If aircraft main electrical power is interrupted for any reason
during checkout, EGI switch shall be rotated to OFF immediately. Failure to position EGI switch to OFF results in
discharging of INS battery.
• Upon restoration of aircraft main electrical power, check for
INS battery warning (MFL EGI 012), perform appropriate
fault isolation procedures, if required, and allow additional
aircraft main electrical power on line to recharge INS bat-
tery. Failure to comply may result in EGI memory loss and
additional discharging of INS battery.
• After EGI switch OFF position is selected, EGI requires 30
seconds to perform power down memory update. Restarting
EGI or removing aircraft main electrical power within 30
seconds causes an incomplete memory update and subse-
quent degraded navigation performance.