The Me-321 'Gigant' WWII Troop Carrying Glider

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On October 12, 1940, Unternehmen Seelöwe, or "Operation Sealion", as the projected invasion of the British Isles was known, was officially postponed by order of the Führer. Priority in objectives had been changed, and Unternehmen Barbarossa, the assault on the Soviet Union, now took precedence over Seelöwe. Adolf Hitler insisted that a final solution in the east must precede the subjugation of Britain, but the latter remained a primary objective, and plans for the mounting of Seelöwe at some indefinite date were still considered of the highest importance.

The Führer believed that the Soviet Union would be crushed in one short campaign, and that the launching of See/Owe might be delayed no more than a year or 18 months, but the outcome of the "Battle of Britain" had rendered obvious the fact that the original plans, based on the assumption that there would be virtually no opposition from the R.A.F. to an invasion, demanded drastic revision.

The conclusion that a means of landing heavy equipment with the first airborne assault had become a prerequisite for any successful invasion of the British Isles had resulted in a highly novel concept, the Grossraumlastensegler glider infinitely larger than any previously envisaged, and capable of accommodating a PzKW IV tank, a self-propelled assault gun complete with crew, fuel and ammunition, or an 88-mm. antiaircraft gun with towing vehicle.

Within less than a week of the postponement of Seelöwe, the Technical Office of the RLM had prepared a broad specification or a Grossraumlastensegler, applied the code-name Unternehmen Warschau (Operation Warsaw) to the program, and had instructed Messerschmitt and Junkers that design studies should be submitted within 14 days-by November 1, 1940-and that the acquisition of materials for an initial quantity of 100 gliders from each manufacturer should commence immediately. Such was the fantastic sense of urgency imparted by the RLM that both manufacturers had to establish special design bureaus solely for the development of their respective gliders, the Messerschmitt bureau under the leadership of Oberingenieur Josef Frohlich being established at Leipheim and dubbed Warschau-Sud, and the Junkers bureau being formed at Merseburg as Warschau-Ost.

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Despite the immensity of the task, both teams submitted detailed design studies on schedule and, on November 6, 1940, were instructed to initiate production immediately, and increase the initial quantity of each glider to 200 machines. At the same time the Messerschmitt and Junkers proposals were assigned the designations Me 263 and Ju 322. Whereas the Junkers team had been instructed to use wood for the construction of its glider, the Messerschmitt team was to employ a welded steel-tube structure. Work on the first airframes began in parallel with the preparation of detail drawings.

The urgency attached to Unternehmen Warschau necessitated both engineering offices and construction shops working literally around the clock, but whereas the Messerschmitt Warschau-Sud program ran surprisingly smoothly, the Junkers Warschau program was beset by difficulties virtually from the outset. Prodigious efforts were made at Leipheim, and while the first airframes were under assembly, the Mannesmann-Werke at Komotau was manufacturing the complete steel-tube fuselage skeletons and the steel-tube wing spars, and the May furniture factory in Stuttgart was producing the wooden wing former ribs, wooden tail assembly components, and secondary wood fuselage fairing structures. In February 1941, almost exactly 14 weeks from the receipt of instructions to proceed with construction, the first example of Messerschmitt's, dubbed Gigant, rolled out of the factory.

 

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Initial Trials:

For initial trials a Ju 90 was allocated to Warschau-SW to serve as the tow plane, and carrying four tons of bricks as ballast, the Me 321 V1 was towed into the air for the first time on February 25, 1941. Although control forces were rather heavy, the general handling characteristics of the Gigant were pronounced surprisingly good, and only minor modifications were called for. However, it was suggested that on long-distance flights some strain would be imposed on the pilot, and that provision for a co-pilot with full dual control was desirable, the decision being taken to introduce this feature with the 101st example of the Gigant.

