operator and organizational maintenance manual

TM 11-5826-215-12DEPARTMENT OF THE ARMY TECHNICAL MANUAL

OPERATOR AND ORGANIZATIONALMAINTENANCE MANUAL

RECEIVING SET,RADIO AN/ARN-30D

HEADQUARTERS DEPARTMENT OF THE ARMY21 AUGUST 1961

WARNING

DANGEROUS VOLTAGES EXIST IN THIS EQUIPMENT

DON’T TAKE CHANCES !

DANGEROUS VOLTAGES EXIST IN:

Power Supply PP-2792/ARN-30D: Re-ceiver, Radio R-1021/ARN-30D: Con-verter, Signal Data CV-265A/ARN-30A,and associated interconnecting wiringwhen the VOL-OFF switch on Control,Radio Set C-3436/ARN-30D is taken outof the OFF position.

Changes in force: C2, C4, C5, and C6

C HANGE

No. 6

TM 11-5826-215-12C 6

HEADQUARTERS,DEPARTMENT OF THE ARMYWASHINGTON , D.C., 31 July 1973

Organizational Maintenance Manual

Including Repair Parts and Special Tool Lists

RECEIVING SET, RADIO AN/ARN-30D AND AN/ARN-30E

TM 11-5826-215-12, 21 August 1961, is changed as follows:

Page 5, paragraph 1.1. Delete paragraph1.1 and substitute:

1.1. Indexes of Publications

a. DA Pam 310-4. Refer to the latestissue of DA Pam 310-4 to determine wheth-er there are new editions, changes, or ad-ditional publications pertaining to the equip-ment.

b. DA Pam 310-7. Refer to DA Pam310-7 to determine whether there are modi-fication work orders (MWO’s) pertainingto the equipment.Paragraph 2. Delete paragraph 2 and sub-stitute:

2. Forms and Records

a. Reports of Maintenance and Unsatis-factory Equipment. Maintenance formsrecords, and reports which are to be usedby maintenance personnel at all mainte-nance levels are listed in and prescribedby TM 38-750.

b. Report of Packaging and HandlingDeficiencies. Fill out and forward DD Form

6 (Report of Packaging and Handling De-ficiencies) as prescribed in AR 700-58 (Ar-my)/NAVSUP PUB 378 (Navy)/AFR 71-4(Air Force)/and MCO P4030.29 (Marinecorps).

c. Discrepancy in Shipment Report (DIS-REP) (SF 361). Fill out and forward Dis-crepancy in Shipment Report (DISREP)(SF 361) as prescribed in AR 55-38 (Ar-my)/NAVSUP PUB 459 (Navy)/AFM 75-34 (Air Force)/and MCO P4610.19 (Ma-rine Corps).

2.1. Reporting of Equipment PublicationImprovements

The reporting of errors, omissions, andrecommendations for improving this pub-lication by the individual user is encour-aged. Reports should be submitted onDA Form 2028 (Recommended Changesto Publications) and forwarded direct toCommander, US Army Electronics Com-mand, ATTN AMSEL-MA-AN, Fort Mon-mouth, N. J., 07703.

1

—

Page 8, paragraph 5. Delete and sub-stitute:

5. Items Comprising Operable Receiving Sets, Radio AN/ARN-30D and AN/ARN-30E

FSN

5826-752-5814

5826-892-1056

5985-270-8399

5826-752-5735

5826-892-1061

5826-505-0645

5826-697-9880

6625-091-0494

5826-611-0865

5826-752-2508

5821-542-7937

5826-752-5730

Qty

1

1

1

1

1

1

1

1

1

1

Nomenclature, Part No., and mfr code

Receiving Set, Radio AN/ARN-30D

Receiving Set, Radio AN/ARN-30E

consisting of:

NOTE

In the usable on code column, number 1 refers toReceiving Set, Radio AN/ARN-30D; number 2 re-fers to Receiving Set, Radio AN/ARN-30E.

Antenna AS-580A/ARN-30; ramshorn type; for receiving VHF;ARC type A-13B

Control, Radio Set C-3436/ARN-30D; 28vdc; 126.90 mHzmax range; ARC type C-81A

Control, Radio Set C-3436A ARN-30D: 28vdc, 108 to 126.90mHz max range; ARC type C-88A

Converter, Signal Data CV-265A/ARN-30A; converter outputindicated on external meters; ARC type B-13A-1

Indicator, Course ID-453/ARN-30: combined cross-pointermeter To-From meter and course selector ARC type IN- 10

Mounting MT-l174/ARN-30A; aluminum; ARC type M-10

Mounting MT-1175/ARN-30A; aluminum; ARC type E-14

Power Supply PP-2792/ARN-30D; crystal rectifier; full wave;ARC type DV-10A

OR

Power Supply; ARC type DV-10A: rectifier type; 26 v ac,ARC part/dwg No. 19840

Receiver Radio R-1021/ARN-30D; 1 band, 108-126.90 mc,190 channels; ARC type R-34A (28v)

Usable on code

1,2

1

2

1,2

1,2

1,2

1,2

1,2

1,2

7. Delete appendix III in its entirety.

2

By Order of the Secretary of the Army:

Official:

CREIGHTON W. ABRAMSGeneral, United States Army,Chief of Staff.

VERNE L. BOWERS,Major General, United States Army,The Adjutant General.

Distribution:

To be distributed in accordance with DA Form 12-36 (qty rqr block No. 148) organizational main-tenance requirements for AN/ARN-30.

3

Changes in force: C 2, C 3, C 4, and C 5

TM 11-5826-215-12* C 5

HEADQUARTERSDEPARTMENT OF THE ARMY

Change

No. 5 WASHINGTON, D.C., 10 June 1965

Organizational Maintenance Manual

RECElVING SET, RADIO AN/ARN-30D AND AN/ARN-30E

Including Repair Parts and Special Tool Lists

(As changed by C 1, 16 Jul 62) TM 11-5826-21S-12, 21 August 1961, is changed as indicated sothat the manual also applies to the following equipment:

Nomenclature Order No.

Receiving Set, Radio AN/ARN-30E . - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 4294-PP-61

The title (as changed by C 1,16 Jul 62) is changed to read as shown above.Note. The parenthetical reference to a previous change (example: “page 5 of C 2”) indicates that pertinent

material was published in that change.

Page 5 (as changed by C 1, 16 Jul 62). Addthe following note below the title of chapter 1:

Note. Receiving Set, Radio AN/ARN-30E is similar toReceiving Set, Radio AN/ARN40D. information in thismanual applies to both sets unless otherwise specified.

After “Control, Radio Set G3436/ARN-30D” add “or Control, Radio C-3436A/ARN-30E” in the following places (as added by C 1, 16Jul 62):

Page 6, figure 2, paragraph 3d, line 9., paragraph 4c, title.Page 8, paragraph 5, chart, line 2, paragraph 6,

chart, line 4.Page 4, figure 1 (as added by C 1, 16 Jul 62).

Add the following note to figure 1:

NOTE :

CONTROL, RADIO SET G3436A/ARN-30E IS SIMIIAR TO CONTROL, RADIOSET G3436/ARN-30D. THE FRONTPANEL OF THE C-3436A/ARN-30E HAS“VHF ILS” ON THE LEFT SIDE INPLACE OF “VHF NAV.”

Page 5, paragraph 2 (page 1 of C 4). Deletesubparagraph o and substitute:

c. Comments on Manuals. The direct report-ing by the individual user of errors, omission,

and recommendations for improving this manualis authorized and encouraged. DA Form 2028(Recommended Changes to DA Publications) willbe used for reporting these improvements. Thisform will be completed using pencil, pen, or type-writer and forwarded direct to Commmanding Gen-eral, U.S. Army Electronics Command, ATTN:AMSEL-MR-(NMP)-MA, Fort Monmouth,N.J., 07703.

Page 6, paragraph 3d (as added by C1, 16 Jul62). Add the following at the end of subpara-graph d: Receiver Set, Radio AN/ARN-30D issupplied with Control, Radio Set C-3436/ARN-30D. The control unit is used to tune only Re-ceiver, Radio R-1021/ARN-30D. Receiver Set,Radio AN/ARN-30E is supplied with Control,Radio Set C-3436A/ARN-30E. This controlunit in addition to controlling the R-1021/ARN-30D can be used to tune an associated glide slopereceiver. It controls the frequency of both Re-ceiver, Radio R1021/ARN-30D and the glideslope receiver. The control unit automaticallytunes the R-1021/ARN-301) and the associatedglide slope receiver to associated glide slope andlocalizer frequencies.

Note. A specific glide slope transmitter frequency is al-ways paired with a specific localizer frequency.

7 8 8 - 3 9 5 - 6 5

Figure 2 (as added by C1, 16 Jul 62). Addthe following note to figure 2:

NOTE:

RECEIVING SET, RADIO AN/ARN-30EI S S U P P L I E D W I T H C O N T R O LRADIO SET G-3436A/ARN-30E INPLACE OF CONTROL, RADIO C-3436/ARN-30D.

, paragraph 5 (as changed by C 1, 16Jul 62). In “Width” column, line 2, add super-script l after: 3¾ and add the following foot-note:

Page 9, paragraph 8 (as added by C1, 16 Jul62). Add subparagraph d .

d. Control, Radio Set C-3436/ARN-30D hastwo electrical connectors mounted on the rearpanel. Control, Radio Set G3436A/ARN-30Ehas three electrical connectors mounted on the rearpanel and has a slight increase indepth of the unit.

Page 10, figure 4 (as added by CAdd the following note to figure 4:

NOTE :

the physical

1,16 Jul 62).

CONTROL RADIO SET C-3486A/ARN-30E IS SIMILAR TO CONTROL, RADIOSET G3436/ARN-30D. THE FRONTPANEL OF THE G3436A/ARN-30E HAS“VHF ILS” ON THE “LEFT SIDE INPLACE OF “VHF NAV.”

Page 14, paragraph 16 (as added by C 1, 16Jul 62). Add paragraph d.

d. The use of Control, Radio Set G3436A/ARN-30E with a glide slope receiver havingsimilar frequency selection control wiring as the

a The width of the G3486A/ARN-30E is 5½ inches.

R-1021/ARN-30D permits the automatic selectionof the associated glide slope frequency with theselected localizer frequency.

Page 15, paragraph 17, chart (as changed byC 1, 16 Jul 62). “Control or indicator” column,line 3. Add superscript a after “switch.” Line5. Add superscript a after “switch.”

Add the following footnote:Page 16, paragraph 19a, line 16 (as added by

C 1, 16 Jul 62). Add the following after “111.9mc.”: When the Control, Radio Set C-3436A/ARN-30E is used and an associated glide slopereceiver is connected into the system, the associatedglide slope receiver frequency will be selectedautomatically with the selection of the localizerfrequency.

Page 29, paragraph 35b, line 10 (as added byC 1, 16 Jul 62). Add the following sentence atend of subparagraph b: If Control, Radio SetC-3436A/ARN-ME is used, also check electricalconnector J3.

Page 32, paragraph 39.4e, last line (page 3 of C4). Delete “TM 8-213” and substitute: TB SIG364 .

Page 33, paragraph 41, chart. In item 4 “Cor-rective measures” column, line 14 (as changed byC 1, 16 Jul 62). Change “(fig. 19)” to: (fig. 19and 19.1).

Page 35, figure 19, caption (as changed by C 1,16 Jul 62). Delete the figure caption and sub-stitute: Control, Radio Set C-3436/ARN-30D,electrical connectors.

Add figure 19.1 (as added by C 1, 16 Jul 62)after figure 19:

a For Control, Radio Set G3430A/ARN-40E, this con-

trol, in addition to selecting the VHF navigation receiverfrequency, also selects the frequency to which an as-sociated glide slope receiver is tuned.

Figure 19.1. Control Radio Bet C-3436A/ARN-30E, electrical connectors.2

, paragraph 44 (as changed by C 1, 16 Subparagraph d(l). Delete the last twoJu1 62), subparagraph c(2). Delete the second lines and substitute: cables tagged in c(2) above.sentence and substitute: Disconnect the cablesfrom the VHF navigational control unit (fig. 19and 19.1).

Page 39 (page 6 of C 4). Delete appendix I and substitute:

Following isnavigation set.

DA

TB

TMTM

TM

TM

Pam 310-4

SIG 364

11-530

a list

11-6625-203-12

11-6625-366-20P

38-750

APPENDIX I

REFERENCES

of references available to the operator and organizational repairman of VHF

Index of Technical Manuals, Technical Bulletins, Supply Manuals (Types 7,8, and 9), Supply Bulletins, Lubrication Orders, and Modification WorkOrders.

Field Instructions for Painting and Preserving Electronics Command Equip-ment.

Installation Practices for Aircraft Electric and Electronic Wiring.Operator md Organizational Maintenance, Multimeter AN\URM-105, In-

cluding Multimeter ME-77/U.Organizational Maintenance Repair Parts and Special Tool Lists: Multimeter

TS-352/U, TS-352A/U, and TS-352B/U.Army Equipment Record Procedures.

Page 44, appendix II, section II (page v of C 2). Delete the item after “Mounting MT-1175/ARN-30A” and substitute:

APPENDIX IV

ORGANIZATIONAL REPAIR PARTS LISTSection I. INTRODUCTION

1. General equipment is authorized to the organization.These equipments are issued on the basis of allow-

a. This manual lists the repair parts authorized ances prescribed in equipment authorization tablesfor organizational maintenance and constitutes a and other documents which are a basis of requisi-basis of requisitioning when the major item of tioning. This equipment is combat essential.

3

b. Columns are as follows:(1)

(2)

(3)

(4)

(5)

(6)

Federal stock number. This column liststhe 11-digit Federal stock number.Designation by model. The dagger (†)indicates model in which the part is used.Description. Nomenclature or the stand-ard item name and brief identifying datafor each item are listed in this columnWhen requisitioning, enter the nomencla-ture and description.Unit of issue. The unit of issue is eachunless otherwise indicated and the sup-ply term by which the individual item iscounted for procurement, storage, requis-itioning, allowances, and issue purposes.Expendability. Nonexpendable itemsare indicated by NX. Expendable itemsare not annotated.Quantity incorporated in unit. This col-umn lists the quantity of each part found

(7)

(8)

in a given assembly, component, or equip-ment.Organizational. An asterisk indicatesthat an item is not authorized for stock-age but if required, may be requisitionedfor immediate use only.Illustration. The “Figure No.” columnlists the figure and reference numbersused for identification of the items in theillustration.

