrical connection between the launcher and the missile.

Figure 1-3. Traversing Unit.

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Optical Sight.

The optical sight assembly (Figure 1-4) consists of an optical sight and an IR tracker assembly. Included in the unit are a boresight test and alignment capability. The gunner tracks the target through a 13 power optical sight. An eyepiece focus control allows the operator to easily adjust the focus of the eyepiece until the crosshairs are seen clearly. The tracker assembly in the sight/sensor receives infrared (IR) energy from the missile during the flight and senses any missile displacement from the tracker axis of line-of-sight. This information is used to generate the command signals which direct the missile toward the target. Boresight adjustments are used to obtain center-band readings for the boresight self-test. Out of band readings during the boresight self-test indicate that the line-of-sight of the optical sight is not properly aligned with the line-of-sight of the tracker assembly. A protective window in front of the lens systems seals out dust, dirt, and moisture for reliable operation. The optics unit attaches to the traversing unit by an over-center locking mechanism and an indexing plate with a floating plug to permit rapid engagement and connections.

The optical sight provides a mounting surface interface for the night sight. No electrical (or other) connections are included at this interface. The night sight cabling is external to the launcher system. The optical sight compares the instantaneous line-of-sight to the target and establishes the amount of correction required by the missile at any moment during flight. The reticle light control illuminates the optical sight cross-hairs.

Figure 1-4. Optical Sight.

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Launch Tube.

The launch tube (Figure 1-5) is constructed of single-wall, laminated fiberglass and holds the encased missile on the launcher. The breech end of the launch tube is equipped with an anodized aluminum alloy fitting which permits rapid installation and removal from the traversing unit. The upper portion of the fitting contains two guide pins for indexing and holding the top of the launch tube breech to the traversing unit trunnion. The bottom of the fitting contains a steel latch pin which mates with the launch latch on the trunnion and locks the launch tube into position. The launch tube supplies the initial stability for the missile trajectory and protects the gunner from exhaust blast.

Figure 1-5. Launch Tube.

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Missile Guidance Set.

The missile guidance set (Figure 1-6) provides facilities for battery installation, and contains the electronic circuitry necessary to develop system operating voltages. It electronically converts information developed by the optical sight and traversing unit into missile steering commands. It consists of 20 printed circuit cards which are installed in the chassis assembly. The power supply assembly utilizes the DC voltage inputs from the battery assembly to develop the DC and AC voltages for system operation. Controls and indicators are provided on the guidance set front panel to select system operation mode and to perform a system self-test. The system self-test provides a visual indication of overall system operational performance by the use of the test-operate switch. Missile position signals, which provide the missile flight path error in pitch and yaw, are developed in the tracker portion of the optical sight. They are applied to the missile guidance set for summing with rate signals from the traversing unit. These summed and processed signals are routed to the missile in flight via the wire-command link to correct the missile flight path.

Figure 1-6. Missile Guidance Set.

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Battery Assembly.

Provided with the TOW2 launcher are two battery assemblies (Figure 1-7). Each battery assembly has two 50 VDC cells and one 24 VDC cell. The battery assemblies are rechargeable on the TOW2 battery charger. One is contained in the missile guidance set and provides system operating power. The other assembly is an operational spare. A fully charged battery assembly should allow you to make 50 firings or simulated firings.

Figure 1-7. Battery assembly.

Power conditioner.

The power conditioner (Figure 1-8) is designed to replace the battery assembly in the missile guidance set. It converts vehicle power to power needed in the missile guidance set to operate the TOW2 weapon system.

Figure 1-8. Power Conditioner.

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Night Sight.

The night sight (Figure 1-9) is a passive device that receives heat emissions (infrared energy) from a target area. It converts the infrared (IR) energy to electrical signals and then to visible light, and displays the visible light as a real-time scene for viewing by an observer. The night sight performs this function as follows. The night sight IR collection function gathers incoming IR energy and images the IR energy onto the converter. The converter converts the IR energy to electrical signals, and then converts the electrical signals to visible light. The converter applies the visible light to the visible imaging function which processes the visible light into a real-time scene for viewing by an observer.

Figure 1-9. Night Sight.

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TOW2 Missile.

The TOW2 missile (Figure 1-10) has a 5.98-inch warhead, whereas the basic TOW had only a 5.6-inch warhead. The TOW2 penetration performance is further enhanced by fuzing at a greater standoff distance. This is accomplished through the use of a probe that is extended by gases as the missile is launched.

A thermal beacon is installed in the rear of the missile opposite the present xenon source. The thermal beacon is tracked by the TOW 2 AN/TSA-4A infrared sight (night sight). It is heated by a thermal source that generates heat through a boron-titanium intermetallic reaction. To help the tracker identify the missile thermal beacon among other natural or jamming sources, the thermal beacon has a mechanical shutter that interrupts its output on command from the launcher. The launcher signal is sent to the missile thermal beacon shutter via wire signal "A" to the beacon electronics package in the missile. The shutter movement is controlled by helium gas obtained from the supply manifold of the actuator.

Figure 1-10. TOW2 Missile.

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Tracking Concept.

The gunner looks through the optical sight (Figure 1-11), acquires and tracks a target. The target can be fixed or moving between the ranges of 65 to 3500 meters. He presses the trigger on the traversing unit with his right thumb as he continues to track the target. This is the only operation the gunner performs during a missile flight, except for tracking the target. The traversing unit sends a positive 24V DC pulse to the missile guidance set causing several things to happen. The missile guidance set generates the "prefire" signal which is sent to the missile to activate the batteries and the gyro. The missile guidance set also sends two signals to the optical sight. The 125V AC, 400 HZ signal will activate the IR tracker motor, and the resolver excitation signal will energize the reference resolver. The reference resolver will send the pitch and yaw reference signals back to the missile guidance set. These signals will be used in generating missile steering commands.

Figure 1-11. TOW2 Tracking Concept.

