INTRODUCTION TO SONAR 



and overhaul cycle planned maintenance actions 

 are to be performed. A cycle schedule also lists 

 quarterly and situation requirement planned main- 

 tenance actions that must be scheduled, as well 

 as monthly planned maintenance requirements. 



Cycle schedules are utilized by department 

 heads, in conjunction with their division officers 

 and leading petty officers, to prepare quarterly 

 planned maintenance schedules. A quarterly 

 schedule is displayed in a holder, known as the 

 maintenance control board, adjacent to the cycle 

 schedule to which it pertains. A quarterly sched- 

 ule gives a visual display of the ship's employ- 

 ment schedule and the planned maintenance to be 

 performed during that particular quarter. A 

 quarterly schedule has 13 columns, one for 

 each week in the quarter, for scheduling main- 

 tenance throughout a 3-month period. 



At the end of each week, the leading petty 

 officer of a division or maintenance group up- 

 dates the quarterly schedule by crossing out 

 (with an X) the preventive maintenance per- 

 formed. If a planned maintenance action is not 

 completed during the week it is scheduled, the 

 leading petty officer circles the action on the 

 quarterly schedule. Uncompleted maintenance is 

 then rescheduled for another week within the 

 same quarter. 



At the close of each quarter, the applicable 

 quarterly schedule is removed from its holder 

 and retained on board as a record of the planned 

 maintenance completed. This record may be 

 discarded at the beginning of the second quarter 

 after the next shipyard overhaul, 



A quarterly schedule also is used by a 

 leading petty officer to arrange a weekly planned 

 maintenance schedule for posting in an appro- 

 priate workspace. The weekly schedule of planned 

 maintenance should not be considered as the 

 total of all work for a given week. This weekly 

 work covers only scheduled planned maintenance 

 and is in addition to other routine work, upkeep, 

 and corrective maintenance to be accomplished. 

 The weekly schedule provides a list of com- 

 ponents In the working area, appropriate page 

 number of the PMS manual, and spaces for the 

 leading PO to use in assigning planned main- 

 tenance tasks to specified personnel. Daily and 

 weekly planned maintenance actions are pre- 

 printed on the forms, and the other maintenance 

 actions are written in by the leading PO as re- 

 quired. When the leading PO is assured that a 

 maintenance task is completed, he crosses out 

 the maintenance requirement number on the 

 weekly schedule. If for some reason a task 

 cannot be completed on the day scheduled, the 



leading petty officer circles the maintenance 

 requirement number and reschedules it for 

 another day. Current status of scheduled main- 

 tenance is readily available by looking at the 

 weekly schedule. 



Maintenance Requirement Card 



A maintenance requirement card (MRC) is a 

 5 by 8 inch card on which a planned maintenance 

 task is defined sufficiently to enable assigned 

 personnel to perform the task. (See fig. 9-2.) 

 A master set of MRCs is maintained in the 

 departmental office. Cards applicable to the 

 equipment in which Sonar Technicians are in- 

 terested are maintained in the workspace. If 



ASW-U/W 



SUB-SYSTEM 



COMPONENT 



AN/S0S-29B, 29C 

 Sonar Detecting- 

 Ranging Set 



BELATED ^ 



None 



EIC-J201000 



M. R. DESCRIPTION 



1. Calculate AN/SOM-2 voltage attenuation 

 factor. 



2. Measure and observe transmitter output 

 pulses. 



SO-9 M-14 



RATES 

 STl 



STGSN 



TOTAL M/M 



2.0 

 ELAPSED TIME: 



1.0 



1. Observe standard safety precautions. 



2. Short across all terminals of 19D terminal board to 

 electrical ground, using a shorting probe. 



TOOLS, PARTS, MATERIALS, TEST EQUIPMENT 



1. Electronic multimeter ("TVM), ME-6 ( )/U or equivalent 



2. Audio oscillator, TS-382 ( )/U or equivalent 



3. Oscilloscope, AN/USM-105 or equivalent 



4. 1/2" Open end wrench 



5. Sound-powered phones (2) 8. Warning tags 



6. Sound Measuring Set, AN/SQM-2 9. 4' Jumper lead 



7. Shielded test lead (2) 10. Shorting probe 



PROCEDURE 



Voltage attenuation factor for AN/SQM-2 Serial 



NOTE 1: Above factor is obtained by performing MR 1 of 

 this MRC. After this factor has been obtained, 

 subsequent accomplishment of this MRC will start 

 with MR 2. 



Prel iminarv 



a. Turn OFF and tag both equipment POWER switches. 



b. Turn OFF and tag both voltage regulator switches. 



c. Turn OFF and tag bullchead power switch. 



1. Calculate AN/SOM-2 Voltage Attenuation Factor. 



a. Remove cover on terminal side of hull relay and 

 junction box. (Cable stuffing tubes are on right 

 when facing terminal side.) 



(Cont ' d on Page 2) 



1 October 1965 



MAINTENANCE REQUIREMENTS CARD 



Figure 9-2. 



98.176 

 Maintenance requirement card. 



150 



