Attachment_4_DMWR_11-6610-402.pdf

RECOMMENDED CHANGES TO PUBLICATIONS AND

BLANK FORMS

Use Part II (reverse) for Repair Parts and Special Tool Lists (RPSTl) and Supply Catalogs/Supply Manuals (SC/SM).

DATE

6 - May - 2009

- 3-18 d-(6) 2

TYPED NAME. GRADE OR TITLE

lectronics Mechanic

N/A

FROM: (Activity

Commander. Tobyhanna Army Depot I I Hap Arnold Blvd Tobyhanna, PA 18466 (Maszeroski)

N/A Change Page 3-18. paragraph (d) Course Resolver Zero and Phasing Tests.

Step (6). line 2.

From: "RESULT: DYM NO.1 SHALL lND1CATE LESS THAN O.05YAC."

TO: "RESULT: DYM NO,I SHALL1NDICATELESS THAN 0.5VAC."

REASON:

Course resolver does not have resolution down to +1- 0.05Y AC.

iDA0350

TELEPHONE EXCHANGE/AUTOVO"!.

PLUS EXTENSION

Commercial (570) 895-8921

DSN 795-8921

SiGNATURE

REPLACES DA FORM 2028,1 DEC 68, WHICH Will BE·USED. Page 1 012 APO PE y4.01 ES

NSAI- ~·bIO- ()!- 3rk -2 7~

, I

DMWR 11-6610-402

DEPOT MAINTENANCE WORK REQUIREMENT

(INCLUDING DEPOT MAINTENANCE REPAIR

PARTS AND SPECIAL TOOLS LIST)

FOR

HORIZONTAL SITUATION INDICATOR

ID-2278B/A

(NSN 6610-01-316-2748)

(P/N 132750-5)

THIS PUBLICATION IS NOT AVAILABLE THROUGH THE US ARMY

PUBLISHING AGENCY. THIS PUBLICATION IS AVAILABLE THROUGH

THE US ARMY COMMUNICATIONS-ELECTRONICS COMMAND.

NOTICE: REPRODUCTION FOR NON-MILITARY USE OF INFORMATION OR ILLUSTRATIONS CONTAINED

IN THIS PUBLICATION IS NOT PERMITTED WITHOUT SPECIFIC APPROVAL OF THE US ARMY

COMMUNICATIONS-ELECTRONICS COMMAND.

Distribution authorized to the Department of Defense and DOD contractors only to protect technical or operational information from automatic dissemination under the International Exchange Program or by other means. This protection applies to the publications required solely for official use and to those containing valuable technical or operational information. This determination was made on 3 February 1987. Other requests for this document will be referred to Commander, US Army Communications- Electronics Command and Fort Monmouth, ATTN: AMSEL-LC-LEO-E-ED, Fort Monmouth, New Jersey 07703-5006.

WARNING – This document contains technical data the export of which is restricted by the Arms Export Control Act (22 USC 2751 et seq.) or Executive Order 12470. Violations of these export laws are subject to severe criminal penalties.

DESTRUCTION NOTICE – Destroy by any method that will prevent disclosure of contents or reconstruction of the document.

US Army Communications- Electronics Command

Fort Monmouth, NJ

CONTAINING NATIONAL MAINTENANCE REPAIR STANDARDS

1 June 2002

ATTACHMENT 4:

SAFETY STEPS TO FOLLOW IF SOMEONE

IS THE VICTIM OF ELECTRICAL SHOCK

DO NOT TRY TO PULL OR GRAB THE INDIVIDUAL

IF POSSIBLE, TURN OFF THE ELECTRICAL POWER

IF YOU CANNOT TURN OFF THE ELECTRICAL POWER, PULL,

PUSH, OR LIFT THE PERSON TO SAFETY

USING A WOODEN POLE OR A DRY ROPE OR SOME OTHER

INSULATING MATERIAL

SEND FOR HELP AS SOON AS POSSIBLE

AFTER THE INJURED PERSON IS FREE OF CONTACT WITH

THE SOURCE OF ELECTRICAL SHOCK, MOVE

THE PERSON A SHORT DISTANCE AWAY AND IMMEDIATELY

START ARTIFICIAL RESPIRATION AND RESUSCITATION

a b

WARNING

DANGEROUS CHEMICALS are used during cleaning processes performed on this equipment. FIRE, POISONING, AND/OR FLESH BURNS may result if personnel fail to observe safety precautions.

WARNING

Be careful when working with 115-volt power connections. DEATH ON CONTACT may result if personnel fail to observe safety precautions.

WARNING

Electrical shock hazard may exist between equipment not connected by a common ground. Be sure to connect common grounds to test instrument and test equipment to power source ground before applying power to avoid possible serious injury to personnel.

WARNING

TRICHLOROTRIFLUOROETHANE, TRICHLOROETHANE and similar chemical solvents will no longer be used for ordinary cleaning of equipment. These substances threaten public health and the environment by destroying ozone in the earth’s upper atmosphere. Suitable nonhazardous cleaning materials will be used instead, such as a clean cloth, water and mild detergent.

WARNING

A periodic review of safety precautions in TB 385-4, Safety Precautions for Maintenance of Electrical/Electronic Equipment, is recommended. When the equipment is operated with case removed, DO NOT TOUCH exposed connections or components. MAKE CERTAIN you are not grounded when making connections or adjusting components inside the test instrument.

WARNING

DO NOT SERVICE OR ADJUST ALONE

Do not attempt internal service or adjustment unless another person, capable of rendering first aid and resuscitation, is present.

