Daily Archives: August 6, 2024

6 August 1969

One of the two Mil Design Bureau Mi-12 heavy lift helicopter prototypes, 1971. (Groningen Airport-Eelde)

6 August 1969: The largest helicopter ever built, the four-engine, transverse-tandem rotor Mil Design Bureau Mi-12, registration CCCP-21142, lifted a payload of 40,204.5 kilograms (88,635.7 pounds) to an altitude 2,255 meters (7,398 feet), setting three Fédération Aéronautique Internationale (FAI) world records for payload to altitude. These records have never been broken by any other helicopter.

The helicopter was flown by Vasily Kolochenko, with L.V. Vlassov, V.V. Juravlev, V.P. Bartchenkov, S.G. Ribalko, and A.I. Krutchkov.

FAI Record File Num #9916 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 35 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9917 [Direct Link]
Status: ratified – current record
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1 (Helicopters)
Category: General
Group: 2 : turbine
Type of record: Altitude with 40 000 kg payload
Performance: 2 255 m
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV, V.P. BARTCHENKOV, S.G. RIBALKO, A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

FAI Record File Num #9937 [Direct Link]
Status: ratified – superseded since approved
Region: World
Class: E (Rotorcraft)
Sub-Class: E-1e (Helicopters: take off weight 3000 to 4500 kg)
Category: General
Group: 2 : turbine
Type of record: Greatest mass carried to height of 2 000 m
Performance: 40 204.5 kg
Date: 1969-08-06
Course/Location: Podmoskovnoe (USSR)
Claimant Vasily Kolochenko (URS)
Crew L.V. VLASSOV, V.V. JURAVLEV,V.P. BARTCHENKO,S.G. RIBALKO,A.I. KRUTCHKOV
Rotorcraft: MIL M-12 (V-12)
Engines: 4 Soloviev D-25 VF

This is the first of two Mil-12 prototypes built by the Mil Design Bureau. (Both had the same registration number: 21142.) They were intended to transport intercontinental ballistic missiles and load them directly into underground silos where there were no existing roads. The aircraft was operated by a six-man crew.

The Mi-12 has a length of 37.00 meters (121 feet, 4.69 inches) and rotor span of 67 meters (219 feet, 9.79 inches). Its height is 12.50 meters (41 feet, 0.13 inches). The helicopter has an empty weight of 69,100 kilograms (152,339 pounds) and maximum takeoff weight of 105,000 kilograms (231,485 pounds).

The Mi-12 uses two main rotor, transmission and twin engine systems from the single rotor Mil Mi-6 helicopter. Each rotor had a diameter of 35.00 meters (114 feet, 9.95 inches). The total disc area is 1,924 square meters (20,710 square feet). The left rotor turns counter-clockwise, as seen from above. The right rotor turns clockwise. (The advancing blades of both rotors are inboard.) With counter-rotating main rotors, the torque created by each rotor system is cancelled out, eliminating the need for a tail, or anti-torque, rotor. This makes the total power produced available for lift.

Three-view illustration of Mil Mi-12. (Aviastar)

The Mil Mi-12 is powered by four Soloviev Design Bureau D-25VF turboshaft engines. The D-25VF has a nine-stage axial-flow compressor section and a three-stage turbine. Each engine is 2.737 meters (8 feet, 11.76 inches) long, 0.508 meters (1 foot, 8.00 inches) in diameter, and weighs 1,200 kilograms (2,646 pounds). In the Mi-12, two engines are coupled to a single gear box, and mounted at the ends of the wings. The D-25VF has a maximum power rating of 4,847 kilowatts (6,500 shaft horsepower). The four engines, combined, produce 19,388 kilowatts (26,000 horsepower).

The helicopter’s internal cargo bay is 4.40 meters (14 feet, 5.23 inches) wide, 4.40 meters (14 feet, 5.23 inches) high, and 28.15 meters (92 feet, 4.27 inches) long. It can carry 40,000 kilograms (88,185 pounds) of cargo internally, or 5,500 kilograms (12,125 pounds) as a sling load.

