I just came off of an Alaskan flight. I used the Exo K2 frame which stands about 24" give or take and it WOULD NOT fit in the overhead compartment. I had to shift the pack sideways along with the other carry on's to get it to fit. I removed the belt/lid and kept it as small as I could (hunting clothes/optics only) and no one questioned it. Flight attendants did not see me shift it sideways and i closed the overhead bin when I was done as it was full. They were good about checking our carry on bags for free on my flight. Possibly be prepared for that.