Edward Bujak. Reckless Fellows: The Gentlemen of the Royal Flying Corps. London and New York: I.B. Tauris, 2015. Much of our understanding of the airmen of the First World War has been dominated by the image of the knight of the air (or debunkings thereof); there hasn't been a lot of work done from a social and cultural perspective. This looks like an excellent corrective, tracking the change in the RFC from an often aristocratic elite to more technocratic and imperial force. There are chapters on training, observers, mechanics, and the Armistice. One chapter looks at Australian airmen, drawing partly on Michael Molkentin's work.
Ian Gardiner. The Flatpack Bombers: The Royal Navy and the Zeppelin Menace. Barnsley: Pen & Sword Military, 2009. As recommended on the Internet! A solid account of the early RNAS air strikes against Zeppelin bases, including the Friedrichshafen raid dreamed up by Pemberton Billing. I might have wished for more on the Admiralty's strategical thinking, but it's still worth it for the operational accounts.
Geoffrey Hawthorn. Plausible Worlds: Possibility and Understanding in History and the Social Sciences. Cambridge: Cambridge University Press, 1993. Perhaps the key theoretical justification for the study of counterfactual history, which -- despite the best efforts of some historians -- I think has value, if done carefully.
Rob Langham. Bloody Paralyser: The Giant Handley Page Bombers of the First World War. Fonthill Media, 2016. Speaking of counterfactuals, many an interwar airpower prophet sighed over the fact that the Handley Page V/1500 didn't get their chance to bomb Berlin before the Armistice and really show the world what bombers could do. On the one hand, the Super Handleys wouldn't have done all that much; on the other, the more ordinary Handley Pages that came before them did plenty, as Rob shows here.
M. Romanych and M. Rupp. 42cm 'Big Bertha' and German Siege Artillery of World War I. Oxford and New York: Osprey, 2013. Everything you always wanted to know about 42cm 'Big Bertha' and German siege artillery of World War I but were too afraid to ask.
Michael J. K. Walsh and Andrekos Varnava, eds. Australia and the Great War: Identity, Memory and Mythology. Carlton: Melbourne University Press, 2016. Oh hai!