Tag Archives: Test Pilot

23 January 1939

H. Lloyd Child, Curtiss-Wright Airplane Division test pilot. (Photograph courtesy of Neil Corbett, Test & Research Pilots, Flight Test Engineers)

23 January 1939:

     Buffalo, N.Y., January 24—(AP)—A Curtiss Hawk 75A pursuit plane, one of 100 being constructed for the French Government, has “substantially exceeded all known speed records” with a free dive of more than 575 miles an hour, it was announced today.

     The speed mark was established yesterday while the ship was undergoing acceptance tests, officials of the Curtiss Aeroplane Division of the Curtiss Wright Corporation said.

     The tests were made by H. Lloyd Child, chief test pilot of the Buffalo Curtiss plant, who said he “felt no ill effects and did not realize” that the speed was presumably the fastest man has ever traveled.”

     National Aeronautic Association officials said that no Federation Aeronautique Internationale records “even approached this speed.”

     The speed of the dive was so great that the marker on the recording airspeed indicator exceeded the instrument’s range and moved off the paper on which the graph of the dive was recorded.

     Aviation experts, who declined to be quoted directly, estimated that the speed might have exceeded 600 miles per hour, compared with the normal falling rate for a 170-pound man of 150 miles an hour.

     The dive was begun at an altitude of 22,000 feet, and the record speed was attained during a 9,000 foot dive.

     At no time during the dive, Child said, did the engine exceed 2,550 revolutions a minute, its normal rated speed in level flight. Hence, he explained, the strain on the motor during the dive was not increased, but was held to the speed of normal operation by the Curtiss electric propeller, with its unlimited blade pitch range.

     Since the motor’s speed was kept at normal during the dive, it was a “free,” rather than a “power” dive as when the motor throttle is opened wide, aviation experts explained.

     Previously, company officials explained, a limiting factor in the speed at which an airplane could dive was the engine’s revolutions each minute, since overspeeding would result to serious damage to the motor.

     The Curtis Hawk 75A pursuit plane is similar to the Curtiss P-36A, the standard pursuit airplane of the United States Army Air Corps.

     It carried two machine guns and is equipped to carry bombs under each wing when on a fighting mission.

     The greatest previously registered speed was 440.681 miles an hour, made by Francesco Agello of Italy over a three-kilometer course in level flight October 23, 1934.

     The world’s land speed record is held by George E. T. Eyston of England at 357.5 miles an hour, established September 16, 1938.

The Cincinnati Enquirer, Vol. XCVIII, No. 291, Wednesday, January 25, 1939, at Page 1, Columns 1 and 2

A U.S. Army Air Corps Curtiss-Wright P-36 Hawk, 12 MD, assigned to Wright Field for flight testing. (U.S. Air Force)

The Oakland Tribune reported:

‘Faster Than Any Man Alive,’ Flier Says After Diving 575 M.P.H.

     BUFFALO, N.Y., Jan. 25.—(AP)—A test pilot who free-power dived a heavily armed pursuit airplane at more than 575 miles per hour claimed today the distinction of having traveled “faster than any other human being.”

     Chief test pilot H. Lloyd Child dropped a Curtiss Hawk 75A through the clouds above Buffalo Airport yesterday at almost 1000 feet a second to exceed “all known speed records,” the Curtiss aeroplane division of the Curtiss-Wright Corporation announced.

     Child was testing the plane for the French Army, which has purchased 100 of the ships. The terrific speed was recorded on instruments installed by the French Government’s representatives, who witnessed the flight.

     The velocity was so great the marker on the indicator exceeded the instrument’s range and moved off the paper roll. Aviation experts said Child probably exceeded 600 miles per hour.

     “I didn’t feel anything,” the test pilot commented, “it was all over too quickly.”

     Child said the dive was part of a day’s work.

     “No danger at all, I would say,” he commented.

     His spare time hobby, skiing, however, “is awful dangerous,” Child asserted.