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Approximately 1.5 seconds after prefire (Figure 1-12), the missile guidance set (MGS) will generate the fire signal which is sent to ignite the missile launch motor. After the launch motor burns out, the missile leaves the tube, and the wings and control surfaces extend for in-flight control. The extending action of the control surfaces activates switches which complete circuits to allow the following sequence of events. The IR source will be energized; the control actuators will be enabled; the safety and arming latch will be unlatched; and after a short time delay the flight motor will ignite. The flight motor burns for 1.5 seconds and boosts the missile to a velocity of about 1025 feet per second. When the flight motor burns out, the missile will be at a range of approximately 350 meters. The IR energy emitted from the missile IR source is detected by the optical sight sensor system. The IR energy is converted into electrical pulses which represent pitch and yaw missile position. These position signals go to the missile guidance set to help generate the steering commands for flight.


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As the gunner tracks the target by moving the traversing unit (Figure 1-13), two signals which represent the horizontal and vertical rate of motion are sent to the missile guidance set. These are the azimuth rate signal and the elevation rate signal. The MGS processes the pitch and yaw reference signals, the pitch and yaw missile position signals, and the azimuth and elevation rate signals into missile steering commands. These commands will be transmitted to the missile through the command link wires to steer the missile to the target.

Upon impact with the target, the nose crush switch will detonate the warhead. After impact, when the traversing unit bridge clamp is opened to remove the empty missile container, the command link wires are automatically severed from the missile container. The empty container can now be removed and the launcher is ready to be reloaded for the next firing sequence.


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TOW2 Missile.

The TOW2 missile (Figure 1-14) is encased in a launch container which is put into the TOW2 launcher when ready for use. The encased missile comes in four practice types, each of which contains an inactive warhead. These types are:

1. Extended range (BTM-71A).2. Normal range (BTM-71A-1).3. Normal range (BTM-71A-2) with MOIC. (missile ordnance inhibit circuit).4. Extended range (BTM-71A-3) with MOIC.

The encased missile also comes in seven attack types, each of which contains a high explosive warhead. These types are:

1. Normal range (BGM-71A).2. Extended range (BGM-71A-1)3. Normal range with MOIC (BGM-71A-2).4. Extended range with MOIC (BGM-71A-3).5. Improved 5-inch warhead (BGM-71C).6. Improved 5-inch warhead with MOIC (BGM-71C-1).7. The TOW2 (BGM-71D).

Figure 1-14. Encased Missile.

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The warhead is a Class A explosive. Do not remove the missile from the launch container. Each encased missile (Figure 1-15) is color coded to include practice types. Refer to TM 9-1425-450-12 for identification and proper markings.

Figure 1-15. Encased Missile.

Inspection of encased missiles is required once a year. Encased missiles in the wooden overpack may be in a plastic bag. If it is in a bag, a humidity indicator is located in the bag (Figure 1-16) and can be seen through the window in the back of the wooden overpack. If the humidity indicator is blue, the encased missile is serviceable. If the humidity indicator is pink, the encased missile is unserviceable. If it is unserviceable, remove the encased missile and turn it in to the appropriate ammunition supply point as soon as possible.

Figure 1-16. Wooden Overpack.

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LESSON ONE

Practice Exercise

The following items will test your grasp of the material covered in this lesson. There is only one correct answer for each item. When you have completed the exercise, check your answers with the answer key that follows. If you answer any item incorrectly, study again that part of the lesson which contains the portion involved.

Situation: You have been asked by a subordinate the following questions pertaining to the TOW2 Weapon System.

1. What interrupts the thermal beacon in the TOW2 missile?A. Hydraulic shutter.B. Mechanical shutter.C. AN/TAS-4A.D. Missile gyro.

2. How many circuit cards are there in the missile guidance set?A. 4B. 6C. 9D. 20

3. How many seconds after prefire does the missile guidance set generate the fire signal?

A. 10B. 5C. 3D. 1.5

4. How many seconds does the missile flight motor burn?

A. 1.5B. 3C. 5D. 10

5. What approximate range, in meters, will the missile be when the flight motor burns out?

A. 1000B. 600C. 350D. 200

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6. Where is the trigger located on the main housing of the traversing unit?

A. Left hand side.B. Right hand side.C. Underneath.D. On top.

7. What transfers signals between the traversing unit and the missile guidance set?

A. Emitter diodes.B. Molded cable.C. IR transmitter.D. Wire signal "A".

8. What is the purpose of the power conditioner?

A. Replaces the battery assembly.B. Operates the radio.C. Operates the traversing unit.D. Operates the boresight test set.

9. What supplies the missile the initial stability for trajectory?

A. Gyros.B. Command signals.C. Launch tube.D. Missile guidance set.

10. Where are the missile position signals (pitch and yaw) developed?

A. Optical sight.B. Traversing unit.C. Missile.D. Power conditioner.

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LESSON ONE

PRACTICE EXERCISE

ANSWER KEY AND FEEDBACK

Item Correct Answer and Feedback

1. B. Mechanical shutter.

The TOW2 missile is equipped with a mechanical shutter to interrupt the thermal beacon. (Page 10, para 2.)

2. D. 20

The missile guidance set contains 20 circuit cards for the purpose of operation. (Page 7, para 1.)

3. D. 1.5

Once the prefire signal is generated, the missile guidance set will generate the fire signal 1.5 seconds later. (Page 12, para 1.)

4. A. 1.5

Once the missile flight motor is ignited it burns for 1.5 seconds of missile flight time. (Page 12, para 1.)

5. C. 350

After 1.5 seconds of missile flight motor burn, the missile is approximately 350 meters from the launcher in range. (Page 12, para 1.)

6. B. Right hand side.

On the right hand side of the traversing unit housing you will find the trigger switch. (Page 4, para 1.)

7. B. Molded cable.

The signals are transmitted by a molded cable between the missile guidance set and the traversing unit. (Page 4, para 1.)

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8. A. Replace battery assembly.

The power conditioner is designed to replace the battery assembly in the missile guidance set. (Page 8, para 2.)

