Category Archives: Aviation

8 August 1957

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Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)
Nikolay Arkadevich Korovin

8 August 1957: At Ramenskoye Airfield, Moscow, Russia, senior test pilot Lieutenant Colonel Nikolay Arkadevich Korovin (Коровин Николай Аркадьевич) was scheduled to take an experimental prototype interceptor to an altitude of 20,000 meters (65,617 feet).

The airplane was the Mikoyan-Gurevich Ye-50/3 (also known as the E-50/3). It was powered by an afterburning turbojet engine and a liquid-fueled rocket engine. This was the third prototype of the series.

The three Ye-50 prototypes were variants of the MiG 21. They were developed from the earlier MiG Ye-2, with a rocket engine installed. This was not merely a booster engine, but the aircraft carried sufficient fuel for as much as 20 minutes of rocket-assisted flight. A planned production interceptor, the Ye-50A, was designated MiG 23U. Only one of these was built.

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

The Ye-50/3 differed from Ye-50/2 with an increased fuel capacity and extended air intake with sharp leading edge. The Ye-50/3 was 4.85 meters (48.72 feet) long with a wingspan of 8.11 meters (21.61 feet). The aircraft had an empty weight of 5,920 kilograms (13,051 pounds), and maximum takeoff weight of 8,500 kilograms (18,739 pounds).

The Ye-50/3 was powered by an A.A. Mikulin AM-9E afterburning turbojet engine rated at 3,800 kilograms force ( pounds thrust) and a liquid-fueled Dushkin S-155 rocket engine. The S-155 used a hypergolic mixture of nitric acid and kerosene as fuel. It produced 1,300 kgf (2,866 pounds of thrust).

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

The Ye-50/3 had been completed in April 1957. Prior to 8 August, Ye-50/3 had made 10 test flights, 6 of which successfully used the rocket engine. It had a maximum speed of 2,460 kilometers per hour (1,529 miles per hour), or Mach 2.33. The service ceiling was 23,000 meters (75,460 feet. Its range was 475 kilometers (295 miles).

The Ye-50/3 was the only one of the three prototypes to be armed. It carried two Nudelman-Rikhter NR-30 30 mm autocannon.

Mikoyan-Gurevich Ye-50/3 (Mikoyan Design Bureau via The Corner of the Sky)

Ramenskoye Airfield was very busy that day. Colonel Korovin’s launch was delayed by traffic on the runway. Finally, he took of at 12:50 p.m. and accelerated into a climb.

At 1:01 p.m., Colonel Korovin radioed that the aircraft was in a spin. 30 seconds later, he called that he was ejecting.

The Ye-50/3 crashed near the village of Radovitsy, approximately 100 kilometers (62 miles) southeast of Ramenskoye. The body of Colonel Korovin was located about 150 meters (164 yards) from the crash site, still in his ejection seat. The parachute had not opened, and the test pilot had been killed on impact.

The accident investigation found that during the delay to takeoff, the liquid oxidizer accumulated in the combustion chamber. This caught fire as the prototype took off. The rocket engine’s turbopump exploded. The explosion damaged the flight control system and the prototype caught fire. The fire burned away a portion of the airplane’s vertical fin. When it entered a spin, Colonel Korovin was unable to recover. It was found that he had removed his gloves and tried to manually pull the ejection seat parachute release cable, but to no avail.

On 9 September 1957, Lieutenant Colonel Korovin was posthumously named a Hero of the Soviet Union.

Cockpit of Mikoyan-Gurevich Ye-50/3. (Mikoyan Design Bureau via The Corner of the Sky)
Коровин Николай Аркадьевич

Nikolay Arkadevich Korovin was born 7 May 1920 at the village of Galanovo in the Votsk Autonomous Oblast (now, the Udmurt Republic). His family were peasants who worked on a collective farm. Korovin completed six grades of formal education.

In 1938 Korovin joined the Red Army. He received further education at a military school in Perm, a city in Russia near the Ural Mountains, graduating in 1939. The following year, he completed pilot training at the Stalingrad Military Aviation School.

From 1941 through 1944, Korovin served as a pilot instructor at Chkalovskaya (now Orenburg, Kazakhstan). In March 1944, he was assigned to combat operations, first with the 91st Guards Aviation Regiment (Ground Attack), and then the 92nd Guards. He fought on the second Ukrainian Front, and in Hungary, Checkoslavakia and Austria. He flew 66 combat missions in the Ilyushin Il-2 Штурмовик (Šturmovík) during the Great Patriotic War.

