While you are close, you are confusing the two ways that "ounces" is used. The ounces listed on a bottle are not a measure of weight, but of volume. So, for example, while 16 liquid ounces of water weighs 1.04 pounds, 16 liquid ounces of molasses weighs 1.49 pounds.
http://www.aqua-calc.com/calculate/food-volume-to-weight
OP, yes, I think that taking all of that liquid on a plane is crazy. Too much risk of it leaking.