A common question among traveling parents is, “Is my carseat allowed to go on the aircraft?”
With very few exceptions, YES, it can!
Booster seats, for instance, are not approved. They require lap and shoulder belts, and aircraft are not yet equipped with more than lap belts. If you have a booster aged child and are traveling with a seat for them, you can break down the back from the bottom and store them in the overhead, put the back in your suitcase and carry on the backless booster, or just take a backless booster with you. Other options are to have a booster waiting at your destination (if possible), or something like a Ride Safer Travel Vest, BubbleBum, or Safety 1st BoostaPak going with you.
For harnessed seats, there are only three US seats that are not aircraft approved. The IMMI/Safety 1st Go Hybrid, Graco Smart Seat, and the Combi Zeus/Zeus 360. You cannot use one of these seats on board. All other carseats carry the sticker which indicate it IS approved for use onboard US-based aircraft.
If your seat is a rear facing only seat, check your manual to see if the base is allowed to be used on board. For most seats a base will simply add length front to back, so it likely won’t ‘be used anyway, but Britax bases, the Canadian Chicco Keyfit, the Peg Perego bases, and a few others are not aircraft approved. If you want to travel with your base, put it in the overhead bin or under the seat in front of the baby. If you can, having a base bought and shipped to your destination is an option as well.
It’s helpful to know your rights as a traveling parent. For information on regulations set by the FAA (governing US carriers), please visit:
https://carseatblog.com/22134/flying-with-a-car-seat-know-your-rights/
Department of Transportation Circular and Department of Transportation Requirements.