All posts by Gunther Arnold

Messerschmitt Me 609 NJ (Nachtjäger, Night fighter), (RS Models)

TYPE: Night- and bad-weather fighter

ACCOMMODATION:  Pilot and radar-operator/navigator

POWER PLANT: Two Daimler-Benz DB 603g liquid-cooled engines, rated at 1,726 hp each

PERFORMANCE: 472 mph at 27.800 ft

COMMENT: As early as 1940, the Messerschmitt design bureau concerned itself with the idea of fusing two fighters into a single airframe to provide a considerable increase in range and payload. The work was based on a RLM edict to simplify the number of combat aircraft to a few basic models.
Known as Messerschmitt Me 109Z Zwilling (twin) and Messerschmitt Me 609, the layouts were primarily intended as Zerstörer (Destroyer), Schnellbomber (Fast bomber or Nachtjäger (Night fighter). Following detailed examinations, the most suitable solution capable of early production indicated the use of a Daimler-Benz DB 605A-powered Messerschmitt Me 109G. A considerable performance increase, however, was to be expected if  2,000 hp Junker Jumo 213 engines were installed, requiring only a few alteration to incorporate complete major components of the standard aircraft. The modifications were limited mainly to the need of a completely new constant –cord wing center section and tailplane that simplified manufacture. Besides relocation of the undercarriage attachment points and the use of larger wheels, the ailerons and outboard leading-edge slots were lengthened and auxiliary fuel tanks were installed. In the course of development work on the twin aircraft, the Messerschmitt Me 309 was also considered and resulted in the Messerschmitt Me 609 destroyer, fast bomber and night fighter. The more powerful engine intended for the Messerschmitt Me 609 led to improvements in flight performance.
For the Night fighter version a FuG 217V/R “Neptun” radar with smal “Hirschgeweih” (Stag’s Antlers) aerial array was provided. These were mounted at the wingtips close to the leading edge. When all work on the unsuccessful Messerschmitt Me 309 was stopped all further effort on the Me 609 was cancelled (Ref.: 24).

Boeing B-29 Superfortress “Enola Gay”, 393rd BS, Heavy, 509th Composite Group with Atomic Bomb “Little Boy”

Boeing B-29 Superfortress “Enola Gay”, 393rd BS, Heavy, 509th Composite Group 

TYPE: High-altitude strategic bomber

ACCOMMODATION: Crew of 12

POWER PLANT: Four Wright R-3350-57 Cyclone turbo-supercharged radials, rated at 2,200 hp each

PERFORMANCE: 339 mph

COMMENT: The Boeing B-29 Superfortress was an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Boeing B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat.

 

Preface of the following three posts

These three posts show pictures of  the most famous aircraft Boeing B-29 Superfortress (Model number B-29-45-MO, Serial number 44-86292, Victor number # 12, (squadron-assigned identification))  – later known as Enola Gay – that dropped the first atomic bomb Little Boy on Hiroshima on 6th August 1945.

Post I shows the B-29 when it arrived from Wendover Army Air Field, Utah, to North Field, Tinian, Marianas on June 1945. The aircraft was flown by aircraft commander Captain Robert A. Lewis and his crew B-9. At that time the tail marking was that of the 393rd BS, Heavy, 509th Composite Group, a circle outline (denoting the 313th Wing) around an arrowhead pointing forward. The aircrafts Victor number was # 12 and the ship lacked of any nose art.

Post II shows the same aircraft at the beginning of August 1945. The aircrafts tail markings were repainted with the tail markings of the 6th Bombardment Group (Circle R), XXI Bomber Command groups as a security measure. It was feared that Japanese survivors on Tinian were reporting the 509th’s activities to Tokyo by clandestine radio. The Victor (identification assigned by the squadron) numbers previously assigned the 393d aircraft were changed number # 82 to avoid confusion with B-29s of the groups from whom the tail identifiers were borrowed.
Although all of the B-29s involved in the Hiroshima- and Nagasaki-Mission were named, the only nose art applied to the aircraft before the atomic bomb missions was that of Enola Gay. With some exceptions, the others were applied some time in August 1945

Post III shows the Enola Gay after the Hiroshima strike. The circle R tail marking of the 6th Bombardment Group, 313th Bomb Wing tail marking was changed back to that of the 509th Composite Group, circle outline around an arrowhead pointing forward. The Victor # 82 and nose art at port side „Enola Gay“ remained unchanged, additional nose art at starboard side was „First Atomic Bomb Hiroshima – August 6/1945“

Boeing B-29 Superfortress “Enola Gay”, 393rd BS, Heavy, 509th Composite Group. Before the Hiroshima strike (Post # I)