     “I wouldn’t be surprised if someone would exceed my speed soon. A diving speed of 700 miles per hour is within the realm of possibility,” he added.

Oakland Tribune, VOL. CXXX—NO. 25, Wednesday, January 25, 1939, Page 3, Columns 2 and 3

The prototype Curtiss-Wright Model 75 Hawk, X17Y, s/n 11923. (Curtiss-Wright Corporation)

The Curtiss-Wright Model 75 was a single-seat, single-engine, low wing monoplane with retractable landing gear. The airplane was designed by Donovan Reese Berlin. Curtiss-Wright intended to offer it as a pursuit for the U.S. Army Air Corps. H. Lloyd Child took the prototype, X17Y,¹ for its first flight 6 May 1935.

Donovan Reese Berlin. A scale model of the Model 75 Hawk stands on his desk. (Niagara Aerospace Museum)

After evaluation by the Air Corps at Wright Field, the rival Seversky Aircraft Corporation SEV-1XP was selected by the Air Corps and 77 P-35s were ordered. Don Berlin worked on improving the Model 75, and in 1937, the Air Corps ordered 210 Curtiss P-36As.

Curtiss-Wright P-36A Hawk. (U.S. Air Force)

Curtiss-Wright also offered versions of the Hawk 75 to foreign governments. Variants were available with fixed or retractable gear, a choice of Pratt & Whitney Twin Wasp or Wright Cyclone engines, and various combinations of machine gun and cannon armament.

The Curtiss Hawk 75 A was 28.8 feet (8.78 meters) long with wingspan of 37.3 feet (11.37 meters) and height of 9.25 feet (2.82 meters). The total wing area was 236.0 square feet (21.93 square meters). With a Pratt & Whitney engine, the airplane had an empty weight of 4,713 pounds (2,127.3 kilograms), and gross weight of 5,922 pounds (2,675.7 kilograms).

French Armée de l’air Curtiss H75-C1 chasseur. (Armée de l’air)

The Armée de l’air initially ordered 100 Hawk 75A-1s, designated H75-C1 in French service. Pratt & Whitney Twin Wasp engines (including spares) were ordered separately. They were delivered to France for final assembly, and were unpainted. These airplanes had minor differences from U.S. Army Air Corps P-36As. For example, the instrument markings were metric. It was French custom to have the throttle off when pushed full forward, and wide open when pulled rearward. The pilot’s seat was different in order to fit the standard French parachute.

The French H75-A1 was powered by an air-cooled, supercharged, 1,829.39-cubic-inch-displacement (29.97 liter) Pratt & Whitney Twin Wasp SC-G [Specification Number PW-5028-C]. This was a two-row 14-cylinder radial engine with a compression ratio of 6.7:1. The SC-G was rated at 900 horsepower at 2,550 r.p.m. at 11,000 feet (3,353 meters), and 1,050 horsepower at 2,700 r.p.m., for take off. The engine drove a three-bladed, 10 foot, 1½ inch (3.086 meters) diameter Curtiss Electric constant-speed propeller through a 16:9 gear reduction. The SC-G was 48.00 inches (1.219 meters) in diameter, 59.90 inches (1.521 meters) long, and weighed 1,423 pounds (645 kilograms).

The Hawk 75A-1 had a maximum cruise speed of 260 miles per hour (418 kilometers per hour) at 19,000 feet (5,790 meters). Its maximum speed was 258 miles per hour (413 kilometers per hour) at Sea Level, 290 miles per hour at 8,200 feet (2,500 meters), and 303 miles per hour (488 kilometers per hour) at 19,000 feet (5,790 meters). Although Child demonstrated a dive at over 575 miles per hour, in service, the Hawk was restricted to a maximum dive speed of 455 miles per hour (732 kilometers per hour). The airplane had a service ceiling of 32,800 feet (9,997 meters), and absolute ceiling of 33,700 feet (10,272 meters).

