As early as October 1940 aircraft designer Willy Messerschmitt proposed to Ernst Udet, Chief of Air Armaments, that the Luftwaffe should procure "tank-carrying gliders". The first technical proposal for such a plane was produced in November of the same year and was eventually designated the Me 321 Gigant (Giant). It was the largest operational glider built in World War II, and was designed to carry heavy tanks and anti-tank weapons as part of an airborne invasion of England. Nevertheless, it had a lot of problem because of heavy weight. No single aircraft was capable of towing a fully loaded Me 321. Different aircraft were designed to solve the towing problem.

At almost the same time a further proposal was made for a powered version of the Gigant, soon designated the Me 323. It was a six-engine super-transport developed from the Me 321, the Me 323, proved to be highly vulnerable due to its slow speed as Allied fighters shot down fourteen 323s during a Tunisian supply operation in 1943. The Messerschmitt Me 323 Gigant was a German military transport aircraft of World War II and was the largest land-based transport aircraft of the war. A total of 213 are recorded as having been made, with the transport plane's first flight in 1942, before it was retired in 1944. A few being converted from the Me 321. They saw action between 1942 and 1944.

Messerschmitt Me 323 [Via Maginot1918]

Messerschmitt Me 323 [Via silodrome.com]

Messerschmitt Me 323 [Via fandavions.free.fr]

A German Messerschmitt Me 323 Gigant (Giant) in Bulgaria [Via WWII Pictures]

The giant Me 323 transport aircraft was being used to bring in supplies, even though it was very vulnerable in a combat zone [Via Phil DeFer]

A Messerschmitt Me 323 in flight (may be landing or taking off), Germany, 1941 [Via B/W: Wikimedia - Color: Jared Enos]

View into the cockpit of the Me 323, 1944 [Via Wikipedia]

Gigant wing, showing wing gun positions and counter-rotating propellers on each wing panel, 21 March 1944 [Via Wikipedia]

Although capable of carrying little more than half the payload of the glider version, the Me 323 gave the Luftwaffe the ability to move tremendous amounts of cargo rapidly and efficiently by air over long distances. It could reach speeds of around 210km/h (130mph), though variants like the D-6 could reach up to 285km/h (177mph). Freight was loaded through the double doors that form the curved nose of the airplane; this was accomplished by a jacking system which enabled the nose to be lowered to a convenient height. 

Messerschmitt Me 323 [Via fandavions.free.fr]

The Messerschmitt could carry up to 25,000lbs (12 tonnes), or 120 fully-equipped men, or an alternative load of small tanks or motor vehicles, when the upper deck is detached. Regularly carried tanks and weaponry to the battlefield. The typical loads it carried were: One 15 cm FH18 field artillery piece (5.5 ton) accompanied by its Sd.Kfz.7 halftrack transport vehicle (11 ton), two 3.6 tonne (4 ton) trucks, 8,700 loaves of bread, an 88 mm Flak gunand accessories, 52 drums of fuel (252 L/45 US gal), 120 men, or 60 stretchers.

Messerschmitt Me 323 [Via fandavions.free.fr]

75-mm anti-tank gun PaK 40, prior to loading into the German transport aircraft Messerschmitt Me 323 [Via Krueger Horst]

German soldiers loading 88-mm anti-aircraft gun into a Messerschmitt Me.323 Giant on the Eastern Front [Via Krueger Horst]

Unloading of German heavy transport aircraft Messerschmitt Me 323 Giant in Italy 1943 [Via Ronnie, Ronnie]

The Me 323 transporting wounded personnel in Grosseto - Italy, 1 March 1943 [Via Wikipedia]

The Me 323 unloading a Renault UE in Tunisia, 1 January 1943 [Via Wikipedia]

Messerschmitt Me 323: Unloading heavy artillery from the plane [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323 [Via www.sandglasspatrol.com]

Messerschmitt Me 323 [Via victormolina1990]

For defensive armament, it was armed with five 13 mm (.51 in) MG 131 machine guns firing from a dorsal position behind the wings through apertures in the sides of the fuselage. A plywood frame was provided for each aperture. They were manned by the extra gunners, radio operator and engineers.

Messerschmitt Me-323 in colour [Via Stewart Callan]

A Messerschmitt Me 323D "Gigant" in flight [Via Wikipedia]

A wrecked German Messerschmitt Me 323D-2 transport at Castlevetrano, Sicily, Italy [Via Wikimedia]

The Illustrated London News overview of the Me 323, drawn by G H Davis, published in 1943. Allied fighter pilots would have been fully aware of where the fuel tanks were located within the wooden frame [Via ww2today.com]

The profile of the Me323 as produced for the Illustrated London News in 1943 [Via ww2today.com]

Messerschmitt Me 323 [Via victormolina1990]

Messerschmitt Me 323 [Via aviadejavu.ru]

Me 323 SG+RD WNr.1230 of I./KGrzbV 323, spring 1943 [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Belly landed in Russia [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Next to JU-52 which was no small plane itself! [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Technicians on duty [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Aiding Axis Allies in Italy [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Soldiers sleeping in the ample shade of its wings [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323: Looks like an Antonov from this angle. Look at the Number of landing gears! [Via falkeeins.blogspot.com.es]

Messerschmitt Me 323 [Via vilingstore.net]

Messerschmitt Me 323 [Via wwiivehicles.com]

Me-323 being shot down by a B-26 Marauder of the Northwest African Coastal Air Force near Cap Corse, Corsica, 1 September 1943 [Via Wikipedia]

The wreckage of a Messerschmitt Me 323 Gigant transport aircraft on the El Aouina airfield in Tunisia [Via www.lonesentry.com]

Used on several fronts, the Me 323 Gigant proved vulnerable to attack from fighters and even medium bombers, and several massacres occurred with whole fleets of the lumbering transports shot down with heavy loss of life. April 22, 1943 was a black day for the TG 5's. Four days previously the Luftwaffe had lost 24 Ju 52's over the Mediterranean, and 35 other "Aunties" were so severely damaged that they broke up after emergency landings. Then the last sixteen aircraft of No. 5 Transport Squadron took off from Trapani for Tunis, with crews totaling 140 men. The "Giants" were carrying fuel for Rommel's Africa Corps.

The North African coast came into view. The planes were due to fly over Cape Bon, and it was there that British fighters attacked the formation. The more maneuverable "Spitfires" and "Marauders" massacred the Germans, and only two "Giants" escaped. The fourteen remaining aircraft either crashed in coastal waters or were destroyed after emergency landings. Two days later, the fifteenth "Giant" was destroyed on the Tunis airport during an air raid. Only nineteen out of 140 pilots, radio operators, air gunners and flight mechanics were rescued; the others were killed or drowned. In one fateful month a great idea which had been turned into reality was irrevocably destroyed.

A single Me 323 returned to its base at Trapani, filled with wounded from Rommel's Africa Corps.