COMMENT: The aircraft B-29 Superfortress (Model number B-29-45-MO, Serial number 44-86292, Victor number # 12, (squadron-assigned identification))  – later known as Enola Gay – was built by the Glenn L. Martin Company at its bomber plant in Bellevue, Nebraska. The bomber was one of the first fifteen B-29s built to the “Silverplate” specification— of 65 eventually completed during and after World War II—giving them the primary ability to function as nuclear “weapon delivery” aircraft. These modifications included an extensively modified bomb bay with pneumatic doors and British bomb attachment and release systems, reversible pitch propellers that gave more braking power on landing, improved engines with fuel injection and better cooling, and the removal of protective armor and gun turrets.
The aircraft was personally selected by Colonel Paul W. Tibbets Jr., the commander of the 509th Composite Group, on 9 May 1945, while still on the assembly line. The aircraft was accepted by the United States Army Air Force (USAAF) on 18 May 1945 and assigned to the 393rd Bombardment Squadron, Heavy, 509th Composite Group. The tail marking was a circle outline around an arrowhead pointing forward. The Crew B-9, commanded by Captain Robert A. Lewis, took delivery of the bomber and flew it from Omaha to the 509th base at Wendover Army Air Field, Utah, on 14 June 1945.
Thirteen days later, the aircraft left Wendover for Guam, where it received a bomb-bay modification, and flew to North Field, Tinian, on 6 July. It was initially given the Victor number # 12, but on 1 August, the tail marking of the 509th Composite Group, circle outline around an arrowhead pointing forward, was changed in circle R tail marking of the 6th Bombardment Group, 313th Bomb Wing, as a security measure and had its Victor number changed to # 82 to avoid misidentification with actual 6th Bombardment Group aircraft.
During July, the bomber made eight practice or training flights and flew two missions, on 24 and 26 July, to drop pumpkin bombs on industrial targets at Kobe and Nagoya. Enola Gay was used on 31 July on a rehearsal flight for the actual mission (Ref. 24).

Boeing B-29 Superfortress “Enola Gay”, 393rd BS, Heavy, 509th Composite Group, Strike on Hiroshima (Post # II)

Comment: On 5 August 1945, the Strike Order 35 was given to deliver the first atomic bomb Little Boy the next day on 6 August. This order not only gives the detailed  time scale of the pre-flight preparations but also the Victor (identifications) number s of all aicraft involved in the attack as well as the names of the aircraft‘s commanding officers. The combat strike consisted of four aircraft with one alternative plane and four weather mission aircraft including one alternative aircraft . Weather Ships had to start at 0200 ET, while the Combat Ships followed one hour later. Victor # 82 was the Enola Gay with Col. Tibbets at the controlls.

Strike Order # 35 from 5 August 1945

ATOMIC BOMB „LITTLE BOY“

Atomic bomb “Little Boy”

Little Boy was 300 cm in length, 71 cm in diameter and weighed approximately 4,400 kg. The design used the gun method to explosively force a hollow sub-critical mass of enriched uranium and a solid target cylinder together into a super-critical mass, initiating a nuclear chain reaction. This was accomplished by shooting one piece of the uranium onto the other by means of four cylindrical silk bags of cordite powder.
The bomb contained 64 kilograms of enriched uranium. Most was enriched to 89% but some was only 50% uranium-235, for an average enrichment of 80%. Less than a kilogram of uranium underwent nuclear fission, and of this mass only 0.7 grams was transformed into several forms of energy, mostly kinetic energy, but also heat and radiation. The bomb had an explosive force of about 20,000 tons of TNT, about the same as the Fat Man bomb dropped on Nagasaki .
The Little Boy pre-assemblies were designated L-1, L-2, L-3, L-4, L-5, L-6, L-7 and L-11. L-1, L-2, L-5 and L-6 were expended in test drops. L-6 was used in the Iwo Jima dress rehearsal on 29 July. This was repeated on 31 July, but this time L-6 was test dropped near Tinian by Enola Gay. Finally, L-11 was the assembly used for the Hiroshima bomb.

STRIKE ON HIROSHIMA, DATE: AUGUST, 6th, 1945

During preparation for the first atomic mission, Tibbets assumed command of the aircraft and named it after his mother, Enola Gay Tibbets, who, in turn, had been named for the heroine of a novel. In the early morning hours, just prior to the 6 August mission, Tibbets had a young Army Air Forces maintenance man, Private Nelson Miller, paint the name just under the pilot’s window. Except for Enola Gay, none of the 509th Composite Group B-29s had yet had names painted on the noses. All other names were given after the mission.
Hiroshima was the primary target of the first nuclear bombing mission on 6 August, with Kokura and Nagasaki as alternative targets. Enola Gay, piloted by Tibbets, took off from North Field, in the Northern Mariana Islands, about six hours’ flight time from Japan, accompanied by two other B-29s, The Great Artiste, piloted by Major Charles W. Sweeney carrying instrumentation, and a then-nameless aircraft later called Necessary Evil, commanded by Captain George Marquardt, to take photographs
After leaving Tinian, the three aircraft made their way separately to Iwo Jima, where they rendezvoused at 8,010 ft and set course for Japan. The aircraft arrived over the target in clear visibility at 32,333 ft. Navy Captain William S. Parsons of Project Alberta, who was in command of the mission, armed the bomb during the flight to minimize the risks during takeoff. His assistant, Second Lieutenant Morris R. Jeppson, removed the safety devices 30 minutes before reaching the target area.
The release at 08:15 (Hiroshima time) went as planned, and the Little Boy took 53 seconds to fall from the aircraft flying at 31,060 feet to the predetermined detonation height about 1,968 feet above the city. Enola Gay traveled 11.5 mi before it felt the shock waves from the blast. Although buffeted by the shock, neither Enola Gay nor The Great Artiste was damaged.
Enola Gay returned safely to its base on Tinian to great fanfare, touching down at 2:58 pm, after 12 hours 13 minutes. The Great Artiste and Necessary Evil followed at short intervals. Several hundred people, including journalists and photographers, had gathered to watch the planes return. Tibbets was the first to disembark and was presented with the Distinguished Service Cross on the spot (Ref.: 24).

