Aft Overhead Panel  700/800/900
Display Selector
IRS Display Unit (ISDU)
HDG/STS –

  • Left window displays present true heading.

  • Right window displays any applicable maintenance status
    codes.

  • During alignment, the right window displays minutes
    remaining until alignment is complete. For alignments
    greater than 15 minutes, the window displays 15 until the
    time remaining reaches 14 minutes. The display then
    counts down in one minute intervals.