FKLPAF COMMENTS
*-- Author : Stephen Burke
      SUBROUTINE FKLPAF(JPL,IERR)
*-----------------------------------------Updates 27/04/92-------                                             
**: FKLPAF.......SB. Error message description updated.                                                       
*-----------------------------------------Updates 07/02/92-------                                             
**: FKLPAF 30205.SB. Initialise IFAIL to please UNDEF.                                                        
*-----------------------------------------Updates----------------                                             
**********************************************************************                                        
*                                                                    *                                        
* Point acquisition during filtering (at plane JPL)                  *                                        
*                                                                    *                                        
* ERROR CONDITIONS;                                                  *                                        
*       IERR =   0  ; normal termination                             *                                        
*   ->  IERR =   1  ; projected vector missing or invalid prob cut   *                                        
*   ->  IERR =   3  ; invalid value in MES array                     *                                        
*   ->  IERR =   4  ; invalid value in MES array, or internal error  *                                        
*       IERR =  12  ; covariance of residuals not positive definite  *                                        
*                                                                    *                                        
*   ->  `Fatal' error                                                *                                        
*                                                                    *                                        
* `Fatal' means that a serious problem occurred, but all errors      *                                        
* are recoverable as no changes are made.                            *                                        
*                                                                    *                                        
* Error codes from FKHUNT are passed back unchanged, but these are   *                                        
* not yet defined.                                                   *                                        
*                                                                    *                                        
**********************************************************************                                        
      LOGICAL FKHUNT
*KEEP,FKECODE.                                                                                                
*KEND.                                                                                                        
*KEEP,FKNPL.                                                                                                  
*                                                                                                             
* Per-track values can go in H1WORK; note that LTRUE and LFIRST must                                          
* be set at least per event.                                                                                  
*                                                                                                             
* This is about 36k words long; the remaining common blocks are                                               
* about 3.6k in total. Some of this could be in /H1WORK/, but the                                             
* blocks would have to be reorganised.                                                                        
*                                                                                                             
* /FKPROJ/                                                                                                    
* /FKFILT/                                                                                                    
* /FKSMTH/                                                                                                    
* /FKINT/                                                                                                     
* /FKRSID/                                                                                                    
* /FKTRUE/                                                                                                    
* /FKDBG/                                                                                                     
*KEEP,FKFLAG.                                                                                                 
*KEEP,FKRJCT.                                                                                                 
*KEEP,FKPROJ.                                                                                                 
*KEND.                                                                                                        
**********************************************************************                                        
         CALL FKERR(IUTIL,IROUT,IWARN,IINF1,IERR)
* See if there's a new digi                                                                                   
      IF (FKHUNT(JPL,SPRO(1,JPL),CPRO(1,1,JPL),IFAIL))
      IF (IFAIL.NE.0) CALL FKERR(IUTIL,IROUT,IWARN,IFAIL,IERR)
*