WARNING

Compressed air is dangerous and can cause serious bodily harm if protective means or methods are observed to prevent a chip or particle (of whatever size) from being blown into the eyes or unbroken skin of the operator or other personnel. Compressed air shall not be used for cleaning purposes except where reduced to less than 30 pounds per square inch gauge (30 psig) and then only with effective chip guarding and personnel protective equipment (industrial safety glasses and full faceshield).

c

CAUTION

Circuit card assemblies and integrated circuits cannot be cleaned with an ultrasonic cleaner. Failure to observe this caution may result in damage to components.

CAUTION

ESD SENSITIVE ITEM

HANDLE IN ACCORDANCE WITH

DOD-STD-1686 AND DOD-HDBK-263

d

FIRST AID PROCEDURES FOR ELECTRIC SHOCK VICTIMS

Before touching a victim of electrical shock, the circuit should be deenergized or the victim freed from the live conductor by using some suitable nonconductive object, such as rope, dry wooden stick, or insulated pole. Artificial resuscitation procedures appropriate to the victim's condition will be started immediately:

a. If the victim has stopped breathing, or the victim's heart has stopped beating; emergency first aid procedures should be started at once. If the victim is not breathing, do the following.

(1) Place victim on his/her back on a firm surface such as the floor or ground, not on a bed or sofa.

(2) Tilt the head straight back. Extend the neck up as far as possible. (This procedure will automatically keep the victim's tongue out of the airway).

(3) Open your mouth wide and place it tightly over the victim's mouth. At the same time, pinch the victim's nostrils shut, or close the nostrils with your cheek, or close the victim's mouth and place your mouth over the victim's nose. For babies and small children, cover both the mouth and the nose of the victim with your mouth.

(4) Blow into the victim's mouth, or nose, with a smooth steady action until the victim's chest raises.

(5) Remove your mouth. Allow the victim to exhale passively and watch the victim's chest fall.

(6) Repeat. This cycle should be continued at the rate of one breath each five seconds.

NOTE

If you are not getting an air exchange, quickly recheck position of heat and adequacy of seal around victim's mouth. If attempts to ventilate are still unsuccessful, sweep fingers through victim's mouth and into throat to remove any foreign bodies. If the rescuer is unable to dislodge any foreign body, turn the victim on the side and give several sharp blows between the shoulder blades to jar it free. After four quick breaths, stop and determine if the heart is beating by gently feeling the carotid pulse. If the heart is beating, return to mouth-to-mouth resuscitation and continue until breathing starts or until a physician tells you to stop.

b. If the carotid pulse is absent or questionable, start artificial circulation by external cardiac compression.

(1) Place the heel of one hand on the lower one half of the breastbone and the other hand on top of the first.

(2) Thrust downward from your shoulders with enough force to depress the breastbone about 1-1/2 to 2 inches.

(3) Relax immediately after each downstroke to permit natural expansion of the chest.

(4) Repeat compressions at the rate of about one per second. The compressions must be regular, smooth, and uninterrupted. If you are alone with the victim, you must alternate mouth-to-mouth breathing with external cardiac compression at the ratio of about 2 to 15 (two breaths, then 15 heart compressions). If you have help, the ratio is five compressions to one inflation; therefore, after five heart compressions, CALL FOR HELP. Continue one or both of the above while the victim is being transported to the hospital until revival, or until told to stop by a physician.

e/(f blank)

c. Once the victim is breathing again, watch carefully for signs of physical shock. Physical shock is a state of collapse or prostration that interferes with normal action of the nervous system; symptoms include weak pulse, chills, nausea, and a pale face. To treat shock:

(1) Have the patient lie down, with the head lower than the feet, if possible.

(2) Loosen tight clothing.

(3) See that the patient has plenty of air.

(4) Wrap the patient in blankets or other coverings as soon as possible. Keep the patient warm as is comfortable until help arrives.

PRINCIPLES OF CORROSIVE CHEMICAL FIRST-AID

1. In the event of contact with the eyes, immediately flush the eyes with water and continue to flush for 15 minutes.

The first few seconds after contact are critical and immediate flushing of the eyes may prevent permanent damage.

Any eyewash fountain is preferred, however, an eyewash hose of any other source of water should be used in an emergency.

Alkali (base) burns are usually more serious than acid burns.

2. Strong chemicals burn the skin rapidly. There is no time to waste. Begin flushing the area with water immediately.

Remove and discard clothing, including socks and shoes (obtain other clothes and shoes). Continue to flood the area, while clothing is being removed.

3. The precautionary warning on the product label should be consulted for full first-aid information. Provide the label information to the attending physician.

4. Neutralizers and solvents (alcohol, etc.) should not be used by the first aider. The spread of skin-absorbing corrosive poison, like phenol, can result in death. (Do not depend upon spilled chemicals to evaporate from your clothes).

Change HEADQUARTERS No. 1 US Army Communications-Electronics Command Fort Monmouth, NJ, 30 November 2007

DEPOT MAINTENANCE WORK REQUIREMENT (INCLUDING DEPOT MAINTENANCE

REPAIR PARTS AND SPECIAL TOOLS LIST) AND CONTAINING NATIONAL MAINTENANCE

REPAIR STANDARDS

FOR

HORIZONTAL SITUATION INDICATOR ID-2278B/A

(NSN 6610-01-316-2748)

DISTRIBUTION STATEMENT D – Distribution authorized to the Department of Defense and U.S. DoD contractors only, for official use or for administrative or operational purposes. This determination was made on 15 June 1995. Other requests for this document must be referred to Commander, US Army Communications Electronics Command and Fort Monmouth, ATTN: AMSEL-LC-LEO-E-ED, Fort Monmouth, New Jersey 07703-5006.

