I seem to draw the lucky straw as far as TSA goes, it's happened to me 3 times. The first was without a duffel, and the pack came down the carousel with the extension collar fully extended and banging around, about to spew its contents. They also confiscated an empty fuel bottle. No problems since going with an added layer, as they seem to not want to bother, or they've not been able to damage or lose anything since it's contained. The pack has been messed up, but not in danger.