An American Saga: Juan Trippe and His Pan Am Empire, by Robert Daley (1980)(**)
This is one of very few books that any serious student of Pan Am simply cannot do without. With an unparalleled knack for uncovering the human drama behind the history, Daley is a master storyteller as well as serious journalist. Now available in Kindle format.
https://www.amazon.com/An-American-Saga-Trippe-Empire-ebook/dp/B0048ELMX8/