Messerschmitt Me.321 Gigant Heavy glider for invasion of Britain & Russia, complete with He111Z Tugplane

In 1940, due to the preparations for the invasion of Britain and Russia, the Luftwaffe's Transport Command realized a need for a larger capacity cargo and troop carrying aircraft. It was decided that the most cost-effective solution was to use giant gliders. Accordingly, the Luftwaffe issued a requirement for rapid development of a very large capacity transport glider to Junkers and Messerschmitt. Two proposals were accepted for construction as the Messerschmitt Me.321 Gigant and the Junkers Ju.322 Mammut. The Me.321 was to be built out of steel tubing framework, with wooden spars and covering of fabric. This allow for quick construction and easy repair. The Me.321 made its maiden flight in February 1941, towed by a Junkers Ju.90. Takeoff of the glider was difficulties, since the Ju.90 was not powerful enough. Heinkel responded by creating the He.111Z Zwilling which combined two He.111 bombers as better tug. The first Me.321 production aircraft entered service in May. In 1943, following the cancellation of the Stalingrad operation, some Me.321 were converted into the Me.323 with six engines