DDG-51

                     DDG 51 CLASS ADVISORY NR 13-95R1                           

                                                                                

  AN-SPY-1D SIGNAL PROCESSOR AND BEAM STEERING CONTROLLER OPERATING TEMPERATURES

                                                                                

      REF/A/RMG/AEGIS PROG MGR/011444ZJUN95//                                   

                                                                                

      AMPN/REF A IS DDG 51 CLASS ADVISORY 13-95.//                              

                                                                                

      RMKS/1.  THE PURPOSE OF THIS CLASS ADVISORY REVISION IS TO EXPAND THE     

      SCOPE OF REF A AND TO WARN THAT OVERTEMPERATURE CONDITIONS MAY NOT        

      ONLY CAUSE CATASTROPHIC CASUALTIES TO THE AN/SPY-1D SIGNAL PROCESSOR,     

      BUT ALSO TO THE BEAM STEERING CONTROLLER CONTAINED IN THE RADAR BEAM      

      PROGRAMMER AND RADAR RECEIVER PROGRAMMER CABINETS.  THIS REVISION         

      PROVIDES INTERIM GUIDANCE ON RECOMMENDED OPERATING TEMPERATURES AND       

      PROCEDURES UNTIL A MODIFICATION TO ALLOW FOR AUTOMATIC SHUTDOWN HAS       

      BEEN INSTALLED.  THIS REVISION SUPERSEDES AND CANCELS REF A.              

                                                                                

      2.  BACKGROUND.                                                           

           A.  FLEET AND NEW CONSTRUCTION FEEDBACK AND DATA REVIEWS             

      IDENTIFIED A SERIES OF CASUALTIES TO THE AN/SPY-1D SIGNAL PROCESSOR       

      DUE TO LOSS OF ELECTRONIC COOLING WATER (ECW) FLOW OR HIGH ECW            

      TEMPERATURE.  MOST OF THESE CASUALTIES OCCURRED DURING INPORT PERIODS     

      DURING INDUSTRIAL AVAILABILITIES OR IN NEW CONSTRUCTION WHEN ECW WAS      

      SECURED AND THE RADAR EQUIPMENT WAS NOT.  WHILE LOSS OF ECW OR HIGH       

      ECW TEMPERATURE WILL TRIGGER EXISTING ALARMS, AN IMPROVED EQUIPMENT       

      PROTECTION DESIGN IS BEING DEVELOPED WHICH CAN REDUCE THE POSSIBILITY     

      OF THESE COSTLY CASUALTIES.                                               

           B.  THE IMPROVED DESIGN WILL MONITOR THE CABINET AIR                 

      TEMPERATURE AND SECURE THE SIGNAL PROCESSOR AND/OR BEAM STEERING          

      CONTROLLER BEFORE EQUIPMENT IS DAMAGED UNLESS OVERRIDDEN BY THE SPY       

      RADAR OPERATOR.                                                           

                                                                                

      3.  ACTION.  UNTIL PARA 2.B. MODIFICATION IS INSTALLED, ALL DDG 51        

      CLASS SHIPS SHOULD COMPLY WITH THE FOLLOWING GUIDANCE TO PREVENT          

      EQUIPMENT DAMAGE:                                                         

           A.  UPON RECEIVING ANY ONE OF THE HIGH TEMPERATURE/LOW ECW FLOW      

      ALARMS AFFECTING THE SIGNAL PROCESSOR AND/OR THE BEAM STEERING            

      CONTROLLER, IMMEDIATELY INVESTIGATE THE COMMAND AND DECISION              

      (C AND D) SKID AND/OR THE CHILLED WATER SYSTEM FOR THE CAUSE OF THE       

      ALARM.                                                                    

           B.  OBSERVE THE SIGNAL PROCESSOR ECW OUTLET TEMPERATURE GAGES IN     

      CSER 2 AND BEAM STEERING CONTROLLER ECW OUTLET TEMPERATURE GAGES IN       

      RADAR ROOM 2 TO MONITOR THE COOLANT TEMPERATURE.                          

           C.  SECURE THE SIGNAL PROCESSOR:                                     

                (1)  WHEN ONE OR MORE OF THE TWELVE ECW OUTLET TEMPERATURE      

      GAGES (SIGNAL PROCESSOR OUTLET/RETURN SIDE) REACHES 90 DEG F, OR          

                (2)  WITHIN 5 MINUTES OF A LOSS OF ECW FLOW.                    

           D.  SECURE THE BEAM STEERING CONTROLLER:                             

                (1)  WHEN ECW OUTLET TEMPERATURE (BEAM STEERING CONTROLLERS     

      OUTLET/RETURN SIDE) REACHES 90 DEG F, OR                                  

                (2)  WITHIN 15 MINUTES OF A LOSS OF ECW FLOW.                   

           E.  WHEN ANY ONE OF THE CONDITIONS LISTED IN PARA 3.C OCCURS,        

      AND THE TACTICAL SITUATION REQUIRES CONTINUED SPY OPERATION, EXTEND       

      THE AFFECTED SIGNAL PROCESSOR CABINET FRAMES TO THE FOURTH LOCKING        

      POSITION TO ALLOW FOR CONVECTION COOLING WITH ROOM AIR (PER CSOSS         

      PROCEDURES MCRP 3 AND CRP 3.1).  THE BEAM STEERING CONTROLLER FRAME,      

      CONTAINED IN THE RADAR BEAM PROGRAMMER AND RADAR RECEIVER PROGRAMMER      

      CABINETS, SHOULD BE EXTENDED IN THE SAME MANNER WHEN ONE OF THE           

      CONDITIONS IN PARA 3.D OCCURS AND CONTINUED OPERATION IS REQUIRED.        

      NOTE THAT THE BEAM STEERING CONTROLLER IS LESS SENSITIVE TO ABNORMAL      

      COOLING WATER CONDITIONS AND THEREFORE MEASURES REQUIRED FOR SIGNAL       

      PROCESSOR PROTECTION SHOULD BE GIVEN PRIORITY.                            

                                                                                

      4.  FOR COMNAVSURFLANT/COMNAVSURFPAC - RECOMMEND ALL DDG 51 CLASS         

      SHIPS BE TASKED TO ADHERE TO PARA 3 GUIDANCE.                             

                                                                                

      5.  FOR NSWC PHD (CODE 4C22)                                              

           A.  ENSURE CSOSS PROCEDURES ARE UPDATED AS PART OF THE ECP           

      MODIFICATION.                                                             

           B.  DEVELOP A CSOSS PROCEDURE FOR BEAM STEERING CONTROLLER           

      OVERTEMPERATURE INCORPORATING PARA 3 GUIDANCE.                            

                                                                                

      6.  THIS ADVISORY DOES NOT AFFECT EOSS, PMS OR CMMP.  IT WILL BE          

      CANCELLED WHEN THE MODIFICATION THAT COMMANDS AUTOMATIC EQUIPMENT         

      SHUTDOWN DURING OVERTEMPERATURE CONDITIONS HAS BEEN APPROVED AND          

      INSTALLED IN ALL DDG 51 CLASS SHIPS AND WHEN ALL APPLICABLE CSOSS         

      PROCEDURES HAVE BEEN UPDATED AND DISTRIBUTED.                             

                                                                                

      7.  ORIG POC IS N. SMITHSON, PMS400F511, DSN 332-5981 (X133) OR           

      COMM (703) 602-5981 (X133).  TECHNICAL POC IS MR. W. DYKSTRA,             

      PMS400B6AI, DSN 332-7296 OR COMM (703) 602-7296.//                        

                                                                                

      BT