The Mi-12 has a maximum range of 500 kilometers (311 statute miles) with a 35,400 kilogram (78,044 pounds) payload. The maximum speed is 260 kilometers per hour (162 statute miles per hour/140 knots) and the service ceiling is 3,500 meters (11,483 feet).

The Mi-12 was not put into series production. The record-setting first prototype is at the Mikhail Leontyevich Mil helicopter factory at Panki-Tomilino, near Moscow.

World Record Mil Mi-12 at Tomolino.
World Record holding Mil Mi-12 at Tomolino. (Yuriy Lapitskyi)

© 2023, Bryan R. Swopes

6 August 1955

Looking out across the right wing of the Boeing 367–80, inverted, at the city of Seattle, 6 August 1955. (Bill Whitehead/Boeing)

6 August 1955: Boeing’s Chief of Flight Test, Alvin M. “Tex” Johnston, barrel-rolled the Model 367-80, prototype of the KC-135 Stratotanker and 707, over Lake Washington.

Twice.

This photograph was taken by the flight test engineer, Bill Whitehead.

Boeing had risked $16,000,000 in a private venture to build the Dash 80 in order to demonstrate its capabilities to potential civilian and military customers, while rivals Douglas and Lockheed were marketing their own un-built jet airliners. Put into production as the U.S. Air Force KC-135 Stratotanker air refueling tanker and C-135 Stratolifter transport, a civil variant was also produced as the Boeing 707, the first successful jet airliner. Though they look very similar, the 707 is structurally different than the KC-135 and has a wider fuselage.

Boeing Model 367-80 (“Dash Eighty”) in flight. (Joe Parke/Wikipedia)

The prototype Boeing Model 367-80 was operated by a pilot, co-pilot and flight engineer. The airplane’s wing was mounted low on the fuselage and the engine nacelles were mounted on pylons under the wing, as they were on Boeing’s B-47 Stratojet and B-52 Stratofortress. The wings and tail surfaces were swept to 35°. The Dash 80 was 127 feet 10 inches (38.964 meters) long with a wingspan of 129 feet, 8 inches (39.522 meters) and overall height of 38 feet (11.582 meters). Its empty weight was 92,100 pounds (41,775.9 kilograms) and loaded weight was 190,000 pounds (86,182.6 kilograms).

In tanker configuration, the Boeing 367-80 refuels a Boeing B-52 Stratofortress. The chase plane is a Lockheed T-33A Shooting Star. (U.S. Air Force)

N70700 was powered by four Pratt & Whitney Turbo Wasp JT3C engines. This engine is a civil variant of the military J57 series. It is a two-spool, axial-flow turbojet engine with a 16-stage compressor and 2-stage turbine. The JT3C-6 (used in the first production 707s) was rated at 11,200 pounds of thrust (49.82 kilonewtons), and 13,500 pounds (60.05 kilonewtons) with water/methanol injection). The JT3C is 11 feet, 6.6 inches (3.520 meters) long, 3 feet, 2.9 inches (0.988 meters) in diameter, and weighs 4,235 pounds (1,921 kilograms).

These gave the 367-80 a cruise speed of 550 miles per hour (885 kilometers per hour) and a maximum speed of 0.84 Mach (582 miles per hour, 937 kilometers per hour) at 25,000 feet (7,620 meters). The service ceiling was 43,000 feet (13,106 meters). Its range was 3,530 miles (5,681 kilometers).

The Boeing 707 has a wider fuselage and is structurally different than teh KC-135. (Boeing)

Boeing continued to use the 367–80 for testing, finally retiring it 22 January 1970. At that time, its logbook showed 2,346 hours, 46 minutes of flight time (TTAF). It was flown to Davis-Monthan Air Force Base, Tucson, Arizona, and placed in storage. In 1990, Boeing returned it to flyable condition and flew it back it to Renton where a total restoration was completed. Many of those who had worked on the Dash 80, including Tex Johnston, were aboard.

The pioneering airplane was presented to the Smithsonian Institution and is on display at the National Air and Space Museum, Steven V. Udvar-Hazy Center. The Boeing 367-80 was designated an International Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers.

