Martin XB-48

The Martin XB-48 was an American medium jet bomber developed in the mid-1940s. It competed with the Boeing B-47 Stratojet, which proved to be a superior design, and was largely considered as a backup plan in case the B-47 ran into development problems. It never saw production or active duty, and only two prototypes, serial numbers 45-59585 and 45-59586,[2] were built.

Role Bomber
Manufacturer Glenn L. Martin Company
First flight 22 June 1947
Status Canceled in 1948
Number built 2
Unit cost
US$11.5 million for the program[1] (equivalent to $119.9 million today)
Martin XB-48 taxiing
Martin XB-48 prototype taxiing, showing spaces between engines for cooling, tandem main gear, and nacelle outriggers

Design and development

In 1944, the U.S. War Department was aware of aviation advances in Germany and issued a requirement for a range of designs for medium bombers weighing from 80,000 pounds (36,000 kg) to more than 200,000 pounds (91,000 kg). Other designs resulting from this competition, sometimes nicknamed "The Class of '45", included the North American XB-45 and the Convair XB-46. Production orders finally went to the North American B-45 Tornado, and even this airplane served only for a couple of years before again being replaced by the much more modern Boeing B-47 Stratojet, although the B-45 had the inherent performance – especially if it was not burdened with a payload – for it to then serve as a reconnaissance aircraft.

All of the bombers comprising the Class of '45 were transitional aircraft, which combined the power of turbojets with the aeronautical knowledge of World War II. The XB-48 was no exception, as its round fuselage and unswept wings showed a distinct influence of Martin's B-26 Marauder medium bomber. Still, where the B-26 had enough thrust with two massive 18-cylinder radial engines, the XB-48 needed no less than six of the new jet engines.

At the time of the XB-48's design, jet propulsion was still in its infancy. And, although it appeared superficially to have six separate engine nacelles – that is, three under each wing – the XB-48 actually had only two, unusually wide, three-engined nacelles. Each of these large nacelles also contained an intricate set of air ducts that constituted the engines' cooling system.

The XB-48 was the first aircraft designed with bicycle-type tandem landing gear, which had previously been tested on a modified B-26. The wing airfoil was too thin to house conventional landing gear mechanisms.[3] The main landing gear was in the fuselage and small outriggers located on each wing were used to balance the aircraft.

Operational history

The XB-48 made its first flight on 22 June 1947, a 37-minute, 73 mi (117 km) hop from Martin's Baltimore, Maryland plant to NAS Patuxent River, Maryland, but blew all four tires on its fore-and-aft mounted undercarriage on landing when pilot Pat Tibbs applied heavy pressure to the specially-designed, but very slow to respond, insensitive air-braking lever. Tibbs and co-pilot Dutch Gelvin were uninjured.[4]

Specifications (XB-48)

Data from "Encyclopedia of US Air Force Aircraft and Missile Systems, Volume II"[5]

General characteristics

  • Crew: three (pilot, co-pilot, and bomber-navigator)
  • Length: 85 ft 9 in (26.14 m)
  • Wingspan: 108 ft 4 in (33.02 m)
  • Height: 26 ft 6 in (8.08 m)
  • Wing area: 1,330 ft² (123.5 m²)
  • Empty weight: 58,500 lb (26,535 kg)
  • Loaded weight: 92,600 lb (42,000 kg)
  • Max. takeoff weight: 102,600 lb (46,540 kg)
  • Powerplant: 6 × General Electric J35 axial flow turbojet, 3,820 lbf (17 kN) each



  • Guns: 2 × .50 in (12.7 mm) M-2 machine guns in tail turret (proposed)[3]
  • Bombs: 1 × 20,000 lb (9,980 kg) or 36 × 250 lb (113 kg)

See also

Aircraft of comparable role, configuration and era

Related lists



  1. ^ Knaack 1988
  2. ^ "Fact Sheet: Martin XB-48." Archived 2007-06-29 at the Wayback Machine National Museum of the United States Air Force. Retrieved: 5 July 2010.
  3. ^ a b Jones 1969
  4. ^ Mizrahi 1999, pp. 50–52.
  5. ^ Knaack, Marcelle Size. Encyclopedia of U.S. Air Force Aircraft and Missile Systems: Volume II: Post-World War II Bombers, 1945–1973. Washington, DC: Office of Air Force History, 1988. ISBN 0-16-002260-6.