Boeing B-29 Superfortress “Enola Gay”, 393rd BS, Heavy, 509th Composite Group, After the Hiroshima mission (Post # III)

Comment: After the Hiroshima Mission the Enola Gay‘s circle R tail marking of the 6th Bombardment Group, 313th Bomb Wing tail marking was changed to that of the 509th Composite Group, circle outline around an arrowhead pointing forward. The Victor # 82 remained unchanged, Additional First Atomic Bomb Hiroshima – August 6/1945 was painted on starboard side of Enola Gay.
After the war, the Enola Gay returned to the United States, where it was operated from Roswell Army Air Field, New Mexico. In May 1946, it was flown to Kwajalein, Marshall Islands, for the Operation Crossroads nuclear tests in the Pacific, but was not chosen to make the test drop at Bikini Atoll.
Since 2003, the entire restored Boeing B-29 Enola Gay has been on display at National Air and Space Museums’s Steven Udvar-Hazy Center, Chantilly, Fairfax County, Virginia.

 

Plans for more atomic attacks on Japan

Major General Leslie R. Groves expected to have another Fat Man atomic bomb ready for use on 19 August, with three more in September and a further three in October; a second Little Boy bomb (using U-235) would not be available until December 1945. On 10 August, he sent a memorandum  to General of the Army Georg C. Marshall in which he wrote that “the next bomb … should be ready for delivery on the first suitable weather after 17 or 18 August.” Marshall endorsed the memo with the hand-written comment, “It is not to be released over Japan without express authority from the President”, something President Harry S. Truman had requested that day. This modified the previous order that the target cities were to be attacked with atomic bombs “as made ready”. There was already discussion in the War Department about conserving the bombs then in production for Operation Downfall (proposed Allied plan for the invasion of the Japanese home islands near the end of World War II), and Marshall suggested to Secretary of War Henry L. Stimson that the remaining cities on the target list be spared attack with atomic bombs.
Two more Fat Man assemblies were readied, and scheduled to leave Kirtland Field, New Mexico, for Tinian on 11 and 14 August, and Tibbets was ordered by Major General Curtis LeMay to return to Albuquerque, New Mexico, to collect them. At Los Alamos, New Mexico, technicians worked 24 hours straight to cast another plutonium core.  Although cast, it still needed to be pressed and coated, which would take until 16 August. Therefore, it could have been ready for use on 19 August. Unable to reach Marshall, Groves ordered on his own authority on 13 August that the core should not be shipped.
On Marshall’s orders, Major General John E. Hull looked into the tactical use of nuclear weapons for the invasion of the Japanese home islands, even after the dropping of two strategic atomic bombs on Japan (Marshall did not think that the Japanese would capitulate immediately). Colonel Lyle E. Seeman reported that at least seven Fat Man-type plutonium implosion bombs would be available by X-Day, which could be dropped on defending forces. Seeman advised that American troops not enter an area hit by a bomb for “at least 48 hours”; the risk of nuclear fallout was not well understood, and such a short time after detonation would have exposed American troops to substantial radiation.
Ken Nicols, the District Engineer of the Manhattan Engineer District, wrote that at the beginning of August 1945, “planning for the invasion of the main Japanese home islands had reached its final stages, and if the landings actually took place, we might supply about fifteen atomic bombs to support the troops.” An air burst 1,800–2,000 ft  above the ground had been chosen for the (Hiroshima) bomb to achieve maximum blast effects, and to minimize residual radiation on the ground, as it was hoped that American troops would soon occupy the city (Ref.: 24).

Messerschmitt Me 509 (RS Models)

TYPE: Fighter, Fighter bomber, Project

ACCOMMODATION: Pilot only

POWER PLANT: One Daimler-Benz DB 605B liquid-cooled engine, rated at 1,455 hp

PERFORMANCE: 470 mph (estimated)

COMMENT:  Although the Me 509 can trace its roots back to the Messerschmitt Me 309, very little information has survived. The aircraft was to be of an all-metal construction. A new fuselage was designed, with the pressurized cockpit being moved well forward near the nose.  The Daimler Benz 605B 12-cylinder engine was buried in the fuselage behind the cockpit, and drove a three-bladed, Me P 6 reversible-pitch propeller by an extension shaft which passed beneath the cockpit (similar to the US Bell P-39 Airacobra).  The wing was tapered and had rounded wingtips, and was mounted low on the fuselage.  Other Me 309 components were to be used, such as the tricycle landing gear, and the vertical tail assembly was similar to the one used for the Me 309 V1.  Armament was not decided upon for the 509, but it is thought that two MG 131 13mm machine guns and two MG 151 20mm cannon were to be used. Although there were advantages of better cockpit visibility and relocation of the engine weight from the nose gear. That was important, since the Me 309’s nose gear often collapsed. The Messerschmitt Me 509 design and development was stopped when the Me 309 program was ended in mid-1943.
In April 1945, the Japanese completed a very similar project, the Yokosuka R2Y Keiun. Although no firm evidence exists, it is possible that the Messerschmitt Me 309/509 information was licensed to the Japanese military, as were a number of other German designs (Messerschmitt Bf 109, Heinkel He 100, Messerschmitt Me 163, Messerschmitt Me 410, among others). (Ref.: 17).

