3 minutes wait for IRS
On aircraft equipped with LITTON IRS the ground speed check, must be performed after 3 minutes aircraft stop (this is because the Ground Speed resets to "0" after 3 minutes), may be that is the question.
However it is only to compare the Ground Speed readings between the IRSs, to find any abnormal reading, not for shut Off.
This is described on Airbus SOP.
Last edited by Bad to the bones; 15th September 2008 at 17:36.