9. C. Launch tube.

The launch tube being mounted to the traversing unit provides the missile a stable platform for trajectory. (Page 6; para 1.)

10. B. Traversing unit.

The missile position signals are developed in the traversing unit. (Page 4, para 1.)

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LESSON TWO

TOW2 FUNCTIONAL THEORY

Soldier's Manual Task: 093-411-3911093-411-3915

OVERVIEW

TASK DESCRIPTION:


LEARNING OBJECTIVE:

ACTIONS: When you have completed this lesson, you should be able to identify the purpose and function of the major operating signals of the TOW2 Weapon System.


STANDARDS: Identify the purpose and function of the Traversing Unit, Missile Guidance Set, Night Sight, Optical Sight, Battery Power Conditioner, and the TOW2 Missile in accordance with the information contained in this subcourse booklet.

REFERENCES: The material contained in this lesson was derived from the following publications:

TM 9-1425-450-12.TM 9-1425-450-34-1.TM 9-5855-450-24.

INTRODUCTION

This lesson contains the block diagrams, functional diagrams, and functional theory for the TOW2 weapon system and its components authorized for replacement or adjustment by DS/GS maintenance personnel. In this lesson maintenance personnel will become familiar with the function of the TOW2 weapon system.

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Traversing Unit.

The Traversing Unit (Figure 2-1) is an electro-mechanical assembly which is used to attach the optical sight and launch tube. Mechanically the traversing unit consists of a trunnion (1), elevation drive system (2), equilibrator (not shown), elevation and azimuth locking mechanism (3), viscous dampers (not shown), and main housing (4). The thumb operated trigger (5) is located near the right hand control knob (6) and is used to initiate the firing sequence. When the trigger is pressed, +24 VDC (Volts Direct Current) is fed through the trigger switch to the missile guidance set where the timed missile launch sequence signals are produced. During the tracking process the rate tachometer generators transform mechanical motion of the traversing unit into electrical analogs of the rate of the motion. The generated elevation and azimuth rate information is applied to the missile guidance set. These are processed and become part of the steering command signals which control the missile in flight. Cable assemblies transmit electrical signals between the missile guidance set, optical sight, traversing unit, and missile.

The traversing unit is checked for proper operation in the system check-out procedure. In this procedure a balance check is performed. The system checks the elevation and azimuth tachometers. The desired indications for this check are not out-of-band readings, but movements to the direction of the applied force, as indicated on azimuth/elevation cross on the missile guidance set.

Figure 2-1. Traversing Unit.

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Traversing Unit.

Electrically the traversing unit consists of a wire cutter switch, wiring harness, trigger (firing) switch, and elevation and azimuth rate tachometer generators. The electrical wiring of the traversing unit (Figure 2-2) carries the signals that the AN/TAS-4A generates as well as the signals from the missile guidance set. It also carries signals and voltages from the optical sight (OSS) and the missile guidance set (MGS), and from the trigger/rate tachometers and the MGS. Signals from the breech and MGS are the pitch, yaw, fire, prefire, wire cutter, and trigger signal.

Figure 2-2. Traversing Unit Wiring Harness.

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Optical Sight

The optical sight (Figure 2-3) contains the tracker optical system, the infrared (IR) sensor, the preamplifier, the internal electrical boresight circuits, and the reference resolver. The optical sight compares the instantaneous line-of-sight to the missile with the instantaneous line-of-sight to the target and establishes the amount of correction required by the missile at any moment during the flight. Crosshairs in the tracker optical system are used to assist in tracking the target and thereby establishing a reference line from the optical sight to the target. The IR sensor receives IR energy from the missile in flight, and thereby establishes a reference line from the IR sensor to the missile. The preamplifier receives signals from the IR sensor, amplifies them, and delivers them to the missile guidance set. The internal electrical boresight circuits are used to verify the alignment of the optical sight with the IR sensor. This alignment establishes a common reference between the target and the missile in flight. The reference resolver generates electrical reference signals which are representative of the pitch and yaw planes between the optical sight and the target. The reference signals are utilized in conjunction with signals from the IR sensor to determine the magnitude and direction of guidance correction signals required by the missile.

Figure 2-3. Optical Sight.

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Night Sight.

The Night Sight (Figure 2-4) is an electro-optical system that includes both IR and visible light optics. The afocal assembly optics gathers IR energy and collimates it onto the scan mirror. Either of two magnifications may be used. The IR imager optics (optical imager) focuses the IR energy from the scan mirror into infrared detectors in the detector/Dewar. The detectors convert IR energy to video signals. The video signals are processed by the video electronics. The video is converted to visible light by an emitter assembly (LED array). The visual collimator transfers the visible light from the emitter assembly onto a scan mirror. The objective lens/roof mirror assembly optics directs this light onto the display reticle for viewing through the eyepiece optics.

WFOV: Wide field of view. NFOV: Narrow field of view.

Figure 2-4. Night Sight.

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Missile Guidance Set.

The Missile Guidance Set (MGS) (Figure 2-5) is the "BRAINS" of the TOW2 weapon system. it contains the necessary circuitry to develop the operating voltages, timing signals, and excitation voltage required to develop reference signals for pitch and yaw commands for the missile. When timing signals are applied to the excitation generator and self-test card, it generates a programmed resolver excitation voltage which is sent to the optical sight for development of reference voltages. When the missile is in flight, the pitch and yaw error signals from the optical sight are applied to the pitch and yaw error detector cards respectively. The signals are then compared with the pitch and yaw reference signals. The pitch error detector card output is applied to the pitch command signal generator card and combined with the output of the elevation rate generator. The output of the pitch command signal generator card is applied to the yaw command signal generator card where its frequency modulates an oscillator. Similarly, the output of the yaw error detector card is applied to the yaw command signal generator card and combined with the output of the azimuth rate generator. The yaw command signal generator card frequency modulates a second oscillator. The outputs of these two oscillators, which have different center frequencies, are multiplexed and sent down the wire command link to the missile. This multiplexed signal is decoded into pitch and yaw steering signals by the missile electronic circuits.