Boeing B-29A Superfortress “Rattle N’ Roll”, 6th Bomber Group, 313th Bomb Wing, XXth USAAF, (Academy Models)

TYPE: High-altitude strategic bomber

ACCOMMODATION: Crew of 11

POWER PLANT: Four Wright R-3350-23 Duplex-Cyclone air-cooled turbocharged radial piston engines, 2,200 hp each

PERFORMANCE:  357 mp

COMMENT: The Boeing B-29 Superfortress was an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Boeing B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat.
One of the largest aircraft of World War II, the B-29 was designed with state-of-the-art technology, which included a pressurized cabin, dual-wheeled tricycle landing gear, and an analog computer-controlled fire-control system that allowed one gunner and a fire-control officer to direct four remote machine gun turrets. The $3 billion cost of design and production, far exceeding the $1.9 billion cost of the Manhattan Project (development oft he atomic bomb), made the B-29 program the most expensive of the war. The B-29 remained in service in various roles throughout the 1950s, being retired in the early 1960s after 3,970 had been built.
Before World War II, the United States Army Air Force (USAAF) concluded that the Boeing B-17 Flying Fortress, which would be the Americans’ primary strategic bomber during the war, would be inadequate for the Pacific Theater, which required a bomber that could carry a larger payload more than 3,000 miles
In response, Boeing began work on pressurized long-range bombers in 1938. Boeing’s design study for the Model 334 was a pressurized derivative of the Boeing B-17 Flying Fortress with nosewheel undercarriage. Although the Air Corps lacked funds to pursue the design, Boeing continued development with its own funds as a private venture. In April 1939, Charles Lindberg convinced General Henry H. Arnold to produce a new bomber in large numbers to counter the Germans’ bomber production. In December 1939, the Air Corps issued a formal specification for a so-called “superbomber” that could deliver 20,000 lb of bombs to a target 2,667 mi away, and at a speed of 400 mph. Boeing’s previous private venture studies formed the starting point for its response to the Air Corps formal specification.
Boeing submitted its Model 345 on May 1940, in competition with designs from Consolidated Aircraft Model 33, which later became the Convair B-32 Dominator, Lockheed XB-30 and Douglas XB-31 Raidmaster. Douglas and Lockheed soon abandoned work on their projects, but Boeing received an order for two flying prototypes, which were given the designation XB-29, and an airframe for static testing on August 1940, with the order being revised to add a third flying aircraft on December. Consolidated continued to work on its Model 33, as it was seen by the Air Corps as a backup if there were problems with Boeing’s design. Boeing received an initial production order for 14 service test aircraft and 250 production bombers in May 1941, this being increased to 500 aircraft in January 1942. The B-29 featured a fuselage design with circular cross-section for strength. The need for pressurization in the cockpit area also led to the B-29 being one of very few American combat aircraft of World War II to have a stepless cockpit design, without a separate windscreen for the pilots.
Manufacturing the B-29 was a complex task that involved four main-assembly factories. Thousands of subcontractors were also involved in the project. The first prototype made its maiden flight on September 1942. The combined effects of the aircraft’s highly advanced design, challenging requirements, immense pressure for production, and hurried development caused setbacks. Unlike the unarmed first prototype, the second was fitted with a Sperry defensive armament system using remote-controlled gun turrets sighted by periscopes and first flew on December 1942, although the flight was terminated due to a serious engine fire.
On February 1943, the second prototype experienced an engine fire and crashed. Changes to the production craft came so often and so fast that, in early 1944, B-29s flew from the production lines directly to modification depots for extensive rebuilds to incorporate the latest changes. USAAF-contracted modification centers and its own air depot system struggled to handle the scope of the requirements. By the end of 1943, although almost 100 aircraft had been delivered, only 15 were airworthy. This prompted an intervention by General Hap Arnold to resolve the problem, with production personnel being sent from the factories to the modification centers to speed availability of sufficient aircraft to equip the first bomb groups in what became known as the “Battle of Kansas”. This resulted in 150 aircraft being modified in the five weeks, between March and April 1944.
The most common cause of maintenance headaches and catastrophic failures was the engines. Although the Wright R-3350 Duplex Cyclone radials later became a trustworthy workhorse in large piston-engined aircraft, early models were beset with dangerous reliability problems.
In wartime, the B-29 was capable of flight at altitudes up to 31,850 feet at speeds of up to 350 mph (true air speed)). This was its best defense because Japanese fighters could barely reach that altitude, and few could catch the B-29 even if they did attain that altitude.