The Armée de l’air H75A-1 was armed with four FN-Browning de Belgique mle 1938 7.5 mm. × 54 mm MAS machine guns, with two mounted on the engine cowl, synchronized to fire through the propeller arc, and one in each wing. 2,200 rounds of ammunition were carried. The 7.5 mm (the bullet diameter was actually 7.78 mm, or .306-caliber) was a shorter, less powerful cartridge than the .303 British (7.7 × 56 mm) or U.S. standard .30-06 Springfield (7.62 × 63 mm) cartridges.

France followed with orders for Hawk 75A-2, 75A-3 and 75A-4 fighters. These had different combinations of guns and engine variants.

After the surrender of France to invaders from Nazi Germany, many Curtiss Hawks made their way to England. In service with the Royal Air Force, these airplanes were called the Mohawk.

Curtiss H75-C1s in service with France, World War II. (Armée de l’air)

Henry Lloyd Child was born at Philadelphia, Pennsylvania, 25 May 1904, the second of two children of Edward Taggart Child, a consulting engineer in shipbuilding, and Lillian Rushmore Cornell Child. He was baptized at the Church of the Good Shepherd, Rosemont, Pennsylvania, 22 December 1913. Child graduated from Flushing High School in Flushing, New York, then attended the Haverford School in Philadelphia.

Henry Lloyd Child, 1926. (The Class Record)

“Skipper” Child majored in mechanical engineering at the University of Pennsylvania where he was a member of the Hexagon Senior Engineering Society and the Phi Sigma Kappa (ΦΣΚ) and Sigma Tau (ΣΤ) fraternities. He was a member of the varsity and all-state soccer team, and also played football and tennis. Child graduated with a bachelor of science degree, 15 June 1926.

After graduation from college, Child went to work for the Curtiss-Wright Corporation as an engineer.

Child joined the United States Navy, 23 November 1927. He was trained as a pilot at Naval Air Station Hampton Roads, Norfolk, Virginia, and was commissioned as an Ensign. He was promoted to lieutenant (junior grade), 7 November 1932, and to lieutenant, 11 November 1935.

While maintaining his commission in the Navy, Child returned to Curtiss-Wright as a test pilot.

Mr. And Mrs. Henry Lloyd Child (née Allene Anne Gausby), 28 October 1939.

Henry Lloyd Child married Miss Allene Ann Gausby of Hamilton, Ontario, Canada, 28 October 1939. They had met in July 1938, while playing in a tennis tournament at Muskoka, Northern Ontario. They would have a daughter, Beverley L. Child.

Miss Allene Anne Gausby

H. Lloyd Child worked for Lockheed from 1958 to 1968, when he retired. He died at Palmdale, California 5 August 1970 at the age of 66 years.

H. Lloyd Child’s high speed dive was the subject of an 8-page article in “True Comics” #6, November 1941. (Parents’ Magazine Press)

See: http://comicbookplus.com/?dlid=24805

Curtiss advertisement, 1940. (Curtiss-Wright Corporation)

¹ At this time, American experimental aircraft were prohibited from carrying the national identifier, “N-,” to lead their registration mark.

© 2022, Bryan R. Swopes

14 January 1953

Convair XF2Y-1 Sea Dart Bu. No. 137634 during high-speed taxi on San Diego Bay (National Naval Aviation Museum)

14 January 1953: During a high-speed taxi test on San Diego Bay, Convair Chief Test Pilot Ellis Dent (“Sam”) Shannon inadvertently made the first flight of the prototype XF2Y-1 Sea Dart, Bu. No. 137634. The airplane flew approximately 1,000 feet (305 meters) across the bay.

Sam Shannon with the Convair XF2Y-1 Sea Dart. (Image courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

The Sea Dart was a prototype single-seat, twin-engine, delta-winged fighter designed and built by the Convair Division of General Dynamics Corporation at San Diego, California. It was equipped with retractable skis in place of ordinary landing gear to allow it to take off and land on water, snow or sand.

