Martin B-57 Canberra

The Martin B-57 Canberra is an American-built, twin jet engine tactical bomber and reconnaissance aircraft that entered service with the United States Air Force (USAF) in 1953. The B-57 was a license-built version of the English Electric Canberra; the Glenn L. Martin Company later modified the design to produce several different variants.

The Canberra was the first U.S. jet bomber to drop bombs during combat. Its retirement in 1983 ended the era of the tactical bomber that had its beginning with the World War I De Havilland DH-4. The three remaining flightworthy WB-57Fs are technically assigned to the NASA Johnson Space Center, next to Ellington Field in Houston, as high-altitude scientific research aircraft, but are also used for testing and communications in the U.S. and Afghanistan.


Martin B-57 Canberra
Class Aircraft
Type Bomber
Manufacturer Glenn L. Martin Company
Origin United States of America
Country Name Origin Year
United States of America 1953
Country Name Operational Year Retirement Year
China View
Pakistan 1954 1985 View
United States of America 1954 1983 View
ManufacturerName Production From Production To Quantity
Glenn L. Martin Company 403 View

At the outbreak of the Korean War in 1950, the USAF found itself in dire need of an all-weather interdiction aircraft. The piston-engined Douglas A-26 Invaders were limited to fair weather operations and were in short supply. On 16 September 1950, the USAF issued a request for a jet-powered bomber with a top speed of 630 mph (1,020 km/h), ceiling of 40,000 feet (12,190 m), and range of 1,150 miles (1,850 km). Full all-weather capability and secondary reconnaissance role had to be included in the design. To expedite the process, only projects based on existing aircraft were considered. The contenders included the Martin XB-51, and the North American B-45 Tornado and AJ Savage.

Unusually, the service considered foreign aircraft, including the Canadian Avro Canada CF-100 Canuck and the new British English Electric Canberra, which had not yet officially entered service with the Royal Air Force (RAF). The AJ and B-45 were quickly dismissed, because their outdated designs had limited growth potential. The CF-100, an all-weather interceptor, was too small and lacked sufficient range. The XB-51, while very promising and much faster, had limited maneuverability, a small weapons bay and limited range and endurance.

On 21 February 1951, a British Canberra B.2 flown by Roland Beamont became the first jet to make a nonstop unrefueled flight across the Atlantic Ocean, arriving in the United States for USAF evaluation. In a 26 February flyoff against the XB-51, the Canberra emerged a clear winner. It was officially taken up by the USAF on 25 May 1951.

However, because its production lines were working at full capacity to meet the Royal Air Force orders, English Electric was unable to produce additional aircraft quickly enough for USAF requirements, and on 3 April 1951, Martin was granted a license to build Canberras, designated B-57 (Martin Model 272) in the United States. To expedite production, the first B-57As were largely identical to the Canberra B.2, with the exception of more powerful Armstrong Siddeley Sapphire engines of 7,200 lbf (32 kN) of thrust instead of Rolls-Royce Avons, also license-built in the United States as Wright J65s. In addition, canopy and fuselage windows were slightly revised, the crew was reduced from three to two, wingtip fuel tanks were added, engine nacelles were modified with additional cooling scoops, and the conventional "clamshell" bomb bay doors were replaced with a low-drag rotating door originally designed for the XB-51.

The first production aircraft flew on 20 July 1953, and was accepted by the USAF a month later on 20 August. During the production run from 1953 to 1957, a total of 403 B-57s were built.

The B-57A was not considered combat-ready by the USAF and the aircraft were used solely for testing and development. One of the aircraft was given to the National Oceanic and Atmospheric Administration (NOAA) which fitted it with a new nose radome and used it to track hurricanes. The aircraft was placed into limited production. Particularly contentious were the cockpit arrangement and the lack of guns, the Canberra having been designed as a high-speed, high altitude bomber rather than for close air support. The definitive B-57B introduced a new tandem cockpit with a bubble canopy, the engines were now started with a pyrotechnic cartridge, the airbrakes were moved from the wings to the sides of the fuselage for increased effectiveness, the controls were now boosted, four hardpoints were fitted under the wings, and the aircraft was given gun armament in the form of eight 0.50 in (12.7 mm) Browning machine guns in the wings, later replaced by four 20 mm M39 cannons. The first B-57B flew on 18 June 1954. The aircraft initially suffered from the same engine malfunctions as the RB-57As and several were lost in high-speed low-level operations due to a faulty tailplane actuator which caused the aircraft to dive into the ground. The USAF considered the B-57B inadequate for the night intruder role and Martin put all aircraft through an extensive avionics upgrade. Regardless, by the end of 1957, the USAF tactical squadrons were being re-equipped with supersonic North American F-100 Super Sabres. The complete retirement was delayed, however, by the start of the Vietnam War.

Role Tactical bomber
Manufacturer Martin
First flight 20 July 1953
Introduction 1954
Retired 1983 (USAF)
1985 (Pakistan)
Status Retired (3 still used by NASA)
Primary users United States Air Force
Pakistan Air Force
Republic of China Air Force
Number built 403
Unit cost US$1.26 million (B-57B)
Developed from English Electric Canberra
Variants Martin RB-57D Canberra
Developed into Martin/General Dynamics RB-57F Canberra


General characteristics

  • Crew: 2 (pilot,navigator )
  • Length: 65 ft, 6 in (20.0 m)
  • Wingspan: 64 ft 0 in (19.5 m)
  • Height: 14 ft 10 in (4.52 m)
  • Wing area: 960 ft² (89 m²)
  • Empty weight: 27,090 lb (12,285 kg)
  • Loaded weight: 40,345 lb (18,300 kg)
  • Max. takeoff weight: 53,720 lb (24,365 kg)
  • Powerplant: 2 × Wright J65-W-5 turbojets, 7,220 lbf (32.1 kN) each
  • Zero-lift drag coefficient: 0.0119
  • Drag area: 11.45 ft² (1.06 m²)
  • Aspect ratio: 4.27

Performance

  • Maximum speed: Mach 0.79 (598 mph, 960 km/h) at 2,500 ft (760 m)
  • Cruise speed: 476 mph (414 knots, 765 km/h)
  • Stall speed: 124 mph (108 knots, 200 km/h)
  • Combat radius: 950 mi (825 nm, 1,530 km) with 5,250 lb (2,380 kg) of bombs
  • Ferry range: 2,720 mi (2,360 nm, 4,380 km)
  • Service ceiling: 45,100 ft (13,745 m)
  • Rate of climb: 6,180 ft/min (31.4 m/s)
  • Wing loading: 42 lb/ft² (205 kg/m²)
  • Thrust/weight: 0.36
  • Lift-to-drag ratio: 15.0

Armament

  • Guns: 4× 20 mm (0.787 in) M39 cannon, 290 rounds/gun
  • Bombs:
    4,500 lb (2,000 kg) in bomb bay, including nuclear bombs
    2,800 lb (1,300 kg) on four external hardpoints, including unguided rockets

Avionics

  • APW-11 Bombing Air Radar Guidance System
  • SHORAN bombing system

APS-54 Radar Warning Receiver

End notes