The General Electric Central Fire Control system on the B-29 directed four remotely controlled turrets armed with two .50 Browning M2 machine guns each. All weapons were aimed optically, with targeting computed by analog electrical instrumentation. There were five interconnected sighting stations located in the nose and tail positions and three Plexiglas blisters in the central fuselage. Five General Electric analog computers (one dedicated to each sight) increased the weapons’ accuracy by compensating for factors such as airspeed, lead, gravity, temperature and humidity. The computers also allowed a single gunner to operate two or more turrets (including tail guns) simultaneously. The gunner in the upper position acted as fire control officer, managing the distribution of turrets among the other gunners during combat. The tail position initially had two .50 Browning machine guns and a single M2 20 mm cannon. Later aircraft had the 20 mm cannon removed, sometimes replaced by a third machine gun.
The crew would enjoy, for the first time in a bomber, full-pressurization comfort. This first-ever cabin pressure system for an Allied production bomber was developed for the B-29 by Garrett AiResearck and  a long tunnel joining the forward and rear crew compartments. Crews could use the tunnel if necessary to crawl from one pressurized compartment to the other.
In early 1945, Major General Curtiss LeMay, commander of XXI Bomber Command—the Marianas-based B-29-equipped bombing force—ordered most of the defensive armament and remote-controlled sighting equipment removed from the B-29s under his command. The affected aircraft had the same reduced defensive firepower as the nuclear weapons-delivery intended Silverplate B-29 airframes and could carry greater fuel and bomb loads as a result of the change. The lighter defensive armament was made possible by a change in mission from high-altitude, daylight bombing with high explosive bombs to low-altitude night raids using incendiary bombs. As a consequence of that requirement, Bell Atlanta (BA) produced a series of 311 B-29Bs that had turrets and sighting equipment omitted, except for the tail position, which was fitted with AN/APG-15 fire-control radar. That version could also have an improved APQ-7 “Eagle” bombing-through-overcast radar fitted in an airfoil-shaped radome under the fuselage. Most of those aircraft were assigned to the 315th Bomb Wing, Northwest Field, Guam.
In September 1941, the USAAF’ plans for war against Germany and Japan proposed basing the B-29 in Egypt for operations against Germany, as British airbases were likely to be overcrowded.  By the end of 1943, plans had changed, partly due to production delays, and the B-29 was dedicated to the Pacific Theater. A new plan implemented deployed the B-29 units to attack Japan from four forward bases in southern Cina, with five main bases in India, and to attack other targets in the region from China and India as needed. The XX Bomber Command, initially intended to be two combat wings of four groups each, was reduced to a single wing of four groups because of the lack of availability of aircraft, automatically limiting the effectiveness of any attacks from China.
This was an extremely costly scheme, as there was no overland connection available between India and China, and all supplies had to be flown over the Himalayas, either by transport aircraft or by B-29s themselves, with some aircraft being stripped of armor and guns and used to deliver fuel.
The solution to this problem was to capture the Mariana Islands, which would bring targets such as Tokyo, about 1,500 mi north of the Marianas within range of B-29 attacks. The Joint Chiefs of Staff agreed in December 1943 to seize the Marianas.
US forces invaded Saipan  on 15 June 1944 what was secured by 9 July. Operations followed against Guam and Tinian, with all three islands secured by August.
Naval construction battalions (Seabees) began at once to construct air bases suitable for the B-29, commencing even before the end of ground fighting. In all, five major airfields were built: two on the flat island of Tinian, one on Saipan, and two on Guam. Each was large enough to eventually accommodate a bomb wing consisting of four bomb groups, giving a total of 180 B-29s per airfield. These bases could be supplied by ship and, unlike the bases in China, were not vulnerable to attack by Japanese ground forces. The bases became the launch sites for the large B-29 raids against Japan in the final year of the warand  the first combat mission was launched from there on 28 October 1944, with 14 B-29s, the first attack on the Japanese capital since the Doolittle Raid in April 1942.
Boeing B-29A Superfortress “Rattle N’ Roll” showed here belonged to the 6th Bomber Group, 313th Bomb Wing, XXth USAAF, stationed at North Field, Tinian, Marianas
The most famous B-29s were the Silverplate series. These aircraft were extensively modified to carry nuclear weapons. Serious consideration was given to using the British Lancaster bomber, as this would require less modification. The most significant modification was the enlargement of the bomb bay enabling each aircraft to carry either the  “Little Boy”, an enriched uranium gun-type fission  weapon or “Fat Man”, a plutonium implosion-type nuclear weapon.
Little Boy was dropped on Hiroshima on 6 August 1945 by B-29 Enola Gay, flown by Colonel Paul W. Tibbets Jr and the Fat Man was dropped on Nagasaki on 9 August 1945 by B-29 Bockscar, flown by Mayor Charles W. Sweeney.
Japan surrendered to the Allies on 15 August, six days after the bombing of Nagasaki and effectively ended World War II (Ref.: 24).

