Originally Posted by
FWAAA
Sure, the box is slightly too tall, but it's going to fit in an overhead bin (OP is likely on a 738) and I'd carry it on.
Usual risks apply.
Yes it will fit if you manage to get it on-board, but yes they are fully entitled to refuse to allow it as a carry-on as it is over the permitted dimensions.
All depends how lucky you feel really
