Has anyone taken their baby overseas?

We hope to go on 2 trips next year, one to china (bubs not coming) but one to the US and I would like to take bubby on this one....

I have a lot of questions... we will be staying with a friend so once we get there, no dramas... just worried about the plane... how would i change her nappy? how would she sleep? i cant hold her for 24 hrs or how ever long it takes.....

She will be 1.