Should I take a car seat on a plane for a 5 month old?

Traveling to Dallas for the first time with a baby on plane....

Are you looking at it in terms of comfort for you and the child or safety??
Since the child is under the age of 2, you can hold them on your lap...no charge.
If you bring the car seat, unless you purchased a ticket for the seat next to you, there won't be a place for that car seat if the flight is full. In that case, you'll have to check it with the gate agent, pick it up at the gate in DFW on arrival, and hold the child during the flight.
Good luck

You aren't required to, but its a really good idea to take one. Kids do better when they have their seat on the plane, same as in the car. They are less likely to want to run around and such since they are used to being put in a car seat whenever traveling. And believe it are not, they are safer. Should turbulence happen, they are less likely to be injured or scared.

Another thing to consider: will you be doing any traveling by car once you get to your destination? Then you will need the car seat anyway, or you will have to purchase one when you get there. Do not rely on a car seat from a rental company! Its dangerous. Car seats expire 6 years after the date of manufacture, and are not safe if not taken care of properly. It must never have been in a wreck, never dropped, include all the original pieces and manual, and be installed correctly, something the rental staff will not help you with. On that note, remember too, that it is better NOT to check car seats as luggage. Think of how your luggage gets banged around - well, if your car seat gets banged around, it is no longer safe to use. A car seat is only made to withstand being dropped/in an accident once! And if it gets dropped and you don't know about it, you unwittingly put your child in danger. Better all around to take the seat on the plane.

And the airline is very unlikely to replace the seat if they do damage it. Just check to make sure that your car seat is FAA approved for aircraft use, should say so somewhere on a label on the seat.

Also - if you are planning on having your baby as a lap baby, you should know the truth of what can really happen, check the links below. Flight attendants refer to lap babies as MISSILES!!!! That's right, b/c missiles is what they become when there is heavy turbulence or other problems or rough flights. They give the count as "127 pax (passengers) and 3 missiles". Is a missile what you want your baby to be?

Hopefully someone will be kind enough to let you have their seat so you can let your baby stretch out. I flew from California to North Carolina with one kid and a lap child. The lady we were supposed to sit next to asked to move so I had all three seats. That was nice, but she did look annoyed.