The XF2Y-1 was 52 feet, 7 inches (16.027 meters) long with a wingspan of  33 feet, 8 inches (10.262 meters) and height of 16 feet, 2 inches (4.928 meters) with the skis retracted. The airplane had an empty weight of 12,625 pounds (5,727 kilograms) and maximum takeoff weight of 21,500 pounds (9,752 kilograms).

Convair XF2Y-1 Sea Dart Bu. No. 137634 in flight over San Diego, California. (National Naval Aviation Museum)

The prototype XF2Y-1 was powered by two Westinghouse J34-WE-32 single-shaft axial-flow turbojet engines. The engine used an 11-stage compressor and 2-stage turbine. It was rated at 3,370 pounds (14.99 kilonewtons) of thrust, and 4,900 pounds (21.80 kilonewtons) with afterburner. The J34-WE-32 was 15 feet, 4.0 inches (4.674 meters) long, 2 feet, 1.6 inches (0.650 meters) in diameter, and weighed 1,698 pounds (770.2 kilograms).

The YF2Y-1 service test prototypes that followed were powered by Westinghouse XJ46-WE-2 engines. The J46 was also a single-shaft axial-flow turbojet, but had a 12-stage compressor and 2-stage turbine. These were rated at 4,080 pounds of thrust  (18.15 kilonewtons), and 6,100 pounds (27.13 kilonewtons) with afterburner. The J46-WE-2 was 15 feet, 11.7 inches (4.869 meters) long, 2 feet, 5.0 inches (0.737 meters) in diameter and weighed 1,863 pounds (845 kilograms).

The YF2Y-1 service test aircraft had a maximum speed of 695 miles per hour (1,118 kilometers per hour) at 8,000 feet (2,438 meters), and 825 miles per hour (1,328 kilometers per hour)—Mach 1.25— at 36,000 feet (10,973 meters). The service ceiling was estimated at 54,800 feet (16,073 meters), and the range was 513 miles (826 kilometers).

There was one XF2Y-1 and four YF2Y-1 aircraft built, but only two of the service test aircraft ever flew. The XF2Y-1 prototype is in storage at the Smithsonian Institution National Air and Space Museum’s restoration facility. One YF2Y-1, Bu No. 135763, is displayed at the San Diego Air and Space Museum, and another, Bu. No. 135764, is in the collection of the Harold F. Pitcairn Wings of Freedom Aviation Museum at Horsham, Pennsylvania, about 30 minutes north of Philadelphia.

Convair XF2Y-1 Sea Dart Bu. No. 137634 taxis to the seaplane ramp at the north end of San Diego Bay. (National Naval Aviation Museum)

Ellis Dent Shannon was born at Andalusia, Alabama, 7 February 1908. He was the third of five children of John William and Lucy Ellen Barnes Shannon.

He was commissioned as a second lieutenant the Alabama National Guard (Troop C, 55th Machine Gun Squadron, Cavalry) 21 May 1926. He transferred to the Air Corps, United States Army, in 1929. In 1930, he was stationed at Brooks Army Airfield, Texas.

Lieutenant Ellis Dent Shannon, Air Corps, United States Army

In 1932 Shannon was was assigned as a flight instructor and an aviation advisor to the government of China.

On 24 December 1932, Shannon married Miss Martha Elizabeth Reid at Shanghai, China. They had son, Ellis Reid Shannon, born at Shanghai, 24 August 1934, and a daughter, Ann N. Shannon, born at Baltimore, Maryland, in 1940.

Shannon and his family returned to the United States in 1935 aboard SS Bremen, arriving at New York.

He was employed by the Glenn L. Martin Co., Baltimore, Maryland, in 1936 as a test and demonstration pilot. He traveled throughout Latin America, demonstrating the company’s aircraft. As a test pilot, he flew the Martin Model 187 Baltimore, the B-26 Marauder, PBM Mariner and the Martin JRM Mars.

