Flying Solo with Two Under 2 - Castle Rock,CO

Do you have a laptop that can play a DVD for your 2 year old? Or even better, a portable DVD player? I have flown several times with my twins and when they were 2 they weren't really movies (due to their short attention span) but I recorded several of their favorie shows on my DVR and then put them on a DVD. (Shows from PBS, Nick Jr, etc.)
Snacks are always a must! I usually bring several snacks they like but also keep a couple "treat"-like snacks for those moments where you need to pull out something really special to avoid a meltdown. Fruitsnacks or M&M's always excite my kids! I also stock up on new toys/activities. I go to Target and get a bunch of items from the $1 bins.... coloring books, stickers, board books, etc. New things always get them interested! Best wishes!

At least for when you are trying to get to your gate, you can have somebody go to the check in counter with you and get special pass to help you get the kids and car seats through the airport. They have to leave immediately once you get the items to the gate, but that may be helpful for at least getting to the plane!

Get a backpack with a leash attached for your 2 year old. The 2 yr old can put lots of little toys and snacks in the backpack and you can put the leash around your wrist while going through the airport and juggling all the bags and tickets.

Take a portable DVD player if you have one. Lots of snacks too!

The 2 year old is the one you'll have to keep distracted.. I'd bet the 5 month old doesn't even blink (i hope for your sake lol) We brought the iPad with us when we flew last month and that kept our 2.5 yo busy.. when she was younger (even like 3 months ago) she was a breeze to fly with! I agree with the dry snacks and keep your eye on the sippy cup, ours exploded when we opened it up mid-flight. I was laughing SO hard, hubby didn't think it was as funny. Maybe take an empty one then fill it up otherwise the air pressure change makes it like a shaken up soda.. Ask the airline for a helper and check as much as you can and try to have a happy upbeat attitude, if you're nervous and anxious the kids will be too. And don't worry.. it's only 3 hours.. the hard part is getting to and from the airplane, once your seated you're good to go!

I definitely second the suggestion of getting the seat behind the bulkhead! More legroom!
Check the carseats... a lot of them won't fit in the airplane seat anyway! OR... does someone on the other end have some car seats you can borrow? My hubby and I used to have 2 sets of car seats... one set in each car, so obviously one set was not being used... maybe someone there does the same thing?
Magnadoodle is great, as well as Color Wonder products. If you have a portable DVD player or iPad/iPod/iPhone so that the 2YO can watch a little something here and there. It may not be an entire show, but your child may watch just long enough for you to feed the baby.
Make sure you have your 2YO lovey/paci/blanket/favorite toy...
Sippee cup for the 2YO... bring 2... s/he will need to be able to pop the ears...
If you ask the flight attendants, they will bring you extra juice if you need it... just gotta ask.
Don't know if you EBF or if you bottle feed... but remember that the baby will also need to pop his/her ears.
Make sure someone is meeting you at the airport, and let them know you will need help (so that they aren't waiting for you at the curb.)
Umbrella stroller AND a baby carrier... at the end of a 3 hour flight, your 2YO may be tired and will probably NOT want to walk... the 2YO can sit in the stroller and you can wear your baby.

And you know... a lot of people will understand. They see you are outnumbered by two very young children... And those who don't can go to HELLO! Did I just think that? LOL

You've gotten a lot of great suggestions. The only thing I would add is to bring lots and lots of wipes, diapers and a change of clothes for you too. We had a 4 hour flight to the Dominican republic with our 7 month old. Wouldn't you know it, we had two pooply diapers on the flight, and hubs and I both got treated to some "decorating" (spit up on our clothes). I always feel more together when I don't have spit up on me.

Also, even if you decide to have a "lap baby" and don't spring for the extra seat cost, alert the flight staff, they will try their darndest to give you an extra seat.

Everyone on the plane was sympathetic to our little guy, and to us, loads of smiles as he giggled, and wriggled and stared at all the "aunties" and "uncles" on the plane.

Call on the attendants to help you. They can mind one child in their seat as you take the other to the lav.

If it makes things easier, plan for you and your two year old to eat while at the gate on both ends, that way you don't have to worry about food on the tray tables.

Good luck to you, your FIL and your family. You are doing a wonderful thing.

Check as much baggage as possible at the curb.
Call the airlines and request a helper.
If you haven't purchased your tickets yet, try to get the first set of seats, can't remember the term. They have the most leg room.
Splurge and get your 5m old his own seat so that your hands are free to help with the 2y.
Try to feed the kids right before the flight.
For foods, take single packaged dry foods - cereals, little crackers, etc.
For toys, take a magna doodle pad that has the pen attached.

When I flew with 2 under 2, I checked the car seats and spent the extra money to check the bags I didn't need during the flight. On the flight I just had my purse and a large bag for the kids stuff. I had a blanket for each kid. For my oldest I packed some of his smallest toys that he liked to play with, cars and books. A sippy cup for him and some of his favorite snack treats and suckers to help with the popping ears. For my baby I just brought a few of his favorite toys. For both boys I brought a change of clothes, diapers, wipes, and all the normal stuff I need for my baby. During the flight the baby sat on my lap and the almost 2 year old next to me. It worked really well for me. When I got on the plane I clear the seat of pillows and blankets that the airlines put there. I put the boys toys in the back of the seat in front of me with the sippy cup and a snack, it made it easier for me to switch my kids toys out, I didn't have to kept pulling my big bag onto my lap. I put my oldest by the window so he could look outside.