Originally Posted by Black_Dawn
After a while, during descent and less than 180nm from our destination, we realized that the FMS mode was still in CRUISE phase.
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My question is: must we have the FD's on, for the FMS to change its flight phase, or what?
Would it be possible that when you did initiate your descent, the distance to DEST was more than 200 NM ?
In such case, the system would not activate the descent phase.
As now your distance was within 200 NM when you noticed the CRZ phase was still active, the procedure would be to enter your passing CRZ FL on the PROG page, and the descent phase should activate.
IMO it is not a question of AP/FD ON/OFF.