2. Parts for MaintenanceWhen this equipment is used by signal serv-

ice organization organic to theater headquartersor communication zones to provide theatar com-munications, those repair parts authorized up toand including general support are authorized forstockage by the organization operating this equip-ment.

4

SECTION II.

1

1

1

5


Official:J. C. LAMBERT,Major General, United States Army,The Adjutant General.

HAROLD K. JOHNSON,(General, United States Army,Chief of Staff.

6

TM 11-5826-215-12

C 4

TECHNICAL MANUAL

Operator and Organizational Maintenance Manual


TM 11-5826-215-12 HEADQUARTERS,DEPARTMENT OF THE ARMY

CHANGES No. 4 WASHINGTON 25, D. C., 19 February 1963

TM 11-5826-215-12, 21 August 1961, is changed as follows:

Change “DA Form 2391-2” to: DA Form2408-13 in the following places:

Page 29, paragraph 36, line 6.Page 30, paragraph 36j.Page 31, paragraph 37i.Page 5. Make the following changes:After paragraph 1, add—

1.1. Index of Publications

Refer to the latest issue of DA PAM 310-4 todetermine whether there are new editions,changes, or additional publications pertainingto your equipment. Department of the ArmyPamphlet No. 310-4 is a current index of tech-nical manuals, technical bulletins, supply bul-letins, lubrication orders, and modification workorders that are available through publicationssupply channels. The index lists the individualparts (-10, -20, -35P, etc.) and the latestchanges to and revisions of each equipment pub-lication.

Delete paragraph 2 and substitute:

2. Forms and Recordsa. Reports of Maintenance and Unsatisfac-

tory Equipment. Use equipment forms andrecords accordance with instructions in TM 38-750.

b. Report of Damaged or Improper Ship-ment. Fi l l ou t and fo rward DD Form6 (Report of Damaged or Improper Ship-ment) as prescribed in AR 700-58, (Army),NAVSANDA publication 378 (Navy), andAFR 71-4 (Air Force).

c. Comments on Manual. Forward all com-ments on this publication direct to: Command-ing Officer, U.S. Army Electronics MaterielSupport Agency, ATTN: SELMS-MP, FortMonmouth, N.J. (DA Form 1598 (Record ofComments on Publications), DA Form 2496(Disposition Form), or letter may be used.)

Page 32. Delete section I and substitute:

Section I. MAINTENANCE SERVICE AND INSPECTION

38. Scope of Maintenance a. Daily maintenance service and inspectionNote. The pilot will not perform preventive or cor- (par. 39.2).

r e c t i v e m a i n t e n a n c e . b. Cleaning (par. 39.4).The maintenance duties assigned to the or- c. Intermediate maintenance service and in-

ganizational maintenance repairman are listedbelow together with a reference to the para-

spection (par. 39.6).d. Periodic maintenance service and inspec-graphs covering the specific maintenance func-

tion. The duties include instructions for per- tion (par. 39.7).

forming preventive maintenance and corrective e. Repairs and adjustments:

maintenance and do not require tools or test (1) Removal and replacement of vhfequipment other than those allocated at second navigation control unit panel lampsechelon (par. 89). (par. 42).

1

(2) Removal and replacement of vhfnavigation control unit and course in-dicator knobs (par. 43).

(3) Removal and replacement of majorcomponents of vhf navigation set(par. 44).

39. ToolS, Materials, and Test EquipmentRequired

The tools, materials, and test equipment re-quired for maintenance at the organizationallevel are:

a.

b.

c.

d.

f .

Tool Kit, Radio Repair TK-115/G.Multimeter AN/URM-105 (multimeter).Fine sandpaper, No. 000.

A clean, dry, lint-free cloth.

A soft bristle brush.Cleaning Compound (Federal stock No.

e .

7930-395-9542) .

39.1. Preventive Maintenance

Preventive maintenance is the systematiccare, servicing, and inspection of equipment toprevent the occurrence of trouble, to reducedowntime, and to assure that the equipment isserviceable. Preventive maintenance is the re-sponsibility of all echelons concerned with theequipment and includes the inspection, testing,and repair or replacement of components thatinspection and tests indicate would probablyfail before the next scheduled service period.Preventive maintenance service and inspectionsof Receiving Sets Radio AN/ARN–30D andAN/ARN-30E at the organizational level aremade at daily, intermediate, and periodic in-tervals unless otherwise directed by the com-manding officer. The maintenance servicesshould be performed concurrently with theinspection schedules of the aircraft.

a. Systematic Care. The procedure given inparagraphs 39.2 through 39.8 cover systematiccare essential to proper upkeep and operationof the equipment. The cleaning operations(par. 39.4 a through d) should be performedonce a day. If the equipment is not used daily,however, the cleaning operations must be per-formed before operation, after any extended

2

shutdown, or once a week while the equipmentis kept in standby condition. The other itemsmust be checked before the equipment is placedin operation after shutdown, during operation,or after it is turned off, as specified in the ap-plicable paragraph.

b. Maintenance and Service Inspection. Themaintenance service and inspection charts(par. 39.3, 39.6, and 39.8) outline inspectionsto be made at specific intervals. These inspec-tions are made to determine combat serviceabil-ity; that is, to determine that the equipment isin good general (physical) condition, in goodoperating condition, and likely to remain com-bat serviceable. To assist the organizational re-pairman in determining and maintaining com-bat serviceability, the charts indicate what toinspect, how to inspect, and what the normalconditions are; the References column lists theparagraph that contains additional informa-tion. If the defect cannot be remedied by theorganizational maintenance repairman, higherechelon maintenance or repair is required.required. Records and reports of these inspec-tions must be made in accordance with TM 38-750.

c. Maintenance Forms and Records. Maintenance forms and records to be used and main-tained on this equipment are specified in TM38-750. Paragraph 2 contains additional in-formation concerning submission of specificforms.

39.2. Daily Maintenance Service andInspection

Daily maintenance service and inspections ofthe AN/ARN-30D and AN/ARN-30E are re-quired in an aircraft installation. Paragraph39.3 specifies services and inspections that mustbe accomplished daily and under special condi-tions listed below:

a. Following the last flight of each day orpreceding the next day’s flight.

b. When the equipment is replaced after re-moval for any reason.

c. At least once a week if the equipment ismaintained in standby condition.

39.3. Daily Maintenance Service and Inspection Chart

Note. The items numbers in the chart below are not consecutive; they are taken from the complete periodicmaintenance service and inspection chart (par. 39.8).

39.4. CleaningNote. Perform the following procedures as refer-

enced by the maintenance and service inspection charts.

Inspect all components of the vhf navigationset. The exterior surfaces should be clean,free of moisture, dirt, grease, and fungus.

a. Remove moisture and loose dirt with theclean soft cloth.

Warning: Cleaning compound is flammableand its fumes are toxic. Provide adequateventilation. DO not use near a flame.

b. Remove grease, fungus, and ground-in dirtwith a cloth dampened (not wet) with cleaningcompound..

c. Remove dirt from the exposed connectorswith a brush, and remove moisture with a drycloth.

Caution: Do not press on the course indicat-or glass when cleaning; the glass may be dam-aged.

d. Clean the front panel of the vhf naviga-tion control unit and the course indicator glass;use a soft clean cloth. If dirt is difficult to re-move, dampen the cloth with water; mild soapmay be used to make the cleaning more effec-tive.

e. Remove rust and corrosion from metal sur-faces by lightly sanding them with fine sand-paper. Brush two thin coats of paint on thebare metal to protect it from further corrosion.Refer to applicable cleaning and refinishingpractices specified in TM 9-213.

39.5. Intermediate Maintenance Service andInspection

The intermediate inspection provides verifi-cation of satisfactory operation at intervals be-tween the daily and perioric inspections. Per-form the maintenance functions indicated in theintermediate maintenance and inspection chart(par. 39.6) every 25 flying hours. The inter-mediate inspection should be performed con-currently with the intermediate maintenanceperformed on the aircraft in which the equipments is installed. Adjustments of the main-tenance interval must be made to compensatefor any unusual operating conditions. Equipment maintained in a standby (ready for im-mediate operation) condition, must have inter-mediate maintenance performed on it. Equip-ment in limited storage (requires service be-fore operation) does not require intermediateinspection.

3

39.6. Intermediate Maintenance Service and Inspection Chart

Note. The items numbers in the chart below are not consecutive; they are taken from the complete periodicmaintenance service and inspection chart (par. 39.8).

be immediately reported to a higher echelon by39.7. Periodic Maintenance Service andInspection

Periodic maintenance on Receiving Sets,Radio AN/ARN-30D and AN/ARN-30E willbe scheduled in accordance with the require-ments of TM 38-750. The equipment will nor-mally be part of an aircraft installation. Theperiodic maintenance inspection should bescheduled concurrently with the periodic main-tenance service schedule out-of-service time toa minimum. Refer to the applicable aircrafttechnical manual for the hours between serviceperiods. All deficiencies or shortcomings will

use of forms and procedures specified in TM38-750. Equipment that has a deficiency thatcannot be corrected by second echelon shouldbe deadlined in accordance with TM 38-750.Perform all the services listed in the periodicmaintenance inspection chart in the sequencelisted. Whenever a normal condition or resultis not observed, take corrective action in ac-cordance with the references.

Note. The periodic maintenance and inspection isperformed by an Aviation Electronic Equipment Re-pairman, MOS 284.1.

39.8. Periodic Maintenance Service and Inspection Chart

4

App. I.

DA Pam 810-4

Par. 35e and f.

TM 11-530

Par 35b, c, and d

Par. 35a.

Par. 41.

39.8. Periodic Maintenance Service and Inspection Chart- (Continued)

5

Delete appendix I and substitute:

APPENDIX I

REFERENCES

Following is a list of references available to the operator and organizational maintenance re-pairman of the vhf navigation set:

DA Pam 310-4 Index of Technical Manuals, Technical Bulletins, Supply Bulletins, Lubrica-tion Orders, and Modification Work Orders.

TM 9-213 Painting Instructions for Field Use.TM 11-530 Installation Practices for Aircraft Electric and Electronic Wiring.TM 11-6625-203-12 Operation and Organizational Maintenance, Multimeter AN/URM-105, in-

cluding Multimeter ME-77/U.TM 33-750 The Army Equipment Record System and Procedures.


EARLE G. WHEELER,General, United States Army,

Official: Chief of Staff.J. C. LAMBERT,Major General, United States Army,The Adjutant General.

Distribution:To be distributed in accordance with DA Form 12-31 requirements for Operators and Crew Members In-

structions for all fixed and rotor wing aircraft.

6

TM 11-5826-215-12C 2

TECHNICAL MANUAL

Operator and Organizational Maintenance Manual


TM 11–5826-215-12

CHANGES No. 2

TM 11–5826–215-12, 21 August 1961, ischanged as follows:

Page 5, paragraph 2. Delete subparagraph dand substitute the following:

d. Parts Lists Form. Forward DA Form2028 (Recommended Changes to DA TechnicalManual Parts Lists or Supply Manuals 7, 8,and 9) direct to the Commanding Officer, U.S.Army Signal Materiel Support Agency, ATTN:SIGMS–ML, Fort Monmouth, N.J., with com-ments on Appendix II and Appendix III.

Add paragraph 2.1 after paragraph 2.

2.1. Index of Equipment Publications

Refer to DA Pamphlet 310-4 to determine

HEADQUARTERS,DEPARTMENT OF THE ARMY

WASHINGTON 25, D. C., 17 September 1962

what Changes to or revisions of this publicationare current.

Page 39. APPENDIX I. REFERENCES.Add the following:

Additional instructions concerning mainte-nance of this equipment are contained in thefollowing publication:

Field and Depot Maintenance Repair Partsand Special Tools List and Maintenance Allo-cation Chart:

TM 11–5826–220–35P, Power Supply PP–2792/ARN–30D; Power Supply, ARC TypeDV-10A (PT/DWG 19840).

Pages 40 thru 49. Appendix II and AppendixIII. Delete and substitute the following:

APPENDIX II (SUPERSEDED)

MAINTENANCE ALLOCATION

Section I. INTRODUCTION

1. General

a. This section assigns maintenance func-tions to be performed on components, assem-blies, and subassemblies by the lowest appro-priate maintenance echelon.

b. Columns in the maintenance allocationchart are as follows:

(1) Component. This column shows onlythe nomenclature or standard itemname. Additional descriptive data isincluded only where clarification is (2)necessary to identify the component.Components, assemblies, and subas-

semblies are listed in topdown order.That is, the assemblies which are partof a component are listed immediatelybelow that component, and the subas-semblies which are part of an assem-bly are listed immediately below thatassembly. Each generation break-down(components, assemblies, or sub-as-semblies) are listed in disassemblyorder or alphabetical order.

Maintenance function. This columnindicates the various maintenancefunctions allocated to the echelons.

i

(a)

(b)

(c)

(d)

(e)

( f )

(g)

(h)

(i)

( j)

Service. To clean, to preserve, andto replenish lubricants.Adjust. To regulate periodically toprevent malfunction.Inspect. To verify serviceabilityand to detect incipient electrical ormechanical failure by scrutiny.Test. To verify serviceability andto detect incipient electrical or me-chanical failure by use of specialequipment such as gages, meters,etc.Replace. To substitute serviceablecomponents, assemblies, or subas-semblies, for unserviceable compo-nents, assemblies, or subassemblies.Repair. To restore an item to serv-iceable condition through correctionof a specific failure or unserviceablecondition. This function includesbut is not limited to welding, grind-ing, riveting, straightening, and re-placement of parts other than thetrial and error replacement of run-ning spare type items such as fuses,lamps, or electron tubes.Align. To adjust two or more com-ponents of an electrical system sothat their functions are properlysynchronized.Calibrate. To determine, check, orrectify the graduation of an instru-ment, weapon, or weapons system,or components of a weapons systemOverhaul. To restore an item to com-pletely serviceable condition as pre-scribed by serviceability standardsdeveloped and published by heads oftechnical services. This is accom-plished through employment of thetechnique of “Inspect and RepairOnly as Necessary” ( IROAN). Max-imum utilization of diagnostic andtest equipment is combined withminimum disassembly of the itemduring the overhaul process.Rebuild. To restore an item to astandard as near as possible to orig-inal or new condition in appearance,performance, and life expectancy.This is accomplished through themaintenance technique of complete

(3)

(4)

(5)

disassembly of the item, inspectionof all parts or components, repair orreplacement of worn or unservice-able elements using original manu-facturing tolerances and or specifi-cations, and subsequent reassemblyof the item.

