1+_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. W. MAGLEY       ]    PASS PROGRAM NOTE        ]     102805       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  08/09/88  ]
 ] IBM/282-8939       ]      RELEASE NOTE( )        ] REV A: 05/21/92  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI-7D AND SUBS                ]  CREW (X)  GROUND ( )  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW (X)  GNC (X)  VU ( )  SM/PL ( )]  G6                             ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:  TRANSITIONS                                     ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.176, 4.227                                   ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]        MPS THRUST VECTOR CONTROL LOST IF MM602 PRO EARLY            ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]  SOME LEGAL, MANUAL MAJOR MODE TRANSITIONS ARE INAPPROPRIATE        ]
 ]  UNTIL CERTAIN CONDITIONS ARE MET.  NO SOFTWARE PROTECTION          ]
 ]  EXISTS TO PREVENT THESE TRANSITIONS IF THE CONDITIONS ARE NOT      ]
 ]  MET, AND IN MANY CASES THE TRANSITION IS NOT REVERSIBLE.           ]
 ]                                                                     ]
 ]  A SUBSET OF THIS ISSUE CONCERNS MANUAL TRANSITIONS FROM MM601 TO   ]
 ]  MM602 BEFORE MPS ZERO THRUST.  THE ASCENT DAP WILL BE DEACTIVATED, ]
 ]  AND THE LAST COMMANDED SSME POSITIONS MAINTAINED, WHILE THE GRTLS  ]
 ]  DAP (RCS ONLY) WILL BECOME THE ACTIVE DAP.  A LOSS OF CONTROL IS   ]
 ]  PROBABLE.                                                          ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ]  EXERCISE CAUTION WHEN PERFORMING MANUAL MAJOR MODE TRANSITIONS.    ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM:   JEAN L. ZOPHY      DATE 07/14/92]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:  ROBERT N. HINSON   DATE 07/20/92]                             ]
 ]     -------------------      ---------] DARRELL E. STAMPER 07/30/92 ]
 ]PF MGR: KIRK A. SHIREMAN  DATE 07/22/92]------------------- -------- ]
 ]       MARK M. HAMMERSCHMIDT   07/23/92] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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