820 of the C-135 series and 1,010 Model 707 aircraft were built from 1957–1979.

(The Boeing Model 367-80 is on display at the Steven F. Udvar-Hazy center, Smithsonian Institution National Air and Space Museum. (Photo by Dane Penland, National Air and Space Museum, Smithsonian Institution)

© 2024, Bryan R. Swopes

6 August 1945

Major Richard Ira Bong, United States Army Air Forces. (U.S. Air Force)

6 August 1945: After serving three combat tours flying the Lockheed P-38 Lightning in the Southwest Pacific, Major Richard Ira Bong, Air Corps, United States Army, was assigned as an Air Force acceptance test pilot for new Lockheed P-80 Shooting Star jet fighters at the Lockheed Air Terminal, Burbank, California.

The P-80A was a brand new jet fighter, and Major Bong had flown just 4 hours, 15 minutes in the type during 12 flights.

Shortly after takeoff in P-80A-1-LO 44-85048, the primary fuel pump for the turbojet engine failed. A back-up fuel pump was not turned on. The Shooting Star rolled upside down and Bong bailed out, but he was too low for his parachute to open and he was killed. The jet crashed at the intersection of Oxnard Street and Satsuma Avenue, North Hollywood, California, and exploded.

Site of the crash of Major Richard I. Bong’s Lockheed P-80A-1-LO fighter, 44-85048, at Oxnard Street and Satsuma Avenue, North Hollywood, California. (Contemporary news photograph)
This graphic appeared in the Los Angles Times, 7 August 1945, at Page 3. (Los Angeles Times)
General Douglas MacArthur with Major Richard I. Bong.
General Douglas MacArthur with Major Richard I. Bong.

Richard I. Bong was known as the “Ace of Aces” for scoring 40 aerial victories over Japanese airplanes between 27 December 1942 and 17 December 1944 while flying the Lockheed P-38 Lightning. He was awarded the Medal of Honor, which was presented by General Douglas MacArthur, 12 December 1944. [The following day, General MacArthur was promoted to General of the Army.]

The citation for Major Bong’s Medal of Honor reads: “For conspicuous gallantry and intrepidity in action above and beyond the call of duty in the Southwest Pacific area from 10 October to 15 November 1944. Though assigned to duty as gunnery instructor and neither required nor expected to perform combat duty, Major Bong voluntarily and at his own urgent request engaged in repeated combat missions, including unusually hazardous sorties over Balikpapan, Borneo, and in the Leyte area of the Philippines. His aggressiveness and daring resulted in his shooting down eight enemy airplanes during this period.”

General of the Army Henry H. (“Hap”) Arnold and Major Richard I. Bong, circa 1945.

The Lockheed P-80-1-LO was the United States’ first operational jet fighter. It was a single-seat, single-engine low-wing monoplane powered by a turbojet engine. The fighter was designed by a team of engineers led by Clarence L. (“Kelly”) Johnson. The prototype XP-80A, 44-83020, nicknamed Lulu-Belle, was first flown by test pilot Tony LeVier at Muroc Army Air Field (now known as Edwards Air Force Base), 8 January 1944.

Lockheed P-80A-1-LO shooting Star 44-85004, similar to the fighter being test flown by Richard I. Bong, 6 August 1945. (U.S. Air Force)

The P-80A was a day fighter, and was not equipped for night or all-weather combat operations. The P-80A was 34 feet, 6 inches (10.516 meters) long with a wingspan of 38 feet, 10.5037 inches (11.84919 meters) ¹ and overall height of 11 feet, 4 inches (3.454 meters).

The leading edges of the P-80A’s wings were swept aft 9° 18′ 33″. They had an angle of incidence of +1° at the root and -0° 30′ at the tip. There was 3° 50′ dihedral. The total wing area was 237.70 square feet (22.083 square meters).

The fighter had an empty weight of 7,920 pounds (3,592 kilograms) and a gross weight of 11,700 pounds (5,307 kilograms). The maximum takeoff weight was 14,000 pounds (6,350 kilograms).

