Tag Archives: Pratt & Whitney Double Wasp SSB2-G

24 June 1942

Aviation, , , , , , , ,
Vought-Sikorsky F4U-1 Corsair, Bu. No. 02170, with test pilot Willard Bartlett Boothby, 24 October 1942. This is the twenty-fifth production F4U-1. (Rudy Arnold/National Air and Space Museum NASM-XRA-1294)

24 June 1942: The first production Vought-Sikorsky F4U-1 Corsair, Bu. No. 02155, made its first flight at Stratford, Connecticut. (Some sources state 25 June.)

The Corsair was designed by Rex Buren Beisel, and is best known for its distinctive inverted “gull wing,” which allowed sufficient ground clearance for its 13 foot, 4 inch (4.064 meter) diameter propeller, without using excessively long landing gear struts. The prototype XF4U-1, Bu. No. 1443, had first flown 29 May 1940, with test pilot Lyman A. Bullard in the cockpit.

The F4U-1 was had a length of 33 feet, 4.125 inches (10.163 meters), wingspan of 40 feet, 11.726 inches (12.490 meters) and overall height (to top of propeller arc) of 15 feet, 0.21 inches (4.577 meters). The wings’ angle of incidence was 2°. The outer wing had 8.5° dihedral and the leading edges were swept back 4°10′. With its wings folded, the width of the F4U-1 was 17 feet, 0.61 inches (5.197 meters), and gave it a maximum height of 16 feet, 2.3 inches (4.935 meters). When parked, the Corsair’s 13 foot, 4 inch (4.064 meter) propeller had 2 feet, 1.93 inches (65.862 centimeters) ground clearance, but with the fighter’s thrust line level, this decreased to just 9.1 inches (23.1 centimeters). The F4U-1 had an empty weight of 8,982 pounds (4,074.2 kilograms) and gross weight of 12,162 pounds (5,516.6 kilograms).

Vought-Sikorsky F4U-1 Corsair, Bu. No. 02170, with test pilot Willard Bartlett Boothby, 24 October 1942. (Rudy Arnold/National Air and Space Museum NASM-XRA-1301)

The F4U-1 variant of the Corsair was powered by an air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter) Pratt & Whitney Double Wasp SSB2-G (R-2800-8) two-row, 18-cylinder radial engine, with a compression ratio of 6.65:1. The R-2800-8 had a normal power rating of 1,675 horsepower at 2,550 r.p.m. and 44.0 inches of manifold pressure (1.490 bar) at 5,500 feet (1,676 meters); 1,550 horsepower at 21,500 feet (6,553 meters); and 2,000 horsepower at 2,700 r.p.m. with 54.0 inches of manifold pressure (1.829 bar) for takeoff. The engine turned a three-bladed Hamilton Standard Hydromatic constant-speed propeller with a diameter of 13 feet, 4 inches (4.064 meters) through a 2:1 gear reduction. The R-2800-8 was 7 feet, 4.47 inches (2.247 meters) long, 4 feet, 4.50 inches (1.334 meters) in diameter and weighed 2,480 pounds (1,125 kilograms).

Vought-Sikorsky F4U-1 Corsair, circa 1942. (Rudy Arnold)

The F4U-1 had a cruise speed of 186 miles per hour (299 kilometers per hour) at Sea Level. Its maximum speed at Sea Level was 365 miles per hour (587 kilometers per hour). During flight testing, an F4U-1 reached 431 miles per hour (694 kilometers per hour) at 20,300 feet (6,187 meters) with War Emergency Power. The service ceiling was 38,200 feet (11,643 meters) and its maximum range was 1,510 miles (2,430 kilometers) with full main and outer wing tanks.

The Corsair was armed with six air-cooled Browning AN-M2 .50-caliber machine guns, three in each wing, with 400 rounds of ammunition per gun.

Three Browning AN-M2 .50-caliber machine guns and belted ammunition installed in the left wing of a Vought-Sikorsky F4U-1 Corsair, 11 August 1942. (Vought-Sikorsky VS-6015)

A total of 12,571 Corsairs were manufactured by the Vought-Sikorsky Aircraft Division (F4U-1), Goodyear Aircraft Corporation (FG-1D) and Brewster Aeronautical Corporation (F3A-1). The Corsair served the U.S. Navy and Marine Corps in World War II and the Korean War. Corsairs also served in other countries’ armed forces. Its last known use in combat was in Central America in 1969.

