Nazi Germany (1940)
Prototype Wooden Glider – 2 Built
The Ju 322 “Mammut” was a prototype wooden glider developed by Junkers in 1940 in anticipation of the Invasion of Britain. The design was riddled with flaws and eventually scrapped in 1941 after two prototype models were made. Instead, the RLM decided to use the Me 321 as their main heavy glider. No part of the Ju 322 is known to have survived to the present day.
History of the Mammut
Operation Sealion (Invasion of Britain) was to commence in the fall of 1940, and the Germans lacked a means of transporting supplies and troops effectively. In that same year, the Reichsluftfahrtministerium, the German Ministry of Aviation or RLM, issued a demand to Messerschmitt and Junkers to design and develop a glider capable of carrying a very heavy payload. The conditions were that the glider was to be able to carry some of the heaviest equipment in service with the Wehrmacht. Messerschmitt developed the Me 321 as a result, and Junkers with the Ju 322.
The Ju 322 “Mammut” (Mammoth) was designed as a fully wooden heavy transport glider which was originally designed to carry at least 44,000lbs (19,900kg). This weight was around enough for a Panzer III/IV, FlaK 88, or a StuG III/IV or a full load of 100 troops and all necessary support equipment. The Ju 322 was designed so that cargo was to be loaded into the plane from the nose, which could be folded. The cockpit had a single position, and was located on the outside of the cargo hold on the left wing. The glider would be on a carriage which would be dropped right after take off or while airborne. The designers noted that the carriage was extremely heavy, and could not be dropped from a high altitude without it breaking. They also noted that if the carriage were to be dropped from a lower altitude, there was the risk of it bouncing back up and hitting the glider. Many different kinds of gears were experimented on, using from as little as 8 wheels to 32 wheels. As for landing, the glider was fitted with four sprung landing skids. The production variants were suppose to be fitted with three turrets armed with MG 15s. Two turrets would be located on either side of the nose, near the front of the wings and the other turret would be located near the back of the cargo compartment. The Ju 322V1 and V2 were not armed.
After two prototype models were produced, stationary tests began. It was found that the Ju 322V1 had troubles with the materials it was built with. An observation made by engineers were that the wooden structure of the glider were weakened by rot. It was agreed that this was to be blamed on poor manufacturing techniques.
When a Panzer III was loaded onto the plane, the floor broke and the Panzer III fell straight through it. This incident was partly to be blamed on the ramp design and poor wood quality. Due to this flaw, the original design was not able to be met and the maximum cargo weight was reduced twice. The first reduction was to 35,280lbs (16,000kg), the second reduction was to 24,255lbs (11,000kg). The reduced weight of cargo and reinforced floor solved the problem of loading tanks and equipment on, but at the expense of payload. As a result of this along with other changes, the designers had to reduce the plane’s maximum cargo weight to 24,255lbs (11,000kg).
A common misconception is that there was a competition between Messerschmitt and Junkers to develop the best glider and dominate the glider market. However, it was not a competition at all and each company were given specific guidelines. Messerschmitt was allowed to use steel while Junkers was only allowed to use wood. This was because the RLM was anticipating a shortage of steel, in which case the RLM could fall back on the Junkers design. It is also worth noting that the Ju 322V1 used eight tons of steel to strengthen the airframe, despite the RLM’s orders.
As the Ju 322 was in prototype stage, only two models were ordered and constructed. The only two models are known as Ju 322V1 and Ju 322V2. V1 was the only model to see testing, while V2 stood by in case V1 was destroyed. During testing of the V1, construction began on 98 airframes, although none were completed.
The Ju 322V1 made its first and only flight in April of 1941 at Merseburg Airfield. According to the reports, the Ju 90* towplane failed to lift the glider off the ground on full throttle. In a subsequent attempt, the glider was able to get off the ground. However shortly after takeoff, the tow plane pilot noticed two immediate flaws. First, the glider could not maneuver or change direction and it had no pilot during the test. Second, the glider had extremely poor vertical stability such that its wings would sway in small arcs which swung the tow plane dangerously. Because of this, the glider was immediately cut from the tow plane after take off. The glider ended up landing in a field not far from the airfield. It took over two weeks for the glider to be transported back to the airfield by towing. This was the Mammut’s only test flight, and it was deemed a failure.
* – It is interesting to note that the Ju 90 which towed the Ju 332 on it’s maiden flight was one of the two Ju 90s meant to be sent to South Africa before the war, and were therefore fitted with Pratt and Whitney Twin Wasp engines which had 900hp each.
Financially exhausted and convinced that the Ju 322 will not be successful, Junkers finally terminated the projected in May 1941. As a result, the two Ju 332s were cut up and used as firewood, along with all the uncompleted airframes and spare parts still in factories.
|Ju 332 “Mammut” Specifications|
|Wingspan:||204 ft 6 ¾ in / 62.3 m|
|Weight (Empty):||64,400lbs / 29,211kg|
|Weight (Loaded):||99,690lbs / 45,219kg|
|Length:||26.3m / 86ft 3.5in|
|Wing Area:||6,865 ft² / 634 m²|
3x Gunners (Intended)
|Armament:||3x MG 15 7.92mm (Intended)|
- Charter – Assistant Writer
- Mizutayio – German Translator
Mrazek, J. (2011). Airborne combat : The glider war/Fighting gliders of World War II. Mechanicsburg, PA: Stackpole Books., Hartmann, B. (n.d.). Junkers Ju 322 ‘Mammut’. LuftArchiv.de – Das Archiv der Deutschen Luftwaffe., Stemp, P. (2014). KITES, BIRDS & STUFF – AIRCRAFT OF GERMANY. S.l: LULU COM., Images: Side Profile Views by Ed Jackson – Artbyedo.com