BIG Towing Problems:

A major problem was provided by the lack of a suitable tow plane. The Ju-90 possessed barely sufficient power to tow the glider off the ground with minimum ballast, and although work had commenced on the Heinkel-Zwilling intended specifically to act as an Me 321 tug, it was obvious that some considerable time must elapse before this unique aircraft could be made available to the Schleppstaffeln. An interim solution was the so-called Troika-Schlepp or triple-tow arrangement of three Bf 110C fighters evolved after a great deal of experimentation. The Troika-Schlepp demanded a very high degree of proficiency, on the part of the tow plane pilots, and in theory the three Bf 110 fighters took off in close-vee formation towing the Gigant by means of 10-mm. steel cables, that of the lead aircraft being 328 ft. in length and those of the port and starboard aircraft being 262 ft. long.

Apart from the ever-present danger of collision during the take-off, the Troika-Schlepp method had the disadvantage of necessitating a concrete runway at least 3,950 ft. in length, and the preliminary preparations for take-off were so complicated that it was utterly impossible to send up several gliders simultaneously. The take-off sequence called for the Gigant to un stick first at around 55 m.p.h., followed by the outboard tow planes and finally the lead tow plane. After leaving the runway the Bf 110s virtually hung on their airscrew's, their pilots having to exercise a high degree of skill to maintain control, and during the climb-out at approximately 80 m.p.h. the strain on the steel cables increased and slackened in a series of violent jerks until the trio of tow planes and their charge leveled-off at operational altitude and speed, the latter being 120-130 m.p.h. In turbulent conditions the Troika-Schlepp was described by tow plane pilots as "hair-raising", and as was to be expected, the test and training programs were fraught with accidents.

Trials with the Troika-Schlepp had been initiated before the completion of the first Gigant, a JU 52/3m standing in for the glider. As a safety precaution the transport was usually towed off the ground with its outboard engines idling, and during one of the earliest tests the "train" had just left the ground when the left-hand Bf-110 tug suddenly broke violently to port. The pilot of the Ju 52/3m immediately pulled the cable-jettisoning lever and gave his idling engines full throttle, but the port cable failed to part company with the transport, and as the pilot of the Ju 52/3m struggled to gain altitude, the trailing cable cut a farm cart in two, demolished farm buildings, uprooted trees, and finally became entangled with a telegraph line. The aircraft was virtually jerked to a standstill in mid air, but the sturdy trimotor remained airborne complete with trailing cable to which was now attached a full-size telegraph pole! Despite this baggage the pilot succeeded in landing the aircraft at Merseburg.

Part of the training program for the Troika-Schlepp included formation take-offs by trios of Bf 110s trailing cables but without gliders in tow. One of the first of these formation takeoffs ended in disaster. At Merseburg when the starboard aircraft veered to port, became entangled with the cable trailed by the center aircraft, and both aircraft crashed. Shortly afterwards, during the first Troika-Schlepp trials in which a Gigant was actually used, the tow planes and their charge had just climbed out of the airfield at Obertraubling, near Regensburg, when the towline snapped.

With remarkable presence of mind, the pilot of the Gigant, Alfred Röhm, ignited his unused take-off rockets, pulled the giant glider around in a steep turn, his port wingtip virtually brushing the ground, streamed his braking chute and effected a perfect landing.

On another occasion at Merseburg, the pilot of a Gigant pulled his cable-release at an altitude of 1,300 ft. and promptly banked to starboard to make his landing approach. Unfortunately for the port tow plane his cable had not disengaged, and the Bf 110 was wrenched violently sideways, its rear fuselage breaking off.

Despite the hazardous triple-tow methods necessitated by the lack of a sufficiently powerful tow plane, the test program of the Gigant itself progressed relatively smoothly, although on one occasion during operational trials with a Gigant carrying 120 troops, the take-off rockets under one wing failed to ignite, the glider veered to starboard, its three Bf 110 tow planes colliding, and the entire "train" crashing to its destruction in a forest near the airfield boundary, 129 lives being lost. Another casualty was Otto Bräutigam whose Gigant crashed when water ballast shifted during the first overload trials.

