Blohm & Voss BV 238
During World War II, the Blohm and Voss BV 238 was a German flying boat. When it first flew in 1944, it was the heaviest aircraft ever built. The BV 238 had an empty weight of 120,769 pounds, but only one was ever built due to the resources required to construct it. It was also the largest aircraft produced by any Axis power during the war.
Antonov AN-225 Mriya
The longest and heaviest plane ever built six turbofan engines power this strategic airlift cargo aircraft. It was originally developed to transport the Buran spaceplane for the USSR in the 80s. It has the longest wingspan of any aircraft built at the time and any current operational aircraft globally and can take off with a maximum weight of 640 tons.