I flew Malaysian airlines with dd4 when she was five months old, by myself. NEVER AGAIN. LOL. She was a difficult baby, though, cried a lot and wouldn't comfort suck.

The airline was great, the staff were very helpful, but I found that it was very disruptive to have her in the bassinette and settled only to be told I had to put her on my lap again when there was turbulence and the seatbelt sign was on. (How it was any safer to have her just in a little lap belt than velcro-ed into the bassinette was beyond me, but, oh well.)

At one point on the way back, they let me sit in business class for a while, probably to give the people in cattle class a break! Staff were great at holding her when I needed a toilet break.

I found it very helpful to check my stroller at the gate rather than through luggage, so that I didn't have to carry her. If I ever had to fly with a baby again I'd probably take a sling.

Another thing - it was hysterically funny trying to get a passport picture of her that would meet requirements. In the one that was accepted she looks like she's just been told she's going to be dropped from the plane at 30,000 feet.