How can an INS/IRS be realigned in flight if alignment is lost for some reason?

Question

Answer

By setting the INS mode selector to "ALIGN" and then flying straight and level with NO airspeed variations for 
 at least 10 minutes.

Answer

By setting the INS mode selector to "ALIGN" and waiting for the required time.

Answer

By setting the INS mode selector to "GPS" and realigning the INSARS through the GPS.

Answer

It can NOT, the aircraft must be stationary on the ground for alignment to be performed.

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