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