Figure 2-5. Missile Guidance Set.

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Battery Assembly.

The battery assembly (Figure 2-6) has three separate rechargeable storage batteries, which are electrically independent and can be individually removed and replaced. The battery is installed in the missile guidance set and provides output voltages of +24 VDC, +50 VDC, and -50 VDC. Voltages from the battery are supplied to the power supply assembly where they are converted into the TOW2 weapon system operating voltages. A fully charged battery assembly should allow 50 firings or simulated firings. Test equipment required to test the battery assembly are the power monitor cable, digital multimeter, and the missile guidance set test set.

Figure 2-6. Battery Assembly.

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TOW2 Missile.

The TOW2 missile (Figure 2-7).with its shutter beacon can penetrate obscurants. When the night sight picks up the infrared from the missile, it will transmit the missile location to the missile guidance set. At the same time the missile guidance set checks the line-of-sight (LOS) of the target. The wire link signals from the TOW2 system are pitch and yaw. These pitch and yaw signals are separated and passed to discriminator circuits inside the missile electronics. The discriminator changes the sine wave pitch and yaw signals into square wave signals that contain the change of control fin correction data. Zero crossing detectors are modified by this pitch and yaw square wave. This modifies the time on the limit stops, and changes the direction in pitch (elevation) and yaw (azimuth) of the missile. Four missile actuators are required and provide independent control of fin operation. The modulated signals from the missile guidance set are transmitted by the command wire link to the missile where they are demodulated by the missile into steering commands.

Figure 2-7. TOW2 Missile.

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LESSON TWO

Practice Exercise



1. What voltages are supplied by the battery assembly?A. +24 VDC, +50 VDC, and -50 VDC.B. +24 VDC, -24 VDC, and +50 VDC.C. +28 VDC, +24 VDC, and -24 VDC.D. +128 VAC, -50 VDC, and +50 VDC.

2. When the trigger is pressed what signal is sent to missile guidance set?A. +120 VDC.B. +60 VDC.C. +24 VDC.D. -12 VDC.

3. What transforms mechanical motion of the traversing unit into analogs?A. +24 VDC.B. Pitch error detectors.C.. Yaw error detectors.D. Rate tachometer generators.

4. What verifies the alinement of the optical sight with the IR sensor?A. Yaw plane.B. Reference resolvers.C. Boresight circuits.D. Rate tachometer generators.

5. What assembly of the night sight converts video to visible light?A. Emitter assembly.B. IR detectors.C. Scan mirror.D. Afocal assembly.

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6. What is received by the optical sight to electronically process into pitch and yaw reference signals?

A. Pitch and yaw command pulses.B. Azimuth rate signals.C. Elevation rate signals.D. IR energy.

7. Where are the pitch and yaw reference signals demodulated into steering signals?

A. Missile.B. Missile guidance set.C. Traversing unit.D. Optical sight.

8. Where is the IR source generated that is used to track the missile?

A. Traversing unit.B. Optical sight.C. Missile guidance set.D. Missile.

9. What is required from the missile in order for the optical sight to continue to provide missile position data to the missile guidance set?

A. Pitch and yaw commands.B. Azimuth rate signals.C. Elevation tachometer signals.D. IR energy.

10. How many actuators are required for independent fin control?

A. 1B. 2C. 3D. 4

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LESSON TWO

PRACTICE EXERCISE



1. A. +24 VDC, +50 VDC, and -50 VDC.

The battery assembly provides output voltages of +24 VDC, +50 VDC and -50 VDC. (Page 26, para 1.)

2. C. +24 VDC.

When the operator presses the trigger it sends a +24 VDC signal to the missile guidance set. (Page 21, para 1.)

3. D. Rate tachometer generators.

The mechanical motion of the traversing unit is transformed into analogs by the rate tachometer generators in the traversing unit. (Page 21, para 1.)

4. C. Boresight circuits.

The optical sight and IR sensor alinement is verified by the boresight circuits. (Page 23, para 1.)

5. A. Emitter assembly.

The video is converted to visible light by an emitter assembly. (Page 24, para 1.)

6. D. IR energy.

The optical sight receives IR energy to electronically process into pitch and yaw reference signals for the missile guidance set. (Page 23, para 1.)

7. A. Missile.

The pitch and yaw reference signals are sent from the traversing unit to the missile guidance set where they are modulated with other signals. These modulated signals are sent to the missile where they are demodulated into steering signals. (Page 27, para 1.)

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8. D. Missile.

Once the missile leaves the launch tube it begins to generate an IR energy source that permits the optical sight/night sight to track the missile to the target. (Page 27, para 1.)

9. D. IR energy.

IR energy is required to be produced by the missile until impact in order for the optical sight to keep the missile guidance set continually updated with missile position data. (Page 23, para 1.)

10. D. 4 Actuators.

Four missile actuators are required and provide independent control of missile fin operation. (Page 27, para 1.)

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LESSON THREE

TOW2 TEST, MEASUREMENT, AND DIAGNOSTIC EQUIPMENT


OVERVIEW

TASK DESCRIPTION:

Direct Maintenance on the TOW2 Weapon System, test equipment, and provide technical assistance to TOW2 repairers.

LEARNING OBJECTIVE:

ACTIONS: When you have completed this lesson, you should be able to identify the purpose and function of the test, measurement, and diagnostic equipment (TMDE) of the TOW2 Weapon System.


STANDARDS: Identify the purpose and function of the test, measurement, and diagnostic equipment (TMDE) of the TOW2 Weapon System in accordance with the information contained in this subcourse booklet.


TM 9-4935-450-14.TM 9-4935-455-14.TM 9-4935-451-14.

INTRODUCTION

The test, measurement, and diagnostic equipment (TMDE) is designed to provide the necessary test equipment to maintain and verify the TOW2 weapon system. Each contact support team (CSS) and maintenance shop is equipped with the equipment required to sustain their operation. This lesson describes the characteristics and functions of the major test equipment required to maintain the TOW2 weapon system.