  • Jones, Lloyd S. U.S. Bombers, B-1 1928 to B-1 1980s. Fallbrook, CA: Aero Publishers, 1962, second edition 1974. ISBN 0-8168-9126-5.
  • Mizrahi, Joe. "The Last Great Bomber Fly Off". Wings, Volume 29, Number 3, June 1999.

External links

Allison J35

The General Electric/Allison J35 was originally developed by General Electric (GE company designation TG-180) in parallel with the Whittle-based centrifugal-flow J33, and was the United States Air Force's first axial-flow (straight-through airflow) compressor engine. The J35 was fairly simple, consisting of an eleven-stage axial-flow compressor and a single-stage turbine. With the afterburner, which most models carried, it produced a thrust of 7,400 lbf (32.92 kN).

Like the J33, the design of the J35 originated at General Electric, but major production was by the Allison Engine Company.


B48 may refer to:

B48 (New York City bus), a bus line in Brooklyn

HLA-B48, a HLA-B serotype

Martin XB-48, an American aircraft

BMW B48 Engine, an engine BMW AG produces.

Boeing B-47 Stratojet

The Boeing B-47 Stratojet (company Model 450) is a retired American long-range, six-engined, turbojet-powered strategic bomber designed to fly at high subsonic speed and at high altitude to avoid enemy interceptor aircraft. The primary mission of the B-47 was as a nuclear bomber capable of striking targets within the Soviet Union.

Development of the B-47 can be traced back to a requirement expressed by the United States Army Air Forces (USAAF) in 1943 for a reconnaissance bomber that harnessed newly developed jet propulsion. Another key innovation adopted during the development process was the swept wing, drawing upon captured German research. With its engines carried in nacelles underneath the wing, the B-47 represented a major innovation in post-World War II combat jet design, and contributed to the development of modern jet airliners. Suitably impressed, in April 1946, the USAAF ordered two prototypes, designated "XB-47"; on 17 December 1947, the first prototype performed its maiden flight. Facing off competition such as the North American XB-45, Convair XB-46 and Martin XB-48, a formal contract for 10 B-47A bombers was signed on 3 September 1948. This would be soon followed by much larger contracts.

During 1951, the B-47 entered operational service with the United States Air Force's Strategic Air Command (SAC), quickly becoming a mainstay of its bomber strength by the late 1950s. Over 2,000 were manufactured to meet the Air Force's extensive demands, driven by the tensions of the Cold War. The B-47 was in service as a strategic bomber until 1965, at which point it had largely been supplanted by more capable aircraft, such as the Boeing B-52 Stratofortress. However, the B-47 was also adapted to perform a number of other roles and functions, including photographic reconnaissance, electronic intelligence, and weather reconnaissance. While never seeing combat as a bomber, reconnaissance RB-47s would occasionally come under fire near to or within Soviet air space. The type remained in service as a reconnaissance aircraft until 1969; a handful served as flying testbeds up until 1977.

Convair XB-46

The Convair XB-46 was a single example of an experimental medium jet bomber which was developed in the mid-1940s but which never saw production or active duty. It competed with similar designs, the North American XB-45 and Martin XB-48, all of which saw little use after the successful development of the Boeing XB-47.

Fat Man

"Fat Man" was the codename for the nuclear bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945. It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation marked the third nuclear explosion in history. It was built by scientists and engineers at Los Alamos Laboratory using plutonium from the Hanford Site, and it was dropped from the Boeing B-29 Superfortress Bockscar piloted by Major Charles Sweeney.

The name Fat Man refers to the early design of the bomb because it had a wide, round shape; it was also known as the Mark III. Fat Man was an implosion-type nuclear weapon with a solid plutonium core. The first of that type to be detonated was the Gadget in the Trinity nuclear test less than a month earlier on 16 July at the Alamogordo Bombing and Gunnery Range in New Mexico. Two more were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946, and some 120 were produced between 1947 and 1949, when it was superseded by the Mark 4 nuclear bomb. The Fat Man was retired in 1950.

Glenn L. Martin Company

The Glenn L. Martin Company was an American aircraft and aerospace manufacturing company founded by aviation pioneer Glenn L. Martin. The Martin Company produced many important aircraft for the defense of the US and allies, especially during World War II and the Cold War. During the 1950s and 60s, the Martin Company moved from the aircraft industry into the guided missile, space exploration, and space utilization industries.