1st, 2d, 3d, 4th, and 5th echelon. Thesymbol X indicates the echelon re-sponsible for performing that particu-lar maintenance operation, but doesnot necessarily indicate that repairparts will be stocked at that level.Echelons higher than the echelonmarked by X are authorized to per-form the indicated operation.

Tools required. This column indicatescodes assigned to each individual toolequipment, test equipment, and main-tenance equipment referenced. Thegrouping of codes in this column of themaintenance allocation chart indicatesthe tool. test, and maintenance equip-ment required to perform the mainte-nance function.

Remarks. Entries in this column willbe utilized when necessary to clarifyany of the data cited in the precedingcolumns.

c. Columns in the allocation of took for main-tenance functions are as follows:

(1) Tools required for maintenance func-tions. This column lists tools, test, andmaintenance equipment required toperform the maintenance functions.

(2) 1st, 2d, 3d, 4th, and 5th echelon. Thedagger (†) symbol indicates the eche-lons normally allocated the facility.

(3) Tool code. This column lists the toolcode assigned.

2. Maintenance by Using Organizations

When this equipment is used by signal serv-ices organizations organic to theater headquar-ters or communication zones to provide theatercommunications, those maintenance functionsallocated up to and including fourth echelon areauthorized to the organization operating thisequipment.

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APPENDIX Ill (SUPERSEDED)

BASIS ISSUE ITEMS LIST


1. Scope

This appendix lists items supplied for initialoperation. The list includes tools, parts, andmaterial issued as part of the major end item.The list includes all items authorized for basicoperator maintenance of the equipment. Enditems of equipment are issued on the basis ofallowances prescribed in equipment authoriza-tion tables and other documents that are a basisfor requisitioning.

2. Columns

a. Source, maintenance, and recoverabilitycode. Not used.

b. Federal stock number. This column liststhe 1l-digit Federal stock number.

c. Designation by model. The dagger (†)indicates model in which the part is used.

d. Description. Nomenclature or the stand-ard item name and brief identifying data foreach item are listed in this column. When req-uisitioning, enter the nomenclature and de-scription.

e. Unit of issue. The unit of issue is eachunless otherwise indicated and is the supplyterm by which the individual item is countedfor procurement, storage, requisitioning, allow-ances, and issue purposes.

f. Expendability. Nonexpendable items areindicated by NX. Expendable items are not an-notated.

g. Quantity authorized. Under “Items Com-prising an Operable Equipment,” the columnlists the quantity of items supplied for the ini-tial operation of the equipment.

h. Illustration. The Item No. column lists thereference symbols used for identification of theitems in the illustration or text of the manual.

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B Y O RDER OF THE S ECRTARY OF THE A R M Y :

Official:J. C. LAMBERT,

Major General, United States Army,The Adjutant General.

G. H. DECKER,General, United States Army,

Chief of Staff.

Distribution:

To be distributed in accordance with DA Form 12-31 requirements for Organizational Maintenance Instruc-tions for all fixed and rotor wing aircraft.

x

TM 11-5826-215-12

Technical Manual

No. 11-3826-215-12

HEADQUARTERS,DEPARTMENT OF THE ARMY

WASHINGTON 25, D.C., 21 August 1961

RECEIVING SET, RADIO AN/ARN-30D

CHAPTERSection

CHAPTERSection

Section

CHAPTERSection

1.I.

II.

2.I.

II.

III .

IV.

3.I.

II.

INTRODUCTIONGeneralScope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Forms and records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description and dataPurpose and use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Technical characterist ics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Table of components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Nomenclature and common name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of vhf navigation control unit . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of course indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of rack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of power supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Description of vhf navigation receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Additional equipment required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .System application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .OPERATING INSTRUCTIONSOperator’s controls and indicatorsVhf navigation control unit, operator’s controls and indicators . . . . . . . .Course indicator, operator’s controls and indicators . . . . . . . . . . . . . . . . .Operation under usual conditionsTypes of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Operating l imitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Start ing procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Determining g aircraft bearing relative to VOR stationFlying course to or from VOR station . . . . . . . . . . .

. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .

Making VOR approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Flying to objective other than VOR station . . . . . . . . . . . . . . . . . . . . . . . . . .Making approximate ground-speed checks . . . . . . . . . . . . . . . . . . . . . . . . . . .Making front course localizer approaches . . . . . . . . . . . . . . . . . . . . . . . . . . .Making back course localizer approaches . . . . . . . . . . . . . . . . . . . . . . . . . . .Intersecting localizer signal using VOR station . . . . . . . . . . . . . . . . . . . . . .Operating as communication equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Stopping procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Operation under unusual conditions

. . . . . . . . . . . . .

Emergency operat ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Jamming and anti jamming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Operator’s inspection procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Extent of coverage . . . . . . . . . . . . . . . . . . . . . . . . . . . Preflight inspections, power off . . . . . . . . . . . . . . . . . . . . Preflight inspections, power on . . . . . . . . . . . . . . . . . . . . . . . . . . . .Flight inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ORGANIZATIONAL MAINTENANCE INSTRUCTIONSGeneralScope of maintenance instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Corrective maintenanceVisual inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Equipment performance checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Removal and replacement of vhf navigation control unit -

panel lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Paragraph

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Removal and replacement of vhf navigation control unitand course indicator knobs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Removal and replacement of major components of vhf navigation set . . . 44C H A P T E R 4 . DEMOLITION OF MATERIEL TO PREVENT ENEMY USE

Authority for demolition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45Methods of destruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

A P P E N D I X I . REFERENCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .II. MAINTENANCE E ALLOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

III. BASIC ISSUE ITEMS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . .GLOSSARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

353538383839404750

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3

Figure 1. Receiving Set, Radio AN/ARN-30D.4

CHAPTER 1

INTRODUCTION

Section 1.

1. Scope

This manual describes Receiving Set ,Radio AN/ARN-30D (fig. 1) and coversthe operating instructions to be used bythe aircraft pilot, copilot, and crewmem-bers pe r fo rming nav iga t ion p roceduresand o rgan iza t iona l ma in tenance p roce -dures to be performed by the organiza-t ional repairman or aircraft crew chief.It includes preflight, flight, and functionalchecks for verifying normal operation ofthe equipment, and replacement of compo-nents and parts available to second echelonmaintenance personnel.

2. Forms and Records

a. Unsatisfactory Equipment Reports .Fill out and forward DA Form 468 (Unsat-isfactory Equipment Report) to the Com-manding Officer, U. S. Army Signal Mate-riel Support Agency, ATTN: SIGMS-ML,Fort Monmouth, N, J . , as prescribed inAR 700-38.

GENERAL

b. Report of Damaged or Improper Shipment . Fill out and forward DD Form 6(Report of Damaged or Improper Shipment)as prescribed in AR 700-58 (Army).

c. Maintenance Forms. P r e p a r e DAForm 2391-2 (Aircraft Flight Report andMaintenance Record – Aircraft Inspectionand Maintenance) in accordance with in-structions on the form. All postflight andpreflight inspections will be recorded onthis form, .

d. Parts Lists Form. Forward DA Form2028 (Recommended Changes to DA Tech-nical Manual Parts Lists or Supply Man-uals Parts Lists or Supply Manuals 7, 8,and 9) direct to the Commanding Officer,U. S. A r m y Signal Materiel SupportAgency, AT TN: SIG MS- ML, Fort Mon-mouth, N, J., with comments on parts list-ings.

e. Comments on Manual. Forward a l lother comments on this publicat ion di-rect to the Commanding Officer, U. S.A r m y S i g n a l M a t e r i e l S u p p o r t A g e n t ,ATTN: SIGMS-PA2d, Fort Monmouth, N. J,

Section II. DESCRIPTION AND DATA

3. Purpose and Usea. Receiving Set, Radio AN/ARN-30D is

an a i rborne , ve ry h igh- f requency (vhf )radio set which provides for reception of190 vhf channels whose frequencies are atall the 0.l-megacycle (me) steps between108.00 mc and 126.90 mc. Operat ion inth i s f r equency range pe rmi t s r ecep t ionand interpretation of vhf omnidirectionalradio range (VOR) signals and of localizersignals broadcasted by ground stat ions.Reception and interpretation of these sig-nals provide the operator with data usedin navigation.

b. The navigational data enable the op-erator to perform the following:

(1)

(2)

(3)

(4)

(5)

(6)

Determine the bearing of the air-craft with respect to a VOR sta-tion.Fly a desired course to or from aVOR station,Fly to an object ive other than aVOR station.M a k e approximate groundspeedchecks.Fly to the intersection of a localizerand VOR signal.Approach a runway associated witheither a VOR or a localizer sta-tion.

c. Rece iv ing Se t , Radio AN/ARN-30Dhas p rov i s ions fo r connec t ion to a vh f

5

t r ansmi t t e r . When connected to a vhft r ansmi t t e r , Receiving Set, Radio AN/ARN-30D, which is primarily a navigationset, can also be used as a communicationset . Certain port ions of this equipment(Indicator, Course ID-453/ARN-30) canalso be added to components of other equip-ment to permit glide-slope navigation pro-cedures to be performed.

d. Figure 2 is a block diagram showingthe operation of Receiving Set, Radio AN/ARN-30D. Both VOR and localizer naviga-t ion s ignals broadcasted by ground sta-tions are induced into Antenna AS-580A/ARN-30. Receiver, Radio R-1021/ARN-30D is tuned to the signals at the antennaby frequency selection signals developedin Control, Radio Set C-3436/ARN-30D.Tuning Receiver, Radio R-1021/ARN-30Dto these signals produces audio and navi-gation data outputs. Audio outputs are ap-plied to the intercommunication system of

the aircraft to permit voice and/or codesignals to be heard by the operator.

e. Navigation data outputs of Receiver,Radio R-1021/ARN-30D are applied toConverter , Signal Data CV-265A/ARN-30A which, in turn, processes either VORor localizer navigation signals; the signaltype selected is determined by a signal.f rom Cont ro l , Rad io Se t C-3456/ARN-3QD. The output of Converter, Signal DataCV-265A/ARN-30A is displayed on Indi-cator, Course ID-453/ARN-30 to show thebearing of the aircraft relative to the VORstation or to the localizer station. An out-put from a gl ide-slope receiver is dis-played on Indicator, Course ID-453/ARN-30 when a glide-slope receiver is beingused. High voltage required for operationof Receiver, Radio R-1021/ARN-30D andConverter , Signal Data CV-265A/ARN-30A i s supp l i ed by Power Supp ly PP-2792/ARN-30D.

Figure 2. Receiving Set, Radio AN/ARN-30D, operational block diagram.

6

4. Technical Characteristics

a. Receiving Set, Radio AN/ARN-30D.

Total input power. . . . 2.5 amperes at 28 volts dc(70 watts).

Total weight. . . . . . . Approximately 26 pounds.b . An tenna AS-680A/ARN-30 .

Type . . . . . . . . . . . . Two broadband dipoles.c. Control, Radio Set C-S-3436/ARN-30D.

Input power. . . . . . . . 80 ma at 28 volta dc (2.24watts).

d. Converter, Signal Data CV-265A/ARN-30A.Input power. . . . . . . . 0.52 ampere at 28 volts dc

(14.56 watts).High-voltage power . . 22 ma at 260 volts dc (5.72

watts) (VOR operation),7 ma at 260 volts dc(1.82 watts) (localizeroperation).

c. Indicator, Course lD-453/ARN-30.Pointer sensitivity . . . 150 ± 7.5 microampere.Flag sensitivity. . . . . 245+11 microampere.TO-FROM meter sen- 90 ± 15 microampere.

sitivity.Selector dial . . . . . . . 360 compass scale, marked

every 2° .

f . Power Supply PP-2892/ARN-30D.Input power. . . . . . . . 1.22 amperes at 26 volts

dc (31.72 watts)(100-maoutput).

Efficiency . . . . . . . . 85% (100-ma outout).Temperature rise . . . . 11°C or less (100-ma out-

put).Ripple . . . . . . . . . . . 0.3%.Output voltage . . . . . 260 V Ol tS dc at 100 ma.Output current. . . . . . 200 ma maximum, continu-

ous at 55° C; 100 mamaximum, continuous at71° C; 200 ma maximum,intermitted at 71°C.

Regulation . . . . . . . . 2% (15- to 150-ma out-put).

g. Receiver, Radio R-1021/ARN-30D.Frequency range . . . . 108.00-126.90 mc.Number of channels . . 190.Channel spacing . . . . 100 kc (O. 1 me).Channeling time . . . . 4 seconds maximum.Input power. . . . . . . . 1.8 amperes at 28 volts dc

(50.4 watts).High-voltage power . . 85 ma at 260 volts do

(22.1 watts).Types of signals re- VOR, localizer, and com-

ceived. munication.Weight. . . . . . . . . . . 6.7 pounds.T y p e . . . . . . . . . . . . . . . . . Superheterodyne, double-

conversion, crystal-con-trolled.

Type of modulation. . . Amplitude.Input impedance. . . . . 50 ohms.

Number of tubes . . . . 14.Sensitivity . . . . . . . . 6 db signal-plus-noise to

noise with 3 microvolts(measured across a 50-ohm source), maximum at1,000 cps, 30% modu-lation. Agc knee nohigher than 5 micro-v o l t .

Bandwidth . . . . . . . . 6 db down l 24 from centerfrequency.

60 db down ±70 kc fromcenter frequency.

T u n i n g . . . . . . . Electrically actuated, crys-tal-controlled. Nineteencrystals on megacycledrum; fundamental fre-quency range; 48.15 to57.15 mc in 0.5-mcsteps. Ten crystals onfractional megacycledrum; frequency range:10.00 to 10.90 mc in0.1-mc steps.

Intermediate frequen-t i e s :

First if . . . . . . . . Variable from 11.70 to12.60 mc.

Second if. , . . . . . 1.7 mc (fixed).If. rejection . . . . . . . 100 db, minimum.Image rejection . . . . . 70 db, minimum.Spurious response re- 80 db, minimum.

jection.Age . . . . . . . . . . . . . Output constant within 4.5

db from 10 to 200,000m i c r o v o l t .