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Missile Guidance Set Test Set (AN/TSM-152).

The missile guidance set test set (Figure 3-1)(MGSTS) provides the capability of rapidly isolating a TOW2 missile guidance set (MGS) failure to the printed circuit card level. The test set interfaces with the MGS test signals, and permits control of microprocessor fault diagnostic functions, generates necessary test signals, and provides a display of test results. The test set is also used in TOW2 system verification. It displays fault isolation error codes (2 or 3 digit error codes). Connecting cables are stored inside the top cover of the case. Some of the error codes are listed on the test set front panel. Test point jacks, a voltage select knob, and control push-button switches (ready, trigger, and reset) allow missile guidance set system maintenance checks to be made. The test set can be operated from an internal rechargeable battery or from alternating current line power.

Figure 3-1. Missile Guidance Set Test Set.

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Electrical Cable Test Set (AN/TSM-149).

The electrical cable test set (Figure 3-2) is used to check out traversing unit cables (2W1 and 2W3), and the traversing unit internal wiring harness. It allows most common shorts to shield, and continuity checks to be performed through the traversing unit. It contains the 23-position wire selection switch, the toggle switch for selection of short or continuity checks, and the wafer switch for selection of the function to be tested. The continuity fixture is part of the electrical cable test set.

Figure 3-2. Electrical Cable Test Set.

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Amplifier Test Set (AN/TAM-5).

The amplifier test set (Figure 3-3) is used during checkout of the night sight, with the AN/TAM-3. Functions of the amplifier test set include operation, verification, troubleshooting, and alinement of the postamplifier assembly used with the AN/TAS-4A night sight. The test set is used in conjunction with the night vision sight test set, modified to support the TOW2 night sight. Major controls of the amplifier test set are video channel select, gain select, and signal select. Mode of operation is determined by the manual/auto, stop/start, and reset switches. Major items for the various test configurations include the use of the vehicle power conditioner, a load box, several new cables, and the night vision sight test set target source. Internally, the amplifier test set contains one circuit card and a power module.

Figure 3-3. Amplifier Test Set (AN/TAM-5).

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Electrical Circuit Test Set (AN/TSM-158).

The electrical circuit test set (Figure 3-4) is used for TOW2 system checkout. The electrical circuit test set, when placed in the breech of the traversing unit, gives electrical access to the TOW2 weapon system umbilical interface. The test set simulates the missile electrical identifier signature as an aid to system testing.

Figure 3-4. Electrical Circuit Test Set.

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AN/TAM-3A Test Set, Night Vision Sight.

The AN/TAM-3A Test Set, Night Vision Sight, (Figure 3-5) contains the necessary equipment to perform any maintenance requiring an oscilloscope, multimeter, or power supply for the TOW2 weapon system.

There are three special tool containers. Each provides storage for the UUT (Unit Under Test) mount assembly and interface, and other special tools and test equipment needed to test and repair the TOW2 weapon system. The AN/TAM-3A consists of three containers, and they are as follows:

1. Box 1. Special tools container (UUT mount assembly and interface).

2. Box 2. Oscilloscope (SC502), digital multimeter (SC501), power supply (6284A), and the frame (SC503).

3. AN/TAM-3A collimator and closed cycle cooler test set.

Figure 3-5. AN/TAM-3A Test Set, Night Vision Sight.

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Battery Charger Monitor Unit.

The battery charger monitor unit (Figure 3-6) is used to perform voltage and continuity checks of the battery charger 4884 A/T. It provides test jacks and switches used when troubleshooting and performing final inspection of the battery charger. J1 through J9 provide test jacks to connect a multimeter. J2 and J3 check battery B1 for +24 VDC. J5 and J6 check battery B2 for +50 VDC, and J8 and J9 check battery B3 for -50 VDC. Connectors B1, B2, and B3 are utilized when checking the battery assembly for proper operating voltages. Switch S1 is used to open and close the circuit while performing voltage checks.

Figure 3-6. Battery Charger Monitor Unit.

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Power Conditioner Test Adapter.

The power conditioner test adapter (Figure 3-7) is used to troubleshoot and perform checkout procedures of the TOW2 vehicle power conditioner. It provides test jacks and switches for the purpose of testing the power conditioner for proper operation under load and no-load conditions. It provides the necessary interface to confirm acceptance of the power conditioner. The input switch distributes 24 VDC through the test adapter to the TOW2 vehicle power conditioner (TVPC). B1, B2, and B3 are three way toggle switches to check for power output voltages of the TVPC. The monitor switch is used to increase/decrease simulated load. Hi and Lo jacks are used to monitor output voltages to the missile guidance set.

Figure 3-7. Power Conditioner Test Adapter.

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TOW Supplemental Test Equipment.

The TOW supplemental test equipment kit (TA-20)(Figure 3-8), used to test and align the TOW2 traversing unit (TU), consists of two cases. These are the TU test fixture No. 1 (box 1), and test fixture No. 2. (box 2). The supplemental kit is used to perform the boresight alinement when used with the auto collimator. The cases contain special tools and fixtures used to perform the azimuth and elevation test, the chain compliance test, the bridge clamp test, and traversing unit troubleshooting. The kit is stored on the curbside wall of the improved contact support set (ICSS).

Figure 3-8. TOW2 Supplemental Test Equipment.

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LESSON THREE

Practice Exercise



1. What is used to confirm the acceptance of the power conditioner?A. Battery assembly.B. Oscilloscope.C. Electrical circuit test set.D. Power conditioner test adapter.

2. What jacks on the battery charger monitor unit are provided for checking the battery assembly?A. J1 through J9.B. B1, B2, and B3.C. J1 and J2.D. J4 and J5.

3. What piece of test equipment is used to gain access to the TOW2 system umbilical interface?A. Missile guidance set.B. Amplifier test set.C. Electrical circuit test set.D. Boresight test set.

