Hellobee Boards

So, one thing yo can do is buy a seat and bring your car seat on board. Or, if your baby is a lap child, you can bring on board a boppy type pillow and use that to try to get her horizontal. I'd get seats that are not in the bulkhead so the arm rests can be raised, you might get lucky and have an empty seat in your row.

I was on a flight once where they offered us some kind of contraption that we could put on the floor of the plane and put the baby in, but we declined.

We flew to London with our 9 month old, and there were extra seats for her to sleep on. We also had Ergo to put her in otherwise. It went really well both ways.

When our LO was that age, we lucked out and had an extra seat. We had to bring her car seat on the trip, and they let us bring it on the plane for free. It was amazing. On the way back, the flights were sold out, so we did the Ergo. It wasn't horrible, but I definitely liked the car seat better (she actually slept most of the way). Ergo works ... just plan on passing baby back and forth a few times. The aisles are great for soothing/walking/bouncing.

I just got back from my first flight with my 4 mo old! Granted he's much younger than your baby but he's a big baby--20 lbs! I find our tula (similar to ergo) so uncomfortable to sit in but the ring sling worked great! I can tighten it and stand up/bounce around or loosen it a bit so his bum is on my lap but still supported cozy like a blanket. And my hands can be free. It was a life saver my whole trip, he took every nap in it. I just wish someone else could have worn him once in a while, I can't figure out how to get it on someone else properly.

I recently saw this baby airplane sling thing that looked promising..
http://www.babystrollersplace.com/products/infant-airplane-seat-flyebaby-airplane-baby-comfort-system?utm_medium=cpc&utm_source=googlepla&variant=1049926992&gclid=CPPDham_isUCFdcegQodtToAoQ

We flew to Spain when LO was nine months, I just wore her in the Ergo and stuck a boob in her mouth and she was great.

@MrsClownfish: I thought this looked really cool when my LO was little and we were going on a trip, but I did some research and I read that these are pretty strongly recommended against by flight attendants. They are definitely not FAA approved and some flight attendants might make you not use it. Also, they hook to the tray table in front of you which is pretty flimsy so if the person in front leans their chair back, the baby might get hit on the head.