Hey
We have flown to the UK 3 times with little ones. DS was the same age as your little one the first time he flew and i won't lie he was horrid horrid horrid!

When we did it with just DD1 she was fine made no sound whatsoever.

Anyway we always fly Singapore Airlines - we won't fly with anyone else they are great! And we try and go with the mid afternoon flight because then they will get tired and hopefully sleep through alot of the flight as they get bored on those things.

GL