Audio output. . . . . . . With 1,000 cps, 30% mod-,ulation, 108.00 to 117.90mc, at least 300 milli-watts into 300 ohms.

With 1,000 cps, 30% mod-ulation, 118.00 to 126.90mc, at least 70 milli-watt into 300 ohms.

With 1,000 cps, 85% mod-ulation, 118.00 to 126.90mc, at least 300 milli-watts into 300 ohms.

Squelch sensitivity. . . Adjustable from 0.1 to 5microvolts (may be ex-tended to 15 microvoltsby adjustment of if. sen-sitivity control, whichalso affects agc knee).

Total harmonic dis- Less than 25% with 100tortion. microvol t , 350- to

2,500-cps modulation.Audio frequency re- Within 6 db of rated output

eponse. from 350 cps to 2,500cps .

7

5. Table of Components(fig. 1)

The components of Receiving Set, Radio AN/ARN-30D are listed in the following table.

6. Nomenclature and Common Name

A list of the nomenclature assignmentsfor the components of Receiving Set, RadioAN/ARN-30D is given below. A commonname is indicated after each item.

7. Description of Antenna(fig. 3)

a. The antenna is a rams-horn a n t e n n awi th two d ipo les . The forward (short)dipole is used as a glide-slope antenna andis used for gl ide-slope signal receptionif such equipment is installed in the air-craft. The V-shaped rear dipole is the VORand localizer antenna and is used for re-ception of VOR and localizer signals.

b. Each antenna is terminated with a

UG-291/U coaxial connector. located inthe antenna base. The dipoles are set ina rubber block, which is fastened to thepedestal support.

c. The pedestal support has two drain-age tunnels at i ts base that permits theescape of accumulated moisture when theantenna is mounted in an upright position.When the antenna is mounted in an in-verted position, a hole is drilled throughthe white-marked depression in the topof the rubber block to provide for mois-ture drainage.

8. Description of Vhf Navigation ControlUnit

(fig. 4)

a. The vhf navigation control unit is asingle-chassis unit with operating controlsand a frequency indicator on the front paneland e lec t r i ca l connec to r s on the r ea rpanel. Lock fasteners on the sides of thefront panel allow the vhf navigation controlunit to be mounted in a location accessibleto the pilot and copilot of the aircraft,

b. Edge-l ight ing of the vhf navigat ioncontrol unit is provided by two midget,f lange-base lamps instal led in red-fi l terlight housing assemblies located on thefront panel . Power fo r these l amps i sbrought in through a separate wire, whichis to be connected to the electrical systempanel- l ight control of the aircraft . Thelight is t ransmitted through translucentwhite index lines and control designationson the face of an opaque panel.

8

Figure 3. Antenna.

c. L i g h t i s a l s o t r a n s m i t t e d t h r o u g htranslucent areas behind front-panel con-trol knobs to a t ranslucent white circleon each knob. When power is applied tothe equipment, the translucent white areasglow red, permitting identification of thecontrols and their settings.

9. Description of Converter(fig. 5)

a. The converter is a single-chassisunit with input and output connectorslocated at the rear of the chassis. Coni-cal studs on the lower right- and left-hand corners of the front panel allowthe converter to be fastened on MountingMT-1175/ARN-30A.

b. Adjustment controls on the frontpanel are not required for any operating

procedure, but are set and locked by ane lec t ron ic nav iga t ion repa i rman dur ingalignment.

10. Description of Course Indicator

a. The course ind ica to r ( f ig . 6 ) i s apanel-type indicator unit, consisting of sixi n d i c a t i n g e l e m e n t s o n e c o n t r o l . T h eind ica t ing e l emen t s , moun ted beh ind aglass window, Include horizontal and ver-tical pointers (fig. 12), horizontal and ver-t ical red flag mechanisms, a TO-FROMmeter, and a selector dial cal ibrated indegrees .

b. Fluorescent blue and yellow sectors(fig. 6) are marked in the area covered bythe vert ical pointer . These sectors indi-cate right and left deflections of the ver-tical pointer, which is pivoted at the top.

9

Figure 4. Vhf navigation control unit.

Figure 6. Course indicator.

11. Description of Mounting(fig. 7)

Figure 5. Converter.

The horizontal pointer (fig. 12) associatedwith glide-slope operations pivoted at theleft side.

c. The course and reciprocal pointersmove around the outer rim of the calibratedselector dial as the course selector knob isoperated.

d. Connection to other units in the vhfnavigation set is provided by an electricalconnector at the back of the course indi-cator (fig. 6). Holes in three of the indi-cator front-panel corners are used in theinstallation of the course indicator on theinstrument panel of the aircraft.

a. The mounting is normally mounted inthe interior of the aircraft and supportsthe rack (para 12). Shock mounts are lo-ca ted a t each corne r o f the mount ing .Grooved studs on the shock mounts connectto snapsl ides on the rack to secure therack. Holes in each of the grooved studsare use d for the instal lat ion of safetywires.

b. Two ground straps, which are fas-tened from the two rear shock mounts tothe mounting frame, ground all componentsthat set on the mounting to minimize radio-frequency (rf) noise. Eight holes in thechannel frame secure the mounting to theframe of the aircraft.

12. Description of Rack(fig. 8)

a. The rack provides a shock-mountedsupport for both the vhf navigat ion re-ceiver and the converter . These compo-nents are installed in individual compart-ments in the rack, and are scoured by

10

Figure 7. Mounting.

nut-and-l ink arrangements on the frontend of the rack. These nut-and-l ink ar-rangements engage conical studs locatedon the fronts of the components beingmounted. Holes in each knurled nut of thenut-and-l ink arrangements are used forthe installation of safety wires.

b. The rear of the rack is a distributionbox with electrical connectors on its frontand top panels. The front-panel connectorsmate with connectors mounted on the vhfnavigation receiver and the converter. Theconnec to r s on the top o f the r ack a reconnected by cables to remotely installedunits of the vhf navigation set.

c. Snapslides on the four corners ofthe rack are used to install the rack onthe mounting. These snapsl ides are se-cured to the grooved studs on the mount-ing shock mounts (fig. 7). Holes in thevert ical f langes of each of these snap-slides (fig. 8) permit the installation ofsafety wires.

13. Description of Power Supply(fig. 9)

The power supply is a s ingle-chassis ,plug-in type unit with a f in-type coverfor heat dissipation. A receptacle on thebottom of the power supply (J101) mates

with a power supply connector on the vhfnavigation receiver . Three studs on thebottom of the power supply are arrangedto insure correct mating. The power sup-ply is mounted on four shock mounts lo-cated on the vhf navigation receiver (fig.1). When mounted, the power supply issecured by four snapslide fasteners (fig.9). These snapslides are similar to Mount-ing MT-1175/ARN-30A snapslides (para12c) in that they have holes for safetywires in their vertical flanges.

14. Description of Vhf Navigation Receiver(fig. 10)

a. T h e v h f n a v i g a t i o n r e c e i v e r i s athree-chassis assembly. Two of the chas-sis are contained within a main housingand the third chassis is located both in-side the main housing and in an inter-connecting box subassembly located at therear of the main housing.

b. A screwdriver control, two multipinconnec to r s ( J2 and J3 ) , and a coax ia lconnector are located on the front panelof the receiver. One of the multipin con-nectors has a wire plug inserted in it anda protective cap mounted over i t . Thisprotective cap and wired plug can be re-moved and the connector used to makeelectrical connection to a vhf communica-tion transmitter. This connection permitsuse of the vhf navigat ion receiver as avhf communication receiver.

c. Four shock mounts and an electricalconnector are located on the top of thein te rconnec t ing box subassembly . Themounts and connector are used to providemechanical and electrical connections tothe power supply. Another multipin con-nector (J4), located at the rear of theinterconnecting box subassembly, permitsconnection of the vhf navigation receiverto the rack.

d. Two frequency windows located onthe right-hand side of the. vhf navigationreceiver provide a visual indicat ion ofthe megacycle and fract ional megacyclefrequencies to which the circuits of thevhf navigation receiver are tuned. Thefront window provides visual access tofract ional megacycle dial readings. The

11

Figure 8. Rack

Figure 9. Power supply,

r ea r window prov ides v i sua l access t cmegacycle dial readings, These windowsare not viewable when the vhf navigationreceiver is instal led on the rack, unlessthe converter is removed from the rack.

15. Additional Equipment Required

The following equipments are not sup-plied with the vhf navigation set but are re-quired for its use. The additional equip-ments are normally part of the aircraftwiring system.

a . Coax ia l Cab le . R a d i o F r e q u e n c yCable RG-58/U is required to connect theantenna to the vhf navigation receiver. Itshould be no longer than necessary.

b . C o a x i a l C o n n e c t o r s . R a d i o F r e -quency Plugs UG-88/U are required toterminate the ends of the coaxial cablebetween the antenna and vhf navigat ionr e c e i v e r .

c. Cable Harness Connectors. C a b 1 eharness connectors (2 ARC Type 14050 orequivalent, 1 ARC Type 14320 or equiva-lent, and 1 ARC Type 15912 or equivalent)are required to terminate various ends ofthe cable harness between the rack, courseindicator, and vhf navigation control unit,

d . Cab le Assembly Connec tors . T w ocab le assembly connec to r s (ARC Type16115 or equivalent) are required to ter-minate the ends of the cable assembly be-tween the vhf navigation receiver and thevhf navigation control unit,

e. Power Cable Connec tor , A p o w e rcable connector (ARC Type 14321 or equiv-alent) is required to terminate the powercable supplying low-voltage (lv) power tothe rack.

f. Cable Harness and Cable Assembly.A cable harness and a cable assembly arerequired for interconnection between thevarious components of the vhf navigationset. They are fabricated from individualwires, which are not supplied with the vhfnavigation set , and from the connectorsdesc r ibed in c a n d d a b o v e . T h e w i r e

12

Figure 10. Vhf navigation receiver.

s i ze va r i e s wi th each ins ta l l a t ion . Theac tua l l eng th o f the cab le ha rness andcable assembly depends upon the locationof the various components of the vhf navi-gation set in the aircraft. Refer to the ap-propriate aircraft technical manual.

g. Aircraft Primary Power Source. A 28-vo l t d i r ec t -cu r ren t (de ) p r imary sourcecapable of delivering 2.5 amperes is re-quired to operate the vhf navigation set.

16. System Application

The vhf navigation set receives, inter-prets, and provides indication of aircraftnavigational data contained in two types ofvhf radio transmissions: VOR and local-i z e r .

a. VOR Reception.(1) The VOR signals received by the

vhf navigation set are broadcastedin a l l d i r ec t ions a round a VORstation (fig. 13). T h es e signalshave two components. The first oft h e s e c o m p o n e n t s h a s a p h a s ewhich is the same in all directionsof transmission. This phase is as-signed a reference value of 0°. The

(2)

second component has a variablephase which changes with the di-rection of signal transmission. Thedifference between the phase of thetwo signal components is propor-t ional a t any given point to theangular difference between t h em a g n e t i c n o r t h h e a d i n g o f t h etransmitter and the bearing of thetransmit ted s ignal at that point .For example, a signal received ata point that lies on the 90° bearingof the VOR station has a differenceof 90° between its two signal com-ponents.

The vhf navigation set comparesthe two components of the VORsignal to determine the differencebetween the phase of the variablecomponent and the f ixed (refer-ence) component. This differenceis displayed on the course indi-cator of the vhf navigation set asthe magnetic bearing of the VORstation for the point at which thesignal is received. With the mag-netic bear i n g determined, the

13

bearing of the aircraft relative tothe VOR station can be determined,and flight courses can be flown toor from the VOR station. Receiptof the navigational data containedin the signals from two VOR sta-tions permits a flight course to bep lo t t ed to ano the r ob jec t ive bytriangulation, and permits an ap-proximation to be made of ground-speed.

b. Localizer Reception.(1) Localizer signals received by the

vhf navigation set are broadcastedas two narrow (5°) beams whichproject in front and to the rear ofthe localizer transmitter (fig. 16).These signals also have two com-ponents. On the centerline of therunway associated with the local-izer signal, these two componentshave the same s igna l s t r eng th ,However, on each side of this cen-terline, the strength of one of thecomponents increases, a n d thestrength of the other componentdecreases. The component that in-

(2)

creases on one side of the center-l ine i s t he componen t tha t de -creases on the other side.The vhf navigation set comparesthe two components of the local-i ze r s igna l to de te rmine whichcomponent has the greatest s ig-nal strength, If both signals havethe same strength, the course in-dicator in the vhf navigation setindicates that the aircraft is on therunway centerline. If one signal hasgreater amplitude than the other,the aircraft course indicator indi-cates the direction in which the air-craft must be flown to fly a center-line course. With this informationavailable, the aircraft can be flownon an approach to the runway or toany point that lies on a projectionof the runway centerline.

c. Combined VOR-Localizer Reception.By alternately tuning to both the VOR andlocalizer signals, or by using two vhf nav-igation sets in the same aircraft, the air-craft can be flown to a point of intersectionof the localizer and VOR signals.

14

CHAPTER 2

OPERATING INSTRUCTIONS

Section I. OPERATOR’S CONTROLS AND INDICATORS

Note. This section covers only items used by the operator; items used by maintenance personnel are cov-ered in instructions for the appropriate maintenance echelon.

17. Vhf Navigation Control Unit, Operator’s Control and Indicators(fig. 11)

18. Course Indicator, Operator’s Controls and Indicators(fig. 12)

15

Figure 11. Vhf navigation control unit, operator’s Figure 12.controls and indicators.

Section II. OPERATION UNDER USUAL CONDITIONS

19. Types of Operation

a. The vhf navigation set can be operatedwith either VOR or localizer stations toperform a number of navigational proce-dures. The vhf navigation set can also beoperated, in part , as communication re-ceiving equipment. During VOR naviga-tional procedures, the vhf navigation seti s t u n e d t o a n e v e n - n u m b e r e d , 10th-megacycle frequency between 108.2 mc and112.0 mc or to either an odd- or even-numbered, 10th-megacycle frequency be-tween 112 .1 mc and 117 .9 mc . Dur inglocalizer procedures, the vhf navigationset is tuned to odd-numbered, 10th-mega-cycle frequencies between 108.1 mc and111.9 mc. During procedures that use thevhf navigation set as communication re-ceiving equipment, the set is tuned to any

frequency between 108.00 mc and 126.9m c t h a c o r r e s p o n d s t o t h e o p e r a t i n gfrequency of an in-range vhf transmitter.

