You have to check out Derek Roberson's War Storyhttp://www.goodreads.com/book/show/467507.War_Story
It follows an English RAF squadron in WW1. It has a great dark soldiers humor about it. In the beginning of the war everything is all chivalrousness and full of honor, but by the end its all down in the mud trying to survive. It does a good job of showing the decay of the pilots through this change.
A lot of the pilots are stiff lip upper class Englishmen as well, which makes for a good read.
theres two other books in the serious both good, but the time line is wierd to work out. This is best to read first. Oh each is pretty stand alone.
EDIT: It reminds me a lot of the Union story lines in Abercrombies Heroes. There is definitely a sergeant Tunny story line.