This caption card identifies 'Curtiss XP-40, V-1710-21 Allison,' referring to the prototype aircraft that led to the famous P-40 Warhawk fighter series. Originally a converted P-36 Hawk airframe fitted with a liquid-cooled Allison inline engine, the XP-40 first flew in 1938 and paved the way for one of the most widely produced American fighters of World War II. Project: 218191