 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] SMS: B22629      ]
 ]  J. KIEL           ]    BFS PROGRAM NOTE         ] DR: 109686       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: 02/19/97   ]
 ] BNA/D 922-3714     ]      RELEASE NOTE ( )       ]                  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ]   OI26 THROUGH OI27           ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]           MAJOR SOFTWARE AREA:            ] OPS MODES AFFECTED:     ]
 ]BSL( ) BSS( ) GNC( ) SEQ(X) SM/SP( ) IPL( )]    1, 6                 ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: ASCENT, SSME, HIP                                ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: MG038120/ 3.3.1.14 SSME HIP                    ]
 ]_____________________________________________________________________]
 ] TITLE: ERRONEOUS CMD PATH FAIL ALARM AFTER BFS ENGAGED              ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] THE BFS SOFTWARE WILL, UPON ENGAGEMENT, ANNUNCIATE A COMMAND PATH   ]
 ] FAILURE ALARM 'MPS CMD C(L,R)' FOR A PREVIOUSLY FAILED SSME WHEN    ]
 ] THE FOLLOWING CONDITIONS ARE PRESENT: (1) THE FAILED SSME IS IN     ]
 ] EITHER THE SHUTDOWN PHASE (FOR SSME CONTROLLER INITIATED SHUTDOWNS  ]
 ] ONLY) OR IN THE POST SHUTDOWN PHASE, (2) THE MPS LIMIT CONTROL      ]
 ] SWITCH IS IN THE AUTO POSITION, AND (3) THE THROTTLE COMMAND ISSUED ]
 ] BY BFS IS PRECEDED BY THE SAME COMMAND FROM PASS. IN THIS SCENARIO, ]
 ] THE BFS PERCEIVES THE THROTTLE COMMAND AS A NEW COMMAND SINCE THE   ]
 ] I/O BUFFER HAD BEEN EMPTY PRIOR TO ENGAGEMENT AND NOW CONTAINS THE  ]
 ] THROTTLE COMMAND. THE SSME CONTROLLER DOES NOT ACKNOWLEDGE THE      ]
 ] THROTTLE COMMAND AS NEW SINCE IT WAS RECEIVING THIS COMMAND FROM    ]
 ] PASS PRIOR TO BFS ENGAGEMENT. THIS RESULTS IN THE NUISANCE ALARM.   ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ]  THE USER SHOULD BE AWARE THAT AN ERRONEOUS COMMAND PATH FAIL ALARM ]
 ]  AND MESSAGE 'MPS CMD C(L,R)' WILL BE GENERATED BY THE BFS SOFTWARE ]
 ]  WHEN ENGAGED UNDER THE CONDITIONS DESCRIBED ABOVE. IN ADDITION,    ]
 ]  THE AMBER ENGINE STATUS LIGHT WILL BE ILLUMINATED UNTIL THE NEXT   ]
 ]  NEW ENGINE COMMAND IS PROCESSED BY THE FAILED ENGINE'S CONTROLLER. ]
 ]                                                                     ]
 ]  NO USER RESPONSE IS REQUIRED.                                      ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]BNA:<S> D. CORBIN         DATE 03/11/97]                             ]
 ]    --------------------      ---------]                             ]
 ]ASD:   ERIC C. BINGHAM    DATE 04/15/97]                             ]
 ]    --------------------      ---------]  MELVIN R. ROTHER  06/27/97 ]
 ]PF MGR:  JOHN RUPPERT     DATE 06/19/92]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_____________________________________________________________________]
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