"The Unsubstantial Air" by Samuel Hynes is a well researced and written book about the Americans that flew in WW1 told through their correspondence and interviews. Substantial care is taken to provide details of life as a pilot, and the conditions at home and in Europe during WW1. Mr. Hynes is a former Marine Corps WW2 pilot and a Professor at Princetion University. He has written "Flights of Passage," his memoirs as well as other books.

Enjoy.