We took Leah on a plane when she was 5 months! She loved it i think. Was just a short flight to spain. Didnt effect her in any way. Airline's couldnt have helped more. + you get on the plane first. They let you keep your pram/buggy till just before you board. They give you blankets etc etc . Great experience for us as parents and i'm sure it was a great experince for her aswell. just do it.