1. File this sheet in front of the manual for reference.

2. This change is made (1) to restore original foldout illustrations, (2) to supply part number information in the repair parts and special tools list (RPSTL) portion of this DMWR for set screws and course and heading knobs, and (3) to include new Appendix D for the hex wrench required to adjust the course and heading knobs.

3. New or updated text is indicated by a vertical bar in the outer margin of the page.

4. Remove old pages and insert new pages as indicated below.

Remove Pages Insert Pages

A/(B Blank) A/(B Blank) iii iii iv iv 3-4 3-4 3-5 3-5 3-10 3-10 3-11 3-11 3-14 3-14 3-15 3-15 3-68 3-68 3-123 3-123 3-134 3-134 3-136 3-136 B-16-1 B-16-1 D-1 – D-2 FP-1/(FP-2 Blank) FP-3/(FP-4 Blank) FP-5/(FP-6 Blank) DA Form 2028 DA Form 2028 (8 pages)

By Order of the Commanding General, CECOM:

DENNIS L. VIA

Commanding Official:

RICKI L. SULLIVAN

Colonel, United States Army

Garrison Commander C080002

Major General, United States Army

Change 1 A/(B Blank)

LIST OF EFFECTIVE PAGES

Insert latest change pages; dispose of superseded pages in accordance with applicable policies.

NOTE: On a change page, the portion of the text affected by the latest change is indicated by a vertical line in the outer margin of the page. Changes to illustrations are indicated by a vertical line in the margin next to the figure title.

Dates of issue of original and changed pages are:

Original ……………………………. 1 June 2002 Change 1 …………………………. 30 November 2007

The total number of pages in this DMWR is 279, consisting of the following:

Page *Change No. No.

Page *Change No. No.

Page *Change No. No.

Title ............................. 0 3-69 – 3-122 ................ 0 B-8-1 Safety .......................... 0 3-123 ........................... 1 Figure B-9 A .................................. 1 3-124 – 3-133 .............. 0 B-9-1 B Blank ........................ 0 3-134 ........................... 1 Figure B-10 a – d ........................... 0 3-135 ........................... 0 B-10-1 i – ii .............................. 0 3-136 ........................... 1 Figure B-11 iii – iv .......................... 1 3-137 – 3-144 .............. 0 B-11-1 v – vi ........................... 0 4-1 – 4-4....................... 0 Figure B-12 1-1 – 1-6 ...................... 0 5-1 – 5-2....................... 0 B-12-1 2-1 – 2-8 ...................... 0 6-1 – 6-2 ...................... 0 Figure B-13 3-1 – 3-2 ...................... 0 A-1 – A-2 ..................... 0 B-13-1 3-3 ............................... 0 B-1 – B-7 ..................... 0 Figure B-14 (1 of 3) 3-4 – 3-5 ...................... 1 Figure B-1 ................... 0 Figure B-14 (2 of 3) 3-6 – 3-9 ...................... 0 B-1-1 ............................ 0 Figure B-14 (3 of 3) 3-10 – 3-11................... 1 Figure B-2 ................... 0 B-14-1 – B-14-2 3-12 – 3-13 .................. 0 B-2-1 ........................... 0 Blank 3-14 – 3-15 .................. 1 Blank ........................... 0 Figure B-15 3-16 ............................. 0 Figure B-3 (1 of 4) ....... 0 B-15-1 3-17 – 3-19................... 0 Figure B-3 (2 of 4) ....... 0 Figure B-16 3-20 – 3-21................... 0 Figure B-3 (3 of 4) ....... 0 B-16-1 3-22 – 3-23 .................. 0 Figure B-3 (4 of 4) ....... 0 Blank 3-24 ............................. 0 B-3-1 – B-3-3 .............. 0 B-I-1 – B-I-22 3-25 – 3-26................... 0 Figure B-4 ................... 0 C-1 – C-4 3-27.............................. 0 B-4-1 ............................ 0 D-1 – D-2 3-28 ............................. 0 Figure B-5 .................... 0 FP-1 3-29 – 3-31 .................. 0 B-5-1 ........................... 0 FP-2 Blank 3-32.............................. 0 Figure B-6 .................... 0 FP-3 3-33 – 3-35................... 0 B-6-1 ........................... 0 FP-4 Blank 3-36 – 3-37 .................. 0 Figure B-7 .................... 0 FP-5 3-38 – 3-67 .................. 0 B-7-1 ........................... 0 FP-6 Blank 3-68 ............................. 1 Figure B-8

* DMWR 11-6610-402

i

Depot Maintenance US ARMY COMMUNICATIONS- Work Requirement ELECTRONICS COMMAND

FORT MONMOUTH, NJ

No. 11-6610-402 Washington, DC, 1 June 2002

DEPOT MAINTENANCE WORK REQUIREMENT

HORIZONTAL SITUATION INDICATOR

ID-2278B/A

(NSN 6610-01-316-2748)

(PN 132750-5)

TABLE OF CONTENTS

Page

CHAPTER 1 INTRODUCTION ......................................................................................................... 1-1

Section I. General........................................................................................................................... 1-1 1-1. Purpose .......................................................................................................................... 1-1 1-2. Scope ............................................................................................................................. 1-1 1-3. Maintenance Forms, Records and Reports .................................................................... 1-1 1-4. Reporting Equipment Improvement Recommendations (EIR's).................................... 1-1 1-5. Deviations and Exceptions............................................................................................. 1-2

Section II. Description, Data Plates, and Tabulated Data................................................................ 1-3 1-6. Description..................................................................................................................... 1-3 1-7. Data Plates ..................................................................................................................... 1-4 1-8. Tabulated Data............................................................................................................... 1-5 1-9. Modifications................................................................................................................. 1-6

Section III. Mobilization Requirements............................................................................................ 1-5 1-10. General........................................................................................................................... 1-6

* This manual supersedes DMWR 11-6610-402, dated 28 February 1995.

REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS

You can help improve this manual. If you find any mistakes, or if you know of a way to improve the procedures, please let us know. Mail your letter, DA Form 2028 (Recommended Changes to Publications and Blank Forms) or DA Form 2028-2 located in back of this manual directly to: Commander, US Army Communications- Electronics Command and Fort Monmouth, ATTN: AMSEL-LC-LEO-D-CS-CFO, Fort Monmouth, New Jersey 07703-5006. The fax number is 732-532-1413, DSN 992-1413. You may also e-mail your recommendations to AMSEL-LC-LEO-PUBS-CHG@mail1.monmouth.army.mil

In either case, a reply will be furnished directly to you.

(INCLUDING DEPOT MAINTENANCE REPAIR PARTS AND SPECIAL TOOLS LIST)

CONTAINING NATIONAL MAINTENANCE REPAIR STANDARDS

FOR

ii

TABLE OF CONTENTS - Continued

Page

CHAPTER 2 TECHNICAL SUPPORT REQUIREMENTS.............................................................. 2-1

Section I. General.......................................................................................................................... 2-1 2-1. Facilities........................................................................................................................ 2-1 2-2. Support Items ................................................................................................................ 2-1

Section II. Standards....................................................................................................................... 2-1 2-3. Quality of Material........................................................................................................ 2-1

CHAPTER 3. MAINTENANCE, OVERHAUL, AND REPAIR........................................................ 3-1

Section I. General.......................................................................................................................... 3-1 3-1. Scope............................................................................................................................. 3-1

Section II. Safety ............................................................................................................................ 3-1 3-2. Hazardous Voltage........................................................................................................ 3-1

Section III. Preshop Analysis........................................................................................................... 3-1 3-3. Purpose.......................................................................................................................... 3-1 3-4. Repair Tags ................................................................................................................... 3-1 3-5. Preshop Analysis........................................................................................................... 3-1 3-6. Functional Test Procedure ............................................................................................ 3-1 3-7. Trouble Analysis Procedure.......................................................................................... 3-62

Section IV. In-Process Review ........................................................................................................ 3-62 3-8. Inspection...................................................................................................................... 3-62

Section V. Disassembly .................................................................................................................. 3-64 3-9. Disassembly Procedures ............................................................................................... 3-64 3-10. Cleaning ........................................................................................................................ 3-115 3-11. Painting ......................................................................................................................... 3-115

Section VI. Repair............................................................................................................................ 3-116 3-12. Repair............................................................................................................................ 3-116

Section VII. Assembly ...................................................................................................................... 3-118 3-13. Scope............................................................................................................................. 3-118 3-14. Refinishing.................................................................................................................... 3-118 3-15. Assembly Procedures.................................................................................................... 3-119 3-16. Electrical Resistance and Insulation Breakdown Tests ................................................. 3-138 3-17. Electrical Zeroing Procedure......................................................................................... 3-139

CHAPTER 4 FINAL ASSEMBLY AND TESTING ......................................................................... 4-1

4-1. Scope............................................................................................................................. 4-1 4-2. Final Assembly ............................................................................................................. 4-1 4-3. Final Performance Check.............................................................................................. 4-4

CHAPTER 5 QUALITY ASSURANCE/QUALITY CONTROL REQUIREMENTS ...................... 5-1

Section I. General.......................................................................................................................... 5-1 5-1. Responsibility for Inspection ........................................................................................ 5-1 5-2. Terms and Definitions................................................................................................... 5-1 5-3. Inspection and Test Equipment..................................................................................... 5-1 5-4. Certification of Personnel, Materials and Processes ..................................................... 5-1 5-5. Quality Assurance Plan................................................................................................. 5-1

Section II. Inspection Requirements............................................................................................... 5-1 5-6. First Article Inspection.................................................................................................. 5-1 5-7. Acceptance Inspection .................................................................................................. 5-2

TABLE OF CONTENTS - Continued

Page

CHAPTER 6 PACKAGING FOR SHIPMENT AND STORAGE ..................................................... 6-1

6-1. Requirements ................................................................................................................. 6-1 6-2. Packaging....................................................................................................................... 6-1