Vought-Sikorsky F4U-1 Corsair, circa 1942. (Rudy Arnold/National Air and Space Museum NASM-XRA-1329)

© 2019, Bryan R. Swopes

15 June 1946

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The Navy Demonstration Team Hellcats taxi out for their first public performance, Craig Field, Jacksonville,Florida, 15 June 1946. (Butch Voris collection)
The Navy Flight Demonstration Team Hellcats taxi out for their first public performance, Craig Field, Jacksonville, Florida, 15 June 1946. (Butch Voris collection)

15 June 1946: At Craig Field, Jacksonville Florida, the United States Navy’s Navy Flight Demonstration Team made its first public appearance at the municipal airport’s dedication ceremony. A flight of three lightened Grumman F6F-5 Hellcat fighters, led by Officer-in-Charge Lieutenant Commander Roy Marlin Voris, flew a fifteen minute aerobatic performance.

The team had been formed for the purpose of raising public political support for the Navy. Their fighters were painted overall glossy sea blue with “U.S. NAVY” on the fuselage in gold leaf. A single numeral, also gold leaf, on the vertical fin identified each individual airplane.

Five weeks later, 21 July, the team would first call themselves The Blue Angels.

The pilots of the Navy Flight Demonstartion Team with one of their Grumman F6F-5 Wildcat fighters. (Butch Voris Collection)
The pilots of the Navy Flight Demonstration Team with one of their Grumman F6F-5 Hellcat fighters. Left to right: Lieutenant Al Taddeo, Lieutenant (j.g.) Gale Stouse, Lieutenant Commander Roy “Butch” Voris, Lieutenant Maurice N. Wickendoll, and Lieutenant Melvin Cassidy.  (Butch Voris Collection)

In addition to Lieutenant Commander Voris, other pilots in the original demonstration team were Lieutenant Commander Lloyd G. Barnard, Lieutenant Melvin Cassidy, Lieutenant Alfred Taddeo, Lieutenant Maurice N. Wickendoll and Lieutenant (j.g.) Gale Stouse.

Flight leader Lieutenant Commander Roy W. "Butch" Voris with his F6F-5 Hellcat, circa May–August 1946. (U.S. Navy)
Flight leader Lieutenant Commander Roy W. “Butch” Voris with his Grumman F6F-5 Hellcat, Bu. No. 80097, circa May–August 1946. (U.S. Navy)

The Grumman F6F-5 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 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 Hellcat became operational in 1944.

The F6F-5 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). It has an empty weight of 9,238 pounds (4,190 kilograms) and maximum takeoff weight of 15,300 pounds (6,940 kilograms).

The F6F-5 Hellcat is powered by a 2,804.4-cubic-inch-displacement (45.956 liter) air-cooled, supercharged, Pratt & Whitney Double Wasp SSB2-G (R-2800-10W) twin-row 18-cylinder radial engine with water injection. The engine had with 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. 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 F6F-5 had a maximum speed of 276 knots (318 miles per hour/511 kilometers per hour) at Sea Level and 330 knots (380 miles per hour/611 kilometers per hour) at 23,400 feet (7,132 meters). The Hellcat’s service ceiling was 35,100 feet (10.698 meters) and it had a combat radius of 820 nautical miles (944 miles/1,519 kilometers). The maximum ferry range is 1,330 nautical miles (1,531 miles/2,463 kilometers).

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

Between 1942 and 1945, the Grumman Aircraft Engineering Corporation, Bethpage, New York, built 12,275 F6F Hellcats. This was the largest number of any aircraft type produced by a single plant.

Four Grumman F6F-5 Four Grumman F6F-5 Hellcat fighters of the Navy Flight Demonstration Team, circa May–August 1946
Four Grumman F6F-5 Four Grumman F6F-5 Hellcat fighters of the Navy Flight Demonstration Team, circa May–August 1946

© 2019, Bryan R. Swopes

26 May 1942

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Northrop Corporation XP-61 Black Widow at Hawthorne.
Northrop Corporation XP-61 prototype 41-19509 at Northrop Field, 1942. (U.S. Air Force)

26 May 1942: The prototype Northrop XP-61-NO Black Widow, 41-19509, made its first flight at Northrop Field, Hawthorne, California, with free-lance test pilot Vance Breese at the controls. (Breese had taken the North American Aviation NA-73X, prototype of the Mustang, for its first flight, 20 October 1940.)

