Oh god, why.... how.... It's turned out to be what exactly I expected. It's a fvckin' jet engine with wings, it even closer to a rocket than a plane given how small the wings are.... Also, even if she use wind magic to lessen air resistance, she doesn't have gravity magic to lessen the G. And if the machine accelerate a lot, I don't even know which would get destroyed first, her body or the "backpack strap".
And she dares to call herself an military/gun otaku while doesn't even know what her tools can bring to a war balance? Isn't that the point of gun enthusiast, understand how a weapon or machine is awesome because it can disturb the status quo? Sure plane technology doesn't change WW I very much, but if I was sent back to medieval era as a strategist, I would sell myself as a slave to get myself an hot air balloon. It's just that critical to get a good view of situation and not playing a blind chess.
I do enjoy the story, but this mishmash of fantasy and modern tech is just asked to be commented.