APPENDIX A REFERENCES

APPENDIX D COMPONENTS OF END ITEM (COEI) AND

BASIC ISSUE ITEM (BII) LIST D-1

..... A-1

APPENDIX B REPAIR PARTS AND SPECIAL TOOLS LIST.......................................................... B-1

APPENDIX C EXPENDABLE AND DURABLE ITEMS................................................................... C-1

Change 1 iii iv Change 1

LIST OF ILLUSTRATIONS

Figure Title Page

1-1. Horizontal Situation Indicator ……………………………………………………………. 1-2 1-2. Indicator Displays ………………………………………………………………………… 1-3 1-3. Manufacturer’s Nameplate ……………………………………………………………….. 1-6 2-1. Fabrication of Post Locator Tool, T7406 ………………………………………………… 2-3 2-2. Fabrication of Torque Adjuster Tool, T6377 …………………………………………….. 2-4 2-3. Fabrication of Case Gage Tool, T7382-002 ……………………………………………… 2-5 2-4. Test Console ……………………………………………………………………………… 2-6 2-5 Adapter Box ……………………………………………………………………………… 2-7 2-6. Digital Data Transmitter …………………………………………………………………. 2-8 3-1. Test Setup ………………………………………………………………………………... 3-2 3-2. Deleted (see FO-1) ………………………………………………………………………. 3-4 3-3. Servo Amplifier Circuit Card Assembly A1A2, Schematic Diagram …………………… 3-6 3-4. Bearing Electronics Circuit Card Assembly A1A3, Schematic Diagram ……………….. 3-8 3-5. Deleted (see FO-2) ………………………………………………………………………. 3-10 3-6. Course Deviation Circuit Card Assembly A1A5, Schematic Diagram …………………. 3-12 3-7. Deleted (see FO-3) ………………………………………………………………………. 3-14 3-8. Horizontal Situation Indicator, Final Assembly ………………………………………… 3-67 3-9. Internal Mechanism Assembly, A1 ………………………………………………........... 3-70 3-10. Internal Mechanism Subassembly, A1A1 ………………………………………………. 3-76 3-11. Course Counter Assembly ………………………………………………………………. 3-84 3-12. Course Deviation Circuit Card Assembly, A1A5 ………………………………………. 3-87 3-13. Range Electronics Circuit Card Assembly, A1A4 ……………………………………… 3-89 3-14. Bearing Electronics Circuit Card Assembly, A1A3 ……………………………………. 3-92 3-15. Servo Amplifier Circuit Card Assembly, A1A2 …………………………………........... 3-94 3-16. Front Plate Assembly, A1A1A5 ………………………………………………………… 3-99 3-17. Motor Plate Assembly, A1A1A1 ……………………………………………………….. 3-103 3-18. Synchro Plate Assembly, A1A1A2 ………………………………………………........... 3-106 3-19. Interconnect Circuit Card Assembly, A1A1A4 …………………………………………. 3-109 3-20. Rear Cover Assembly, A1A1A6 …………………………………………………........... 3-111 3-21. Meter Movement Assembly, A1A1A3 ………………………………………………….. 3-113 3-22. Chemical Coating Treated Surfaces …………………………………………………….. 3-144 6-1. Shipping and Storage Container ………………………………………………………… 6-2 FO-1. Internal Mechanism Assembly AI, Interconnect Diagram ……………………………… FP-1 FO-2. Range Electronics Circuit Card Assembly A1A4, Schematic Diagram ………………… FP-3 FO-3. Interconnect Circuit Card Assembly A1A1A4, Schematic Diagram …………………… FP-5 v

LIST OF TABLES

Number Title Page

1-1. Physical and Electrical Characteristics ................................................................................................... 1-5 2-1. Inspection and Test Equipment............................................................................................................... 2-1 3-1. Azimuth Dial Does Not Zero Properly Or Is 180 Degrees Out of Phase................................................ 3-40 3-2. Azimuth Dial Rotates In Opposite Direction Or In Only One Direction................................................ 3-40 3-3. Heading Marker And Course Arrow Do Not Rotate In Unison With Azimuth Dial .............................. 3-40 3-4. Azimuth Servo Loop Does Not Exhibit Proper Sensitivity .................................................................... 3-41 3-5. Azimuth Servo Loop Does Not Exhibit Proper Accuracy ...................................................................... 3-41 3-6. Azimuth Dial Exhibits Erratic Movement Such As Hunting or Jumping............................................... 3-41 3-7. Azimuth Servo Loop Exhibits Excessive Error Voltage or Error Voltage

Varies More Than Allowable Limit .................................................................................................... 3-42 3-8. Bearing Pointer No. 2 Does Not Zero Properly ...................................................................................... 3-42 3-9. Bearing Pointer No. 2 Rotates In Opposite Direction Or Only One Direction ....................................... 3-42 3-10. Bearing Pointer No. 2 Servo Loop Does Not Exhibit Proper Sensitivity ............................................... 3-43 3-11. Bearing Pointer No. 2 Servo Loop Does Not Exhibit Proper Accuracy ................................................. 3-43 3-12. Bearing Pointer No. 2 Exhibits Erratic Movement Such As Hunting or Jumping.................................. 3-43 3-13. Bearing Pointer No. 2 Servo Loop Exhibits Excessive Error Voltage or Error

Voltage Varies More Thank Allowable Limit, Or Is Not Present ....................................................... 3-44 3-14. Course Resolver Angles Are Erratic, Incorrect, Out of Phase, Or Not Present ...................................... 3-44 3-15. Course Resolver Out Of Phase Voltage Is Not Within Tolerance .......................................................... 3-44 3-16. Course Resolver In Phase Voltage Is Not Within Tolerance .................................................................. 3-45 3-17. Course Resolver ORZ Test Fails ............................................................................................................ 3-45 3-18. Heading Datum Synchro Inoperative Or Out Of Phase .......................................................................... 3-45 3-19. Heading Datum Synchro Null Out Of Tolerance.................................................................................... 3-45 3-20. Heading Datum Synchro Error Voltage Out Of Tolerance..................................................................... 3-46 3-21. Course Datum Synchro Is Inoperative.................................................................................................... 3-46 3-22. Course Datum Synchro Out Of Phase .................................................................................................... 3-46 3-23. Course Datum Synchro Null Out Of Tolerance...................................................................................... 3-46 3-24. Course Datum Synchro Error Voltage Out Of Tolerance ....................................................................... 3-46 3-25. Heading Warning Flag Fails To Appear Or Disappear From View When