4. What piece of test equipment is used to aline the postamplifier in the AN/TAS-4A?A. Boresight collimator.B. Amplifier test set.C. AN/TAM-3A collimator.D. IR collimator.

5. How many test points are there on the electrical circuit test set?A. 8B. 10C. 16D. 20

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6. What piece of test equipment is used to check out cables 2W1 and 2W3 of the traversing unit?

A. Electrical circuit test set.B. Traversing unit test set.C. Collimator test set.D. Electrical cable test set.

7. What piece of test equipment displays two/three digit error codes when checking faults?

A. Missile guidance set test set.B. Amplifier test set.C. Electrical circuit test set.D. Electrical cable test set.

8. What is used with test fixtures No.1 and No.2 to aline the TOW2 traversing unit?

A. Boresight test fixture.B. IR collimator.C. Auto collimator.D. AN/TAS-4A test adaptor.

9. What are the two test conditions in which the power conditioner test adapter checks the power conditioner?

A. Load and continuity.B. AC load only.C. DC load only.D. Load and no load.

10. Where are test fixtures No.1 and No.2 stored?

A. Amplifier test set cover.B. Missile guidance set cover.C. ICSS shelter.D. QA/QC shelter.

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LESSON THREE

PRACTICE EXERCISE



1. D. Power conditioner test adaptor.

When confirming the acceptance of the power conditioner, the power conditioner test adapter is used. (Page 39, para 1.)

2. B. B1, B2, and B3.

These jacks are used to check the battery assembly under operating conditions. (Page 38, para 1.)

3. C. Electrical circuit test set.

To gain access to the TOW2 system umbilical interface the electrical circuit test set is used. (Page 36, para 1.)

4. B. Amplifier test set.

The AN/TAS-4A is a night vision sight and the amplifier test set is used to aline the postamplifier in the AN/TAS-4A. (Page 35, para 1.)

5. C. 16

For use in test and checkout procedures, the electrical circuit test set is equipped with 16 test points. (Page 36, para 2.)

6. D. Electrical cable test set.

Cables 2W1 and 2W3 in the traversing unit are checked by the use of the electrical cable test set. (Page 34, para 1.)

7. A. Missile guidance set test set.

The two/three digit error codes are displayed on the missile guidance test set during fault isolation. (Page 33, para 1.)

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8. C. Auto collimator.

To align the traversing unit, the auto collimator is used with test fixtures No. 1 and No. 2. (Page 40, para 1.)

9. D. Load and no load.

The two test conditions in which the power conditioner is checked are load and no load conditions. (Page 39, para 1.)

10. C. ICSS shelter.

The test fixtures are stored in the ICSS shelter. (Page 40, para 1.)

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LESSON FOUR

TOW2 TRAINING SET


OVERVIEW

TASK DESCRIPTION:


LEARNING OBJECTIVE:

ACTIONS: When you have completed this lesson, you should be able to identify the purpose and use of the TOW2 training equipment.


STANDARDS: Identify the purpose and use of TOW2 training set in accordance with the information contained in this subcourse booklet.


TM 9-6920-450-12.TC 23-24.TC 23-24 (Test).

INTRODUCTION

The TOW2 training set is a crew-portable trainer that is used for gunner training, teaching instructors, practice, and qualification with the TOW2 launcher. In this lesson you will be given the purpose and use of the TOW2 training equipment. This information is vital to personnel who will use and maintain this equipment.

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Training Set.

The training set provides a safe economical way of training TOW2 gunners without firing tactical missiles. The training set may be used in any simulated tactical operation and will operate in all weather conditions in which the TOW2 gunner can track the target. The training set (Figure 4-1) is used with the TOW2 launcher system to train the TOW2 gunner in tracking targets. There are two modes of operation. They are practice and qualification. The training set consists of a target set, instructor console, battery assemblies, cable set case, and connecting cables.

Figure 4-1. Training Set.

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Target set.

The target set consists of a thermal target board, target source, and a power supply/modulator (Figure 4-2).

Figure 4-2. Target Set.

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Instructor Console Unit (ICU).

The instructor console (Figure 4-3) is a self-contained battery powered unit that includes electronic circuits necessary to process error signals from the missile guidance set (MGS). The MGS compares the detected infrared energy (IR) signals from the optical sight pitch and yaw reference to develop TOW2 gunner tracking error signals. The error signals are then applied to the instructor console for further processing. After error signals are processed they are applied to the score and line-of-sight (LOS) meters located on the front panel of the ICU.

Figure 4-3. Instructor Console.

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Cable Set Case.

Figure 4-4. Cable Set Case.

Connecting Cables.

Figure 4-5. Connecting Cables.

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Battery Assemblies.

Two nickel cadmium battery assemblies are issued with each training set. One battery assembly provides power for the instructor console. The other is a spare and can replace the first battery assembly if necessary. The battery assemblies are identical to one used with the TOW missile guidance set and are rechargeable on the TOW battery charger (Figure 4-6).

Figure 4-6. Battery Assembly.

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Operation of the TOW2 Training Set.

The target set (Figure 4-7) is mounted on a vehicle that is located at a realistic distance from the gunner. The TOW gunner's performance in a tactical situation is measured and evaluated by the missile hitting the target. However, in the training situation, no missile is actually fired. Since you cannot see if the TOW gunner has hit the target, the evaluation of the gunner must be done by the training equipment. The target source which simulates the missile IR energy is located on the target. Therefore, if the TOW gunner keeps his line of sight on the target, the TOW2 system will believe the missile is on target and no pitch or yaw error signals will be generated by the missile guidance set. The instructor console of the training set, when connected to the missile guidance set of the TOW2 weapon system, monitors the pitch and yaw error signals. The instructor console then scores the TOW gunner's ability to keep the line of sight on target. The training set must provide the following: target, missile loading, missile launch, and missile flight.

Figure 4-7. Tactical Training.

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Target.