The Ilyushin Il-2 Šturmovík was the most-produced aircraft of the Second World War. (NASM)

Korovin remained in the Soviet Air Force following the War. He graduated from a senior officers tactical school at Taganrog, Rostov Oblast, in 1950, and then, in 1951, became a senior test pilot for the State Red Banner Scientific-Testing Institute for the Air Force (GK NII VVS). In 1955, Korovin flew government tests of the MiG 19.

During his military career, Lieutenant Colonel Nikolay Arkadevich Korovin was awarded the Order of Lenin, Order of the Red Banner, Order of the Patriotic War 1st Degree, and Order of the Red Star (two awards). His remains were buried at the military cemetery at Chkalovskaya.

© 2017, Bryan R. Swopes

8 August 1955

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8 August 1955: While being carried aloft by a Boeing B-29 Superfortress, the Bell X-1A was being readied for it’s next high-altitude supersonic flight by NACA test pilot Joe Walker. During the countdown, an internal explosion occurred. Walker was not injured and was able to get out. The X-1A was jettisoned. It crashed onto the desert floor and was destroyed.

A number of similar explosions had occurred in the X-1D, X-1-3 and the X-2. Several aircraft had been damaged or destroyed, and Bell Aircraft test pilot Skip Ziegler was killed when an X-2 exploded during a captive flight. A flight engineer aboard the B-29 mothership was also killed. The B-29 was able to land but was so heavily damaged that it never flew again.

Debris from the X-1A crash site was brought back to Edwards AFB for examination. It was discovered that a gasket material used in the rocket engine fuel systems was reacting with the fuel, resulting in the explosions. The problem was corrected and the mysterious explosions stopped.

Test pilot Joe Walker “horsing around” with the Bell X-1A, 1955. (NASA)

© 2015, Bryan R. Swopes

8 August 1946

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Convair XB-36 Peacemaker 42-13570 engine run-up
The prototype Consolidated-Vultee XB-36, 42-13570, stands at the end of the runway with all six engines running. (U.S. Air Force)

8 August 1946: At Fort Worth, Texas, the Consolidated-Vultee Aircraft Corporation XB-36 prototype, 42-13570, made its first flight. Convair test pilots Beryl Arthur Erickson and G.S. “Gus” Green, along with Chief Flight Test Engineer James D. “J.D.” McEachern, were in the cockpit. Six other crew members were aboard.

Chief Test Pilot Beryl Arthur Erickson. (Convair)

In a 1992 interview published in Code One Magazine, Erickson said that he and his crew had been ready to take off at 5 a.m., but they didn’t get their release until noon. The Texas summer temperature was 100 degrees (37.8 °C.), but inside the cockpit, the temperature was 140° F. (60 °C.) The engines were overheating and the oil pressure was low. When they pushed the throttles forward, the XB-36 accelerated smoothly and lifted off at 110 knots (126.6 miles per hour, 203.7 kilometers per hour). The retired test pilot said, “The XB-36 controlled nicely in the takeoff run and in the transition to steady climb. We flew conservatively with the gear down. The flight was uneventful and lasted thirty-eight minutes.”

Chief Test Pilot Beryl Arthur Erickson at the aircraft commander’s station of the Consolidated-Vultee XB-36 long-range heavy bomber. (Code One).

The B-36 was the largest and heaviest airplane built up to that time. It was designed as a long-range heavy bomber, able to reach targets on the European continent from the United States and return, should England fall to Nazi Germany during World War II. With the end of the war, its purpose was changed to that of a long range strategic bomber, carrying large nuclear weapons that weren’t even imagined when the design process had begun.

A size comparison between the Convair XB-36 prototype and a Boeing B-29 Superfortress.
A size comparison between a Boeing B-29-55-BA Superfortress, 44-84017, and the Consolidated-Vultee XB-36 prototype, Carswell AFB, June 1948. (U.S. Air Force Historical Research Agency)

The XB-36 was 162 feet, ½ inch (49.390 meters) long with a wing span of 230 feet (70.104 meters), nearly 90 feet longer than that of the B-29 Superfortress that it would replace. Its height was 46 feet, 9-7/8 inches (14.272 meters) to the tip of the vertical fin. The wings’ leading edges were swept aft 15° 5′ 39″, and the trailing edges, 3°. They had 2° dihedral. The wings’ angle of incidence was 3° and they incorporated 2° of negative twist. The total wing area was 4,772 square feet (443.33 square meters). The prototype’s empty weight was 131,240 pounds (59,530 kilograms), and it had a maximum gross weight of 274,929 pounds (124,706 kilograms).