Power Is Applied Or Removed ........................................................................................................... 3-46 3-26. "To-From" Arrow Is Inoperative Or Does Not Work Properly .............................................................. 3-48 3-27. "To-From" Arrow Does Not Remain Out Of View When Deenergized

As Center Display Section Is Rotated ................................................................................................. 3-48 3-28. Current Required To Drive "To-From" Arrows Into Full View Is Less Than That Required ................ 3-48 3-29. "To-From" Arrows Show Evidence Of Sticking Or Binding ................................................................. 3-49 3-30. Course Bar Mechanism Is Inoperative Or Deflects In Opposite Direction............................................. 3-49 3-31. Course Bar Will Not Remain Centered When Deenergized As Center Display

Section Is Rotated 360 Degrees .......................................................................................................... 3-49 3-32. Current Required To Drive Course Bar Is Less Or More Than Specified .............................................. 3-49 3-33. Course Bar Does Not Return To Center When Current Is Suddenly Removed...................................... 3-50 3-34. Course Bar Shows Evidence Of Sticking or Binding ............................................................................. 3-50 3-35. NAV Warning Flag Is Inoperative.......................................................................................................... 3-50 3-36. Current Required To Drive NAV Warning Flag Into View Is Less Or More

Than That Specified ............................................................................................................................ 3-50 3-37. NAV Warning Flag Fails To Remain Fully In View When Less Than Required

Current Is Applied As Center Display Section Is Rotated 360 Degrees ............................................. 3-51 3-38. NAV Warning Flag Shows Evidence Of Sticking Or Binding............................................................... 3-51 3-39. Digital Distance, Digital Course, And Digital Bearing Circuits Are All Inoperative............................. 3-51 3-40. Distance Shutter Is Inoperative............................................................................................................... 3-52 3-41. Distance Shutter Remains Out Of View With Invalid Addresses Applied............................................. 3-52 3-42. All Distance Counters Are Inoperative................................................................................................... 3-52 3-43. Course Bar Does Not Respond As Specified And NAV Warning Flag Is Always In View................... 3-53 vi

LIST OF TABLES - Continued

Number Title Page

3-44. Course Bar Does Not Deflect In Response To Digital Input, NAV Warning Flag In View, Bearing Pointer No. 1 Parked At 90 Degrees and Does Not Respond To Digital Inputs ................... 3-53

3-45. NAV Warning Flag Out Of View With I/O Status ................................................................................ 3-53 3-46. NAV Warning Flag Out Of View With O/O Status............................................................................... 3-54 3-47. NAV Warning Flag Out Of View With O/I Status ................................................................................ 3-54 3-48. NAV Warning Flag In View With I/I Status.......................................................................................... 3-54 3-49. NAV Warning Flag Out Of View With Even Parity.............................................................................. 3-54 3-50. NAV Warning Flag Output Voltage Is Not Within Tolerance............................................................... 3-55 3-51. Bearing Pointer No. 1 Does Not Respond To Digital Inputs Nor will It Park At

90 Degrees As Required..................................................................................................................... 3-55 3-52. Bearing Pointer No. 1 Does Not Respond To Digital Inputs But Remains Parked At

90 Degrees.......................................................................................................................................... 3-55 3-53. Bearing Pointer No. 1 Does Not Respond To Digital Inputs and Remains Pointed At

Any Random Angle............................................................................................................................ 3-56 3-54. Bearing Pointer No. 1 Responds To Digital Inputs But Rotates To Random Angles ............................ 3-56 3-55. Bearing Pointer No. 1 Servo Loop Exhibits Excessive Error Voltage Or Error

Voltage Varies More Than Allowable Limit...................................................................................... 3-56 3-56. Bearing Pointer No. 1 Does Not Exhibit Proper Accuracy .................................................................... 3-57 3-57. Decoded Bearing No. 1 Sine and Cosine Outputs Are Not Present, Out Of

Tolerance, Or Out Of Phase ............................................................................................................... 3-57 3-58. Bearing Pointer No. 1 Responds Properly To Digital Inputs But Will Not Park At

90 Degrees Or Leave Parked Position As Required ........................................................................... 3-58 3-59. Range Counter Does Not Slew To 3333 And/Or Range Shutter Does Not

Disappear From View......................................................................................................................... 3-58 3-60. Course Bar Does Not Deflect To Area Between First And Second Dots On Right, And/Or NAV Warning Flag Does Not Disappear From View........................................................... 3-58 3-61. Bearing Pointer No. 1 Does Not Rotate 45 Degrees .............................................................................. 3-59 3-62. Range Counter Does Not Slew to 0000 And/Or Range Shutter Does Not Come Into View ................. 3-59 3-63. Course Bar Does Not Deflect To Center And/Or NAV Warning Flag Does

Not Come Into View .......................................................................................................................... 3-59 3-64. Bearing Pointer No. 1 Does Not Rotate to 0 Degrees, Then Park at 90 Degrees................................... 3-59 3-65. Range Counter Changes From 0000 to 7777 And Shutter Disappears, Then Reappears....................... 3-60 3-66. Course Bar Deflects From Center To Right Stop and NAV Warning Flag