Lockheed P-80 Shooting Star production, alongside P-38 Lightnings. (SDASM)

Early production P-80As were powered by either an Allison J33-A-9 or a General Electric J33-GE-11 turbojet engine. The J33 was a licensed version of the Rolls-Royce Derwent. It was a single-shaft turbojet with a 1-stage centrifugal compressor section and a 1-stage axial-flow turbine. The -9 and -11 engines were rated at 3,825 pounds of thrust (17.014 kilonewtons). The J33s were 8 feet, 6.9 inches (2.614 meters) long, 4 feet, 2.5 inches (1.283 meters) in diameter and weighed 1,775 pounds (805 kilograms).

The P-80A had a cruising speed of 445 miles per hour (716 kilometers per hour) at 20,000 feet (6,096 meters). Its maximum speed was 548 miles per hour (882 kilometers per hour) at 2,700 feet (823 meters) and and 501 miles per hour (806 kilometers per hour) at 34,700 feet (10,577 meters).² The service ceiling was 45,000 feet (13,716 meters).

Lockheed P-80A-1-LO Shooting Star 44-85155, similar to the jet fighter which Major Bong was flying, 6 August 1945. (U.S. Air Force)

The P-80A Shooting Star was armed with six air-cooled Browning AN-M2 .50-caliber aircraft machine guns mounted in the nose.

Dick Bong poses with “Marge,” his Lockheed P-38J Lightning. A large photograph of his fiancee, Miss Marjorie Vattendahl, is glued to the fighter’s nose.

¹ Wing span with rounded wing tips. P-80As with squared (“clipped”) tips had a wing span of 37 feet, 7.5037 inches (11.46819 meters).

² Several hundred of the early production P-80 Shooting stars had all of their surface seams filled, and the airplanes were primed and painted. Although this process added 60 pounds (27.2 kilograms) to the empty weight, the decrease in drag allowed a 10 mile per hour (16 kilometers per hour) increase in top speed. The painted surface was difficult to maintain in the field and the process was discontinued.

© 2018, Bryan R. Swopes

6 August 1945 (5 August 1945 UTC)

Silverplate Martin-Omaha B-29-45-MO Superfortress 44-86292, “Dimples 82,” at Tinian, Mariana Islands, August 1945. Note the “Circle Arrow” tail code. (U.S. Air Force)

6 August 1945: At 0245 hours local time (1445 hours, 5 August, UTC), a four-engine, long range heavy bomber of the 509th Composite Group, United States Army Air Forces, took off from North Field on the island of Tinian in the Northern Mariana Islands, on the most secret combat mission of World War II.¹

Colonel Paul Warfield Tibbets, Jr., United States Army Air Forces, Commanding Officer, 509th Composite group, and aircraft commander of the B-29 Superfortress, Enola Gay. (U.S. Air Force)
Colonel Paul Warfield Tibbets, Jr., United States Army Air Corps, Commanding Officer, 509th Composite Group, and aircraft commander of the B-29 Superfortress, Enola Gay. (U.S. Air Force)

The Martin-Omaha B-29-45-MO Superfortress, 44-86292, under the command of Colonel Paul Warfield Tibbets, Jr.,² was carrying Bomb Unit L-11, the first nuclear weapon to be used during war. This was an 8,900-pound (4,037 kilogram) “gun type” fission bomb, the Mark I, code-named Little Boy. It contained 64.15 kilograms (141.42 pounds) of highly-enriched uranium. The bomb was 10 feet, 6 inches (3.2004 meters) long with a diameter of 2 feet, 4 inches (0.711 meters). The gun tube had a bore diameter of 165 millimeters (6.496 inches) and a length of 6 feet (1.8 meters). It weighed approximately 1,000 pounds (454 kilograms).

