 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ]    H. STOVALL      ]    PASS PROGRAM NOTE        ]     101774       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: 04/10/89   ]
 ]  IBM/483-1715      ]      RELEASE NOTE( )        ]                  ]
 ]____________________]_____________________________]__________________]
 ] OI/FLIGHT EFFECTIVITY:        ]  USER AFFECTED:                     ]
 ]  OI8B AND SUBS                ]  CREW (X)  GROUND ( )  DUMP ONLY ( )]
 ]_______________________________]_____________________________________]
 ]        MAJOR SOFTWARE AREA:       ] OPS MODES AFFECTED:             ]
 ]SSW ( )  GNC (X)  VU ( )  SM/PL ( )]   G1                            ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA: GUID, ADI                                        ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.3, 4.168                                     ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]          OMS 1 ATTITUDE ERRORS ON ADI DURING MPS DUMP               ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]   THE MPS DUMP STARTED AT OMS 1 IGNITION RESULTS IN BURN ATTITUDE   ]
 ]   ERRORS.  THE DUMP INITIALLY PITCHES AND YAWS THE VEHICLE UNTIL    ]
 ]   STOPPED BY OMS ENGINE GIMBALING.  THE LARGEST RESULTING ATTITUDE  ]
 ]   ERROR IS IN PITCH AND MAY BE UP TO SIX DEGREES NOSE HIGH,         ]
 ]   DEPENDING ON THE ATTITUDE ERROR AT IGNITION.  THE MPS DUMP ALSO   ]
 ]   CHANGES THE BODY THRUST DIRECTION.  THE ADI ERROR NEEDLE          ]
 ]   CALCULATIONS USE THE INITIAL OMS TRIM ANGLES TO DETERMINE THE     ]
 ]   BODY THRUST DIRECTION.  THE MPS DUMP THEREFORE INTRODUCES         ]
 ]   INACCURACIES IN THE ERROR NEEDLES.  GUIDANCE HOWEVER COMMANDS     ]
 ]   THE VEHICLE ATTITUDE BASED ON SENSED ACCELERATION AND OPERATES    ]
 ]   CORRECTLY.  AFTER THE INITIAL PITCH UP, THE VEHICLE WILL PITCH    ]
 ]                 - CONTINUED ON SUPPLEMENTAL SHEET -                 ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ]    AT THE START OF THE OMS 1 BURN, EXPECT MPS DUMP INDUCED VEHICLE  ]
 ]    RATES AND RESULTING ATTITUDE ERRORS.  ALSO, AFTER THE RATES ARE  ]
 ]    STABILIZED, EXPECT ABOUT ONE DEGREE OF PITCH AND YAW ERROR       ]
 ]    NEEDLE DEFLECTION.  FOR MANUAL OMS 1, CENTERING THE NEEDLES      ]
 ]    THROUGHOUT THE BURN WILL RESULT IN SMALL BURN RESIDUALS AND      ]
 ]    MINIMAL FUEL WASTING.                                            ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 04/18/89]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: SAM ANKNEY           DATE 04/20/89]                             ]
 ]    --------------------      ---------]  JACK G. BOYKIN    04/21/89 ]
 ]PF MGR: MOISES N. MONTEZ  DATE 04/20/89]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
 @



 +_____________________________________________________________________
 ]                                                                     ]
 ]                       SUPPLEMENTAL SHEET                            ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] AUTHOR:            ]                             ] DR:              ]
 ] H. STOVALL         ]    PASS PROGRAM NOTE        ]     101774       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: 04/10/89   ]
 ] IBM/483-1715       ]      RELEASE NOTE ( )       ]                  ]
 ]____________________]_____________________________]__________________]
 ] TITLE:                                                              ]
 ]         OMS 1 ATTITUDE ERRORS ON ADI DURING MPS DUMP                ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ]    DOWN TO THE CORRECT GUIDANCE SOLUTION, BUT THE PITCH ERROR       ]
 ]    NEEDLE MAY INDICATE UP TO 2.5 DEGREES NOSE DOWN.  THIS           ]
 ]    INDICATED ERROR WILL DECREASE AND STABILIZE AT ABOUT ONE         ]
 ]    DEGREE DOWN APPROXIMATELY THIRTY SECONDS INTO THE BURN.          ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]USER RESPONSE:                                                       ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 @
