DDG-51

                      DDG 51 CLASS ADVISORY NO. 17-95                           

                                                                                

  MK 34 GUN WEAPON SYSTEM AND SPS-64 SURFACE SEARCH RADAR VIDEO ALIGNMENT ISSUE 

                                                                                

      RMKS/1.  THIS ADVISORY WARNS OF A POTENTIAL SAFETY HAZARD WHEN USING      

      AN/SPS-64 SURFACE SEARCH RADAR INPUT TO THE MK 34 GUN WEAPON SYSTEM       

      (GWS).                                                                    

                                                                                

      2.  THE MK 34 GWS HAS THE CAPABILITY TO UTILIZE RADAR VIDEO INPUT         

      FROM THE SPS-64 RADAR FOR TARGETING AND CAN ENGAGE TARGETS USING          

      COMMAND AND DECISION (C AND D) MANUAL TRACK DATA OR USING                 

      "SHOOT-ON-BALLTAB" AT THE GUN CONSOLE OPERATOR'S POSITION.  WHEN THE      

      SPS-64 IS POWERED DOWN, THE RELATIVE/TRUE CONVERTER DOES NOT MAINTAIN     

      ALIGNMENT AND WHEN POWER IS RESTORED, THE CONVERTER MUST BE               

      REALIGNED.  EVEN AFTER REALIGNMENT HAS BEEN PERFORMED, AN ERROR OF UP     

                                                                                

      TO ONE DEGREE BEARING MAY EXIST.  AS A RESULT THE DATA PROVIDED TO        

      THE MK 34 GWS CAN INTRODUCE LARGE ERRORS IN TARGETING.  ORIG IS           

      WORKING WITH NSWC LOUISVILLE (MK 34 GWS ISEA), NSWC CRANE (SPS-64         

      ISEA), NSWC DAHLGREN AND LOCKHEED MARTIN TO DEVELOP AND IMPLEMENT A       

      SOLUTION TO THIS PROBLEM.  WE WILL PROVIDE A MESSAGE UPDATE TO ALCON      

      NLT 31 DEC 95.                                                            

                                                                                

      3.  ACTION.  UNTIL A SOLUTION HAS BEEN FOUND, WHEN ENGAGING TARGETS       

      WITH THE MK 34 GWS, COMBAT SYSTEM OPERATORS (E.G. ASUWC, AAWC) SHOULD     

      NOT USE SPS-64 DATA AS A RADAR SENSOR INPUT AT THE CONSOLE.               

                                                                                

      4.  FOR COMNAVSURFLANT/COMNAVSURFPAC - REQUEST DDG 51 CLASS SHIPS BE      

      TASKED TO ADHERE TO THE PROVISIONS OF PARA THREE ABOVE.                   

                                                                                

      5.  THIS ADVISORY HAS NO IMPACT ON CSOSS, PMS, OR TECHNICAL               

      DOCUMENTATION.  IT WILL BE CANCELLED WHEN CORRECTIVE ACTION HAS BEEN      

      DEVELOPED AND IMPLEMENTED.                                                

                                                                                

      6.  POINT OF CONTACT IS MR. NORM SMITHSON, PMS400F511, DSN 332-5981,      

      EXT 133 OR COMM (703) 602-5981 EXT 133.  TPOC IS MR. N. MANIQUIS,         

      PMS400B31, DSN 332-7296, EXT 239 OR COMM (703) 602-7296 EXT 239.//        

                                                                                

      BT