Diagram of “Little Boy” gun-type uranium fission bomb. (Wikipedia)

The gun fired a hollow uranium projectile, consisting of a stack of nine rings of varying thickness contained within a sheet metal can, and with a 4 inch (10.16 centimeters) inside diameter, against a cylindrical uranium target insert. The projectile was 7 inches (17.78 centimeters) long. The target insert consisted of a stack of six uranium rings with a 1 inch (2.54 centimeter) inside diameter, held in place by a steel rod through the center. It was also 7 inches long, and had an outside diameter of 4 inches. The projectile weighed 38.53 kilograms (84.94 pounds) and the target, 25.6 kilograms (56.44 pounds). When the projectile came in contact with the target, the two completed a “critical mass.” A fission chain reaction resulted, releasing an incredible amount of energy.

Although it was considered to be a very inefficient weapon, it had such a reliable design that it had never been tested. Six Mark I bombs were built, but L-11 was the only one ever to be detonated.

Code named "Little Boy," the Mark I bomb unit L-11, prior to loading aboard Enola Gay, 5 August 1945. (U.S. Air Force)
Code named “Little Boy,” the Mark I bomb unit L-11, prior to loading aboard Enola Gay, 5 August 1945. (U.S. Air Force)

On the morning before the mission, Colonel Tibbets had his mother’s name painted on the nose of the airplane: Enola Gay. He had personally selected this bomber, serial number 44-86292, while he was visiting the Glenn L. Martin Company plant at Bellevue, Nebraska, 9 May 1945. An employee of the plant told him that the airplane had passed its acceptance tests with no faults of any kind. The B-29 was accepted by the Army Air Corps on 15 May and flown to the 509th’s base at Wendover, Utah, by Captain Robert Alvin Lewis, a B-29 aircraft commander who would act as Tibbets’ co-pilot on the atomic bombing mission.

509th Composite Group operations order. (U.S. Air Force)

The B-29 Superfortress was designed by the Boeing Airplane Company as its Model 345. Produced in three versions, the B-29, B-29A and B-29B, it was built by Boeing at Renton, Washington, and Wichita, Kansas; by the Bell Aircraft Corporation at Marietta, Georgia; and the Glenn L. Martin Company at Fort Crook (now Offutt Air Force Base), Omaha, Nebraska. A total of 3,943 Superfortresses were built.

The B-29 was the most technologically advanced airplane built up to that time, and required an immense effort by American industry to produce.

The B-29 Superfortress was 99 feet, 0 inches (30.175 meters) long with a wingspan of 141 feet, 3 inches (43.053 meters) and an overall height of 27 feet, 9 inches (8.458 meters). The standard B-29 had an empty weight of 74,500 pounds (33,793 kilograms) and gross weight of 120,000 pounds (54.431 kilograms).

Enola Gay at Tinian, with crew members.
Enola Gay at Tinian, with crew members.

The 509th Composite Group was equipped with specially modified “Silverplate” B-29s, which differed from the standard production bombers in many ways. They were approximately 7,200 pounds (3,266 kilograms) lighter. The bombers carried no armor. Additional fuel tanks were installed in the rear bomb bay. The bomb bay doors were operated by quick-acting pneumatic systems. The bomb release mechanism in the forward bomb bay was replaced by a single-point release as was used in special Royal Air Force Avro Lancaster bombers. A weaponeer’s control station was added to the cockpit to monitor the special bomb systems.

Colonel Paul W. Tibbets, Jr., waves from the cockpit of the Silverplate Martin-Omaha B-29-45-MO Superfortress Enola Gay, 44-86292, just before starting engines at 02:27 a.m., 6 August 1945. (Sergeant Armen Shamlian, United States Army Air Forces. National Archives and Records Administration)

Enola Gay had four air-cooled, supercharged, 3,347.662-cubic-inch-displacement (54.858 liter) Wright Aeronautical Division R-3350-41 (Cyclone 18 787C18BA3) two-row 18-cylinder radial engines with direct fuel injection. The R-3350-41 had a compression ratio of 6.85:1 and required 100/130 aviation gasoline. It was rated at 2,000 horsepower at 2,400 r.p.m. at Sea Level, and 2,200 horsepower at 2,800 r.p.m, for take-off. The engines drove four-bladed Curtiss Electric reversible-pitch propellers with a diameter of 16 feet, 8 inches (5.080 meters), through a 0.35:1 gear reduction. The R-3350-41 was 6 feet, 2.26 inches (1.937 meters) long, 4 feet, 7.78 inches (1.417 meters) in diameter and weighed 2,725 pounds (1,236 kilograms).

