The Messerschmitt Me 263 "Scholle" (plaice) was a rocket-powered fighter aircraft developed from the Me 163 "Komet" towards the end of World War II. Three prototypes were built but never flown under their own power as the rapidly deteriorating military situation in Germany prevented the completion of the test program. Using only the above description and what you know about the world, "The Messerschmitt Me 263 flew in battle during WWII." is definitely correct, incorrect, or inconclusive? 