"War Horse" the book is actually written for young readers, and I read it recently with a group of my Middle Schoolers. It's a great story, but there's no aviation involved (I guess it would be pretty hard to get a horse into an aeroplane). The author could have done a bit more research....he has his 1914 British Tommies wearing steel helmets, etc. For the most part, however, it's pretty good, and written from the horse's persepctive.
I hope the movie turns out well.