Disappears, Then Reappears............................................................................................................... 3-60 3-67. Bearing Pointer No. 1 Rotates From 90 Degrees To 132 Degrees, Then Parks At 90 Degrees ............. 3-60 3-68. Range Counter Slews Continuously But Range Shutter Does Not Remain

Continuously Out Of View................................................................................................................. 3-60 3-69. Course Bar Deflects Back And Forth Between Right And Left Stops, But NAV

Warning Flag Does Not Remain Out Of View................................................................................... 3-61 3-70. Bearing Pointer No. 1 Does Not Rotate Continuously Clockwise In Steps But Parks

At 90 Degrees..................................................................................................................................... 3-61 3-71. Displays Do Not Function As Specified For Short Word Gap .............................................................. 3-61 3-72. NAV Warning Flag Comes Into View With High And/Or Low Clock Rate Applied

But Normal Input Level...................................................................................................................... 3-61 3-73. NAV Warning Flag Comes Into View With Any Combination Of High Or Low

Clock Rates And High Or Low Input Levels ..................................................................................... 3-62 3-74. Inspection Requirements........................................................................................................................ 3-62 3-75. Paint Requirements ................................................................................................................................ 3-116 5-1. Verification Testing ............................................................................................................................... 5-2

1-1

CHAPTER 1

INTRODUCTION

SECTION I - GENERAL

1-1. PURPOSE.

These instructions constitute the Depot Maintenance Work Requirement (DMWR) for Horizontal Situation Indicator, ID- 2278B/A, part number 132750-5. The Horizontal Situation Indicator is illustrated in Figure 1-1.

1-2. SCOPE.

These instructions are for use by depot/contractor personnel. They apply to Horizontal Situation Indicator, ID-2278B/A, (hereinafter called the indicator) and, in case of conflict, take precedence over all other documents pertinent to its overhaul and inspection. This manual covers preshop analysis, removal of major assemblies, disassembly, repair, reassembly, testing and packaging of equipment for reshipment. The following appendices are also provided as part of this DMWR publications.

a. Appendix A - References. This appendix provides a list of references pertinent to depot maintenance.

b. Appendix B - Repair Parts and Special Tools List. This appendix presents an illustrated parts list for identification and procurement of parts required for depot maintenance.

c. Appendix C - Expendable Supplies and Materials. This appendix provides a list of consumable supplies and materials required to support depot maintenance of the indicator.

1-3. MAINTENANCE FORMS, RECORDS, AND REPORTS.

a. Reports of Maintenance and Unsatisfactory Equipment. Department of the Army forms and procedures used for equipment maintenance will be those prescribed by DA PAM 738-750, as contained in Maintenance Management Update.

b. Report of Item and Packaging Deficiencies. Fill out and forward Report of Discrepancy (ROD) (SF364) as prescribed in AR 735-11-2.

c. Discrepancy in Shipment Reports. Fill out and forward Discrepancy in Shipment Report (DISREP) (SF361) as prescribed in AR 55-38.

d. Consolidated Index of Army Publications and Blank Forms. Refer to latest issue of DA Pamphlet 25-30 to determine whether there are new editions, or additional publications pertaining to the equipment.

1-4. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIR'S).

EIR's will be prepared using SF 368 (Product Quality Deficiency Report). Instructions for preparing EIR's are provided in DA PAM 738-750, The Army Maintenance Management System (TAMMS). EIR's should be mailed directly to Commander, U.S. Army Communications-Electronics Command, ATTN: AMSEL-LC-LEO-D-CS-CFO , Fort Monmouth, NJ 07703-5006.

A reply will be furnished directly to you.

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1-5. DEVIATIONS AND EXCEPTIONS.

The following deviations and exceptions apply to this manual.

a. Contractor Deviations. When any work segment as set forth in this depot maintenance work requirement cannot be accomplished in a manner other than specified, prior approval of the procuring activity shall be obtained by immediately submitting to the contracting officer a written notice containing the following information.

(1) Serial Number (if applicable) part number, and NSN of affected equipment.

(2) Work elements which will not be completed, or which will not be accomplished exactly as specified herein.

(3) Reason for accomplishment or deviation.

(4) Action taken to correct condition causing non-accomplishment or need for deviation.

(5) Data relative to availability of parts required, if applicable.

(6) Estimated task-hours required for completion.

(7) Instruction and inspection required to maintain the integrity of the end item because of such omission or deviation.

b. Depot Deviations. Refer to DESCOM-R-702-1.

Figure 1-1. Horizontal Situation Indicator

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Figure 1-2. Indicator Displays

SECTION II. DESCRIPTION, DATA PLATES, AND TABULATED DATA

1-6. DESCRIPTION.

The indicator is an hermetically sealed, integrally lighted navigation instrument that presents a pictorial view of the aircraft's flight path as viewed from above. The unit provides, from remote inputs, the following information in an integrated display (see Figure 1-2):

a. Aircraft Position. The horizontal position of the aircraft is represented by a fixed aircraft symbol located in the center of the display in line with stationary upper and lower lubber lines. The center display section rotates about the position of the aircraft symbol.

b. Magnetic Heading. An azimuth dial, indexed in degrees, indicated aircraft magnetic heading as read against the fixed upper lubber line. The dial is servo driven and rotates in response to an externally supplied synchro input. When heading information is invalid or there is an electrical failure within the indicator, the heading flag comes into view.