The training set target board (Figure 4-8) is used instead of the tactical object to provide the target. The target board is normally mounted on a vehicle to provide a moving target.

Figure 4-8. Target.

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Simulated Missile Flight.

Since no missile is actually launched, the training set must simulate missile feedback to the TOW2 weapon system. During a tactical missile flight toward a target, the missile sends IR energy back toward the optical sight. This allows the missile guidance set to direct the missile to the target. The training set target source sends out the same IR energy as the tactical missile (Figure 4-9).

Figure 4-9. Simulated Missile Flight.

The target source (Figure 4-10) has an IR lamp which sends out IR energy. Power to run the power supply/modulator comes from the vehicle battery. Heat strips on the target board make the target visible to the night sight.

Figure 4-10. Target Source.

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Simulated Missile Loading.

The missile simulation round (MSR)(Figure 4-11), a separate issue item, is the same size, shape, and approximate weight as the TOW encased missile and is loaded exactly like the TOW tactical round..

Figure 4-11. Simulated Missile Loading.

Simulated Missile Launch.

The blast simulator (Figure 4-12), a separately issued item, is used to simulate a missile launch when placed in the MSR. When the launcher trigger is pressed by the TOW gunner, the blast simulator explodes in the MSR simulating the sound of a tactical missile firing.

Figure 4-12. Simulated Missile Launch.

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Separate Issue Items.

Missile Simulation Round (MSR).

Figure 4-13. Missile Simulation Round (MSR)

Blast Simulator.

Figure 4-14. Blast Simulator.

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LESSON FOUR

Practice Exercise


Situation: You have been asked by a subordinate the following questions pertaining to the TOW2 training set.

1. What is the purpose of the TOW trainer?

A. Checkout the MGS.B. Evaluate timing circuits.C. TOW2 gunner training.D. Scores missile tracking.

2. What major items make up the M70 training set?

A. Instructor console, batteries, target set, cable set case, cables.

B. Target set, missile guidance set, tripod, instructor console, and traversing unit.

C. Instructor console, M70 cable set, target source, missile guidance set, and traversing unit.

D. Target board, target source, battery assembly, missile guidance set, and tripod.

3. What supplies power for the instructor console?

A. Tactical vehicle batteries.B. Nickel cadmium battery (TOW battery).C. Missile guidance set (MGS).D. Power supply modulator.

4. What item used with the training set is a separate issue item?

A. Missile simulation round.B. M70E2 cable set.C. Instructor console.D. Target board.

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5. What is the purpose of the power supply/modulator?

A. Simulates infrared target.B. Scores gunner's performance.C. Provides power for target source.D. Provides power for instructor console.

6. How many training modes can be selected using the TOW2 training set?

A. 4B. 3C. 2D. 1

7. What is the size of the target board?

A. One meter square.B. One ft. square.C. 576 in. square.D. 157 in. square.

8. What item of TOW2 training equipment monitors and evaluates the tracking performance of the gunner?

A. Power supply/modulator.B. Instructor console.C. Target set.D. Target source.

9. What item of the TOW2 training equipment simulates missile firing?

A. Battery assembly.B. Blast simulator.C. Target source.D. Missile simulator round.

10. What is the purpose of the heat strips on the target board?

A. Night sight operation.B. Optical sight operation.C. Instructor console operation.D. Target source operation.

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LESSON FOUR

PRACTICE EXERCISE



1. C. TOW2 gunner training.

By using the TOW2 training equipment, the soldier does not need tactical rounds for training. (Page 47, para 2.)

2. A. Instructor console, batteries (2), target set, cable set case, cables (3).

Although there are many major items in a complete TOW weapon system the M70 training set consists of: the instructor console, batteries (2), target set, cable set case, and cables (3). (Page 47, para 3.)

3. B. Nickel cadmium battery (TOW battery).

There are many parts of the TOW system and training equipment that may be operated from vehicle power, the instructor console requires batteries for operation. (Page 51, para 1.)

4. A. Missile simulation round.

The missile simulation round is used in TOW gunner training, but it is a separate issue item and is not part of the training set. (Page 56, para 1.)

5. C. Provides power for target source.

The power supply modulator converts vehicle power to be used by the target source. (Page 48, para 7.)

6. C. 2.

When using the TOW2 training equipment you may select practice mode or qualification mode. (Page 47, para 2.)

7. A. One meter square.The thermal target board is approximately one meter square. (Page 48, para 2.)

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8. B. Instructor console.

When the training set is in use, the instructor's console monitors and evaluates the gunner's performance. (Page 52, para 1.)

9. B. Blast simulator.

The missile firing simulation is produced by the blast simulator during the use of the training equipment. (Page 55, para 2.)

10. A. Night sight operation.

In order for the night sight to operate properly, it must be able to sense heat; therefore, the target board has heat strips to generate heat for the night sight. (Page 48, Figure 4-2.)

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LESSON FIVE

TOW2 MAINTENANCE CONCEPT

Soldier's Manual Task 093-411-3911093-411-3915

OVERVIEW

TASK DESCRIPTION:

Direct maintenance on the TOW2 Weapon System, test equipment and provide technical assistance to TOW2 repairers.

LEARNING OBJECTIVE:

ACTIONS: When you have completed this lesson you should be able to identify the maintenance concept for the TOW2 Weapon System.


STANDARDS: Identify TOW2 maintenance concept in accordance with the information contained in this subcourse booklet.

REFERENCES: The material contained in this lesson was derived from the following publications:TM 9-4935-484-14.TM 9-1425-450-12.TC 23-24.

INTRODUCTION

The effectiveness of any missile system depends upon the maintenance program. The TOW2 Weapon System maintenance program will consist of unit, intermediate (DS/GS), and depot maintenance. This lesson outlines the three levels and an overview of the responsibilities, and the test, measurement and diagnostic equipment required to perform these tasks.

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TOW2 Maintenance Concept.