In 1961, the Martin Company merged with American-Marietta Corporation, a large sand and gravel mining company, forming Martin Marietta Corporation. In 1995, Martin Marietta merged with aerospace giant Lockheed to form the Lockheed Martin Corporation.

Guy M. Townsend

Guy Mannering Townsend III (October 25, 1920 – March 28, 2011) was a retired United States Air Force brigadier general, test pilot, and combat veteran. As an Air Force officer, he served as chief of bomber test at Wright-Patterson Air Force Base, flew as co-pilot on the first flight of the B-52 Stratofortress, was test force director for the XB-70 Valkyrie, and served as program director for the C-5 Galaxy and B-1 Lancer. He was the first military pilot to fly the B-47 Stratojet, B-50 Superfortress, B-52 Stratofortress, and the prototype of the KC-135 Stratotanker. During his years at Boeing, he was the head of the Supersonic Transport operations organization.

Ilyushin Il-22

For the 1970s Airborne Command Post aircraft of the same designation, see Ilyushin Il-18

The Ilyushin Il-22, USAF/DOD designation Type 10, was the first Soviet jet-engined bomber to fly. It used four Lyulka TR-1 turbojets carried on short horizontal pylons ahead and below the wing. The engines did not meet their designed thrust ratings and their fuel consumption was higher than planned. These problems meant that the aircraft could not reach its required performance and it was cancelled on 22 September 1947.

List of United States bomber aircraft

This is a list of United States bomber aircraft

List of accidents and incidents involving military aircraft (1945–1949)

This is a list of accidents and incidents involving military aircraft which occurred between 1945 and 1949, grouped by the year in which the accident or incident occurred. Not all of the aircraft were in operation at the time. For more exhaustive lists, see the Aircraft Crash Record Office or the Air Safety Network or the Dutch Scramble Website Brush and Dustpan Database. Combat losses are not included except for a very few cases denoted by singular circumstances.

List of bomber aircraft

The following is a list of bomber airplanes and does not include bomber airships, organized by era and manufacturer. A bomber is a military aircraft designed to attack ground or sea targets.

List of radars

This is a list of radars. A radar is an electronic system used to detect, range (determine the distance of), and map various types of targets.

Martin B-26 Marauder

The Martin B-26 Marauder is an American twin-engined medium bomber built by the Glenn L. Martin Company in Middle River, Maryland (just east of Baltimore) from 1941 to 1945. First used in the Pacific Theater of World War II in early 1942, it was also used in the Mediterranean Theater and in Western Europe.

After entering service with the United States Army aviation units, the aircraft quickly received the reputation of a "widowmaker" due to the early models' high accident rate during takeoffs and landings. This was due to the fact that the Marauder had to be flown at exact airspeeds, particularly on final runway approach or when one engine was out. The unusually high 150 mph (241 km/h) speed on short final runway approach was intimidating to many pilots who were used to much slower approach speeds, and whenever they slowed down to speeds below what the manual stipulated, the aircraft would often stall and crash.The B-26 became a safer aircraft once crews were re-trained, and after aerodynamics modifications (an increase of wingspan and wing angle-of-incidence to give better takeoff performance, and a larger vertical stabilizer and rudder). The Marauder ended World War II with the lowest loss rate of any USAAF bomber.A total of 5,288 were produced between February 1941 and March 1945; 522 of these were flown by the Royal Air Force and the South African Air Force. By the time the United States Air Force was created as an independent military service separate from the United States Army in 1947, all Martin B-26s had been retired from U.S. service. After the Marauder was retired the unrelated Douglas A-26 Invader then assumed the "B-26" designation which led to confusion between the two aircraft.

North American B-45 Tornado

The North American B-45 Tornado was an early American jet-powered bomber designed and manufactured by aircraft company North American Aviation. It has the distinction of being the first operational jet bomber to enter service with the United States Air Force (USAF), as well as being the first multiengine jet bomber in the world to be refueled in midair.The B-45 originated from a wartime initiative launched by the U.S. War Department, which sought a company to develop a jet-propelled bomber to equal those being fielded by Nazi Germany, such as the Arado Ar 234. Following a competitive review of the submissions, the War Department issued a contract to North American to develop its NA-130 proposal; on 8 September 1944, work commenced on the assembly of three prototypes. However, progress on the program was delayed by post-war cutbacks in defense expenditure, but soon regained importance due to growing tensions between America and the Soviet Union. On 2 January 1947, North American was issued with a production contract for the bomber by the USAF, which had been designated B-45A. On 24 February 1947, the first prototype performed its maiden flight.