DFS 230B-1 (Huma Models)

TYPE: Transport glider

ACCOMMODATION: Pilot plus 9 equipped troops 600 lb cargo

POWER PLANT: None

PERFORMANCE: Maximum towing speed 130 mph

COMMENT: The DFS 230 was a German transport glider operated by the Luftwaffe in World War II. It was developed in 1933 by the Deutsche Forschungsanstalt für Segelflug (DFS – “German Research Institute for Sailplane Flight”). The glider was the German inspiration for the British Hotspur glider and was intended for airborne assault operations.
The structural design oft he DFS 230 was thoroughly conventional. The wing comprised a single mainspar at approximately one-third cord with plywood covering forward and fabric aft, the long-span ailerons with inset tabs were fabric covered, and a central keel member or boom intended to absorb the impact transmitted to it from the sprung steel skid. Provision was made for either a single or dual control, and, in addition to the pilot, accommodation was provided  for nine men who were seated on the central boom, six facing forward, and four backward. Entry and exit to the cramped interior was by a single side door. The front passenger could operate its only armament, a 7,9 mm MG 15  machine gun on flexible mounting in upper decking of forward fuselage . A large loading door was  provided at the rear of the cabin in the fuselage portside, and the loading of bulky items of freight was facilitated  by a detachable beneath the wing at the starboard side of the fuselage. Up to 1,200 kg of freight could be loaded or 660 lb of freight in addition to the full complement of 10 men .
For take-off a two-wheel dolly was provided, this being jettisoned once the glider was airborne, it landed by means of a landing skid. The DFS 230s usually employed the Seilschlepp or cable-tow, being attached to a 131 ft cable, but for night and bad weather missions the Starrschlepp (ridgid-tow) arrangement was used. By means of a cable running along the tow rope the pilots of the tow-plane and of the freight glider were able to communicate with each other which made blind flying possible, when necessary. The towing speed of the DFS-230 was approximately 116 mph. It dropped its landing gear as soon as it was safely in the air, and landed by means of a landing skid. The DFS-230 could be towed by a Junkers Ju 52 (which could tow two with difficulty), Heinkel He 111, Junkers Ju 87, Henschel Hs 126, Messerschmitt Me 110, or a Messerschmitt Me 109.
The DFS-230 had the highest glide ratio (8:1) of any World War II military glider other than the Soviet Antonov A-7. This was because it was thought that the glider had to be capable of a long approach during landing, so that it could be released a greater distance from the target so the sound of the towing aircraft did not alert the enemy.
It had been realized that glider operations were hazardous once the enemy’s ground defences had been alert, the DFS 230 providing an excellent target for small arms fire during its low, shallow landing approach. The DFS 230B was therefore fitted with an external parachute pack beneath the rear fuselage this chute being intended  for deployment in the event of a rapid, diving descent necessary to avoid ground fire.
Late production version was the DFS 230C-1 with nose braking rockets for pin-point landing. A single DFS 230 was converted to an auto-gyro by replacing the wings with the 3-bladed rotor from a Focke-Achgelis Fa 223 helicopter, mounted on a pylon above the fuselage. The undercarriage was revised to include long oleo shock absorbers with a wide track for stability. Towed behind a Junkers Ju52/3M during trials, it was found that the low towing speed and low approach speed made the combination more vulnerable to attack.
The DFS 230 played significant roles in the operations at Fort Eben-Emael, the Battle of Crete, and in the rescue of Italian Dictator Benito Mussolini. It was also used in North Africa. However, it was used chiefly in supplying encircled forces on the Eastern Front. Although production ceased in 1943, it was used right up to the end of the war, for instance, supplying Berlin and Breslau until May 1945.
In total more than 1.600 aircraft had been built (Ref.: 24).

Messerschmitt Me 323D-1 „Gigant“, 5./ TG 5, (Italeri Models)

