Blohm and Voss BV 238

Following the development of the 6 engine BV222 Wiking seaplane and it having attained production status, (if 13 units total could be considered production), work began on the BV-238 which was even larger. It had one of the largest wingspans of the time (197 feet), and weighed the most of any plane up to that time, 220,000 lbs fully loaded. Development was started in 1941, flight trials were finally carried out in 1944. However it was strafed and sunk by Allied planes while docked on a lake near Hamburg, by either American Mustangs or British Typhoons, depending on the story. It was salvaged but later towed out to deep water and sunk. Other prototypes were in progress but were never completed.