Every time I get ready to go on a trip that requires air travel I worry about the gear. I don't trust checking luggage containing my camera gear. Too risky. That means I must carry it on. I have a large rolling bag that fits under the seat if not in the upper bins, but if I must put it there my knees are closer to my nose than the floor. On a recent trip to Chile I had to do this. Not on the Chilean Airline (Latam) mind you, but on the small United jet that carried me from Houston to ABQ.
It is really tough to get 2 camera bodies, 4 lenses, a tripod, batteries, chargers, light source, etc. etc. in a bag that weighs less than 14 pounds. On a homeward bound flight from New Zealand I knew my camera bag was overweight. I though I had gotten away with it until just as I was entering the gate an attendant pulled me aside and weighed the bag. This cost me $100. When I got home I bought a photographer's vest. Though dorky, and fully loaded will add about 30 pounds to my girth, I may resort to the trench coat trick when I return to New Zealand.
Even if I successfully board with my roll-on camera bag I still have a problem. Now I need a bag I can hike with that holds a minimum of one camera body and a couple of lenses. The bag I have is small and light but has a cross chest strap that is not fit for use by women. I just bought a new Lowepro Fastpack that I plan to carry on the plane and use for hiking. I have regretfully come to the conclusion that I need to be content with less camera baggage. I will leave the big bag home. Going to Puget Sound soon. I'll tell you how this worked out.