TYPE: Military transport aircraft

ACCOMMODATION: Crew of five plus 130 troops or 10,000–12,000 kg payload

POWER PLANT: Six Gnome-Rhone 14N radial engines, rated at 1,164 hp; each

PERFORMANCE: 177 mph

COMMENT: The Messerschmitt Me 323 „Gigant“ (“Giant”) was a German military transport aircraft of World War II. It was a powered variant of the Messerschmitt Me 321 military glider and was the largest land-based transport aircraft to fly during the war. In total, 213 were made, with 15 being converted from the Me 321
The Me 323 was the result of a 1940 German requirement for a large assault glider in preparation for Operation Seelöwe (Operation Sea Lion), the projected invasion of Great Britain. The DFS 230 light glider developed by Deutsches Forschungsinstitut für Segelflug, (German Research Institute for Sailplanes)  had already proven its worth in the Battle of Fort Eben-Emael in Belgium, the first ever assault by gliderborne troops, and would later be used successfully in the invasion of Crete in 1941.
However, in order to mount an invasion across the English Channel, the Germans would need to be able to airlift vehicles and other heavy equipment as part of an initial assault wave. Although Operation Sea Lion was cancelled, the requirement for a heavy air transport capability still existed, with the focus shifting to the forthcoming Operation Barbarossa, the invasion of the Soviet Union.
On 18 October 1940, Junkers and Messerschmitt were given just 14 days to submit a proposal for a large transport glider. The emphasis was still very much on the assault role; the ambitious requirement was to be able to carry either an 88 mm gun and its half-track tractor, or a Panzer IV medium tank. The Junkers Ju 322 Mammut (Mammouth) reached prototype form, but was eventually scrapped due to difficulties in procuring the necessary high-grade timber for its all-wood construction, and as was discovered during the Mammuts only test flight, an unacceptably high degree of instability inherent in the design. The proposed Messerschmitt aircraft was originally designated Me 261w—partly borrowing the designation of the long-range Messerschmitt Me 261, then changed to Messerschmitt Me 263 later reused for Messerschmitt’s improved rocket fighter design, and eventually became the Me 321. Although the Me 321 saw considerable service on the Eastern Front as a transport, it was never used for its intended role as an assault glider.
Early in 1941, as a result of feedback from Transport Command pilots in Russia, the decision was taken to produce a motorized variant of the Me 321, to be designated Me 323. French Gnome-Rhone GR14N radial engines, rated at 1,164 hp, for take-off as used in the Bloch MB 175 aircraft were chosen for use. This would reduce the burden on Germany’s strained industry.
Initial tests were conducted with four Gnome engines attached to a strengthened Me 321 wing, giving modest speed of 130 mph – 50 mph slower than the Junkers Ju 52 transport aircraft. A fixed undercarriage was fitted, with four small wheels in a bogie at the front of the aircraft and six larger wheels in two lines of three at each side of the fuselage, partly covered by an aerodynamic fairing. The rear wheels were fitted with pneumatic brakes that could stop the aircraft within 660 ft.
The four-engined Me 323C was considered a stepping-stone to the six-engined D series. It still required the five-engined Heinkel He 111Z Zwilling (Twin) or the highly dangerous „vic-style“ Troika-Schlepp formation of three Messerschmitt Me 110 heavy fighters and underwing-mounted Walter HWK 109-500 Starthilfe rocket-assist take-off units to get airborne when fully loaded, but it could return to base under its own power when empty. This was little better than the Me 321, so the V2 prototype became the first to have six engines and flew for the first time in early 1942, becoming the prototype for the D-series aircraft.
To reduce torque, the aircraft was fitted with three counterclockwise rotation engines on the port wing and three clockwise rotation engines on the starboard wing, as seen looking forward from behind each engine – resulting in the propellers rotating “away” from each other at the tops of their arcs.
Like the Me 321, the Me 323 had massive, semicantilever, high-mounted wings, which were braced from the fuselage out to the middle of the wing. To reduce weight and save aluminium, much of the wing was made of plywood and fabric, while the fuselage was of metal-tube construction with wooden spars and covered with doped fabric, with heavy bracing in the floor to support the payload.
The “D” series had a crew of five – two pilots, two flöight engineers, and a radio operator. Two gunners could also be carried. The flight engineers occupied two small cabins, one in each wing between the inboard and centre engines. The engineers were intended to monitor engine synchronisation and allow the pilot to fly without worrying about engine status, although the pilot could override the engineers’ decisions on engine and propeller control.
Maximum payload was around 12 tonnes, although at that weight, the Walter HWK 109-500 Starthilfe rocket-assisted take-off units used on the Me 321 were required for take-off. These were mounted beneath the wings outboard of the engines, with the wings having underside fittings to take up to four units. The cargo hold was 36 ft long, 10 f) wide and 11 ft high. Typical loads were one 15 cm sFH 18 heavy field howitzer (5.5 ton) accompanied by its Sd kfz 7 half-track artillery tractor vehicle (11 ton), two 4 ton trucks, 8,700 loaves of bread, an 88 mm Flak gun and accessories, 52 drums of fuel (45 US gal), 130 men, or 60 stretchers.
Some Me 321s were converted to Me 323s, but most were built as six-engined aircraft from the beginning. Early models were fitted with wooden, two-blade propellers, while later versions had metal, three-blade, variable-pitch versions.
The Me 323 had a maximum speed of only 136 mph at sea level. It was armed with five 13 mm MG 131 machine guns firing from a dorsal position behind the wings and from the fuselage. They were manned by the extra gunners, radio operator, and engineers.
By September 1942, Me 323s were being delivered for use in the Tunisian campaign. They entered service in the Mediterranean theatre in November 1942. High losses among Axis shipping required a huge airlift of equipment across the Mediterranean to keep Rommel’s Afrika Korps supplied.
A total of 198 Me 323s were built before production ceased in April 1944. Several production versions were built, beginning with the Me 323D-1. Later D- and E- versions differed in the choice of power plant and in defensive armament, with improvements in structural strength, total cargo load, and fuel capacity also being implemented. Nonetheless, the Me 323 remained underpowered. A proposal to install six BMW 801 radials did not occur. The Me 323 was also a short-range aircraft, with a typical range (loaded) of 620–750 mi. Despite this, the limited numbers of Me 323s in service were an asset to the Germans, and saw extensive use .
The aircraft shown here belonged to 5./ TG 5 (5th Gruppe/ Transportgeschwader 5, 5th Sqn,/Transport Group 5) (Ref.: 24).

