When I travel and absolutely have to have a detector when i arrive, I put one in checked luggage and one in carry-on. I use a very large rectangular bag so each part can be well padded with clothing. But I'm actually more worried that the carry-on detector will be damaged. I've had some close calls with people cramming their stuff in the overheads. I recently flew to alaska with an F75 and an Xterra 705, both in checked luggage, and had no problems. But I was there for a couple days before I needed the machines, so if they'd been delayed the airlines could have gotten my luggage to me in plenty of time.