During the preparation for a possible invasion of Britain during World War II (called Operation Sealion), the Oberkommando des Heeres (OKH) required a cargo glider that would carry about 130 equipped soldiers because it was not possible to ship all the important weapons and goods by naval vessels. Cargo gliders were also needed to secure bridgeheads in a short time. The capture of Fort Eben-Emael was, for the German army leaders, the proof that gliders are crucial for these scenarios. Operation Sealion (Unternehmen (Undertaking) Seelöwe in German) was a World War II German plan to invade Britain. ... The Oberkommando der Heeres (OKH) was Germanys Army High Command from 1936 to 1945. ... A bridgehead is literally a military fortification that protects the end of a bridge that is closest to the enemy. ... Eben-Emael was a Belgian fortress in between Liège and Maastricht, near the Albertcanal, defending the Belgian-German border. ...

However, the Me 321 glider was ultimately so heavy that she needed to be towed by three Messerschmitt Me 110 fighters, which was a waste of much-needed combat aircraft. The Messerschmitt Bf110 (later Me110) was a twin-engine heavy fighter in the service of the Luftwaffe during World War II. History Based around the concept of the long-range Zerstörer or Destroyer Fighter the Bf110 enjoyed some success in the Polish and French campaigns. ...

The German web site WaffenHQ.de serves pictures and a lengthy description of the Me 321 glider.

Specifications

Function: Transport Glider
First Flight: March 7, 1941
Service Delivery: June 1941
Gliders are heavier-than-air aircraft primarily intended for un-powered flight. ... March 7 is the 66th day of the year in the Gregorian Calendar (67th in Leap years). ... 1941 was a common year starting on Wednesday (link will take you to calendar). ...

Final Delivery: April 1942

Dimensions:
Wing span: 55 m (180'5")
Length: 28.15 m (92'4")
Height: 10.15 m (33'4")
Weights:
Empty: 12,400 kg (27,300 lb)
Maximum: 34,400 kg (75,800 lb)
Performance:
Maximum Speed: 160 km/h (100 mph) on tow
Initial climb: 2.5 m/s (490 ft/min) (towed with three Me 110 airplanes)
Weapons:
4 MG 15 machine guns The Messerschmitt Bf110 (later Me110) was a twin-engine heavy fighter in the service of the Luftwaffe during World War II. History Based around the concept of the long-range Zerstörer or Destroyer Fighter the Bf110 enjoyed some success in the Polish and French campaigns. ... The MG 15 was a 7. ...

see also

There was also a motorized Version built, the Me 323 "Gigant" with six 895 kW engines. This resulted in the biggest land-based cargo airplane of the Second World War. The Messerschmitt Me 323 Gigant was a German transport aircraft of the Second World War. ... Power kilowatt (symbol: kW) is a unit for measuring power, equal to one thousand watts. ...