The TOW2 Weapon System employs a combination of maintenance procedures. Some of these procedures are done at the unit, intermediate DS/GS support and depot. In this lesson each maintenance level will be explained as to what level of maintenance does what procedure. Maintenance allocation charts (MAC) must be used to determine who performs what maintenance function.

Unit Maintenance.

Unit maintenance is the responsibility of and is performed by a using organization on its assigned equipment (Figure 5-1). At the organizational maintenance level, the user can perform the system self-test, the boresight alignment check, and preventive maintenance procedures, and may replace any assembly shown to be defective by the self-test. Unit missile maintenance operations are characterized by:

1. General cleaning of TOW2 Weapon System.2. Perform TOW2 Weapon System preventive maintenance checks and

service (PMCS).3. Notify direct support to perform semi-annual or annual

verification.4. Perform spot painting.5. Perform system checkout procedures.

Figure 5-1. Unit Equipment.

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Intermediate Maintenance (Direct Support/General Support) (DS/GS).

The intermediate maintenance units will provide for checkout and fault isolation for the TOW2 Weapon System. Maintenance support equipment includes the Land Combat Support System (LCSS), the Contact Support Set (CSS), the Improved Contact Support Set (ICSS), and the TOW Field Test Set (TFTS).

The repairman will repair, aline, and calibrate modules, printed circuit cards, and boards constructed with only conventional piece parts. Unserviceable modules, cards, and boards constructed with solid state elements or a combination of solid state and conventional piece parts are evacuated to the designated depot for repair and return to stock. Intermediate DS/GS maintenance operations are characterized by:

1. Providing Battle Damage Assessment (BDA) teams.

2. Providing and maintaining an Operational Readiness Float (ORF).

3. Providing a technical supply system.

4. Providing maintenance support teams to assist technicians at the user level in performing unit maintenance.

5. Providing shop support for LRU repair and LRU Direct Exchange (DX) for all missile systems in the division.

6. Providing contact Support Teams (CSS).

7. Evacuating unserviceable PCB's and subassemblies directly to intermediate GS/Depot level repair facilities.

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DS/GS Equipment.

Figure 5-2. DS/GS Equipment.

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Depot Maintenance Equipment.

Anniston Army Depot in Anniston, Alabama, is the depot maintenance facility charged with handling the overflow from General Support units. At this maintenance facility unserviceable modules, cards, and boards constructed with solid state elements or a combination of solid state and conventional piece parts are repaired and returned to stock. As a general rule, the depot activity repairs those items for which support units lack the proper maintenance facilities or expertise. Depot maintenance operations are characterized by:

1. Providing the interface between depot and DS/GS missile units.

2. Routing repaired items into the supply system.

3. Receiving, screening and routing all incoming items to the appropriate repair facility.

4. Performing diagnosis and repair of SRU's.

5. Repairing of components, assemblies, PCB's, and DX items.

6. Providing missile repair parts supply for the theater.

Figure 5-3. Depot Equipment.

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LESSON FIVE

Practice Exercise


Situation: You have been asked by a subordinate the following questions pertaining to the TOW2 Weapon System maintenance.

1. What level of maintenance repairs SRU's?A. Depot.B. Unit.C. Unit and DS.D. Intermediate DS.

2. What level of maintenance repairs LRU's?A. Depot.B. Unit.C. Intermediate DS.D. Unit and depot.

3. What maintenance level(s) maintain an ORF?A. Depot.B. Unit.C. Intermediate.D. Organizational.

4. What is the purpose of the maintenance allocation chart?A. Determines who performs what maintenance function.B. Determines if organizational units can provide additional

parts.C. Used for troubleshooting faults in the TOW2 Weapon System.D. Shows what parts can be ordered.

5. What are the levels of maintenance for the TOW2 Weapon System?A. GS, DS, unit.B. Unit, DS/GS, and depot.C. Depot, intermediate, and GS.D. Unit, GS, and depot.

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6. What level of maintenance provides contact support teams (CSS)?

A. Intermediate DS.B. Depot.C. Unit.D. GS.

7. What maintenance level provides Battle Damage Assessment (BDA) teams?

A. Unit.B. Depot.C. Intermediate.D. Unit and depot.

8. What maintenance facility provides repair parts to the theater?

A. Depot.B. Unit.C. Intermediate.D. Intermediate and unit.

9. At what level of maintenance are checkout and fault isolation of the TOW2 Weapon System SRU's performed?

A. Organizational.B. Direct support.C. Depot.D. Unit.

10. What maintenance facility(s) provide annual or semi-annual verification of the TOW2 Weapon System components?

A. Unit.B. Depot.C. Intermediate DS.D. Organizational.

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LESSON FIVE

PRACTICE EXERCISE



1. A. Depot.

System SRU's are repaired at the depot level and returned to the supply system. (Page 66, para 4.)

2. C. Intermediate DS.

The LRU's for the TOW2 weapon system are repaired at the intermediate DS maintenance facility. (Page 64, para 5.)

3. C. Intermediate.

A system operational readiness float (ORF) is maintained at the intermediate maintenance level. Page 64, para 2.)

4. A. Determines who performs what maintenance function.

The maintenance allocation chart has listed the information that determines what maintenance level performs what maintenance function. (Page 63, para 1.)

5. B. Unit, DS/GS, depot.

The TOW2 weapon system, like many other land combat weapon systems has three levels of maintenance. (Page 63, para 1.)

6. A. Intermediate DS.

In the maintenance support of the TOW2 weapon system the intermediate DS maintenance provides the using unit with contact support teams. (Page 64, para 6.)

7. C. Intermediate.

The intermediate maintenance level provides to the using unit Battle Damage Assessment (BDA) teams. (Page 64, para 1.)

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8. A. Depot.

The theater is supplied repair parts by the depot. (Page 66,. para 6.)

9. C. Depot.

The depot performs the checkout and fault isolation of the weapon systems SRU's. (Page 66, para 4.)

10. C. Intermediate DS.

The depot facility provides semi-annual verification of the TOW2 weapon system components. (Page 63, para 3.)

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