The Legend Begins by Roy Grinnell

The first combat, Dec. 20, 1941 of the A.V.G. over the skies southeast of Kunming, China. A formation of Japanese Kwasakid Ki-48 Lilys was intercepted by P-40Bs of the 1st and 2nd squadrons of the A.V.G. Through overcast sky they dove, guns blazing, three bombers were officially credited, their first combat and not a pilot was lost.