In February 1943, Shannon started working as a Chief of Flight Research for the Consolidated Aircraft Company at San Diego, California. While there, made the first flights of the Consolidated XB-24K, a variant of the Liberator bomber with a single vertical tail fin; the XR2Y-1, a prototype commercial airliner based on the B-24 Liberator bomber; the XB-46 jet-powered medium bomber; the XP5Y-1 Tradewind, a large flying boat powered by four-turboprop-engines; the Convair 340 Metropolitan airliner; and the XF-92A, a delta-winged proof-of-concept prototype. Shannon also participated in the flight test program of the YF-102A Delta Dart.

After retiring from Convair in 1956, Ellis and Martha Shannon remained in the San Diego area.

Ellis Dent Shannon died at San Diego, California, 8 April 1982 at the age of 74 years.

Ellis Dent Shannon, Convair Chief Test Pilot, circa 1953. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)

© 2018 Bryan R. Swopes

14 January 1950

This is the second Mikoyan Gurevich I 330 prototype, SI 02.
This is the second Mikoyan Gurevich I 330 prototype, SI 02.

14 January 1950: The Mikoyan Gurevich prototype fighter I 330 SI made its first flight with test pilot Ivan Ivashchenko. It would be developed into the MiG 17.

The MiG 17 was an improved version of the earlier MiG 15. It was a single-seat, single engine fighter armed with cannon, and capable of high subsonic and transonic speed.

Mikoyan Gurevich MiG 17.
Mikoyan Gurevich MiG 17.

The prototype’s wings were very thin and this allowed them to flex. The aircraft suffered from “aileron reversal,” in that the forces created by applying aileron to roll the aircraft about its longitudinal axis were sufficient to bend the wings and that caused the airplane to roll in the opposite direction.

The first prototype I 330 SI developed “flutter” while on a test flight, 17 March 1950. This was a common problem during the era, as designers and engineers learned how to build an airplane that could smoothly transition through the “sound barrier.” The rapidly changing aerodynamic forces caused the structure to fail and the horizontal tail surfaces were torn off. The prototype went into an unrecoverable spin. Test pilot Ivashchenko was killed.

Two more prototypes, SI 02 and SI 03, were built. The aircraft was approved for production in 1951.

More than 10,000 MiG 17 fighters were built in the Soviet Union, Poland and China. The type remains in service with North Korea.

A MiG 17 in flight.
A MiG 17 in flight.
Иван Т. Иващенко летчик-испытатель
Иван Т. Иващенко летчик-испытатель

Ива́н Тимофе́евич Ива́щенко (Ivan T. Ivashchenko) was born at Ust-Labinsk, Krasnodar Krai, Russia, 16 October 1905. He served in the Red Army from 1927 to 1930. He graduated from the Kuban State University in 1932.

Ivashchenko was trained as a pilot at the Lugansk Military Aviation School at Voroshilovgrad, and a year later graduated from the Kachin Military Aviation College at Volgograd.

In 1939, he fought in The Winter War. During the Great Patriotic War, Ivan Ivashchenko flew with a fighter squadron in the defense of Moscow.

From 1940 to 1945, Ivan Ivashchenko was a test pilot. He trained at the M.M. Gromov Flight Research Institute at Zhokovsky, southeast of Moscow, in 1941. He was assigned to Aircraft Factory No. 18 at Kuibyshev (Samara) from 1941 to 1943. Ivashchenko flew the Ilyushin Il-2 Sturmovik fighter bomber extensively. From 1943 to 1945 he was a test pilot for Lavochkin OKB at Factory 301 in Khimki, northwest of Moscow.

In 1945 Ivashchenko was reassigned to OKB Mikoyan, where he worked on the development of the MiG 15 and MiG 17 fighters. He participated in testing ejection seat systems and in supersonic flight.

Ivan T. Ivashchenko was a Hero of the Soviet Union, and was awarded the Order of Lenin, Order of the Red Banner (two awards) and Order of the Patriotic War. Killed in the MiG 17 crash at the age of 44 years, he was buried at the Novodevichy Cemetery in Moscow.