Course indicator, operator’s controlsand indicators.

b. During VOR operation, the naviga-tional procedures are used to:

(1)

(2)

(3)(4)

(5)

Determine aircraft bearing rela-tive to a VOR station (para 22).Fly a course to or from a VORstation (para 23).Make a VOR approach (para 24).Fly to an objective other than aVOR station (para 25).Make an approximate ground-speed check (para 26).

c. During localizer operation, the navi-gational procedures are used to:

(1) Make(para

(2) Make(para

a f r o n t c o u r s e a p p r o a c h27).a back course approach28).

16

d. Localizer and VOR operation can becombined to f ly a course to the inter-sec t ion o f the beam t r ansmi t t ed by alocalizer s tat ion using a specif ic VORstation bearing (para 29).

e. Use o f the vhf nav iga t ion se t a scommunication equipment allows the op-erator to:

(1) Receive any in-range vhf trans-m i t t e r s t a t i o n o u t p u t a t a f r e -quency to which the set can betuned.

(2) Supply B+ power to a vhf trans-mi t t e r ope ra t ing in con junc t ionwith the vhf navigation set.

f. To operate the vhf navigation set forany particular type of operation, performthe following:

(1) Starting procedure (para 21).(2) Procedure for the type of opera-

tion desired (para 22 through 30).(3) Stopping procedure (para 31).

20. Operating Limitations

Performance of the procedures listed inparagraph 19 is limited by the character-istics of vhf transmission. These limita-tions (a-d below) are usually temporary.

a. Reception of Reflected Radio Waves.Vhf radio waves are reflected when theystrike an object the conductivity and di-electric constant of which are differentfrom the atmosphere through which theyare moving. When reflection occurs, thecombined effect of the direct and reflectedwave produces a pattern of alternate lobesof reinforced and cancelled waves in thearea above the reflecting surface. Radioreception may be subject to fading as theaircraft passes through this area. Whenfading occurs, the vert ical pointer mayfluctuate considertibly and the OFF verti-cal flag may show intermittently.

b. Shadow Effect. Large obstacles canproduce a shadow area on the side awayfrom the transmit t ing antenna in whichreception is very poor or nonexistent .This effect can be overcome by increasingaltitude.

c. Duct Effect. Trapping of vhf radiowaves in a tmospher i c duc t s f r equen t lyextends the range of transmitted waves

several t imes over their normal usablerange. This effect can cause a station nor-mally out of range to interfere with thereception of a desired in-range stat ion.Although ducts can extend for miles, a pilotcan usually fly out of them since the ductsare frequently shallow.

d. Usable Transmission Distances. I nvhf transmission, the radiated waves gen-erally travel in an approximately straightline. Therefore, the maxi m u m usabletransmission distance depends on the lo-cation of the transmitting and receivingantennas. The following chart gives theapprox ima te l ine -o f - s igh t t r ansmiss ionrange for various aircraft altitudes.

21. Starting Procedure

a. Before operat ing the vhf navigat ionse t , ce r t a in con t ro l s mus t be opera tedwhich are unique to the particular aircraftin which the equipment is installed. Forthe application of primary power or theconnection of the vhf navigation set audiocircuits to the interphone system of thea i rc ra f t , t hese con t ro l s may inc lude aradio or communications master powerswi tch , a push- to - rese t c i r cu i t b reakerbutton, or an intercornmunication switch.For proper operat ion of these controls ,refer to the applicable aircraft technicalmanual.

b. Rotate the SQUELCH control on thevhf navigation control unit (fig. 11) to theextreme counterclockwise position.

c. Opera te the VOL-OFF swi tch and

17

control knob on the vhf navigation controlunit clockwise until a click is heard, in-dicating that the vhf navigation set is en-ergized.

d. Allow 5 minutes for the vhf navigationset to warm up.

e. Operate the megacycle channel selec-tor switch and/or the fractional megacyclechannel selector switch on the vhf naviga-tion control unit so that the MC dials in-dicate the frequency of an in-range VORtransmi t t e r . Refe r to the ae ronau t i ca lchart used during the flight for the fre-quency and location of the in-range VORtransmi t t e r .

f. Turn the VOL-OFF switch and controlknob on the vhf navigation control unitclockwise until the dot-dash code or voicesignal for the s tat ion to which the vhfnavigation set was tuned (e above) is atthe desired volume,

Note. In some aircraft, the VOL-OFF switch andcontrol knob on the vhf navigation set is operatedto the maximum clockwise position. The amount ofaudio output from the vhf navigation set to the in-terphone system of the aircraft is then determinedby a control in the interphone system itself. Forproper operation of these controls, refer to the ap-plicable aircraft technical manual.

Warning: The OFF vertical flag of thecourse indicator is an indication of signalstrength and reliability. If the OFF verti-cal flag does not go out of view or if Itfluctuates, it is an indication that the sig-nal received is not of sufficient strengthto be reliable or the vhf navigation set isnot functioning properly. Under no circum-stances should navigat ion be at temptedwith the vhf navigation set if the OFF ver-tical flag is visible.

g. Check the course indicator (fig. 12)to insure that the OFF vertical flag is outof sight.

h. Operate the megacycle channel selec-tor switch and/or the fractional megacyclechannel selector switch on the vhf naviga-tion control unit (fig. 11) so that the MCdials indicate a frequency to which no in-range VOR or localizer station assignmentis made. If duct effect (para 20c) is ex-perienced, choose another unassigned orout-of-range frequency.

i. Rotate the SQUELCH control on thevhf navigation control unit (fig. 11) clock-wise until the vhf navigation receiver noiseoutput is at the level desired with the air-craft engines and all electrical equipmentoperating normally.

j. Operate the megacycle channel selec-tor switch and/or the fractional megacyclechannel selector switch on the vhf naviga-tion control unit back to the settings es-tablished in e above. The station callsignshou ld be hea rd ; if not, back off theSQUELCH control on the vhf navigationcontrol unit (fig. 11) counterclockwise untilreception is at a satisfactory level.

22. Determining Aircraft Bearing Relativeto VOR Station

a. Perform the starting procedure givenin paragraph 21.

b. Set the megacycle channel selectorswitch and fractional megacycle channelselector switch on the vhf navigation con-trol unit (f ig. 11) to the posi t ions thatcause the MC dials to indicate the fre-quency of the VOR stat ion relat ive towhich the aircraft bearing is to be de-termined,

c. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21f). Note the identifying signal to be surethat the proper station is tuned in. Be surethat the OFF vertical flag (fig. 12) is outof sight on the course indicator and thatthe TO- FROM meter is indicating eitherTO or FROM.

Warning: Do not use the vhf navigationset for navigational purposes if the OFFvertical flag on the course indicator (fig,12) is visible or if the TO-FROM meterdoes not indicate.

d. Rotate the course selector knob onthe course indicator (fig, 12) until the ver-tical pointer is centered (selector dial set-ting 18).

e. Read the course selector bearing towhich the course pointer is pointing andnote whether it is TO or FROM. This isthe bearing of the aircraft relative to theVOR station being received.

18

Note. The TO-FROM meter will indicate TO whenthe course pointer is set to a course that is towardthe VOR station, and FROM when the course point-er is set to a reciprocal heading. The general loca-tion of the aircraft with respect to the VOB stationmay be determined as follows: If the course indica-tor shows 135° TO, the aircraft is northwest of theVOR station; if the indicator shows 135° FROM, theaircraft is southeast of the VOR station.

23. Flying Course to or from VOR Station


b. Set the megacycle channel selectorswitch and/or fractional megacycle chan-nel selector switch on the vhf navigationcontrol unit (fig. 11) to the positions thatcause the MC dials to indicate the fre-quency of the VOR station to which, orfrom which, the aircraft is to be flown.

c. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21 f). Note the identifying signal to be surethat the proper s tat ion is tuned in. Besure that the OFF vertical flag (fig. 12)is out of sight on the course indicator andthat the TO-FROM meter is indicatingeither TO or FROM.

Warning: Do not use the vhf navigationset to fly to or from the VOR station if theOFF vertical flag on the course indicator(fig. 12) is visible, or if the TO-FROMmeter does not indicate.

d. Rotate the course selector knob on thecourse indicator (fig. 12) until the coursepointer points to the desired course to orfrom the VOR station. Figure 13 showssix aircraft with a selected course of 90°.

Note. In the following step, if the course chosenis in the general direction of the VOR station andthe aircraft is less than approximately 70° from theselected course, the TO-FROM meter indicates TOas shown by aircraft A, B, and C. If the course cho-sen is in the general direction away from the VORstation and the aircraft is less than approximately70° from the selected course, the TO-FROM meterindicates FROM as shown by aircraft D, E, and F.If the course chosen is in either direction relativeto the VOR station, but is in the vicinity of 900 fromthe selected course, the TO-FROM meter indicatesneutral (no indication is visible). In the latter case,it is necessary to visually determine aircraft posi-tion with respect to the desired course.

e. See that the TO-FROM meter on thecourse indicator has the required readingfor the desired direction of flight.

f. Turn the aircraft unti l i ts magneticheading is the same as the bearing estab-lished on the course indicator (c above) ifa definite TO or FROM indication is seenon the TO-FROM meter.

g. Observe the position of the verticalpointer on the course indicator (fig. 12).

Warning: VOR operation supplies onlyposition information. Direction or headinginformation must still be obtained fromthe magnetic compass, The rule of flyingtoward the pointer in the following step isapplicable only i f the course indicatorbearing, the compass heading, and the de-sired course are the same.

h. Posit ion the aircraft on the desiredcourse by flying toward the pointer on thecourse indicator; that is , i f the vert icalpointer is left of center (in the blue area),fly a heading somewhat to the left (as il-lustrated by aircraft C and F) and hold thechosen heading until just prior to reachingthe desired course; if the pointer is rightof center (in the yellow area), fly a head-ing somewhat to the right (as illustratedby aircraft A and D) and hold the chosencourse until just prior to reaching the de-sired course. Do not make excessive head-ing changes to keep the vertical pointercentered. Fly the general trend of the ver-t ical pointer to prevent overcorrect ing.

Note. In the following step, the initial interceptangle depends on the displacement from the desiredc o u r s e . If far off-course (the vertical pointer ishard over), an initial intercept angle up to 90° canb e c h o s e n . If only slightly off-course, interceptangles of only 5° to 10° are required. When the ver-tical pointer is centered, the aircraft is on the se-lected course (as shown by aircraft A and E). At-tempt to keep the vertical pointer directly in thec e n t e r . If the vertical pointer fluctuates, fly thegeneral trend of the vertical pointer to prevent overcorrection. If the aircraft compass heading and thecourse indicator bearing are about 180° apart, it in-dicates that the aircraft is heading in a direction op-posite to the desired course. An attempt to fly to-ward the pointer u n d e r this condition causes thepointer to move still further left or right. To correctthe situation, make a 180° turn and then fly towardthe pointer.

19

i. Reduce the intercept angle of the air-craft as the desired course is approachedto prevent overshooting the course.

j. Maintain the desired course whenreached.

24. Making VOR Approach

Warning: Approaches that use a VORstation must be authorized and performedin accordance with published information.


b. Fly a desired course to the VOR sta-tion (para 23).

c. Watch for the following indicationsthat the aircraft has arrived over the VORstation:

(1) The signal heard on the aircrafti n t e r c o m m u n i c a t i o n s y s t e m i n -creases in volume and may be dis-torted.

Figure 13. Flying to or from VOR station.

20

(2)

(3)

The vertical pointer on the courseindicator (fig. 12) swings abruptlyfrom side to side.The OFF vertical flag may appearand disappear in rapid succession.

d. Let down in accordance with the in-structions published for the VOR stationin question.

25. Flying to Objectivc Other Than VORStation


b. Determine the magnetic bearing of theo b j e c t i v e f r o m t h e t w o V O R s t a t i o n sclosest to the object ive, by referr ing tothe appropriate navigation map. (In an ex-ample shown in figure 14, the objectivelies 30° magnetic from VOR station X and330° magnetic from VOR station Y, and theaircraft is near VOR station X at the startof the procedure.)

c. Fly the appropriate course to or fromone of the VOR stations (30° from stationX, in the example), by following the sameins t ruc t ions p rov ided to f ly a des i r edcourse to or from a VOR station (para 23).

d. Check the ve r t i ca l po in te r on thecourse indicator (f ig. 12) frequently inorder to s t ay on course (A, f ig . 14) .

Note. The time at which station Y is tuned in thefollowing steps depends on the distances betweenthe objective and the VOR stations. Remain tunedto station X as long as possible. If the aircraft isequipped with two vhf navigation sets, use the sec-ond set to perform steps e and f b e l o w .

e. Operate the megacycle channel selec-tor switch and/or the fractional megacyclechannel selector switch on the vhf naviga-tion control unit (fig. 11) so that the fre-quency -of station Y appears on MC dials,before the bearing of VOR stat iomn Y(330° in the example) is reached.

f. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21 f ). Note the ident ifying signal to besure that the proper station is tuned in.Be sure that the OFF vertical flag (fig.12) is out of sight on the course indicatorand the TO- FROM meter is indicatingeither TO or FROM.

g. Rotate the course selector knob on the

course indicator (fig. 12) so that the coursepointer is pointed to the VOR station Ybearing (33 for a 330° bearing in B, fig.14). The vertica1 pointer will swingtowards the side of the course indicatoron which the VOR s ta t ion i s loca ted ,

h. Use the directional gyro of the air-craft (or the first vhf navigation set) tomaintain the course from station A (30°).

i. Observe the vert ical pointer on thecourse indicator (fig. 12) of the vhf navi-gation set tuned to VOR station Y. Whenit centers, the aircraft is over the chosenobjective (C, fig. 14).

