I am currently flying small helicopters in Washington state, and when it came time to build a small portable survival bag, that could hold the essentials, and some stuff for the helicopter I looked here first. The ACU Utility Backpack was exactly what I was looking for, and I ordered one. It fit nicely into the small under-seat storage area of the helicopter just fine. When I move up to larger birds, I'll probably donate this bag to the company and buy a bigger one. (Like the Black Bugout bag that happens to be in competition right now).