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c. Selected Heading. A heading marker, located adjacent to and read against the outer edge of the azimuth dial, indicates the selected heading. The heading marker is manually positioned to the desired heading by means of the heading set knob. Once set, the heading marker rotates in synchronism with the azimuth dial. Heading error is the difference between the selected heading and the magnetic heading as indicated by the azimuth dial. The heading set knob is also mechanically linked to the heading datum synchro. This synchro generates an electrical output for use by other aircraft systems, which is equivalent.

d. Selected Course. A course arrow, tip and tail, located adjacent to the inner edge of and read against the azimuth dial, indicates the selected course. The course arrow is manually positioned to the desired course by the course set knob. Once set, the course arrow rotates in synchronism with the azimuth dial. In addition, the course counter in the upper right hand corner, presents the digital equivalent of the selected course. The course arrow, together with the course deviation bar and scale, navigation warning flag and to-from arrow are all part of the center display section. Consequently, when the course arrow is positioned, the entire center display section rotates. The course set knob is also mechanically linked to the course datum synchro. This synchro generates an electrical output for use by other aircraft systems, which is equivalent to course error. Course error is the difference between the magnetic heading as read on the azimuth dial and the selected course.

e. Course Deviation. The course deviation bar deflects rightward or leftward to indicate displacement of the aircraft to the right or to the left, respectively, of the selected course. The extent of displacement is proportional to the amount of deflection as read against the four dot course deviation scale. The course deviation bar consists of a meter movement driven by a dc input signal. This signal is developed from the digital data input which consists of three binary words representing course deviation, distance to the nearest transmitting station and bearing to a destination. The course deviation word is decoded within the indicator, converted to its dc analog equivalent, supplied as an output to an external system, then switched back into the indicator to actuate the course deviation bar. In addition, the course deviation word includes two status bits.

These bits are likewise decoded, converted to analog dc, outputted, then switched back to actuate the navigation warning flag.

Consequently, when course deviation information is invalid or unavailable, the navigation warning flag comes into view.

f. Ambiguity Indication. The to-from arrow represents the direction of flight, respectively, toward or away from a transmitting station along the selected course. The arrow is operated by a meter movement in response to a remove dc input.

For a "to" indication, the arrow appears on the same side as the tip of the course arrow. For a "from" indication, the arrow appears on the opposite side, tail end of the course arrow.

g. Bearing Information. Bearing pointers No. 1 and 2 (tips and tails) rotate about the outer perimeter of the azimuth dial.

Bearing pointer No. 2 is driven by a servo mechanism in response to a remote synchro input. Bearing point No. 1, also servo driven, responds to the bearing word included in the digital data input. This word is decoded within the indicator then converted to its dc sine and cosine equivalents. In this form, it is used to actuate the servo mechanism. The status bits contained within the bearing word are also decoded such that when bearing information is invalid or not present, bearing pointer No. 1 is parked 90 degrees from the lubber line.

h. Range Information. The range counter indicates the slant range distance to the selected transmitting station. The range of display is zero to 999.99 kilometers. Distance information is received as a binary word in the digital input data stream. The word is decoded within the indicator to logic levels which drive the magnetically actuated counter wheels to the appropriate numeral. Likewise, the status bits are decoded such that when distance information is unreliable, the distance shutter comes into view to partially obscure the numerals.

1-7. DATA PLATES.

a. Manufacturer's Nameplate. The manufacturer's nameplate is located at the rear of the indicator below the interface connector. Should a new nameplate be required, manufacture replacement in accordance with MIL-P-19834, Type I, Style III using aluminum foil conforming with Federal specification QQ-A-250/1. Mark nameplate per MIL-STD-130 as illustrated in Figure 1-3.

b. Overhaul Data Plates. Overhaul data plates will be manufactured in accordance with MIL-P-514 and placed adjacent to the manufacturer's nameplate. The data plate will include the following: initials of the facility performing the overhaul or modification, contract number (contractor use only), data, part number and total operating time since new. When sufficient space is not available on the existing data plate to add information, the plate will be replaced and all pertinent data transferred to the new plate. Data will not be stamped directly on any part, assembly, or item of equipment.

1-5

1-8. TABULATED DATA.

The physical and electrical characteristics of the indicator are listed in Table 1-1.

Table 1-1. Physical and Electrical Characteristics

Characteristic Parameter

Primary Power 115 vac, 400 Hz, 15 va

Lighting Power 5 vac, 400 Hz, 5 va

Physical Dimensions:

Length (including knobs and connector)

Length (case only)

Width

Height

9.5 inches

8.0 inches

5.0 inches

4.25 inches

Weight 6.75 lbs max

Operating Ambient Temperature -54˚C to +71˚C

Mounting Hole Spacing:

Horizontal

Vertical

4.50 inches

3.75 inches

Hermetic Sealing Requirements:

Filling Medium

Leak Rate

90% nitrogen, 10% helium at one atmosphere.

Not to exceed 5 micron cubic feet per hour at a pressure of one atmosphere (5.2 x 10-5 standard cubic centimeter per second).

1-6

1-9. MODIFICATIONS.

Horizontal situation indicators, ID-2278A/A, are modified to ID-2278B/A, in accordance with MWO 1-1520-237-50-59, prior to return to serviceable condition.

Figure 1-3. Manufacturer's Nameplate

SECTION III. MOBILIZATION REQUIREMENTS

1-10. GENERAL.

All requirements of this…