If the buckle latch is facing the plastic shell of the car seat, then flip it over so it's facing the airplane seat, which will make it easier to undo when you go to get it off the plane.

When installing a fwd facing car seat, recline the airplane seat all the way first, thread the seatbelt through the fwd facing belt path, buckle and tighten.

This puts the widest part of the seat on top which makes it easier to get down the narrow plane aisle.

carry the seat upside down with the seat resting on your forearm.

Here are some tips I found helpful when using ours on the plane: You don't know how it would be treated in the cargo hold and the airlines will most likely not reimburse you if it's damaged because they classify them as 'fragile' so you check it at your own risk.

Oh and definitely use the car seat on board the plane. It has always worked this way for us and we have taken 10 trips to WDW with ds now so we have quite a bit of experience with this. It should be brought up on to the jetway in Atlanta for you and you won't have to retag it for the last part of your trip.

When you go to get on your first flight, you should request a gate check tag for the stroller and have them put Atlanta and Orlando airport codes on the tag. Then they brought it out and put it on the jetway (in Atlanta) anyway so it's a good thing it was already sitting there when we walked off the plane otherwise, we would have left it behind! I do remember once the gate agent at our home airport asked us if we wanted it to go straight through to our destination and we said yes because we had a short layover and didn't want to have to wait for the stroller to come out. We have flown Delta numerous times, through Atlanta, and always had or gate checked stroller brought out for us to use between connecting flights.

Delta airlines car seat check