Originally Posted by
karlpenney
This happened on our CUN-YHZ flight a couple weeks ago, also on an A321. They didn't ask for volunteers, but simply told the passengers in rows 18-20 to move to the back. I guess they just needed to move the CG back for takeoff, since they were allowed to return after we reached cruise altitude.
On larger jets it’s normally only a takeoff issue. Once in the air, the airplane is trimmed accordingly.