Daily Archives: June 26, 2020

26 June 1948

Convair B-36A-1-CF (S/N 44-92004, the first -A model built) in flight. (U.S. Air Force photo)
Convair B-36A-1-CF 44-92004, the first B-36A built. (U.S. Air Force)

26 June 1948: The 7th Bombardment Wing, Very Heavy, at Carswell Air Force Base, Fort Worth, Texas, received the United States Air Force’s first Consolidated-Vultee Aircraft Corporation (“Convair”) B-36A, a six-engine, very long range heavy bomber. Its mission was to serve as a nuclear-capable deterrent until the Boeing B-52 Stratofortress came into service five years later. A total of 22 B-36As were delivered by February 1949. These were not armed and were used for crew training. Most were later converted by Convair to RB-36E reconnaissance bombers, beginning in 1950.

The B-36A differed from the XB-36 prototype in several areas, but two features were the most apparent: The cockpit had been completely revised and now covered by a large dome. The single-wheel main landing gear was replaced by four-wheel bogies to better spread the airplane’s weight over the runway surface.

A crew of thirteen airmen with their Convair B-36A-10-CF Peacemaker, 44-92014. (LIFE Magazine via Jet Pilot Overseas)
A crew of thirteen airmen with their Convair B-36A-10-CF Peacemaker, 44-92013, at Carswell AFB, 1949. (LIFE Magazine via Jet Pilot Overseas)

The B-36A was 162.1 feet (49.4 meters) long with a wingspan of 230.0 feet (70.1  meters) and overall height of 46.8 feet (14.3 meters). The wings had 2° dihedral, an angle of incidence of 3° and -2° twist. The wings’ leading edges were swept aft to 15° 5′. The airplane’s total wing area was 4,772 square feet (443.33 square meters). Its empty weight was 135,020 pounds (61,244 kilograms). The combat weight was 212,800 pounds (96,524 kilograms) and maximum takeoff weight (MTOW) was 310,380 pounds (140,786 kilograms).

Convair B-36A 44-92015 at Carswell Air Force Base.

The initial production version of the Peacemaker was powered by six air-cooled, supercharged, 4,362.5 cubic-inch-displacement (71.489 liter) Pratt & Whitney Wasp Major R-4360 Pusher (R-4360-25) four-row, 28-cylinder radial engines rated at 2,500 horsepower at 2,550 r.p.m. at 37,000 feet (11,278 meters), and 3,000 horsepower at 2,700 r.p.m. for takeoff. Each engine drove a 19-foot (5.791 meter) three-bladed propeller through a 0.381:1 gear reduction. The R-4360-25 was 9 feet, 1.75 inches (2.788 meters) long and 4 feet, 4.50 inches (1.334 meters) in diameter. It weighed 3,483 pounds (1,580 kilograms).

Convair B-36A 44-92015

The six radial engines gave the bomber a maximum speed of 300 knots (345 miles per hour/556 kilometers per hour) at 31,600 feet (9,632 meters). It took 53 minutes for the giant airplane to climb to an altitude of 20,000 feet (6,396 meters). The service ceiling for the B-36A was 39,100 feet (11,918 meters), and combat ceiling was 35,800 feet (10,912 meters). The ferry range was 9,136 miles (14,702 kilometers).

The B-36As initially carried no defensive armament. The maximum bomb load was seventy-two 1,000 pound bombs (total, 72,000 pounds/32,659 kilograms) carried in four internal bomb bays. With a bomb load of 10,000 pounds (4,536 kilograms), the B-36A had a combat radius of 3,370 nautical miles (3,878 miles/6,241 kilometers).

Designed during World War II when nuclear weapons were unknown to aeronautical engineers, the bomber was designed to carry up to 86,000 pounds (39,009 kilograms) of conventional bombs. It could carry a single 43,600 pound (19,777 kilogram) T-12 Cloudmaker, a conventional explosive earth-penetrating bomb, or, later, several Mk.15 thermonuclear bombs. By combining the bomb bays, one Mk.17 15-megaton thermonuclear bomb could be carried.

