This is a bit of a cheat for this thread as this book is primarily about the pioneering years of civil aviation, but Fate is the Hunter by Ernest K Gann is a fantastic read. To qualify for inclusion in this thread, though, the author flew right through WW2 as a civilian pilot attached to US Military Airlift Command, mainly on C47s and C87s (the transport version of the Liberator). Some great tales, I especially like the bit when he narrowly avoids redesigning the Taj Mahal with a severely overloaded C87 by dropping full flap at the last second and scraping over the top.