Traveling with an infant on an airplane

My wife and I have taken our 2-1/2 year old daughter on numerous trips including 3 trips to visit family in Europe (11 hour flights). When our daughter was 2 months we brought our own car seat when we went to Europe (usually you can check it in for free) but after that we were able to find private taxi services that provided car seats for us for the rides to/from the airport. I would recommend searching for a taxi service that offers car seats or just bring yours with you. As far as the plane ride you have nothing to worry about with a 1.5 hour trip. You can bring a small arsenal of books/toys as extra stuff but I find that kids are super excited and interested in the whole experience that it takes all of their attention. Walking down the aisles and hanging out in the back of the plane always did the trick for us. I would recommends bringing a change of clothes and plenty of diapers/wipes. Kids love to find the most inconvenient time to have a mini 'disaster' in their pants.

Car seat is definitely a Must for safety. Some brand cars like Mercedes sell some in their shops which are lighter to carry. For the flight just make sure to make him drink a baby bottle when the plane leaves and when it lands as the pressure in the ears will hurt and he may cry or scream for that reason. And of course get the seat facing the wall if you can ;-) 

We found the Go-Go Kidz Travelmate useful as you can attach it to the carseat and then carry your child in the carseat around the airport.  If your little one still fits into their bucket carseat and you have a Snap and Go, even better.  We used the Go-Go Kidz Travelmate along with a Corocco car seat because the Corocco carseats are much lighter (14.3 lbs vs 25 lbs for our regular car seat).  You can use that carseat until your child is 40 lbs.  

Tips: You have quite a short flight so make sure you bring a bottle or breastfeed during take-off and landing so their ears acclimate.  At that age they're interested in taking things in and out of things so a ziplock with a bunch of toys inside for them to take in and out will keep them busy.  Make sure you bring extra clothes and lots of snacks.  Also bring extra clothes for you and your husband if possible (you never know what may happen and we have used this enough that we always pack extra clothes for us).  

Do NOT take your baby on a plane as a lap child. Please do spend the extra money so that they have their own seat. Take a car seat on the plane, strap the car seat onto the seat and the baby into the car seat. Safest thing to do for everyone involved. If baby is used to going in a car seat, they'll probably do the same thing they do in the car, fall asleep.

Just to give you a different perspective than some of the other responses, I traveled quite a bit with lap infants when my kids were little, and we never booked them a seat or brought their car seat on the plane, and it was fine. Especially for such a short trip, I don't think the hassles of dragging the car seat around and the cost of buying an extra seat are worth it, but that's just my take on it.  Do have snacks and fun things to do (favorite book, new toy, anything quiet and without loose pieces). Do try to schedule flights around bed/nap time. Don't expect to kick back and read a book yourself - you'll probably be spending the whole time entertaining the baby, whether they have their own seat or not.  But that gets better in a couple years - hang in there! If you're taking a car/cab from the airport to hotel, it's nice to have a packable car seat like the Bubble Bum or RideSafer, but I don't know of one that fits a 10mo. If the car seat is important to you (my kids ride buses all the time without seat belts, but somehow being in a car without a seat belt worries me), most airlines let you check it for free - check it at the curb with the skycap to avoid hauling it through the airport. If you're renting a car, you can rent a car seat along with it. Some car/cab companies can also provide a car seat with advance notice - it never hurts to ask.

Don't worry about having a car seat on the plane.  It isn't necessary.  Sitting on your lap is just fine.  I did it with my son many many times until I couldn't do it anymore when he turned 2.  I even took him to Norway on my lap when he was 20 months old.  And, there are many shuttle services that will provide a car seat for a fee for getting to and from the airport.  To avoid the shuttle fee, I usually take the car seat with me and check it at the gate for free.  I put the car seat on a wheeled cart that folds up and tucks up under my seat while flying.