26. Making Approximate Groundspeed Checks


b. Chart a desired course of flight. (Inan example shown in figure 15, a coursehas been selected that lies on a 30° bear-ing from VOR station X.)

c. Set and fly the desired course in ac-cordance with the instruct ions of para-graph 23. A of figure 15 shows the course .selector knob adjusted so that the coursepointer lies at the dial reading of 3 (cor-responding to 30°), the TO-FROM meterreads FROM, and the vertical pointer iscentered. The aircraft heading indicated onthe magnetic compass may differ from thedesired course (30° in the example) if thereis a headwind: however, adjust the headingto keep the ve r t i ca l po in te r cen te red .

d. Operate the megacycle channel selec-tor switch and the, fractional megacyclechannel selector switch on the vhf navi-gation control unit (fig. 11) so that thefrequency of a second in-range VOR sta-tion is shown on the MC dials. If the air-craft has two vhf navigation sets, use thesecond set to tune the second VOR station.

e. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21f). Note the identifying signal to be surethat the proper station is tuned in. Be surethat the OFF vertical flag (fig. 12) is outof sight on the course indicator and thatthe TO- FROM meter is indicating eitherTO or FROM.

f. Determine the bearing of the second

21

Figure 14. Flying to objective other then VOR station.

VOR station (para 22). (B, figure 15, showsthat the second station (Y) is on a 270°bearing.) Mark this position on the aero-nautical chart used for the flight.

g. Make note of the time and maintainthe course flown in c above.

h. Determine the bearing of the secondVOR station (para 22) again, at the end of

a selected period of time (0.2 hour for ex-ample). (C, figure 15, shows that the sec-ond station (Y) is on a 3 3 0 ° b e a r i n g . )Mark this posit ion on the aeronauticalchar t .

i. Measure the distance (D) on the aero-nautical chart between the two positionsat which the bearings of the second VOR

22

stat ion were determined. (In f igure 15,the distance is 32 miles.)

j. Compute the approx imate g round-speed by dividing the distance measured(i above) by the time selected (h above).In the example shown:

Dis tance 32 milesTime = 160 mph.0.2 hour=

27. Making Front Course LocalizerApproaches


W a r n i n g : Do not proceed if the OFFvertical flag on the indicator (fig. 12) canbe seen after the next step is performed.

b. Operate the megacycle channel se-lector switch and/or the fractional mega-cycle channel selector switch on the vhfnavigation control unit (fig. 11) to indicatea frequency on the MC dials that corres-ponds to the frequency of the local izerstation to be approached.

c. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21f). Note the identifying signal to be surethat the proper s tat ion is tuned in. Besure that the OFF vertical flag (fig. 12) isou t o f s igh t on the cour se ind ica to r .

d. Perform the prel iminary f l ight pro-cedures which are specified by the pub-lished information for the approach beingmade.

e. Check the posit ion of the vert icalpointer on the course indicator (fig. 12)and begin flying toward the localizer sta-tion.

f. Fly left if the vertical pointer on thecourse indicator is lef t of center (bluearea on the dial) (A, fig. 16) and a 150-cycle-per-second (cps) tone is heard onthe aircraft intercommunication system(when used) ; f ly r igh t i f t he ve r t i ca lpointer is right of center (yellow area onthe dial) (B, fig. 16) and a 90-cps tone isheard on the aircraft intercommunicationsystem (when used). Make relatively smallchanges in heading. Small deviations (2.5°)from the center of the localizer beam pro-duce full-scale deflection of the verticalpointer .

g. Maintain the course that keeps thevertical pointer centered in order to makethe approach (C, fig. 16).

28. Making Back Course LocalizerApproaches


W a r n i n g : Do not proceed if the OFFvertical flag on the course indicator canbe seen after the following step is per-formed,

b. Operate the megacycle channel se-lector switch and/or the fractional mega-cycle channel selector switch on the vhfnavigation control unit (fig. 11) to indicatea f r e q u e n c y t h a t c o r r e s p o n d s t o t h efrequency of the Iocal izer s tat ion to beapproached.

c. Perform the prel iminary f l ight pro-cedures which are specified by the pub-lished information for the approach beingmade.

d. Check the posit ion of the vert icalpointer on the course indicator (fig. 12)and begin flying toward the localizer sta-tion.

Note. The indications in the following step arethe opposite of the indications in a front course lo-calizer approach (para 27).

e. Fly left if the vertical pointer on thecourse indicator is right of center (yellowarea of the dial) (A, fig. 17) and a 90-cps tone is heard on the aircraft inter-communication system (when used); f lyright if the vertical pointer is left of cen-ter (blue area of the dial) (B, fig. 17) anda 150-cps tone is heard on the aircraftintercommunication system (when used).

f. Maintain the course that keeps thevert ical pointer on the course indicator(fig. 12) centered (C, fig. 17) to make theback approach.

29. Intersecting Localizer Signal UsingVOR Station


b. Determine the magnetic bearing ofthe desired point of intersect of the local-izer beam and the VOR station by referring

23

Figure 15. Making approximate groundspeed check.

to the appropriate navigation map. (Figure c o m m u n i c a t i o n s y s t e m s u d d e n l y i n c r e a s e s i n

18 shows an example in which the desired strength and may be distorted; the vertical pointer

point of intersect of a localizer lies 60°on the course indicator (fig. 12) swings abruptly from

magnetic from the VOR station and theside to side; the OFF vertical flag on the indicator

aircraft is southwest of the VOR station.)appears and disappears in rapid succession; theTO-FROM meter on the course indicator indicates

Note. If, in the following step, it is necessary to erratically, fluctuating between TO and FROM, and

fly over a VOR station, the following indications we finally steadying into the FROM position as the air-observed: The signal heard over the aircraft inter- craft passes over the VOR station.

24

Figure 16. Making front course localiser approach.

c. Set and f ly the course that corres- d. Operate the megacycle channel se-ponds to the bearing of the intersect point lector switch and/or the fractional mega-relative to the VOR station (para 23). (In cycle channel selector switch on the vhfthe example chosen, this course would be navigat ion control uni t ( f ig. 11) as theon a 60° bearing TO (A, fig. 18) over, and localizer s tat ion radio beam is approa-then FROM (B, fig. 18) the VOR station.) ched so that the frequency of the localizer

25

Figure 17. Making back course localizer approach.

station appears on the MC dials. that the OFF vertical flag (fig. 12) is oute. Listen for the station call sign, Ad- of sight on the course indicator.

just the audio level to the aircraft inter- f. observe the vert ical pointer on thecommunication system if necessary (para course indicator (f ig. 12). The vert ical21f). Note the identifying signal to be sure pointer indicates in the yellow area of thethat the proper station is tuned in. Be sure vertical pointer dial (C, fig. 18) when the

26

localizer is first tuned in. As the coursefrom station A is continued, the verticalpointer moves left. When the centerlineof the localizer beam is reached, the ver-tical pointer centers. The desired point ofintersection is then reached.

30. Operating as Communication Equipment

a. Remove the protect ive cap and the

wired plug from the front panel of the vhfnavigation receiver (fig. 10) and replace itwith the cable connector of a vhf trans-mitter, if a vhf transmitter is to be usedwith the set.

Note. Connection of a vhf communication trans-mitter as in a above automatically applies B+ pow-er to the transmitter when the aircraft 28-volt inputsource and the vhf navigation set are energized asin b through f below.

Figure 18. Intersecting a localizer course.

27

b. Turn on the a i r c ra f t 28 -vo l t i npu tsource to the vhf navigation set, if it isnot already on. Refer to paragraph 21a.

c. Allow approximately 3 minutes forwarmup.

d. Operate the SQUELCH control on thevhf navigation control unit (fig. 11) to theextreme counterclockwise position.

e. Turn the VOL-OFF switch and con-trol knob on the vhf navigation controlunit to the on (clockwise) position. Keepthe knob in the most counterclockwiseposition that does not reenergize the vhfnavigation set.

f. Allow 5 minutes for the vhf naviga-tion set to warm up.

g. Operate the megacycle channel se-lector switch and the fractional megacyclechannel selector switch on the vhf naviga-tion control unit so that the MC dials readthe frequency of an in-range vhf communi-cat ion transmit ter .

h. Turn the VOL-OFF switch and con-trol knob on the vhf navigation controlunit to increase the volume of the audioheard on the aircraft intercommunicationsystem to the desired level.

i. Operate the megacycle channel selec-tor and/or the fractional megacycle chan-nel selector switch on the vhf navigationcontrol unit so that the MC dials read afrequency to which no in-range navigation

or communication stat ion assignment ismade. If duct effect (para 20c) is expe-r i enced , choose ano the r unass igned o rout-of-range frequency.

j. Turn the SQUELCH control on thevhf navigation control unit clockwise untilthe vhf navigation receiver noise output isat the level desired with the aircraft en-gines and al l electr ical equipment oper-ating normally.

k. Operate the megacycle channel selec-tor switch and/or the fractional megacyclechannel selector switch on the vhf naviga-tion control unit so that the MC, dials readthe frequency of the in-range vhf commu-nicat ion transmit ter which is to be re-ceived.

31. Stopping Procedure

a. Rotate the VOL-OFF switch and con-trol knob on the vhf navigation controlunit counterclockwise to OFF.

b. Turn off the aircraft 28-volt input tothe vhf navigation set, if this can be ac-complished without removing the 28-voltsfrom other equipment whose operation isto be continued; disconnect the audio out-put circuits of the vhf navigation set fromthe aircraft intercommunication system.Refer to the applicable aircraft technicalmanual for these procedures.

Section Ill. OPERATION UNDER UNUSUAL CONDITIONS

32. Emergency Operationa. In some cases of failure of the VOR

portions of the vhf navigation set, locali-zer operation can be substituted for VORoperation as an aid to navigation. Simi-larly, failure of the localizer portions ofthe vhf navigation set can be corrected insome instances by substituting VOR oper-ation.

b. If the converter or course indicatorport ions of the vhf navigat ion set fai l ,navigation may be accomplished by usingthe vhf navigation receiver as a commu-n ica t ions r ece ive r . In these cases, callthe VOR or localizer station on the air-craft’s vhf transmitter. Operate the mega-cycle channel selector switch and/or the

28

f r ac t iona l megacyc1e channe l se lec to rswitch on the vhf navigation control unit(fig. 11) so that the MC dials indicate thefrequency of the VOR or localizer trans-mi t t e r . Navigat ional f ixes and ground-controlled air approach (GCA) informationcan be hea rd over the communica t ioncircuits of the vhf navigat ion receiver .

c. If the vhf navigation set is completelyinoperable in an aircraft that has two vhfnavigation sets, merely switch to opera-tion of the second set.

33. Jamming and Antijamminga. Recognition of Jamming. Under real

or s imulated tact ical condit ions, the re-ceiver is likely to be jammed by the enemy.

Jamming may be pe r fo rmed by t r ans -mit t ing a s trong signal on the VOR orlocalizer frequencies, thereby making i tdiff icul t or impossible to hear the des-i r ed s igna l s . Unusua l no i se o r s t ronginterference may also be caused by theenemy.

b. Anti jamming Procedures. When the

Section IV. OPERATOR’S

34. Extent of Coverage

This sect ion contains the detai led in-spections to be made by the operator ofthe vhf navigation set before and duringeach f l ight . Operator’s inspection pro-cedures check the vhf navigation set forf l ight preparedness using visual inspec-t ions and operat ional tests to discoverequipment defects. The preflight inspec-tion is performed in two parts: power off(before aircraft power is applied to theequipment) and power on (after aircraftpower is applied).

35. Preflight Inspections, Power Off

Before power is applied to the vhf navi-gation set through the appropriate switchor circuit breaker in the aircraft, a com-plete visual ins p e c t i o n should be per-formed by the operator. Note all discrep-ancies on DA Form 2391-2.

a. Antenna (fig, 3). Make certain thatthe antenna is not separating from itspedestal and that the pedestal is f i rmlysecured to the aircraft. Check the antennarubber mounting block for cracks or de-terioration. Examine the antenna rods toinsure that they are not deformed, cor-r o d e d , o r s e p a r a t i n g f r o m t h e r u b b e rmounting block. In upright installations,check the drainage tunnels in the antennabase for clogging; in inverted instal la-tions, check the drainage hole in the rub-ber mounting block, Make certain that thepedestal mounting holes are not enlarged.If accessible, check the coaxial connectorsat the antenna base for dirt, making cer-tain that the connectors are secured tothe base.

b. Vhf Navigation Control Unit (fig. 4).

vhf navigation set is being jammed, or re-ception is disturbed by interference, re-ception may be improved by increasingthe clockwise rotation of VOL-OFF switchand control knob on the vhf navigation con-trol unit (fig. 11). In some cases, tuningto a different ground station may improvereception.

INSPECTION PROCEDURE

Make certain that the vhf navigation con-trol unit is secured to its mounting panelby the lock fasteners. See that all acces-sible surfaces are free from dust , dir t ,and grease. Check the front panel controlknobs to make certain that they are notbroken and do not bind when turned. Ifaccessible, check electrical connectors J1and J2 on the rear panel for dirt and tight-ness .

c. Converter (fig. 5). If the converteris accessible, make certain that electricalconnectors J204 and J205 at the rear ofthe converter are mated with correspond-ing rack connectors J302 and J303 and thatthe con ica l s tuds on the conver t e r a refirmly held by the nut-and-link arrange-ments on the rack (f ig. 8) . Make surethat the converter is free of dust , dir t ,and grease.

d. Course Indicator (fig. 6). Make surethat the course indicator is properly se-cured to the aircraft console panel. If therear of the indicator is accessible, seetha t e l ec t r i ca l connec to r J1601 on thecourse indicator is secured to the inputcable. Check the course indicator glassfor cracks and breaks. Operate the courseselector knob to be sure that the knob istight on its shaft and turns freely.

e. Mounting (fig. 7). If the mounting Isaccessible, check the screws that connectthe mounting to the aircraft, making cer-tain that the mounting is secured and thatthe grounding straps are making good con-tact. Check the rubber shock mounts on themounting to make sure that they are notcracked or deteriorated.

f. Rack (fig. 8). If the rack is accessi-ble, make sure that the rack snapslides areclosed, securing the rack to the mounting.

29

Check the connections to electrical con-nectors J304, J305, and J306 on the toppanel of the rear distribution box of therack to make sure that they are tight andfree of dirt.

g. Power Supply (fig. 9). If the powersupply is accessible, make sure that thefour snapslides are securely connected tothe vhf navigation receiver.

h . Vh f Nav iga t ion Rece ive ( f ig . 10) .If the receiver is accessible, make cer-tain that electrical connector J4 at the rearof the unit is mated with correspondingrack connector J301 and that the conicalstuds on the vhf navigation receiver arefirmly held by the nut-and-link arrange-ments on the rack (fig. 8).

