 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] B. KRAUSE          ]    PASS PROGRAM NOTE        ]     101748       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: 05/10/88   ]
 ] IBM/282-8725       ]      RELEASE NOTE( )        ] REV A: 12/13/91  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ]  OI-20 THRU OI-22             ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )] 0, G1, G2, G3, G6, G8, G9       ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:  RM                                              ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS:  4.91                                          ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]        POWER FAIL UNLIKELY FOR RCS MANIFOLD FWD 3/FWD 4 PAIR        ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]   THE RCS RM SOFTWARE DECLARES A POWER FAIL CONDITION FOR THE       ]
 ]   FWD 3/FWD 4 RCS MANIFOLD PAIR IF ALL VALVE OPEN/CLOSE FEEDBACKS   ]
 ]   FOR BOTH MANIFOLDS ARE ZERO.  THIS LOGIC ASSUMES THAT THESE       ]
 ]   MANIFOLDS HAVE A SINGLE POWER SOURCE (MN BUS C).  FWD 3 IS,       ]
 ]   HOWEVER, REDUNDANTLY POWERED BY MN BUS A AND MN BUS C.  A SINGLE  ]
 ]   FAILURE ON MN BUS C WILL ZERO THE FEEDBACKS ON FWD 4 BUT NOT ON   ]
 ]   FWD 3, RESULTING IN A CLOSED, IN DILEMMA, STATUS FOR FWD 4.  THE  ]
 ]   RCS JETS ON FWD 4 WILL BE DESELECTED.                             ]
 ]                                                                     ]
 ]   MULTIPLE POWER OR VALVE FAILURES ARE REQUIRED FOR A POWER FAIL    ]
 ]   ANNUNCIATION FOR THE FWD 3/FWD 4 PAIR.                            ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ]   THE FWD 4 CLOSED STATUS MAY BE OVERRIDDEN (AND THE RCS JETS       ]
 ]   RESELECTED) BY EXECUTING ITEM 41 ON THE OVERRIDE DISPLAY          ]
 ]   (SPEC 51) IN OPS 1, 3, AND 6, OR ITEM 43 ON THE RCS DISPLAY       ]
 ]   (SPEC 23 WITH THE FORWARD RCS SELECTED) IN OPS 1, 2, 3, 6, AND 8. ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: PATTI A. THORNTON    DATE 02/04/92]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:  ROBERT N. HINSON   DATE 02/18/92]                             ]
 ]     -------------------      ---------] DARRELL E. STAMPER 02/19/92 ]
 ]PF MGR: JOHN APPLEWHITE   DATE 02/19/92]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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