The sixteenth B-36A, 44-92020, after conversion to the RB-36E reconnaissance configuration. (U.S. Air Force)
The sixteenth B-36A, 44-92020, after conversion to the RB-36E reconnaissance configuration. (U.S. Air Force)

The RB-36E reconnaissance bomber carried a crew of 22. The radial engines were upgraded to R-4360-41s which increased takeoff horsepower with water injection to 3,500 at 2,700 r.p.m. at Sea Level. Four General Electric J47-GE-19 turbojet engines were added in two two-engine pods at the outer end of each wing. These changes significantly increased the airplane’s maximum speed and altitude capability and reduced the required takeoff distance by 25%. Fourteen reconnaissance cameras were installed. There were four additional radomes on the belly and numerous external antennas for electronic intelligence gathering.

The empty weight of the RB-36E increased to 164,238 pounds (74,497 kilograms) and the maximum takeoff weight to 370,000 pounds (167,829 kilograms).

The maximum speed of the RB-36E was 363 knots (418 miles per hour/672 miles per hour) at 38,200 feet (11,643 meters). Its service ceiling was 46,400 feet (14,143 meters).

The reconnaissance bomber carried eighty 188 pound (85.3 kilogram) T-56 photo flash bombs. Defensive armament consisted of sixteen M24A1 20 mm autocannon in five remotely-operated turrets. 9,200 rounds of ammunition were carried.

Between 1946 and 1954, 384 B-36 Peacemakers were built. They were never used in combat. Only five still exist.

The first Consolidated-Vultee B-36A, 44-92004, was flown to Wright Field, Dayton, Ohio, for structural testing. Redesignated YB-36A, it was tested to destruction.

Convair YB-36 (B-36A) 004 under structural testing at Wright Field. (U.S. Air Force)
Convair YB-36A 44-92004 under structural testing at Wright Field. (U.S. Air Force)

The name, “Peacemaker,” was suggested by a Convair employee. It is a reference to the Colt Model 1873 Single-Action Army® revolver, the classic “six-shooter” of the American frontier, which is also known as the Peacemaker®.

© 2018, Bryan R. Swopes

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26 June 1948

U.S. Air Force Douglas C-47 Skytrain transports unloading supples at Templehof Airport, Berlin, 1948. (U.S. Air Force)
U.S. Air Force Douglas C-47 Skytrain transports unloading supplies at Flughafen Berlin-Templehof, Berlin, 1948. (U.S. Air Force)

26 June 1948: 32 United States Air Force Douglas C-47 Skytrain transports flew 80 tons of supplies to Berlin, the first day of the Berlin Airlift.

At the height of the Cold War, the Union of Soviet Soviet Socialist Republics, occupying eastern Germany following World War II, blockaded the Allied portions of the city of Berlin, cutting off all transportation by land and water. This was followed by the building of the Berlin Wall. The western part of the city was now completely isolated. Josef Stalin hoped to force Britain, France and the United States to abandon Berlin, giving the communists complete control of the devastated country.

Soviet T-55 tanks at Checkpoint Charlie, one of just three access points to the Allied sectors of Berlin. (Central Intelligence Agency)

General Curtis LeMay was asked to transport the needs of the city by air. It was calculated that they would need to supply seventeen hundred calories per person per day, giving a grand total of 646 tons of flour and wheat, 125 tons of cereal, 64 tons of fat, 109 tons of meat and fish, 180 tons of dehydrated potatoes, 180 tons of sugar, 11 tons of coffee, 19 tons of powdered milk, 5 tons of whole milk for children, 3 tons of fresh yeast for baking, 144 tons of dehydrated vegetables, 38 tons of salt and 10 tons of cheese. In total, 1,534 tons were needed daily to keep the over two million people alive. Additionally, the city needed to be kept heated and powered, which would require another 3,475 tons of coal and gasoline.

A U.S. Air Force Douglas C-54 Skymaster on approach to land at Flughafen Berlin-Templehof.

At the height of the airlift, one airplane was landing every 30 seconds. By the end, more supplies were arriving by air than had previously come by rail. The airlift ended 30 September 1949.

2,326,406 tons of food, medicine and coal had been delivered.

101 aviators lost their lives.

