I have traveled a lot with a backpack over the years, and traveling by air seems to be constantly changing with these sort of things. A couple of summers ago, I flew into Denver CO from San Diego, CA. I threw my backpack into a duffle bag that time and had no issues (or dangling straps on the bag). Last summer, three of us flew from San Diego to Milan, Italy. They had heavy duty plastic bins that each backpack loaded into. When we got to Milan, they were all in one piece. Same with the return trip. My advice is to call the carrier you are planning to use and see what they advise. That is how we found out about the bins for the trip to Italy.