Northrop XP-61 41-19509 taking off from Northrop Field. (U.S. Air Force)

The first American airplane designed specifically as a night fighter, the XP-61 was the same size as a medium bomber: 48 feet, 11.2 inches (14.915 meters) long with a wingspan of 66 feet (20.117 meters) and overall height of 14 feet, 8.2 inches (4.475 meters). The prototype was equipped with a mockup of the top turret. Its empty weight was 22,392 pounds (10,157 kilograms), gross weight of 25,150 pounds (11,408 kilograms) and maximum takeoff weight of 29,673 pounds (13,459 kilograms).

Northrop XP-61 41-19509 retracts its landing gear after takeoff. (U.S. Air Force)

The XP-61 was powered by two air-cooled, supercharged, 2,804.4-cubic-inch-displacement (45.956 liter) Pratt & Whitney Double Wasp SSB2-G (R-2800-10) two-row, 18-cylinder radial engines with a compression ratio of 6.65:1. The R-2800-10 had a Normal Power rating of 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 R-2800-10 had a 2:1 gear reduction and drove four-bladed Curtiss Electric constant-speed propellers which had a 12 foot, 2 inch (3.708 meter) diameter. 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 prototype Black Widow had a top speed of 370 miles per hour (595 kilometers per hour) at 29,900 feet (9,114 meters) and a service ceiling of 33,100 feet (10,089 meters). The maximum range was 1,450 miles (2,334 kilometers).

Prototype Northrop XP-61 Black Widow 41-19509 in camouflage. (U.S. Air Force)

The night fighter was crewed by a pilot, a gunner and a radar operator. A large Bell Laboratories-developed, Western Electric-built SCR-720 air search radar was mounted in the airplane’s nose. The gunner sat above and behind the pilot and the radar operator was in the rear fuselage.

SCR-720 Air Search Radar mounted in nose of a Northrop P-61 Black Widow night fighter. (NOAA)

The Black Widow was armed with four Browning AN-M2 .50-caliber machine guns in a remotely-operated upper turret, and four AN-M2 20 mm aircraft automatic cannons, grouped close together in the lower fuselage and aimed directly ahead. This was a superior arrangement to the convergent aiming required for guns mounted in the wings. The fire control system was similar to that used by the B-29 Superfortress. The guns could be fired by either the gunner or the radar operator. The Black Widow carried 200 rounds of ammunition for each cannon.

The eight guns of a P-61 Black Widow converge on target during test firing.
Northrop P-61A-1-NO Black Widow 42-5507 in olive green camouflage. (U.S. Air Force)
Northrop P-61A-1-NO Black Widow 42-5507 in olive green camouflage. (U.S. Air Force)

The XP-61 was built with a center “gondola” for the crew, radar and weapons, with the engines outboard in a twin-boom configuration, similar the the Lockheed P-38 Lightning. The Black Widow did not use ailerons. Instead, it had spoilers mounted on the upper wing surface outboard of the engines. Roll control was achieved by raising a spoiler, decreasing lift on that wing and causing it to drop. A similar system was employed on the Boeing B-52 Stratofortress ten years later.

Northrop P-61A three-view illustration with dimensions. (U.S. Army Air Forces)

The P-61 got its nickname, Black Widow, from the glossy black paint scheme that scientists at the Massachusetts Institute of Technology (M.I.T.) had determined was the best camouflage for a night fighter. Over 700 P-61s were built, with 36 built as the F-15 photo reconnaissance variant. They served in both the Pacific and European Theaters during World War II, and were also used during the Korean War. After the war, the radar-equipped fighter was used for thunderstorm penetration research.

Northrop P-61C-1-NO Black Widow 43-8353 at the National Museum of the United States Air Force. (U.S. Air Force)
Northrop P-61C-1-NO Black Widow 43-8353 at the National Museum of the United States Air Force. (U.S. Air Force)
Northrop P-61C-1-NO Black Widow 43-8353 at the National Museum of the United States Air Force. (U.S. Air Force)

© 2018, Bryan R. Swopes