I have flown with a bromine a few times. Tbh I wouldn’t do it again. The hassle is massive in terms getting the bike, in a case to check in as is the extra cost for a second case or the loss of luggage space if you travel with only one. It was brilliant having a bike when I got to wherever. But could have hired a good bike many times from the LBS or even bought secondhand and it would have cost no more. I know that is not what I am supposed to say. But hey.