Convair XB-36 three-view illustration with dimensions. (U.S. Air Force)

The XB-36 was powered by six air-cooled, supercharged, 4,362.49 cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major TSB1P-G (R-4360-25) 28-cylinder four-row radial engines, with a normal power rating of 2,500 horsepower at 2,550 r.p.m. to 5,000 feet (1,524 meters), and 3,000 horsepower at 2,700 r.p.m. for takeoff. They were mounted inside the wings. The engines were arranged in a “pusher” configuration with intake and cooling air entering through inlets in the wing leading edge. They drove three-bladed Curtiss propellers with a diameter of 19 feet (5.8 meters) through a 0.381:1 gear reduction. The R-4360-25 was 9 feet, 1.75 inches (2.788 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter, and weighed 3,483 pounds (1,580 kilograms).

The airplane’s estimated maximum speed was 347 miles per hour (558 kilometers per hour) at 35,000 feet (10,668 meters) and the cruising speed, 216 miles per hour (348 kilometers per hour). The service ceiling was predicted at 36,080 feet (10,997 meters) with all six engines running. It had an estimated range of 9,430 miles (15,176 kilometers) with a 10,000 pound (4,536 kilogram) bomb load.

The prototype Convair XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)
The prototype Consolidated-Vultee XB-36, 42-13570, lifts off the runway at Fort Worth, Texas. (U.S. Air Force)

The bomber was designed to carry a maximum bomb load of 72,000 pounds (32,659 kilograms): as many as 132 500-pound bombs; 72 1,000 pound; 44 1,600 pound; 28 2,000-pound; or 12 4,000-pounders. Defensive armament was planned as two 37mm cannon in each of the forward upper and lower turrets, with 100 rounds of ammunition per gun; four .50-caliber machine guns in the rear upper and lower turrets with 1,000 rounds per gun; and one 37 mm cannon and two .50-caliber machine guns in the tail. The tail cannon would have 300 rounds, and the machine guns, 1,000 rounds per gun.

After testing, improvements were incorporated into the second prototype, YB-36 42-13571. In June 1948, the XB-36 was modified with R-4360-41 engines, and the main landing gear was changed from a single-wheel design to a 4-wheel bogie. With these and other changes the XB-36 was redesignated YB-36A. It was used for continued testing for the next several years, but was eventually stripped of its engines and equipment and used for firefighter training at the adjacent Carswell Air Force Base.

The YB-36 was selected for production as the B-36A Peacemaker. The B-36 series was produced in both bomber and reconnaissance versions and was in front line service from 1949 to 1959. Beginning with the B-36D, four turbojet engines were mounted beneath the wings in pods similar to those on the Boeing B-47 Stratojet, greatly increasing the bomber’s performance. A total of 384 were built. Only five still exist. The Peacemaker was never used in combat.

The Convair XB-36 in flight. (U.S. Air Force)
The Consolidated-Vultee XB-36 prototype, 42-13570, in flight. (U.S. Air Force)

© 2023, Bryan R. Swopes

8 August 1945

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Fat Man, Nuclear Bomb, Mark III, being prepared at Tinian, Marshall Islands, 8 August 1945. (U.S. Air Force)

“So, the next day, Fat Man, the two armored steel ellipsoids of its ballistic casing bolted together through bathtub fittings to lugs cast into the equatorial segments of the implosion sphere, its boxed tail sprouting radar antennae just as Little Boy’s had done. By 2200 on August 8 it had been loaded into the forward bomb bay of a B-29 named Bockscar after its usual commander, Frederick Bock, but piloted on this occasion by Major Charles W. Sweeney. Sweeney’s primary target was the Kokura Arsenal on the north coast of Kyushu; his secondary was the old Portuguese- and Dutch-influenced port city of Nagasaki, the San Francisco of Japan, home of the country’s largest colony of Christians, where the Mitsubishi torpedoes used at Pearl Harbor had been made.”

—The Making of the Atomic Bomb, by Richard Rhodes, Simon and Schuster, New York, 1986, Chapter 19 at Page 739.