36. Preflight Inspections, Power On

The following procedures are to be fol-lowed while the aircraft is s t i l l on theground. They may be performed while the

aircraft is on the flight line, or, if neces-sary, on the apron or the taxiway.

Note. The following inspection procedure cannotbe performed unless there is a VOR station whichis in-range, but which is not associated with theairfield at which the inspection is being performed.

a. Energize the aircraft switch or cir-cu i t b reake r app ly ing 28-vo l t p r imarypower to vhf navigation set (para 21a).

b. Allow approximately 3 minutes forwarmup.

c. Adjust the aircraft panel light con-trol, Refer to the applicable aircraft tech-nical manual for proper procedures. Thepanel lamps on the vhf navigation controlunit (fig. 4) should light.

d. Turn the VOL-OFF switch and con-trol knob on the vhf navigation control unit(f ig. 11) clockwise to energize the vhfnavigation set. A hiss should be heard overthe aircraft intercommunication system asthe VOL-OFF switch and control knob isturned further clockwise.

e. Set the megacycle channel selectorswitch and/or the fract ional megacyclechannel selector switch on the vhf navi-gation control unit so that the MC dialsindicate the frequency of the localizer sta-tion for the airfield. The OFF vertical flagon the course indicator (fig. 12) should

30

move out of view, the vert ical pointershould center if the aircraft is on the run-way centerline, and the station call signshould be heard either in code or voicesignal over the aircraft intercommunica-tion system.

f. Adjust the VOL-OFF switch and con-trol knob on the vhf navigation control unit(fig. 11). Clockwise rotation of the knobshould increase the amplitude of the stationcall sign heard on the aircraft intercom-munication system; counterclockwise ro-tat ion should decrease the ampli tude ofthe station call sign.

g. Set the megacycle channel selectorand/or fract ional megacycle channel se-lector switches on the vhf navigation con-trol unit so that the MC dials indicate anunassigned or out-of-range frequent y. TheOFF vertical flag on the course indicator(fig. 12) should appear.

h. Adjust the SQUELCH control on thevhf navigation control unit (fig. 11). Thelevel of the hissing noise heard over thea i r c r a f t intercommunication systemshould increase with counterclockwise ro-tation of the SQUELCH control and shoulddecrease with clockwise rotat ion of theSQUELCH control.

i. Set the megacycle channel selectorand/or fract ional megacycle channel se-lector switches on the vhf navigation con-trol unit so that the MC dials indicate thefrequency of the nearest VOR station notimmediately associated with the airport.Refer to the proper aeronautical chart forthe frequency and location of the VORstations. The call sign of the station shouldbe heard on the aircraft intercommuni-cation system, the OFF vertical flag on thecourse indicator (fig. 12) should move outof view, and the TO-FROM meter shouldindicate the direction of the VOR stationwith respect to the heading of the aircraft.

Note. It maybe necessary to adjust the SQUELCHand/or VOL-OFF switch and control knobs to hearthe call sign over the aircraft intercommunicationsystem.

j. Note a l l2391-2.

discrepancies on DA Form

37. Flight Inspection

Per fo rm the fo l lowing checks dur ingairborne operation to check the perform-ance of the vhf navigation set. If the vhfnavigation set should fail or operate un-sat isfactori ly during these checks, notethe nature of the unsatisfactory operationand the conditions under which the failureoccurred. This information is valuable tothe repairman when he corrects the causeof trouble.

a. Apply primary power to the vhf navi-gation set and connect the audio output cir-cuit of the vhf navigation set to the air-craft intercommunication system. Referto the applicable aircraft technical man-ual for the proper procedures.

b. Turn the VOL-OFF switch and con-trol knob on the vhf navigation controlunit (f ig. 11) clockwise to energize thevhf navigation set.

c. Set the megacycle channel selectorand/or the fractional megacycle channelse lec to r swi t ch on , the vhf nav iga t ioncontrol unit so that the MC dials read thefrequency of an in-range VOR station.

d. Listen for the station call sign. Ad-just the audio level to the aircraft inter-communication system if necessary (para21 f). Note the identifying signal to be surethat the proper s tat ion is tuned in. Besure that the OFF vertical flag (fig. 12)is out of sight on the course indicator andthe TO- FROM meter is indicating eitherTO or FROM.

e. Adjust the course selector knob onthe course indicator so that the coursepointer indicates a selected reading on thecourse dial.

f. Fly the aircraft to center the verticalpointer - on the indicator.

g. Set the megacycle channel selectorswitch and fractional megacycle channelselector switch on the vhf navigation con-trol unit (fig. 11) to the nearest localizerstation frequency as read on the MC dials.

h. Check the OFF vert ical f lag on thecourse indicator (fig. 12) to make certainthat it is out of sight as soon as the lo-calizer transmission can be heard on theaircraft intercommunication system,

i. Note al l discrepancies on DA Form2391-2.

31

CHAPTER 3

ORGANIZATIONAL MAINTENANCE INSTRUCTIONS

Section I.

38. Scope of Maintenance InstructionsNote. The pilot will not perform preventive or

corrective maintenance.a. General. Organizational maintenance

of the vhf navigation set, as performed bythe organizational repairman or aircraftcrew chief (second echelon) consists ofpreventive maintenance (para 39), cor-rective maintenance using visual inspec-tion and the equipment performance check-list (para 40 and 41), and removal and re-p lacement o f pane l l amps , knobs , andmajor units (para 42 through 44). Use DAForm 2391 (para 2c) to report all defi-ciencies, malfunctions, or abnormal con-ditions that cannot be remedied. For morespecific details for performing preventiveor corrective maintenance. refer to thetechnical manual covering the aircraft inwhich the vhf navigation set is installed.

b. Tools, Materials, and Test Equip-ment Required. The tools, materials, andtest equipment required for organizationalmaintenance consist of the following:

(1)

(2)

(3)(4)(5)(6)

T o o l E q u i p m e n t T E - 4 1 o r T K -115/U (tool kit).Multimeter AN/URM-105 (mult i-mete r ) .Fine sandpaper, No. 000.A clean dry lint-free cloth.A soft bristle brush.Cleaning Compound (Federal stockNo. 7930-395-9542).

39. Preventive Maintenance

a. Techniques.(1) Use sandpaper to remove rust and

corrosion.(2) Use the cloth or brush for cleaning.

If necessary, clean the parts, in-cluding electrical contacts, with acloth moistened with cleaning com-pound; wipe the parts dry with aclean cloth.

32

GENERAL

Caution: Cleaning compound isflammable and its fumes are toxic.Do not use near a flame; provideadequate ventilation.

b. Instruct ions.(1)

(2)

(3)

4)

(5)

(6)

(7)

Check for completeness and gen-eral condition of the vhf navigationreceiver, converter, vhf navigationcontrol unit, mount, rack, courseindicator , power supply, and an-tenna. Make sure that no knobs,screws, or lamps are missing. Re-place all missing or broken knobs,all missing screws, and all missingor defective panel lamps. Check thecourse indicator face for cracks inthe glass.Remove dirt and moisture from thecomponen t pane1s , cab les , andelectrical connectors. Disconnectthe electrical connectors, clean thecontacts, and reconnect them.Inspect all metal surfaces on thecomponents and electrical connec-tors for rust and corrosion. Re-move the rust and corrosion withfine sandpaper.Inspect the cables and shockmount s fo r cu t s , k inks , b reaks ,f r ay ing , and s igns o f excess ivestrain. Check al l components toassure each is properly secure andproperly safety-wired.Check all controls and accessibleitems (knobs, screws, nuts, etc) tomake sure they are properlytightened. Tighten any loose item.Inspect all controls for easy oper-ation.Check for normal operation of thevhf navigation set; be alert for anyunusual operating conditions. Re-fer to the equipment performancechecklist (para 41).

Section II. CORRECTIVE MAINTENANCE

40. Visual Inspection

a. When the equipment fails to performproper ly du r ing the p re f l igh t o r f l i gh tinspection procedures performed by theoperator. check for the following:

(1)

(2)

(3)

(4)

(5)

W r o n g s e t t i n g o f s w i t c h e s a n dcontrols on the course indicatoro r vh f nav iga t ion con t ro l un i t .Disconnected or poorly connectedcable assemblies, cable harness,primary powerline (LV+), or air-craft intercommunicat ion systemconnection line.C r a c k s i n t h e c o u r s e i n d i c a t o rmeter face.Defective cable harness or cableassembly connector.S h a r p l y b e n t o r b r o k e n c o u r s eselector shaft on course indicator;shafting should rotate freely.

(6) Grounded or broken antenna coax-ial cable.

b. If the above checks do not locate thetrouble, proceed to the equipment per-formance checklist (para 41).

41. Equipment Porformance Checklist

The equipment performance checklistis a systematic troubleshooting proceduret o i s o l a t e t r o u b l e w i t h a m i n i m u n o fwasted effort. Perform the visual inspec-tion (para 40); then, operate the equipmentas d i rec ted in the equ ipment pe r fo rm-ance checklist and look for the normalindicat ions l is ted. If an abnormal indi-cation is observed, follow the correctivemeasures ou t l ined in the f ina l co lumnof the check l i s t and fo l low each s t epin order.

33

Figure 19. Vhf navigation control unit connectors.

42. Removal and Replacement of VhfNavigation Control Unit PanelLamps

a. Unscrew the lamp housing on the vhfnavigation control unit (fig. 4) by graspingthe lamp housing and turning counterclock-wise.

b. Insert a knife blade or other sharpedge between the flange on the end of thelamp bulb and the threading on the lamphousing.

c. Pry out the lamp bulb.d. Replace the defective lamp bulb with

a new lamp bulb. Push the replacementlamp bulb into the lamp housing until thelamp bulb flange is flush with the threadingon the lamp housing.

e. Press the lamp housing gently into thefront panel of the vhf navigation control unitand turn clockwise to lock i t in place.

43. Removal and Replacement of VhfNavigation Control Unit and CourseIndicator Knobs

a. Insert an Allen wrench of appropriatesize in the head of the setscrew that holdsthe knob to the control or switch shaft.

b. Turn the Allen wrench counterclock-wise to loosen the setscrew.

c. Slide the knob off the shaft.d. S1ide the replacement knob on the

shaft.

e. Tigh ten the r ep lacement knob se t -screw with the Allen wrench.

44. Removal and Replacement of MajorComponents of Vhf Navigation Set

Note. These are only general procedures for theremoval and replacement of the components of thevhf navigation set. For detailed procedures and thelocation of the components in or on a particular air-craft, refer to the applicable aircraft technical ma-nual.

a. Removal of Antenna (fig. 3).(1)

(2)

(3)

Remove the hardware that attachesthe antenna to the skin of the air-c ra f t .Slowly pull the antenna a shortdistance from the aircraft,Disconnect the coaxial connector(or connectors i f the gl ide-slopeantenna is being used) from theantenna base.

b. Replacement of Antenna (fig. 3).(1)

(2)

Hold the antenna a short distancefrom the skin of the aircraft andconnect the coaxial cable from thevhf navigation receiver to the VORand localizer UG-291/U connector.If a gl ide-slope receiver is usedin the aircraft, connect the coaxialcable from the glide-slope receiv-e r to the g l ide - s lope UG-291 /Uconnector .Secure the antenna to the aircraftwith the appropriate hardware.

35

c. Removal of KM Navigation ControlUnit (fig. 4).

(1) Loosen the lock fasteners on eachside of the front panel.

(2) Slowly pull the vhf navigation con-trol unit out from the aircraft con-sole panel until the rear panel isexposed. Disconnec t the cab lesfrom vhf navigation control unitconnectors J1 and J2. Set down thevhf navigation control unit and tagthe cables.

d. Replacement of Vhf Navigation Con-trol Unit (fig. 4).

(1)

(2)

Hold the vhf navigation control unita short distance from the aircraftconsole panel and connect thecables tagged) in c(3) above to con-nectors J1 and J2.Slide the vhf control unit into theaircraft console panel and securewith the lock fasteners.

e. Removal of Converter.(1)

(2)

(3)

(4)

Remove the safety wire between thenut- and- link arrangements on theconverter compartment side of therack (fig. 8).Unscrew the knurled “nuts on thenut-and-l ink arrangements whichsecure the converter to the rack.Remove the links of the nut-and-link arrangements from the conicalstuds on the converter (f ig, 5) .Slide the converter forward fromback of the rack to disconnect con-nectors J204 and J205 on the con-verter from connectors J302 andJ303 on the rack,Remove the conver te r f rom therack.

f. Replacement of Converter.(1)

(2)

36

Place the converter in the con-ver te r compar tment o f the rack(fig. 8) . Sl ide the converter to-wards the back of the rack to en-gage connectors J204 and J205 onthe converter with connectors J302and J303 on the rack.Place the links of the rack nut-and-link arrangements (fig. 8) over theconical studs on the converter (fig.5). Tighten the knurled nuts of thenut-and-link arrangements to se-

cure the conver te r to the rack ,(3) Safety wire the nut-and-l ink ar-

rangements .

g. Removal of Vhf Navigation Receiver.—(1)

(2)

(3)

(4)

(5)

(6)

(7)

Tag and d i sconnec t the coax ia lcable from connector J1 ANT (fig.lo ) .Tag and disconnect the cable as-sembly from connector J2.If the vhf navigation receiver isbeing used as part of a communica-tion equipment (para 30), tag anddisconnect the cable to connectorJ3 .Remove the safety wire betweenthe nut-and-l ink arrangements onthe vhf navigation receiver com-p a r t m e n t o f t h e r a c k ( f i g , 8 ) .Unscrew the knurled nuts of thenut-and-link arrangements thatsecure the vhf navigation receiverto the rack, Remove the links of thenu t -and- l ink a r rangements f romthe conical studs on the vhf nav-igation receiver.Slide the vhf navigation receiverforward away from the back of therack to disengage connector J4 onthe vhf navigation receiver fromJ301 on the rack.Remove the vhf navigation receiverfrom the rack. -

h. Replacement of Vhf Navigation Re-ce iver .

