5 Of The Best American Planes Used In World War II A large portion of World War II was fought in the air, and, as such, there was incredibly rapid development of aviation technology. The Allies and Axis Powers were not only battling each other on the beaches, landing grounds, fields, streets, but were also trying to out-engineer each other when it came to the best aircraft. The Nazi's Third Reich may have developed the first jet engine and made the world's fastest aircraft at the time with the Me 262, but it was too little, too late and fortunately...