International flights with prophet

[XJuarezz]

Hello,

I'm flying with from Europe to the U.S. with my Prophet and would appreciate knowing your experiences with this. Flight company is Iberia. I've checked their website and there is a special consideration for musical instruments; my prophet on its flight case would be elegible in measure and weight to fly on cabin with me, but there is this line that says they might send it with regular luggage if there is too much weight on that particular flight.

Recommendations to manage to take it on board? Do's and dont's?

Thank you