While most think of fighter jets as primarily a post-war development, there was one British-built fighter jet that did enter service and saw combat operations during the Second World War. The Gloster Meteor holds the unique distinction of being the only Allied fighter jet to operate during World War II, and its development began during the heat of the conflict in 1940. The aircraft was powered by pioneering turbofan engines which were designed by Frank Whittle and Power Jets Ltd. The Meteor first took to the skies in 1943, and it became operational on July 27th, 1944 with the Royal Air Force (RAF) Squadron No. 616.