1+_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. MAGLEY          ]    PASS PROGRAM NOTE        ]      37570       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE: SEPT. 1987 ]
 ] IBM/282-8939       ]      RELEASE NOTE( )        ] REV A: 06/23/93  ]
 ]____________________]_____________________________]__________________]
 ] 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:  IMU, SSME                                       ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS: 4.1, 4.2, 4.72, V4.9A                          ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ] MAIN ENGINE THROTTLING FOLLOWING INTERMITTENT 3 IMU LOSS            ]
 ]_____________________________________________________________________]
 ] DESCRIPTION:                                                        ]
 ]                                                                     ]
 ] IF ALL IMU'S ARE TEMPORARILY LOST (FAILED AND/OR DESELECTED) AND    ]
 ] NO ACCELEROMETER COUNT UPDATES ARE AVAILABLE TO THE SOFTWARE, AND   ]
 ] THEN DATA FROM AT LEAST ONE IMU IS AGAIN AVAILABLE TO BE SELECTED   ]
 ] BY RM, A SPIKE IN THE SENSED ACCELERATION OUTPUT WILL BE PRODUCED.  ]
 ] THIS ACCELERATION SPIKE DURING POWERED FLIGHT IN ASCENT CAN CAUSE   ]
 ] THE ME THROTTLES TO REDUCE AS LOW AS THE 3G THROTTLING LIMIT OF     ]
 ] ABOUT 65% (I-LOAD KMIN, MSID #V97U4425C). THE THROTTLES WILL REMAIN ]
 ] AT THE LOWERED LEVEL UNTIL THE ACCELERATION REACHES 94.7 FPS        ]
 ] SQUARED (K-LOAD ALIM_2, MSID V97U4309C) OR THE TIME OF THE          ]
 ] ABORT MODE BOUNDARY (APPROX. 1000 SECONDS, I-LOAD T_RTLS_AOA,       ]
 ] MSID V97U4661C) IS CROSSED.                                         ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ] IN THE EVENT THIS ERRONEOUS MODING OCCURS, SELECT MANUAL THROTTLE   ]
 ] CONTROL.                                                            ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM:   JEAN L. ZOPHY      DATE 08/03/93]                             ]
 ]    --------------------      ---------]                             ]
 ]FDSD:   W. R. PRUETT      DATE 08/03/93]                             ]
 ]     -------------------      ---------]                             ]
 ]PF MGR: OANH N. PHAM      DATE 08/10/93] DARRELL W. STAMPER 08/23/93 ]
 ]        M. N. MONTEZ           08/10/93]------------------- -------- ]
 ]        JOHN W. CRAFT, JR.     08/16/93] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________ _____________________________]
 @
 DR37572
