 +_____________________________________________________________________
 ] AUTHOR:            ]                             ] DR:              ]
 ] J. W. MAGLEY       ]    PASS PROGRAM NOTE        ]     101703       ]
 ]____________________]                             ]__________________]
 ] ORG/PHONE:         ] OPS NOTE ( )  USER NOTE (X) ] DATE:  12/08/87  ]
 ] IBM/282-8939       ]      RELEASE NOTE( )        ] REV B: NOV. 1989 ]
 ]____________________]_____________________________]__________________]
 ] 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 ( )]   G6, G3                        ]
 ]_____________________________________________________________________]
 ] SOFTWARE SUB-AREA:  DISP, HUD                                       ]
 ]_____________________________________________________________________]
 ] PRINCIPAL FUNCTIONS:  4.252                                         ]
 ]_____________________________________________________________________]
 ] TITLE:                                                              ]
 ]         HUD ALTITUDE ERROR ANOMALY                                  ]
 ]_____________________________________________________________________]
 ] DESCRIPTION: MM 603, MM 305                                         ]
 ]                                                                     ]
 ]     OFF-SCALE NEGATIVE VALUES OF ALTITUDE ERROR WILL BE INCORRECTLY ]
 ]     REFLECTED ON THE HUD BY A MAXIMUM-SCALE "FLY-TO" INDICATION     ]
 ]     IN THE WRONG DIRECTION.                                         ]
 ]                                                                     ]
 ]     FOR LARGE NEGATIVE VALUES OF ALTITUDE ERROR, HUD PROCESSING     ]
 ]     WILL LIMIT THE ERROR TO -32,768 FEET AND THEN ATTEMPT TO TAKE   ]
 ]     THE NEGATIVE OF THIS NUMBER TO PRODUCE THE "FLY-TO" INDICATOR.  ]
 ]     THIS NEGATION WILL NOT OCCUR BECAUSE +32,768 IS NOT A LEGAL     ]
 ]     SINGLE PRECISION INTEGER.                                       ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ] USER RESPONSE:                                                      ]
 ]                                                                     ]
 ]     BE AWARE OF THIS BEHAVIOR.  IN AN EXTREME LOW ALTITUDE CASE     ]
 ]     (MANY SIGMA LOW), THE HUD GUIDANCE WILL INDICATE "FLY LOWER"    ]
 ]     INSTEAD OF "FLY HIGHER".                                        ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]                                                                     ]
 ]_____________________________________________________________________]
 ]CONCURRENCE:                           ]APPROVAL:                    ]
 ]IBM: WYATT COOPER         DATE 12/14/89]                             ]
 ]    --------------------      ---------]                             ]
 ]SSD: SAM ANKNEY           DATE 12/15/89]                             ]
 ]    --------------------      ---------]M.C. GREMILLION     12/21/89 ]
 ]PF MGR: HOWARD G. LAW     DATE 12/19/89]------------------- -------- ]
 ]       -----------------      ---------] CHAIRMAN, SASCB      DATE   ]
 ]_______________________________________]_____________________________]
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