Martin-Omaha B-29 Superfortress 44-86292, “Enola Gay,” at Tinian. (U.S. Air Force)

With the exception of the tail gunner’s position, all defensive armament—four remotely-operated gun turrets with ten .50-caliber machine guns—were deleted. Their remote sighting positions were also removed. Enola Gay carried 1,000 rounds of ammunition for each of the two remaining Browning AN-M2 .50-caliber machine guns in the tail.

With these changes, the Silverplate B-29s could fly higher and faster than a standard B-29, and the new engines were more reliable. Enola Gay had a cruising speed of 220 miles per hour (354 kilometers per hour) and a maximum speed of 365 miles per hour (587 kilometers per hour). Its service ceiling was 31,850 feet (9,708 meters) and its combat radius was 2,900 miles (4,667 kilometers).

XXI Bomber Command Target Chart for Hiroshima Area. (U.S. Strategic Bombing Survey)
XXI Bomber Command Target Chart for Hiroshima. (U.S. Strategic Bombing Survey)

At 09:15:17 a.m., (mission time; 8:15 a.m., local; 2315, 5 August, UTC), Enola Gay, with a True Air Speed of 275 miles per hour (443 kilometers per hour), was at 30,060 feet (9,162 meters) ³ over the Japanese city of Hiroshima, an industrial center on the island of Honshu, with a population of about 340,000 people. The bombardier initiated the automatic release sequence and the the atomic bomb was dropped. It fell for 44.4 seconds and detonated at an altitude of 1,968 feet (600 meters), about 550 feet (168 meters) from the aiming point, the Aioi Bridge over the Ota River.

Immediately after the bomb was released, Colonel Tibbets put his B-29 into a 60° right bank and entered a 155° turn at full power. During the maneuver, which had been calculated to get the airplane as far away from the blast as possible, Enola Gay lost approximately 1,700 feet (518 meters) of altitude. When the bomb detonated, the bomber was about 11 miles (17.7 kilometers) away. Even at this distance, the shock wave struck the bomber with “. . . violent force. Our B-29 trembled under the impact and I gripped the controls tightly to keep us in level flight.” ⁴

A mushroom cloud climbs over the city of Hiroshima, Japan, 2–3 minutes after detonation, 6 August 1945, photographed from Yoshiura, looking southward, by Technical Sergeant George R. Caron, U.S. Army Air Corps, tail gunner of the B-29 Enola Gay, using a Fairchild Camera and Instrument Company K-20 aerial camera with a 6-3/8″ f/4.5, 4″ × 5″ film negative. (U.S. Department of Defense 450806-O-ZZ999-067)
The mushroom cloud rises over Hiroshima, Japan, 2–3 minutes after detonation. Photographed 6,500 meters from hypocenter (Seizo Yamada)
The mushroom cloud rises over Hiroshima, Japan, 2–3 minutes after detonation. Photographed 6,500 meters (4 miles) from hypocenter. (Seizo Yamada)
Pyrocumulus cloud seen from ground level.
Two-tier cloud, 2–5 minutes after detonation, seen from Kaitaichi, 6 miles east of Hiroshima. Photographer unknown. (The Atlantic)
Pyrocumulus cloud rising over Hiroshima. Photographer unknown. (Atomic Heritage Foundation)
A pyrocumulus cloud from the firestorm spreads laterally as it reaches the upper atmosphere. (U.S. Air Force)
A pyrocumulus cloud from the firestorm spreads laterally as it reaches the upper atmosphere. (U.S. Air Force)
Hiroshima photoggraphed by a reconnaissance airplane several hours after the explosion. (U.S. Air Force)
Hiroshima photographed by a reconnaissance airplane several hours after the explosion. (U.S. Air Force)

Ground Zero, the point on the surface directly below the explosion, was the Shima Hospital. The overpressure is estimated to have been 4.5–6.7 tons per square meter. The two-story brick building was completely obliterated. Of the patients, technicians, nurses and doctors inside, nothing remained.