The Mark III “Fat Man” bomb loaded on its carrier, 8 August 1945. (Manhattan Engineer District)

Fat Man was an implosion-type fission bomb, using plutonium (Pu-239) as the nuclear material. It was a very complex device which used 32 precisely-shaped explosive charges surrounding the spherical plutonium-alloy core, detonating with enough force to compress the core to double its normal density. This caused it to reach “critical mass” and the fission chain reaction began.

The Mark III implosion bomb and its trailer are lowered into the pit in preparation for loading aboard Bockscar, 8 August 1945. (U.S. Air Force)
The Mark III implosion bomb and its trailer are lowered into the pit in preparation for loading aboard Bockscar, 8 August 1945. (U.S. Air Force)

The Mark III bomb, unlike the gun-type “Little Boy,” required testing before combat use. The nuclear component of the bomb, called “Gadget,” had been exploded at 05:29:45 a.m., Mountain War Time, 16 July 1945, at the Trinity Site of the Alamogordo Test Range, in the Jornada del Muerta desert of New Mexico. The explosive yield of the detonation was estimated to be equivalent to 20–22,000 tons of TNT.

The fully assembled combat weapon was 12 feet, 8⅜ inches ¹ (3.261 meters) long, 5 feet, ¼ inch ² (1.530 meters) in diameter, and weighed approximately 10,300 pounds (4,672 kilograms).

Rear fuselage of Bockscar, B-29 44-27297, at Tinian. Note the “Triangle N” and “77” codes. The Enola Gay is in the background. (U.S. Air Force)

¹ Overall length, ± ¼ inch

² Overall diameter, ± ⅛ inch

© 2017, Bryan R. Swopes

8 August 1929

Aviation, , , , , , , ,
Dr. Hugo Eckener (1868–1954)

8 August 1929: The rigid airship Graf Zeppelin, LZ 127, under the command of Dr. Hugo Eckener, departed Lakehurst Naval Air Station, New Jersey, heading east across the Atlantic Ocean on an around-the-world flight. The flight was sponsored by publisher William Randolph Hearst, who had placed several correspondents aboard.

Graf Zeppelin was named after Ferdinand Adolf Heinrich August Graf von Zeppelin, a German general and count, the founder of the Zeppelin Airship Company. The airship was constructed of a lightweight metal structure covered by a fabric envelope. It was 776 feet (236.6 meters) long. Contained inside were 12 hydrogen-filled buoyancy tanks, fuel tanks, work spaces and crew quarters.

A gondola mounted underneath contained the flight deck, a sitting and dining room and ten passenger cabins. The LZ-127 was manned by a 36 person crew and could carry 24 passengers.

LZ 127 was powered by five water-cooled, fuel injected 33.251 liter (2,029.1 cubic inches) Maybach VL-2 60° V-12 engines producing 570 horsepower at 1,600 r.p.m., each. Fuel was either gasoline or blau gas, a gaseous fuel similar to propane. The zeppelin’s maximum speed was 80 miles per hour (128 kilometers per hour).

The route of the flight was from Lakehurst NAS to the LZ 127 home base at Friedrichshafen. Germany. After refueling, it continued across Europe, Russia and Siberia, non-stop to Tokyo, Japan, where it moored and refueled at the Kasumigaura Naval Air Station. This leg crossed 7,297 miles (11,743 kilometers) in 101 hours, 49 minutes. After five days in Japan, Graf Zeppelin headed east across the Pacific Ocean to Mines Field, Los Angeles, California. This was the first ever non-stop flight across the Pacific Ocean. The distance was 5,986 miles (9,634 kilometers) and took 79 hours, 54 minutes. The transcontinental flight from Los Angeles back to the starting point at Lakehurst NAS, 2,996 miles (4,822 kilometers), took 51 hours, 13 minutes.

The total elapsed time for the circumnavigation was 21 days, 5 hours, 31 minutes. The route covered 20,651 miles (33,234 kilometers). The actual flight time was 12 days, 12 hours, 13 minutes, an average of 68.786 miles per hour (110.7 kilometers per hour).

Airship Graf Zeppelin, LZ 127. (Alexander Cohrs)

Graf Zeppelin made 590 flights and carried more than 13,000 passengers. It is estimated that it flew more than 1,000,000 miles. After the Hindenburg accident, it was decided to replace the hydrogen buoyancy gas with non-flammable helium. However, the United States government refused to allow the gas to be exported to Germany. With no other source for helium, in June 1938, Graf Zeppelin was deflated and placed in storage.

© 2020, Bryan R. Swopes