(1)

(2)

(3)

(4)

Place the vhf navigation receiverin the vhf navigation receiver com-partment of the rack (fig. 8). Slidethe vhf navigation receiver towardsthe back of the rack to engage con-nector J4 of the vhf navigation re-ceiver with connector J301 of therack .Place the l inks of the rack nut-and- l ink a r rangements ove r theconical studs (fig. 10) of the re-ceiver. Tighten the knurled nutsof the nut-and-link arrangementsto secure the vhf navigat ion re-ceiver to the rack.Safety-wire the nut-and-l ink ar-rangements.Connect the coaxial cable tagged

as instructed in g(1) above to con-nector J1 ANT.

(5) Connect the cable assembly taggedas instructed in g(2) above to con-nector J2.

(6) If the vhf navigation receiver isused as part of a communicationset (para 30), connect the cabletagged as instructed g(3) aboveto connector J3.

i. Removal of Power Supply.(1) Remove the safety wire and release

the snapslides (fig. 9) that securethe power supply to the vhf nav-igation receiver (fig. 1).

(2) Lift the power supply up and awayfrom the vhf navigation receiver.

j. Replacement of Power Supply.(1) Lower the power supply onto the

rear top of the vhf navigation re-ceiver (f ig. 1 ) . Push the powersupply down until connector J101on the power supply (fig. 9) mateswith the power supply connector onthe vhf navigation receiver.

(2) Secure and safety-wire the snap-slides on the power supply.

k. Removal of Course Indicator.(1) Remove the three rnachine screws

and locknuts that hold the courseindicator to the shock-absorbingpanel of the aircraft.

(2) Slowly slide the course indicatorout of the aircraft panel.

(3) Tag and disconnect the indicatorplug from the indicator.

l. Replacement of Course Indicator.(1) Connect the indicator plug tagged

as instructed in k(3) above to therear of the course indicator.

(2) Slide the course indicator into thec u t o u t in the aircraft shock-absorbing panel.

(3) Secure the indicator to the aircraftp a n e l ; u s e t h e t h r e e m a c h i n escrews and locknuts.

m. Removal of Rack.(1) Remove the converter (e above)

and the vhf navigation receiver (gabove) from the rack.

(2) Tag and disconnect the cable har-ness from connectors J304, J305,and J306 on the rack (fig. 8).

(3) Remove the safety wires from thegroove d s tuds ( f ig . 7 ) on themounting.

(4) Release the snapslides (fig. 8) thatsecure the rack to the mountingshock mounts.

(5) Remove the rack from the mounting.n. Replacement of Rack.

(1) Lower the rack over the mountingso that the rack snapslides (fig. 8)fit over the grooved studs (fig. 7)on the mounting shock mounts.

Warning: Make certain that thegrounding straps on the mountingare making contact with the rack atthe point of contact of the mountingshock mount and rack snapsl ide.

(2) Secure the rack snapslides (fig. 8).(3) Safety-wire the grooved studs on

the mounting shock mounts.(4) Connect the cable harness tagged

as instructed in m(2) above to con-nectors J304, J305, and J306 on therack.

(5) Replace the converter (f above) andvhf navigation receiver (h above)on the rack.

o. Removal of Mounting.(1) Remove the rack from the mounting

(m above).(2) Remove the hardware that secures

the mounting to the surface of thea i rc ra f t .

(3) Remove the mounting.p. Replacement of Mounting.

(1) Clean the surface around the holes.that have been drilled for instal-lation of the mounting. Use emerycloth or fine sandpaper, to insurea bare metal connection for themounting so that proper groundingcan be accomplished.

(2) Secure the mounting to the aircraftmounting surface with the appro-priate hardware.

(3) Replace the rack on the mounting(n above).

37

CHAPTER 4

DEMOLITION OF MATERIEL TO PREVENT ENEMY USE

45. Authority for Demolition

The demolition procedures in paragraph46 will be used to prevent the enemy fromusing or salvaging any parts of the vhfnavigation set. Demolition of the vhf nav-igation set will be accomplished only uponthe order of the commander.

46. Methods of Destruction

Any or all of the methods of destructionbelow may be used. The t ime availablewil l determine the destruct ion methods.Also, the tactical situation will determinehow the destruction order will be carriedout. In most cases, it is preferable to de-molish completely some portions of the vhfnavigation set rather than partially destroyall the components.

a. Smash. Smash the vhf navigation setcomponents: use sledges, axes, hammers,crowbars, and any other heavy tools avail-able.

b. Cut. Cut the cable harness, cables,and coaxial cables; use axes, handaxes,machetes, and similar tools.

c. Burn. Burn as much of the equipmentas is flammable; use gasoline, oil, flame-throwers, and similar tools. Burn the in-struction literature first. Pour gasoline onthe cut cables and internal wiring andIgnite N. Use a flamethrower to burn spareparts or pour gasoline on the spares andignite them, Use incendiary grenades tocomplete the destruction of the vhf nav-igation set components.

Warning: Be extremely careful with ex-plosives and incendiary devices. Use theseitems only when the need is urgent.

d. Explode. Use explosive to completedemolition or to cause maximum damage,before burning, when time does not permitc o m p 1 e t e demolition by other means.Powder charges, fragmentation grenades,or incendiary grenades maybe used. In-cendiary grenades usually are most ef-fective.

e. Dispose. Bury o r sca t t e r des t royedparts or throw them into nearby water-ways. This is particularly important if anumber of parts have not been completelydestroyed.

38

APPENDIX I

REFERENCES

Following is an applicable reference available to the operator of the vhf navigationset:

TM 11-6625-203-12 Operation and Organizational Maintenance, MultimeterAN/URM-105, including Multimeter ME-77/U

39

APPENDIX II

MAINTENANCE ALLOCATION


1. General

a. This appendix assigns maintenancefunctions and repair operations to be per-formed by the lowest appropriate mainte-nance echelon.

b. Columns are as follows:(1) Part or component. This co lumn

shows only the nomenclature ors t andard i t em name . Addi t iona ldescriptive data are included onlywhere clarification is necessary toidentify the part. Components andparts comprising a major end itemare l is ted alphabetical ly. Assem-blies and subassemblies are in al-phabetical sequence with t h e i rcomponents l is ted alphabetical lyimmediately below the assemblylisting.

(2) Maintenance function. This columnindicates the various maintenancefunctions allocated the echelon ca-pable of performing the operations.

(a) Service. To clean, to preserve,and to replenish fuel and lubri-cants .

(b) Adjust. To regulate periodicallyto prevent malfunction.

(c) Inspect. To verify serviceabilityand to detect incipient electricalor mechanical fai lure by scru-tiny.

(d) Test. To verify serviceabil i tyand to detect incipient electricalor mechanical failure by use ofspecial equipment such as gages,meters, etc.

(e) Replace. To subst i tute service-able assemblies, subassemblies,and parts for unserviceable com-ponents,

(f) R e p a i r . To restore an i tem toserviceable condition t h r o u g hcorrect ion of a specif ic fai lure

(g)

(h)

(i)

or unserviceable condition. Thisfunction includes, but is not lim-ited to, inspecting, cleaning, pre-s e r v i n g, adjusting, replacing,welding, riveting, and straight-ening.Al ign . To ad jus t two o r morecomponents of an electrical sys-tem so that their functions areproperly synchronized.

Rebuild. To restore an item to astandard as near as possible tooriginal or new condition in ap-pearance, performance, and lifeexpectancy. This is accomplishedthrough the maintenance tech-nique of complete disassembly ofthe item, inspection of all partsor components, rep a i r or re-placement of worn or unservice-a b 1 e elements using originalmanufacturing tolerances and/orspecifications a n d subsequentreassembly of the item.

Overhaul. To restore an item to

(3)

completely serviceable conditionas prescribed by serviceabil i tys t anda rds deve loped and pub-1 is h e d by heads of technicalservices. This is accomplishedthrough employment of the tech-nique of “Inspect and Repair Onlyas Necessary” ( IROAN). Max-imum uti l izat ion of diagnost icand test equipment is combinedwith minimum disassembly of theitem during the overhaul process.

1st, 2d, 3d, 4th, 5th echelon. T h esymbol X indicates the echelon re-sponsible for performing that par-ticular maintenance operation, butdoes not necessarily indicate thatrepair parts will be stocked at thatl eve l . Eche lons h igher than the

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(4)

(5)

echelon marked by X are author-i z e d t o p e r f o r m t h e i n d i c a t e doperation,Tools required. This column indi-cates codes assigned to each indi-vidual tool equipment, test equip-ment, and maintenance equipmentreferenced. The grouping of codesin this column of the maintenanceallocation chart indicates the tool,test , and maintenance equipmentrequired to perform the mainte-nance function.Remarks . Entries in this columnwill be utilized when necessary toclarify any of the data cited in thepreceding columns,

C . Columns in the allocation of tools formaintenance functions are as follows:

(1) Too l s requ i red for ma in tenancefunctions. This column lists tools,test , and maintenance equipment

(2)

(3)

required to perform the mainte-nance functions.1st, 2d, 3d, 4th, 5th echelan. T h edagger (t) indicates the echelonsallocated the facility.Tool code. This column l is ts thetool code assigned.

2. Maintenance by Using Organizations

When this equipment is used by signalservice organizations organic to the thea-ter headquarters or communication zonesto provide theater communications, thosemaintenance functions allocated up to andincluding fourth echelon are authorized tothe organization operating this equipment.

3. Mounting Hardware

The basic entries of the maintenance al-locat ion chart do not include mountinghardware such as sc rews , nu t s , bo l t s ,washers, brackets, and clamps.

41

Section II.

42

Section III.

46

APPENDIX Ill

BASIC ISSUE ITEMS LIST


1. General

This appendix lists items supplied forinitial operation. The list includes tools,parts, and material issued as part of themajor end item. The list includes all itemsauthorized for basic operator maintenanceof the equipment. End items of equipmentare issued on the basis of allowances pre-scribed in equipment authorization tablesand other documents that are a basis forrequisitioning.

2. Columns

a. Source, Maintenance, and Recover-ability Code.

b. Federal Stock Number. This columnlists the n-digi t Federal s tock number.

c. Designation by Model. Not used.

d. Inscript ion. Nomenc la tu re o r thestandard item name and brief identifyingdata for each item are listed in this col-umn, When requisitioning, enter the no-menclature and description.

e. Unit of Issue. The unit of issue is thesupply term by which the individual item iscounted for procurement, storage, requi-sitioning, allowances, and issue purposes.

f. Expendability. Expendable i tems areindicated by the letter X; nonexpendableitems are indicated by NX.

g. Quanti ty Authorized. Under “ I temsComprising an Operable Equipment,” thecolumn lists the quantity of items suppliedfor the initial operation of the equipment.

h. Illustrations. The “Item No.” columnlists the reference designation used foridentification of the items in the illustra-tion or text of the manual.

47

Section II.

48

GLOSSARY

Back course approach. – A runway lo-calizer approach in which the centeringof the vertical pointer of the indicator isaccomplished by f lying the aircraft inthe direction opposite to the directionof deflect ion of the vert ical pointer .Thus, if the vert ical pointer deflectsto the left, the aircraft is flown to ther igh t , t o cen te r the ve r t i ca l po in te r .Normally, a back course approach in-volves touching down at that runway enda t which the loca l i ze r t r ansmi t t e r i slocated.

Dipole. – A special antenna with two poles,each approximately one-fourth the lengthof the radio waves antenna is to receive.

Duct effect. – The trapping of vhf radiowaves in atmospheric ducts so that thenormal range of those radio waves isgreatly extended.

Front course approach. – A runway local-izer approach in which the aircraft isf l o w n i n t h e s a m e d i r e c t i o n a s t h edirection of deflection of the indicatorvert ical pointer to center the pointer .

Normally, the front course approach-involves touching down at the runwayend which is across the field from thelocalizer t ransmitter .

Glide-slope. - A portion of an instrumentlanding system (ILS) that provides navi-gational information about the aircraft’sangle of gl idepath to the runway let-down point.

Localizer. - A vhf radio system for guid-ing aircraft along an approach path toan airport runway.

Omni. – A term used for VOR operation.Shadow effect. – The disappearance or re-

duction of amplitude of a vhf radio wavecaused by the presence of large obstaclesin the path of the radio beam.

Squelch. – To quiet a receiver automati-cally by reducing the receiver gain whenthe amplitude of receiver inputs dropsbelow a selected level.

V O R . - A vhf radio system that providesnavigational data in the form of bear-ings with respect to the radio trans-mi t t e r .

50

By Order of Secretary of the Army:

Official:R. V. LEE,

Major General, United States Army,The Adjutant General.

Distribution:

Active Army:

DASA (6)USASA (2)CNGB (1)Tech Stf, DA (1) except

CsigO (15)Tech Stf Bd (1)USCONARC (4)USAARTYBD (1)USAARMBD (2)USAIB (1)USARADBD (2)USAABELCTBD (1)U S A A N B D ( 1 )USAATBD (1)ARADCOM (2)ARADCOM Rgn (2)OS Maj Cored (2)OS Base Cored (2)LOGCOMD (2)MDW (1)Armies (2)Corps (5)USATC AD (2)USATC Armor (2)USATC Engr (2)USATC FA (2)USATC Inf (2)Svc Colleges (2)Br SVc Sch (2)GENDEP (2) except

Atlanta GENDEP (None)Sig See, GENDEP (5)Sig Dep (12)Ft Monmouth (68)USASATSA (5)

G. H. DECKER,General, United States Army,

Chief of Staff.

AFIP (1)WRAMC (1)AFSSC (1)USAEPG (2)EMC (1)USACA (2)USMEA (1)USA Caribbean Sig Agcy (1)USA Sig Msl Spt Agcy (12)UMSSA (20)USASSAMRO (1)Army Pictorial Cen (2)USAOMC (3)USA Trans Tml Comd (1)Army Tml (1)POE (1)GSA (1)AMS (1)Sig Fld Maint Shops (2)JBUSMC (2)Yuma Test Sta (2)Units org under fol TOE:

(2 copies each UNOINDC)5-500 (AA-AD)1 1 - 711-1611-5711-9811-11711-15511-500 (AA-AE) (4)11-56711-58711-59211-597

NC: State AC (3); Units-Same as Active Army except allowance is one copy for each unit.USAR: None .For explanation of abbreviation used, see AR 820-50.

U . S. GOVERNMENT PRINTING OFFICE : 1991 0 - 281-486 (42570)

51

TM 11-5826-215-12

PIN : 028211-000

operator and organizational maintenance manual

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