The entrance to Shima Hospital is all that remained following the detonation of the atomic bomb.

The resulting explosion was approximately equivalent in explosive force to the detonation of 16,000 tons (14,515 metric tons) of TNT (16 “kilotons”). An estimated 70,000 people were killed immediately, and another 70,000 were wounded. As many as 160,000 people may have died as a result of the atomic bombing by the end of 1945. More would follow over the next few years.

The shadow of one of the victims of the atomic bomb is etched onto the steps in front of a destroyed building.
The shadow of one of the victims of the atomic bomb is etched onto the steps in front of a destroyed building.

An area of the city with a radius of 1 mile (1.6 kilometers) from the point of detonation (“hypocenter”) was totally destroyed, and combined with the fires that followed, 4.7 square miles (12.17 square kilometers) of the city were destroyed. 69% of all buildings in Hiroshima were completely destroyed and another 6% damaged.

Aerial photograph of Hiroshima, Autumn, 1945. The T-shaped Aioi Bridge in the upper portion of the image was the aiming point of the atomic bomb. (Atomic Archive)
Hiroshima, photographed in the Autumn of 1945. (Atomic Archive)
Col. Tibbets’ B-29, Enola Gay, 44-86292, landing at Tinian Island, 1458, 6 August 1945. Note: “Circle R” identification on tail. (U.S. Air Force)
Martin-Omaha Silverplate B-29 Superfortress 44 86292, Enola Gay, taxis to its hardstand after returning to Tinian, 6 August 1945. (U.S. Air Force)

The bomber was then flown back to Tinian, landing at 1458, after an elapsed time of 12 hours, 13 minutes.

Enola Gay participated in Operation Crossroads, the nuclear weapons test at Bikini Atoll in July 1946. It was transferred to the Smithsonian Institution 30 August 1946 and placed in storage at Davis-Monthan Army Air Field, Tucson, Arizona, 1 September 1946. For decades it sat in storage at different locations around the country, but finally a total restoration was performed. Today, the B-29 is on display at the Steven F. Udvar-Hazy Center, National Air and Space Museum.

Martin-Omaha B-29-45-MO Superfortress 44-86292, Enola Gay, at teh Steven F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum.
Martin-Omaha B-29-45-MO Superfortress 44-86292, Enola Gay, at the Steven F. Udvar-Hazy Center, Smithsonian Institution National Air and Space Museum. (Photo by Eric Long, National Air and Space Museum, Smithsonian Institution )

¹ The Hiroshima mission was originally planned for 1 August 1945, but an approaching typhoon caused it to be delayed.

² The other crew members of Enola Gay on 6 August 1945 were Captain Robert Alvin Lewis, co-pilot; Captain Theodore Jerome (“Dutch”) Van Kirk, navigator; Major Thomas Wilson Ferebee, bombardier; Staff Sergeant Wyatt Edwin Duzenbury, flight engineer; Sergeant Robert H. Shumard, assistant flight engineer; Sergeant Joseph Anton Stiborik, radar operator; Private 1st Class Richard H. Nelson, radio operator; Staff Sergeant George Robert Caron, tail gunner. The weaponeer and mission commander was Captain William Sterling (“Deke”) Parsons, United States Navy. 2nd Lieutenant Morris Richard Jeppson was Parsons’ assistant weaponeer. The radar countermeasures officer was 1st Lieutenant Jacob Beser. (Lieutenant Beser also flew aboard Bock’s Car on the Nagasaki mission, 9 August 1945.)

³ Airspeed and altitude from the escape diagram prepared by navigator Captain Theodore J. Van Kirk.

⁴ Colonel Tibbets, quoted in Return of the Enola Gay,  by Paul Tibbets, Mid Coast Marketing, 1998.

© 2023, Bryan R. Swopes