I always fly southwest and check my gearbag. All I do is remove my reg from my tanks and put the reg's in my carry on. I then make sure my tanks on top of my gearbag so they are the first thing TSA sees if they open my bag. If they open your bag its going to be to check your tanks so I always have those on top. I lock my zippers with a TSA lock as well. I don't think my bag has ever been opened to be honest.