As a fan of historic aviation (particularly WWI) I surely recognized the same "little" errors which have been explained in another review on this page. But!
After reading this book I searched the net for the Name "Kelso" just to know if this is really a true story. It is. At Link to Max von Halder
I found a picture and some personal details of Max von Halder. Even theres some little so called "research errors" in "Flight of Eagles" ...its a true story with some small writers liberties :-))