A lot of planes in the setting use a "pusher" configuration - the main propeller is mounted on the tail, rather than the nose. This is a real-world system, but it's not the most popular, partially because planes naturally pitch up when taking off, meaning the propeller needs to be small to avoid it hitting the ground. So why is it so common in Crimson Skies? Because a lot of planes don't take off from the ground - they're dropped from zeppelins, go on sorties, and then go back to the zeppelin. They don't need to worry about damaging the propeller by hitting the tarmac because many of them will only touch the ground once in their operational careers, and that's when they're shot down.
After the fourth mission in Hawaii when the Fortune Hunters recover the treasure, after foiling the British attempted takeover of Hawaii, pretty much no mention of Hawaii is made again, but given the circumstances, an intervention by the Imperial Japan is almost certain. Britain's international reputation is wounded, and Japan has a cause, even if flimsy, to intervene in Hawaii to 'protect' them from Western Imperialism. With the USA divided among many successor states, a serious attempt to counter them is unlikely by anyone active in the region, and Hawaii would help anchor their position in the Pacific, which given the game is only two years before WWII and with mentions made of Hitler at least implying he plays a similar role as in real history, once Britain and France are occupied in Europe with less, if any, help from Lend-Lease, no matter how the war shakes out, Asia and the Pacific are having a bad time. And Nathan Zachary just flies off soon after setting Hawaii up for a Japanese invasion