© 2017, Bryan R. Swopes

13 January 1942

Heinkel He 280 V-1 DL+AS with engine intake fairings.

13 January 1942:

“. . .The first ejection seats were developed independently during World War II by Heinkel and SAAB. Early models were powered by compressed air and the first aircraft to be fitted with such a system was the Heinkel He 280 prototype jet-engined fighter in 1940. One of the He 280 test pilots, Helmut Schenk, became the first person to escape from a stricken aircraft with an ejection seat on 13 January 1942 after his control surfaces iced up and became inoperable. The fighter, being used in tests of the Argus As 014 impulse jets for Fieseler Fi 103 missile development, had its usual HeS 8A turbojets removed, and was towed aloft from Rechlin, Germany by a pair of Bf 110C tugs in a heavy snow-shower. At 7,875 feet (2,400 m), Schenk found he had no control, jettisoned his towline, and ejected. . . .”

—Wikipedia

Heinkel He 280 V1, DL+AS, the first prototype. The engine intakes and exhausts are faired over. This aircraft was lost 13 January 1942. Helmut Schenk successfully ejected from it. (Unattributed)
A Heinkel He 111 bomber tows the prototype He 280 V1 DL+AS on a snowy runway.

10 January 1964

Boeing B-52H-170-BW 61-023
Boeing B-52H-135-BW Stratofortress 60-0006, similar in appearance to to 61-023. (U.S. Air Force)

10 January 1964: This Boeing B-52H Stratofortress, serial number 61-023, flown by Boeing test pilot Charles F. (“Chuck”) Fisher, was conducting structural testing in turbulence near East Spanish Peak, Colorado. The other crew members were pilots Richard V. Curry and Leo Coer, and navigator James Pittman. Dick Curry was flying the airplane and Chuck Fisher, the aircraft commander, was in the co-pilot’s position. Pittman was on the lower deck.

The bomber was carrying two North American Aviation GAM-77 Hound Dog cruise missiles on pylons under its wings.

The Boeing B-52 Stratofortress had been designed as a very high altitude penetration bomber, but changes in Soviet defensive systems led the Strategic Air Command to change to very low altitude flight as a means of evading radar. This was subjecting the airframes to unexpected stresses. “Ten-Twenty-Three” (its serial number was 61-023, shortened on the vertical fin to “1023”) had been returned to Boeing Wichita by the Air Force to be instrumented to investigate the effects of high-speed, low-altitude flight on the 245-ton bomber.

Flying at 14,300 feet (4,359 meters) and 345 knots (397 miles per hour, 639 kilometers per hour), indicated air speed, the airplane encountered severe clear air turbulence and lost the vertical stabilizer. Several B-52s had been lost under similar circumstances. (Another, a B-52D, was lost just three days later at Savage Mountain, Maryland.)

East Spanish Peak (left), 12,688 feet (3,867 meters) and West Spanish Peak, 13,626 feet (4,153 meters), Sangre de Cristo Mountains, Colorado. (Footwarrior)
East Spanish Peak (left), 12,688 feet (3,867 meters) and West Spanish Peak, 13,626 feet (4,153 meters), Sangre de Cristo Mountains, Colorado. (Footwarrior)
Charles F. Fisher. (Argenta Images)
Charles F. Fisher. (Argenta Images)

Chuck Fisher immediately took control of the B-52. He later reported,

“As the encounter progressed, a very sharp-edged blow which was followed by many more. We developed an almost instantaneous rate of roll at fairly high rate. The roll was to the far left and the nose was swinging up and to the right at a rapid rate. During the second portion of the encounter, the airplane motions actually seemed to be negating my control inputs. I had the rudder to the firewall, the column in my lap, and full wheel, and I wasn’t having any luck righting the airplane. In the short period after the turbulence I gave the order to prepare to abandon the airplane because I didn’t think we were going to keep it together.”

