I have done it. You need to have them swabbed in the security line. When you get onboard in first class You can ask them to put them in the jacket closet, some do, some don't. They fit in most overhead bins, if not on the side in the center. You need to let the air out. I bought a hard case this year and have done this in 12 months.

I used it on a 10 day bike trip to Italy. That was my only bag which I packed helmet, shoes, and clothes. It worked great! My only problem occurred when returning from Italy to Atlanta and had a stop in Paris. The Zipp bag went through the scanner and the security person starting yelling "PLASTIC"! I received a lot of attention until one brave security member unzipped the bag and found a huge chunk of a wheel of Parmigiano-Reggiano cheese! So be careful if you are flying internationally; those dam
French despise good cheese!

Rex