The float plane should not be a problem. I would make sure the bow is in a protective case of some sort. I have one from 3-Rivers that I have used on 2 Alberta bear hunts, that is awesome. I worry a lot more when it comes to commercial flights............
My experience with float planes is they have no problem one piece bows. They deal with fishermen all the time. Now you might want find a case to protect it. That said I've just layed the bow on top of everthing without a problem. They have never charged extra, It's all part of the payload.