Bloody April: Slaughter in the skies over Arras 1917 is an absolutely fantastic book. Gripping, well argued and with a great use of primary sources to build the arguements, it depicts how 'Bloody April' when the Royal Flying Corps (RFC) suffered huge percentage losses primarily due to using inadequate machinery while still pursuing an aggressive policy were not the result of 'lions led by donkeys', but rather the losses were acceptable in the face of what they achieved. He describes an aspect of the air war that I previously knew little about--that of the photographic reconaissance missions and how this was crucial to the ground planners. He argues that it is important while looking at the air war to never forget that it was largely dictated by conditions and necessities created by the ground war and does a great job of putting it into context. In fact, if you're interested primarily in the land war of WWI I would still highly recommend this book as it puts the whole of Allied strategy in early 1917 under scrutiny and does not just deal with the RFC but the linked issues of gunnery and ground offensives. The dogfights are covered within the larger picture, but I suppose if you're looking for a book primarily on the scout fighters, that's not the largest portion of the book. However, it does give a good explanation of the procurement of aircraft (they must have been so angry that striking workers delayed new aeroplanes significantly and meant that pilots had to go up with inferior aircraft), and dogfights are described in the words of those who flew in them, as well as the growing number of kills attained by the Red Baron, the problems with claims made by pilots (apparently, the Germans were far better at checking kills than the British and many British aces may have had somewhat inflated scores while the Red Baron's kills have almost all been matched up with losses from the RFC). In short, there's a very comprehensive coverage of just about every aspect of the RFC and the RNAS during early 1917 in the Arras sector.
Not only, however, is this a book with a good line of argument and a good use of supporting evidence, it's also utterly gripping as a reading book. I read it in (pretty much) one sitting on the ferry back from France, and apparently my mum tried to tell me that we were sailing past some battleships but I was so engrossed I wasn't even aware of this. It's not often that non-fiction is quite that unputdownable, and while I suspect the fact that I do have a greater than normal interest in this period played a part, it cannot be denied that this is a great book. Even if you're not particularly into aircraft. Balanced and enjoyable.