 +_____________________________________________________________________
  AUTHOR:                                          SMS:  B20060     
    CHRIS SEBASTIAN      BFS PROGRAM NOTE          DR:   106444     
 ____________________                             __________________
  ORG/PHONE:          OPS NOTE (X)  USER NOTE ( )  DATE: 05/18/92   
   RID/(213)922-3747       RELEASE NOTE ( )                         
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  OI/FLIGHT EFFECTIVITY:          USER AFFECTED:                     
    OI-20, OI-21, OI-22, OI-23    CREW (X)  GROUND ( )  DUMP ONLY ( )
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            MAJOR SOFTWARE AREA:             OPS MODES AFFECTED:     
 BSL( ) BSS(X) GNC( ) SEQ( ) SM/SP( ) IPL( )      1, 3, 6            
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  SOFTWARE SUB-AREA: DISP                                             
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  PRINCIPAL FUNCTIONS: STS 83-0020 / 4.2.11  HSD                      
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  TITLE:                                                              
   TRANSIENT BAD BEARING DATA ON THE HSD                              
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  DESCRIPTION:                                                        
                                                                      
   ON THE BFS HORIZONTAL SITUATION DISPLAY, THE TACAN BEARING DATA IS 
   DISPLAYED AS THE ABSOLUTE VALUE OF THE TACAN BEARING WITH A RANGE  
   OF 0.00 TO 359.99 DEGREES. A DOWN ARROW IS DISPLAYED NEXT TO THE   
   BEARING DATA WHEN A FLAG IS SET BY GNC INDICATING THAT THE DATA IS 
   INVALID. IT IS POSSIBLE THAT THE HSD WILL READ INVALID DATA AND    
   DISPLAY IT FOR APPROXIMATELY TWO SECONDS BEFORE THE INVALID DATA   
   FLAG IS SEEN, AND THE DOWN ARROW DISPLAYED. IF THIS OCCURS, AND THE
   TRUE TACAN BEARING IS LESS THAN 180 DEGREES, THE TACAN BEARING DATA
   ON THE DISPLAY WILL SHIFT UPWARD 180 DEGREES FROM THE EXPECTED     
   VALUE.                                                             
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  USER RESPONSE:                                                      
                                                                      
   WHEN TACAN BEARING DATA ON THE HSD SHIFTS UPWARD BY 180 DEGREES,   
   WITH THE DOWN ARROW STATUS INDICATOR FOR THAT TACAN CHANNEL        
   APPEARING APPROXIMATELY TWO SECONDS LATER, DISREGARD BEARING DATA  
   FOR THAT TACAN CHANNEL UNTIL THE DOWN ARROW BLANKS.                
                                                                      
                                                                      
                                                                      
                                                                      
                                                                      
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 CONCURRENCE:                           APPROVAL:                    
 RI: <S> J. AGRES          DATE 05/26/92                             
     --------------------      ---------                             
 FDSD:   W. R. PRUETT      DATE 07/09/92                             
      -------------------      --------- DARRELL E. STAMPER 07/17/92 
 PF MGR:JEFFERSON D.POWELL DATE 07/13/92------------------- -------- 
        -----------------      --------- CHAIRMAN, SASCB      DATE   
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