A Douglas C-47 Skytrain clears the rooftops after takeoff from Berlin-Templehof. (Unattributed)
A Douglas C-47 Skytrain clears the rooftops after takeoff from Berlin-Templehof. (Unattributed)

© 2019, Bryan R. Swopes

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26 June 1942

Grumman XF6F-1 Hellcat, Bu. No. 02981.
Grumman XF6F-1 Hellcat, Bu. No. 02981. (Northrop Grumman)

26 June 1942: The Grumman XF6F-1, Bureau of Aeronautics serial number (Bu. No.) 02981, prototype for the Navy and Marine Corps F6F Hellcat fighter, with Grumman’s Chief Engineer and Test Pilot Robert Leicester Hall flying, made a 25-minute first flight at the Grumman Aircraft Engineering Corporation plant, Bethpage, Long Island, New York.

The first Hellcat was powered by an air-cooled, supercharged, 2,603.737-cubic-inch-displacement (42.688 liters) Wright Aeronautical Division Twin Cyclone GR2600B676 (R-2600-10) two-row, 14-cylinder radial engine. This engine had a compression ratio of 6.9:1 and required 100-octane aviation gasoline. The R-2600-10 was rated at 1,500 horsepower at 2,400 r.p.m. at Sea Level, and 1,700 horsepower at 2,600 r.p.m. for takeoff. It turned a three-bladed Curtiss Electric propeller through a 0.5625:1 gear reduction. The R-2600-10 was 4 feet, 6.26 inches (1.378 meters) in diameter and 6 feet, 2.91 inches (1.903 meters) long. It weighed 2,115 pounds (959 kilograms).

Grumman XF6F-1 Hellcat, Bu. No. 02981. (Northrop Grumman)

Beginning with the second prototype, Bu. No. 02982, the Pratt & Whitney Double Wasp SSB2-G (R-2800-10) 18-cylinder engine became the standard powerplant. The R-2800-10 was an air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter), twin-row 18-cylinder radial engine with water injection. The engine had a compression ratio of 6.65:1 and was rated at 1,550 horsepower at 2,550 r.p.m. at 21,500 feet (6,553 meters), and 2,000 horsepower at 2,700 r.p.m. for takeoff, burning 100-octane gasoline. The engine drove a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 1 inch (3.988 meters) through a 2:1 gear reduction. The R-2800-10 was 4 feet, 4.50 inches (1.334 meters) in diameter, 7 feet, 4.47 inches (2.247 meters) long, and weighed 2,480 pounds (1,125 kilograms), each. The engine weighed 2,480 pounds (1,125 kilograms).

Grumman XF6F-1 Hellcat Bu. No. 02981 in flight. (Northrop Grumman)

The first prototype was quickly re-engined to the Pratt & Whitney radial and redesignated XF6F-3. Bob Hall flew it with the new engine on 30 July 1942. A few weeks later, 17 August, the Hellcat’s new engine failed and Hall crash-landed at Crane’s Farm. The airplane was moderately damaged and Hall was seriously injured.

Grumman XF6F-3 Bu. No. 02981 after crash landing in a field at Crane's Farm, Long Island, New York, August 1942. (Grumman)
Grumman XF6F-3 Bu. No. 02981 after crash landing in a field at Crane’s Farm, Long Island, New York, 17 August 1942. (Northrop Grumman)

The airplane was rebuilt and continued in the test program. It was eventually converted to the XF6F-4 with a two-speed turbocharged Pratt & Whitney Double Wasp 2SB-G (R-2800-27) which produced 2,000 horsepower at 2,700 r.p.m. It was armed with four 20 mm cannon.

The first prototype Hellcat was converted to the XF6F-4, seen here at NACA, langley Field, Virginia in 1944. (NASA)
The first prototype Hellcat was converted to the XF6F-4 configuration, seen here at NACA, Langley Field, Virginia in 1944. (NASA)

The Grumman F6F-3 Hellcat is single-place, single-engine fighter designed early in World War II to operate from the U.S. Navy’s aircraft carriers. It is a low wing monoplane monoplane of all metal construction. The wings can be folded against the sides of the fuselage for storage aboard the carriers. Landing gear is conventional, retractable, and includes an arresting hook.

The F6F-3 is 33 feet, 7 inches (10.236 meters) long with a wingspan of 42, feet 10 inches (12.842 meters) and overall height of 14 feet, 5 inches (4.394 meters) in three-point position. It has an empty weight of 9,207 pounds (4,176 kilograms) and gross weight of 12,575 pounds (5,704 kilograms).