The Leipheim plant had been joined in the Gigant assembly program by Messerschmitt's Obertraubling factory, and by the late summer of 1941 had completed deliveries of the first 100 Me 321A-1 gliders and had commenced deliveries of the Me 321B-1, the two sub-types differing in that, whereas the initial version had provision for a single pilot only, the later sub-type featured a wider flight deck with accommodation for pilot and co-pilot.

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In December 1940, the RLM had decided to change the designation of the Messerschmitt glider from Me 263 to Me 321, and thus it was as the Me 321 V1 that the first Gigant began its test program at Leipheim. Featuring a rectangular framework of welded steel tubing covered with fabric over a secondary wood fairing structure, the Me 321 had an immense cargo hold measuring 36 ft. 1 in. in length by 10 ft. 4 in. in width by 10 ft. 10 in. in height, and affording a cubic capacity of 3,814 cu. ft. The cargo hold floor was supported by substantial cross girders and stressed to take distributed loads of up to 44,090 lb., or almost twice the empty weight of the aircraft, and a novel form of direct access was provided, the nose of the fuselage being split vertically to form two outward-hinging doors the full height of the cargo hold. Provision was made for the insertion of an auxiliary deck with which, it was estimated, up to 200 troops could be accommodated. The pilot was seated above the main fuselage structure in front of the leading edge of the wing.

The wing itself comprised a single rectangular girder spar built up of four steel-tube members connected by N-braces and wooden former ribs. The leading edges were plywood covered and the remainder was fabric covered, and the entire trailing edge was hinged, the outer portions acting as ailerons and the inner sections as flaps, the movable surfaces being carried by steel-tube outriggers projecting from the main spar. The center section was braced by a single strut on each side and tapered in chord and thickness, and the outer cantilever sections continued the taper but were set at a dihedral angle.

The entire wooden tail unit and the portion of the fuselage to which it was attached was hinged to give a tail incidence change of minus 5 deg. to plus 2.5 deg. Four sprung skids were provided beneath the forward fuselage, and for take-off a dolly was fitted comprising two Ju 90 main wheels with a cross-axle attached to the aft skids, and two Bf 109 main wheels attached by special swiveling supports to the forward skids, the dolly being jettisonable and weighing 3,748 lb.The Me 321A-1 and B-1 were usually fitted with a defensive armament consisting of two 7.9-mm. MG 15 machine guns fired from positions in the upper portions of each nose door, and when troops were carried, this armament could be supplemented by several 7.9-mm. MG 34 infantry machine guns fired from windows in the hold.

During the development program the number of hydrogen-peroxide take-off rockets that could be attached beneath each wing had been progressively increased, and for maximum-load take-offs up to six 1,102 lb., four 1,653 lb., or three 2,205 lb. rockets could be fitted on each side. The crew of the Me 321B-1 was increased from five to six members by the addition of a co-pilot, the other personnel comprising a radio operator, a loading officer and two gunners.

While the Gigant and the Troika-Schlepp may have been a viable proposition for an operation such as Seelöwe for which they were conceived, it was soon to become patently obvious that they were of limited usefulness on the Eastern Front.

Elaborate preparations had to be made for the transfer of the Me 321 Staffeln as the range of the Bf 110 when used in the Troika-Schlepp role was barely 250 miles, and thus airfields along the transfer route that were to be used by the Me 321s had to be provided with special trucks and ground equipment, loading ramps, aircraft anchoring cables, and tank wagons with siphoning apparatus, as well as the special company which, attached to the Gruppe, was responsible for refueling and servicing the temperamental take-off rockets.

Take-off rockets were powered with hydrogen-peroxide with 1,102 lb thrust each! with a burn time of just 30 seconds. They demanded protective clothing for the workers.

Many of these problems would have been overcome had the Heinkel-Zwilling been available, but when the Me 321 was first consigned to the Eastern Front only the first prototypes of this tow plane had flown.

