 +_____________________________________________________________________
  AUTHOR:                                          DR:              
   BRENT A. MUSAT        PASS PROGRAM NOTE               110464     
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  ORG/PHONE:          OPS NOTE (X)  USER NOTE ( )  DATE:            
  SSOAS/(281)335-2237      RELEASE NOTE( )                  05/05/98
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  OI/FLIGHT EFFECTIVITY:          USER AFFECTED:                     
  OI25 THROUGH OI28               CREW (X)  GROUND (X)  DUMP ONLY ( )
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         MAJOR SOFTWARE AREA:        OPS MODES AFFECTED:             
 SSW (X)  GNC ( )  VU ( )  SM/PL ( )   ALL                           
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  SOFTWARE SUB-AREA: FCOS                                             
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  PRINCIPAL FUNCTIONS: STIM                                           
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  TITLE:                                                              
   PREMATURE FAULT DOWN TO GPC TIME                                   
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  DESCRIPTION:                                                        
                                                                      
   IN THE EVENT OF A TRANSMITTER ENABLE FAILURE ON A BUS REQUIRED     
   FOR MTU READ, OR A LOSS OF ONE OF THE FIRST THREE FLIGHT CRITICAL  
   STRINGS, AND COMMFAULTS ON THE REMAINING TWO MTU ACCUMULATORS,     
   THE PASS WILL IMMEDIATELY FAULT DOWN TO GPC INTERNAL TIME.         
   THE LOSS OF A FLIGHT CRITICAL STRING COULD BE CAUSED BY AN         
   ERRONEOUS NBAT ASSIGNMENT OR BY A F-T-S.                           
                                                                      
   A "TIME MTU" MESSAGE WOULD APPEAR ON THE CRT, AND A REVIEW OF      
   SPEC 2 (NOT AVAILABLE IN G1 OR G3) WOULD INDICATE A TIME SOURCE    
   CHANGE TO A GPC'S INTERNAL TIME.                                   
                                                                      
                                                                      
                                                                      
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 USER RESPONSE:                                                       
                                                                      
   AN ITEM 34, 35, OR 36 ON SPEC 2 (NOT AVAILABLE IN G1 OR G3) WOULD  
   RETRY TIME CORRELATION WITH MTU ACCUMULATORS 1, 2 AND 3,           
   RESPECTIVELY, AND SELECT THAT ACCUMULATOR AS THE NEW TIME SOURCE   
   IF SUCCESSFUL.  AN I/O RESET MIGHT BE NEEDED PRIOR TO THE SPEC 2   
   ITEM(S) IF THE DESIRED ACCUMULATOR HAS BEEN PREVIOUSLY BYPASSED.   
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
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 CONCURRENCE:                           APPROVAL:                    
 SSOAS:  JOHN MAGLEY       DATE 06/23/98                             
       ------------------      ---------                             
 ASD:    ERIC C. BINGHAM   DATE 07/01/98                             
       ------------------      --------- DARRELL E. STAMPER 08/24/98 
 PF MGR: KAYLENE KINDT     DATE 06/30/98------------------- -------- 
       ------------------      --------- CHAIRMAN, SASCB      DATE   
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