A Boeing report on the incident, based on installed sensors and instrumentation aboard -023, said that the bomber had

“. . . flown through an area containing the combined effects of a (wind) rotor associated with a mountain wave and lateral shear due to airflow around a mountain peak. . . Gust initially built up from the right to a maximum of about 45 feet per second [13.7 meters per second](TAS), then reversed to a maximum of 36 feet per second [11 meters per second] from the left, before swinging to a maximum of about 147 feet per second [44.8 meters per second] from the left followed by a return to 31 feet per second [9.5 meters per second].”

Fisher flew the bomber back to Wichita and was met by a F-100 Super Sabre chase plane. When the extent of the damage was seen, the B-52 was diverted due to the gusty winds in Kansas. Six hours after the damage occurred, Chuck Fisher safely landed the airplane at Eaker Air Force Base, Blythville, Arkansas. He said it was, “the finest airplane I’ve ever flown.”

Boeing B-52H-170-BW Stratofortress 61-023, "Ten-Twenty-Three", after losing the vertical fin, 10 January 1964. (Boeing)
Boeing B-52H-170-BW Stratofortress 61-023, “Ten-Twenty-Three”, after losing the vertical fin, 10 January 1964. (Boeing)

61-023 was repaired and returned to service. It remained active with the United States Air Force until it was placed in storage at Tinker Air Force Base, Oklahoma, 24 July 2008.

Charles F. Fisher and the Boeing test crew with B-52H Stratofortress 61-023. (Boeing)
Charles F. Fisher at left,  and the Boeing test crew with B-52H Stratofortress 61-023. (Boeing)

The B-52H is a sub-sonic, swept wing, long-range strategic bomber. It has a crew of five. The airplane is 159 feet, 4 inches (48.6 meters) long, with a wing span of 185 feet (56.4 meters). It is 40 feet, 8 inches (12.4 meters) high to the top of the vertical fin. Maximum Takeoff Weight (MTOW) is 488,000 pounds (221,353 kilograms).

There are eight Pratt & Whitney TF33-PW-3 turbofan engines mounted in two-engine pods suspended under the wings on four pylons. Each engine produces a maximum of 17,000 pounds of thrust (75.620 kilonewtons). The TF-33 is a two-spool axial-flow turbofan engine with 2 fan stages, 14-stage compressor stages (7 stage intermediate pressure, 7 stage high-pressure) and and 4-stage turbine (1 stage high-pressure, 3-stage low-pressure). The engine is 11 feet, 10 inches (3.607 meters) long, 4 feet, 5.0 inches (1.346 meters) in diameter and weighs 3,900 pounds (15,377 kilograms).

The B-52H can carry approximately 70,000 pounds (31,750 kilograms) of ordnance, including free-fall bombs, precision-guided bombs, thermonuclear bombs and cruise missiles, naval mines and anti-ship missiles.

The bomber’s cruise speed is 520 miles per hour (837 kilometers per hour) and its maximum speed is 650 miles per hour (1,046 kilometers per hour) at 23,800 feet (7,254 meters) at a combat weight of 306,350 pounds. Its service ceiling is 47,700 feet (14,539 meters) at the same combat weight. The unrefueled range is 8,000 miles (12,875 kilometers).

With inflight refueling, the Stratofortress’s range is limited only by the endurance of its five-man crew.

The B-52H is the only version still in service. 102 were built and as of June 2019, 76 are still in service. Beginning in 2013, the Air Force began a fleet-wide technological upgrade for the B-52H, including a digital avionics and communications system, as well as an internal weapons bay upgrade. The bomber is expected to remain in service until 2040.

Boeing B-52H-170-BW Stratofortress 61-023 taxiing at Minot Air Force Base, North Dakota. (Senior Airman Cassandra Jones, U.S. Air Force)
Boeing B-52H-170-BW Stratofortress 61-023 taxiing at Minot Air Force Base, North Dakota. (Senior Airman Cassandra Jones, U.S. Air Force)

© 2016, Bryan R. Swopes