Two photos showing the Me-321 Gigant taking off under RATO assisted power (Rocket Assisted Take Off).. You can almost hear the roar..

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The Leipheim and Obertraubling factories had delivered 186 Gigant gliders by the end of 1941, and the remainder of the original order for 200 Gigant's were completed during the first months of 1942, some additional component manufacture being undertaken to keep the lines occupied pending the outcome of trials with the powered derivative, the Me 323.

Apart from some isolated transport duties in rear areas, the Gigant was to see little further service. Most remaining gliders of this type were transferred to Istres in France during the summer of 1943, and in July the Me 321s were assigned the task of ferrying two paratroop divisions to Sicily. The distance involved proved, in the event, to be too great for the He 1hZ towing a fully-laden Me 321, and as no suitable intermediate landing fields were available the operation had to be cancelled.

Messerschmitt's design bureau, working at Leipheim (code-named "Warschau-Sud"), had been allowed to employ a mixed structure of welded steel tube and wood for the airframe of its glider. The Messerschmitt design team, under Josef Frolich, also took a comparatively conventional approach in the layout of its design. The result, designated the Me-263, was a high-wing monoplane with e span of 180 feet 5 1/2 inches and a length of 92 feet 4 1/4 inches. A novel means of access to the cargo hold for that time was provided through a pair of enormous clamshell doors in the fuselage nose. If only personnel were to be carried, an auxiliary second deck could be inserted inside the 3,814-cubic-foot cargo hold to accommodate an estimated 200 soldiers.

The Me-263 was approved for construction on November 6, 1940. From then on, Messerschmitt personnel worked around the clock to complete the prototype, which was redesignated as the Me-321 in December. When completed in February 1941-after a remarkably short construction period of 14 weeks-the Me-321V-1 was the second largest flying machine built up to that time, after the Soviet Tupolev ANT-2Obis. Its normal payload of 48,944 pounds nearly doubled its empty weight of 26,896 pounds.

During its test program at Leipheim, the glider, now called the Gigant ("giant"), displayed surprisingly good flight characteristics. Its greatest limitation lay in the "Schlepp", or towing system. The Ju-90 was just barely able to lug the monster into the air, even with eight hydrogen peroxide rockets mounted under the Me-321's wing to provide 30 seconds of supplemental thrust during takeoff. One frightening solution involved the "Troika-Schlepp", a trio of Messerschmitt Me-110C twin-engine fighters linked together in a V-formation.

Such formation flying, with the fighters tethered by cables to a gigantic glider along a 3,950-foot concrete runway and subsequently towing it for an extended length of time at up to 132 mph, was aptly described by one of the Troika pilots as "hair-raising." Accidents were inevitable, and on one trial flight an Me-321 with 120 troops aboard veered to the right when the takeoff rockets under its right wing failed to ignite. All four aircraft crashed, killing all 129 passengers and crew members. The Luftwaffe came up with another bizarre solution in the form of the Heinkel He-111Z Zwilling ("twin"), a pair of He-111H twin-engine bombers joined together by a common wing center section incorporating a fifth engine.

Satisfied with the Gigant, the Luftwaffe ordered 100 single-seat Me-321A-ls, which were delivered by late summer of 1941. Messerschmitt also produced the Me-321B-1, which featured a wider cockpit for a co-pilot. By September 1941, the first Sondcrstaffcl (GS), composed of five Me-321s and 15 Me-110s, was operational on the Russian front. Operating from Riga, Staffel (GS) 1 participated in the seizure of the Baltic islands of Muhu, Saaremaa and Hiumaa, but during subsequent operations muddy conditions and the 250-mile range of the Me-110 limited the big gliders' practicality in Russia. By the time the 200th and last Me-321 was completed early in 1942, the gliders were being withdrawn from Russia for use in Operation Hercules-an airborne invasion of Malta, using He-lllZs to tow the Gigants, that never materialized. Subsequent transport glider operations to Stalingrad in January 1943 and to Sicily in July 1943 also had to be canceled.

 

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