Soon after its entry to service on 22 April 1948, early B-45 operations were troubled by technical problems, particularly low levels of engine reliability. The USAF found the type to be quite useful during the Korean War, it was used to perform both conventional bombing and aerial reconnaissance missions in this theatre. On 4 December 1950, the first successful interception of a jet bomber by a jet fighter occurred when a B-45 was shot down by a Soviet-built MiG-15 while inside Chinese airspace. During the early 1950s, a total of 40 B-45s were extensively modified so that they could be equipped with nuclear weapons; for this purpose, improvements were made to their defensive systems and the fuel tankage was expanded to increase the type's survivability and range.

In its heyday, the B-45 become an important element of the United States' defense strategy, performing the strategically-critical deterrence mission for several years during the early 1950s, after which time the Tornado was quickly superseded by the larger and more capable Boeing B-47 Stratojet. Both bomber-orientated B-45s and reconnaissance-orientated RB-45s served in quantity in the USAF's Strategic Air Command from 1950 until 1959. The USAF withdrew the last examples of the type in favour of the more advanced Convair B-58 Hustler, an early supersonic bomber. The Tornado was also adopted by the Royal Air Force (RAF) and operated from bases in Britain, where it was repeatedly used to overfly the Soviet Union on various intelligence-related missions. The RAF operated the type until it had introduced its own indigenously-developed jet bomber fleet, initially in the form of the English Electric Canberra.

OKB-1 EF 131

The OKB-1/Junkers EF-131 was a jet bomber produced in Germany and the USSR from 1944.

Roland Beamont

Wing Commander Roland Prosper "Bee" Beamont, (10 August 1920 – 19 November 2001) was a British fighter pilot for the Royal Air Force and an experimental test pilot during and after the Second World War. He was the first British pilot to exceed Mach 1 in a British aircraft in level flight (P.1A), and the first to fly a British aircraft at Mach 2 (P.1B).During the Second World War, he flew more than five hundred operational sorties. He also spent several months as a Hawker experimental test pilot developing the Hawker Typhoon and Tempest, and was responsible for introducing these types into operational squadron service. He pioneered the ground attack capabilities of the Typhoon and led the air to air campaign against the V-1 flying bomb

In 1945 he commanded the Air Fighting Development Squadron at RAF Central Fighter Establishment, before leaving the service in 1947. During his subsequent career as English Electric Aviation chief test pilot (and later for BAC), he directed the flight test programmes of the Canberra, the Lightning, and TSR-2, making the maiden flight of each type.When he retired from test flying in 1968, he had flown 167 different types during a total of 5,100hr and 8,000 flights—of which more than 1,100 were supersonic. He set three Atlantic records in the Canberra, including Britannia Trophy for the first double Atlantic flight in one day. In 1971, he became Panavia flight operations director, responsible for the testing of the Tornado, retiring in August 1979 following the maiden flight of the first production Tornado. After retirement he contributed to aviation journals and wrote a number of books about his experiences.

Beamont was a careful pilot who understood the capabilities of the aircraft he flew. He was proud that he had never broken an aircraft, nor had to bail out or eject. Even when his Tempest was shot down, he had made the best landing possible in the circumstances and got out, free of injury.

Short Sperrin

The Short SA.4 Sperrin (named after the Sperrin Mountains) was a British jet bomber design of the early 1950s, built by Short Brothers and Harland of Belfast. It first flew in 1951. From the onset, the design had been viewed as a fall-back option in case the more advanced strategic bomber aircraft, then in development to equip the Royal Air Force's nuclear-armed V bomber force, experienced delays; the Sperrin was not put into production because these swept-wing designs, such as the Vickers Valiant, were by then available.

As their usefulness as an interim bomber aircraft did not emerge, a pair of flying prototypes were instead used to gather research data on large jet aircraft and to support the development of other technologies, such as several models of jet engines. The two aircraft completed were retired in the late 1950s and ultimately scrapped sometime thereafter.

Sukhoi Su-10

The Sukhoi Su-10 or Izdeliye Ye (Russian: Product E) was a Soviet turbojet-powered bomber aircraft built shortly after World War II.

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