1+_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] R. AVERY           ]    PASS PROGRAM NOTE        ]      105356      ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:            ]
 ] IBM/713-282-8763   ]      RELEASE NOTE( )        ]      12/07/93    ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ] OI-22 AND SUBS                ]  CREW (X)  GROUND (X)  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )]  G1                             ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:  ASCENT GUID                                     ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.2                                            ]
 ]_____________________________________________________________________]
 ] TITLE:   UNEXPECTED ROLL MANEUVER IN MM103                          ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ] FOR AN ENGINE OUT EARLY IN MM102, PFS TAL DROOP GUIDANCE WILL       ]
 ] PROBABLY BE ACTIVATED AT THE START OF MM103.  IF THE MISSION IS ONE ]
 ] WHICH REQUIRES A SIGNIFICANT YAW AT MM103 INITIATION ( E.G., AN     ]
 ] INERTIALLY-TARGETTED MISSION ( V99U7441C EF_PLANE_SW = OFF ) OR ONE ]
 ] IN WHICH THE MECO TARGET PLANE IS SIGNIFICANTLY DIFFERENT THAN THE  ]
 ] ONE ACHIEVED AT SRB SEPARATION ), THEN A ROLL OF AS MUCH AS 10 TO   ]
 ] 12 DEGREES WILL BE PERFORMED.  THIS WILL SHOW UP AS AN APPARENT     ]
 ] DIFFERENCE IN ROLL ATTITUDE ERROR BETWEEN THE BFS AND THE PFS.      ]
 ] THIS DIFFERENCE IS BETWEEN THE ADI ATTITUDE ERROR NEEDLES (DRIVEN   ]
 ] BY PFS ) AND THE ATTITUDE ERROR DISPLAYED ON THE BFS ASCENT TRAJ 2  ]
 ] DISPLAY.  IN ADDITION, THE PFS ADI BALL IN LVIY MODE WILL SHOW      ]
 ] WINGS NOT LEVEL.                                                    ]
 ]                                                                     ]
 ] NEITHER THE PFS NOR THE BFS IS IN ERROR; THE DISCREPANCY EXISTS DUE ]
 ] TO A DIFFERENCE IN THE REFERENCE FRAMES USED BY THE PFS AND THE BFS ]
 ] WHEN THE TAL DROOP LOGIC IS ENGAGED.  TAL DROOP IS ONLY INSTALLED   ]
 ] IN THE PFS.                                                         ]
 ]                                                                     ]
 ] THE VEHICLE WILL RETURN TO WINGS LEVEL WHEN RTLS IS SELECTED.  IN   ]
 ] ADDITION, THE APPARENT DIFFERENCES BETWEEN PFS AND BFS WILL         ]
 ] DISAPPEAR.                                                          ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ] IGNORE BFS ROLL ATTITUDE DIFFERENCES WITH PFS WHILE PFS TAL DROOP   ]
 ] LOGIC IS ACTIVE.                                                    ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM:   HUGH D. STOVALL    DATE 01/24/94]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:ELIZABETH A.FOUNTAIN DATE 01/24/94]                             ]
 ]     -------------------      ---------] DARRELL E. STAMPER 01/24/94 ]
 ]PF MGR:JOHN W. CRAFT,JR.  DATE 01/24/94]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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