In 13 short years, killer drones have gone from being exotic military technology featured primarily in the pages of specialized aviation magazines to a phenomenon of popular culture, splashed across daily newspapers and fictionalized in film and television, including the new season of “24.” What has not changed all that much — at least superficially — is the basic aircraft that most people associate with drone warfare: the armed Predator. The Predator, with its distinctive bubble near the nose and sensor ball underneath, is the iconic image of drone warfare, an aircraft that grew out of 1980s work supported by...