Messerschmitt Me 321B-1 „Gigant“, (Giant), Italeri Models

TYPE: Cargo glider

ACCOMMODATION: Crew of three plus 200 equipped troops or 20,000 kg of cargo / military equipment

POWER PLANT: None

PERFORMANCE: Maximum tow speed 110 mph

COMMENT: The Messerschmitt Me 321 Gigant was a large German cargo glider developed and used during World War II. Intended to support large-scale invasions, the Me 321 had very limited use due to the low availability of suitable tug aircraft, high vulnerability whilst in flight, and its difficult ground handling, both at base and at destination landing sites. The Me 321 was developed, in stages, into the six-engined Messerschmitt Me 323 Gigant, which removed some of the problems with ground handling, but vulnerability to ground fire and aerial attack remained a constant problem during operations of all variants.
During the preparations for a possible invasion of Britain during World War II (Operation Seelöwe, Operation Sea Lion) the Luftwaffe’s Transport Command saw an obvious need existed for a larger-capacity cargo- and troop-carrying aircraft than its mainstay, the Junkers Ju 52.
When the plans for Operation Sea Lion were shelved in December 1940, and planning began for the invasion of the USSR (Operation Barbarossa), the most cost-effective solution to the need for transport aircraft was found to be to use gliders. Accordingly, the Technical Bureau of the Luftwaffe issued a tender for rapid development of a Grossraumlastensegler (“large-capacity transport glider”) to the aircraft manufacturers Junkers and Messerschmitt. The specification called for the glider to be capable of carrying either an 88 mm gun plus its tractor, or a medium tank. The codename Projekt Warschau (Project Warsaw) was used, with Junkers being given the codename Warschau-Ost and Messerschmitt Warschau-Süd.
The Junkers design, the Ju 322 Mammut was unsuccessful, though, due to the company opting to use all-wood construction. Messerschmitt’s design for this transport glider consequently secured the contract for the company. Initially given the RLM designation Me 263, this designation number was later reused for the second-generation rocket fighter developed in 1945, the Messerschmitt Me 263. That number was “freed-up” when the number for this aircraft was switched to Me 321.
The Me 263 had a framework of steel tubing provided by the Mannesmann company, with wooden spars and a covering of doped fabric. This allowed for quick construction and easy repair when needed and also saved weight. The Me 263 was redesignated the Me 321 and was nicknamed Gigant (Giant) due to its huge size.
Its nose stood over 6 m high, and was made up of two clamshell doors, which could only be opened from the inside, when ramps would be used to allow vehicles to drive in or out. Compared to the Ju 52, the Me 321 offered a load area six times larger, around 100 m2, and could accommodate a gross cargo weighing up to 23 tons. The cargo space had been designed to replicate the load space of a standard German railway flatcar, allowing any cargo that could travel by rail to fit into an Me 321. Alternatively, if used as a passenger transport, 120-130 fully equipped troops could be accommodated.
The Me 321 was fitted with a jettisonable undercarriage comprising two Messerschmitt Me 109 mainwheels at the front and two Junkers Ju 90 main wheels at the rear and was intended to land on four extendable skids.
The first flight of theprototype Me 321 V1 took place on February 1941, towed into the air by a Ju 90. It carried 3 tons of ballast. Test pilot Baur reported that the controls were heavy and responses sluggish. They decided to enlarge the cockpit to accommodate a co-pilot and radio operator, and dual controls were fitted. Electric serve motors were also fitted to assist in moving the huge trailing edge flaps and further tests caused a braking parachute to also be added.
The test flights were plagued by take-off difficulties, since the Junkers Ju 90 was not powerful enough, and as an interim measure three Messerschmitt Me 110 heavy fighters were used, in a so-called Troikaschlepp, with the trio of twin-engined fighters taking off together in a V-formation. This was a highly dangerous manoeuvre and Ernst Udet asked Ernst Heinkel to come up with a better aerial towing method. Heinkel responded by creating the Heinkel He 111Z Zwilling (Twins), which combined two He 111 aircraft through the use of a new “center” wing section with a fifth engine added. Underwing-mount, liquid monopropellant Walter HWK 109-500 Starthilfe (rocket-assistet take-off) booster units were also used to assist take-off from rough fields.
The first Me 321 A-1 production aircraft entered service in May 1941, initially towed by Ju 90s and later by the He 111Z and the Troikaschlepp arrangement of three Me 110s. The triple Zerstörer arrangement was very dangerous in the event that one or more of the take-off booster rockets failed. One such failure did occur in 1941, which led to the collision of the tow planes and the deaths of all 129 occupants of the four aircraft. The later Me 321 B-1 variant had a crew of three and was armed with four 7.92 mm MG 15 machine guns.
The Me 321 was less than successful on the Eastern Front for various reasons. As a glider, the Me 321 lacked the ability to make a second or third approach to a crowded landing strip, moving on the ground was impossible without specialized vehicles, and before the introduction of the He 111 Zwilling, the dangerous Troikaschlepp arrangement gave a one-way range of only 400 km which was insufficient for a safe operating zone.
In early 1942, the remaining Me 321s were withdrawn from service in Russia in anticipation of the planned Operation Herkules, the invasion of Malta, in which a fleet of the gliders hauled by He 111Zs was to be used. The plan was abandoned due to a lack of towing aircraft.
In 1943, Me 321s returned to Russia for use in a projected operation to relieve the besieged Stalingrad, but by the time they reached the front line, no suitable airfields remained and they were sent back to Germany.
Following the cancellation of the Stalingrad operation, the Me 321 gliders were mothballes, scrapped, or converted into the powered variant, the Messerschmitt Me 323 Gigant with six 1,200 hp engines, the largest land-based cargo aircraft of World War II. A further proposed operation – in which the remaining Me 321s would have landed troops on Sicily – was also abandoned, due to a lack of suitable landing sites. Ultimately, 200 Me 321s were produced (Ref.: 24).