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).