A Grumman F6F Hellcat ready for takeoff from an Essex-class aircraft carrier, circa 1944. (U.S. Navy)
A Grumman F6F Hellcat ready for takeoff from an Essex-class aircraft carrier, circa 1943. (U.S. Navy)

The F6F-3 Hellcat was powered by a Pratt & Whitney Double Wasp SSB2-G (R-2800-10W) engine with water injection, rated at 2,000 horsepower at 2,700 r.p.m. for takeoff, using 100/130 octane aviation gasoline. The normal power rating was 1,550 horsepower at 2,550 r.p.m. at  22,500 feet (6,858 meters). The engine drove a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 1 inch (3.988 meters) through a 2:1 gear reduction. The engine weighed 2,480 pounds (1,125 kilograms).

Two Grumman F6F-3 Hellcat fighters, Summer 1943.(U.S. Navy)
Two Grumman F6F-3 Hellcat fighters, Summer 1943. (U.S. Navy)

In clean configuration, the F6F-3 had a maximum speed of 321 miles per hour (517 kilometers per hour) at Sea Level, and 384 miles per hour (618 kilometers per hour) at 18,000 feet (5,486 meters). It could climb to 10,000 feet (3,048 meters) in 3.2 minutes, and to 20,000 feet (6,096 meters) in 7.0 minutes. The service service ceiling was 38,800 feet (11,826 meters). It had a combat radius of 335 nautical miles (386 miles/620 kilometers). The maximum ferry range was 1,540 miles (2,478 kilometers).

The Hellcat’s armament consisted of six air-cooled Browning AN-M2 .50-caliber machine guns, mounted three in each wing, with 2,400 rounds of ammunition.

The Grumman Hellcat was the most successful fighter of the Pacific war, with a kill-to-loss ratio of 19:1. It was in production from 1942 to 1945 and remained in service with the United States Navy until 1956. A total of 12,275 were built by Grumman at Bethpage. This was the largest number of any aircraft type produced by a single plant.

High humidity creates visible propeller tip vortices as this Grumman F6F Hellcat prepares to takeoff from an Essex-class aircraft carrier. (U.S. Navy)
High humidity creates visible propeller tip vortices as this Grumman F6F-3 Hellcat prepares to takeoff from USS Yorktown (CV-10), November 1943. (U.S. Navy)
Robert Leicester Hall

Robert Leicester Hall was born at Taunton, Massachussetts, 22 August 1905. He was the son of Bicknell Hall, a mechanical engineer, and Estella Beatrice Lane Hall.

Hall attended the University of Michigan, graduating in 1927 with Bachelor of Science degree in Mechanical Engineering (B.S.M.E.).

In 1929 he went to work for the Fairchild Airplane Manufacturing Company at Farmingdale, New York. While there, Hall met his first wife, Eugenie, a secretary at the plant. They were married in 1930, and lived in a rented home on St. James Avenue, Chicopee City, Massachusetts. Their son, Robert Jr., was born 5 November 1931.

Granville Brothers Gee Bee Model Z, NR77Y, City of Springfield.

Also in 1931, Hall began working for Granville Brothers Aircraft at Springfield, Massachusetts. He designed the Gee Bee Model Z Super Sportster air racer. He left Granville Brothers in 1933 to go to work for the Stinson Aircraft Company in Dayton, Ohio. There he designed the Stinson Reliant.

A Stinson SR-8E Reliant, NACA 94, at the Langley Research Center, 5 August 1936. (NASA)

In 1936, Bob Hall became the Chief Engineer for the Grumman Aircraft Engineering Corporation, Bethpage, Long Island, New York. He designed the F4F Wildcat, F6F Hellcat, F7F Tigercat, and F8F Bearcat fighters, and the TBF Avenger torpedo bomber. As corporate vice president, he supervised the design of the F9F Panther and Cougar jet fighters.

Hall married his second wife, Rhoda C. Halvorsen, 18 January 1939, at New York City, New York.

Hall retired from Grumman in 1970. Two of his sons, Eric and Ben Hall, founded Hall Spars and Rigging of Bristol, Rhode Island.

Robert Leicester Hall died at Newport, Rhode Island, 25 February 1991, at the age of 85 years.

Grumman F6F-3 Hellcat, Bu. No. 4778, Long Island, New York, circa 1942. (Rudy Arnold Collection/NASM)
Grumman F6F-3 Hellcat Bu. No. 26108, Long Island, New York, circa 1943. (Rudy Arnold Collection/NASM)

© 2018, Bryan R. Swopes

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