Originally Posted by
bennijiggs
If I was the mother/father I would have just moved my self to the middle seat, told the unhappy aisle guy that I lost the boarding pass as proof my assigned seat is the middle, then put my child in the window seat free and clear. Tough shiit now for the aisle guy that now gets no extra room and has to now fight me for the arm rest.
Not too far off.
The parent referenced in the OP made the mistake of not bringing an FAA-approved child safety seat on board. If there is an open seat available, a car seat can be used in said open seat, even for a lap child. In such a situation, the car seat goes in the window seat, and the parent goes in the middle seat.
I do not know if a lap child gets priority for an open seat without an FAA-approved child safety seat on board.
From my experience, if you are traveling with an infant in two seats, you have no need for the arm rest that you are sharing with the third person in the row (unless, perhaps, you have massively wide shoulders).