The B-57 is a license-built version of the British English Electric Canberra, manufactured by the Glenn L. Martin Company. The twin-engined tactical bomber and reconnaissance aircraft that entered service with the United States Air Force (USAF) in 1953. Initial Martin-built models were virtually identical to their British-built twinjet counterparts; Martin later modified the design to incorporate larger quantities of US-sourced components and produced the aircraft in several different variants.The B-57 Canberra holds the distinction of being the first jet bomber in U.S. service to drop bombs during combat. The Canberra was used extensively during the Vietnam War in a bombing capacity; dedicated versions of the type were also produced and served as high-altitude aerial reconnaissance platforms (the Martin RB-57D Canberra), and as electronic warfare aircraft. The B-57 Canberra was also sold to export customers abroad; further combat use was seen by the Pakistani Air Force during the Indo-Pakistani War of 1965 and the Indo-Pakistani War of 1971.In 1983, the USAF opted to retire the type; the B-57 Canberra’s retirement marked the ending of the era of the tactical bomber. 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 have also been used for testing and electronic communications in the U.S. and Afghanistan.At the outbreak of the Korean War in 1950, the USAF found itself in dire need of an all-weather interdiction aircraft. The existing inventory of piston-engined Douglas B-26 Invaders had been dispatched in this capacity at the very start of the conflict; however, within only a few months within the theatre, the B-26 had suffered a very high rate of attrition and successes with the type were typically limited. In response to these needs, the USAF requested the British government to provide a private demonstration of the English Electric Canberra, a newly developed jet-powered bomber. On 17 August 1950, the Canberra demonstration was performed at RAF Burtonwood in Warrington, Cheshire, England; during the following month, a team of US test pilots and engineers visited English Electric’s Warton factory to perform a series of flight tests and a detailed technical assessment of the aircraft.On 16 September 1950, the USAF formally issued a request for a jet-powered bomber; the sought aircraft had to possess a top speed of 630 mph (1,010 km/h), ceiling of 40,000 feet (12,000 m), and range of 1,150 mi (1,850 km). Full all-weather capability and a secondary reconnaissance role also had to be included in the design. The American contenders included the Martin XB-51, the North American B-45 Tornado and AJ Savage. To expedite the process, only projects based on existing aircraft were considered and, unusually, the service considered foreign aircraft. These included the Canadian Avro Canada CF-100 and the British English Electric Canberra, which had not yet officially entered service with the Royal Air Force (RAF).As part of the USAF’s evaluation process, all five aircraft were submitted to a series of fly-offs to determine their performance. On 21 February 1951, a British Canberra B.2 (WD932), flown by Roland Beamont, made the transatlantic journey, arriving in the United States to participate in the competition; by making this journey, the Canberra thus became the first jet aircraft to perform a non-stop unrefueled flight across the Atlantic Ocean, travelling from Warton, England, to Gander, Newfoundland and Labrador, Canada, in the record time of 4 hours 37 minutes.General characteristicsCrew: 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 sq ft (89 m2)Empty weight: 27,090 lb (12,285 kg)Gross weight: 40,345 lb (18,300 kg)Max takeoff weight: 53,720 lb (24,365 kg)Zero-lift drag coefficient: 0.0119Drag area: 11.45 ft2 (1.06 m2)Aspect ratio: 4.27Powerplant: 2 × Wright J65-W-5 turbojets, 7,220 lbf (32.1 kN) thrust eachPerformanceMaximum speed: 598 mph (960 km/h, 520 kn) at 2,500 ft (760 m)Maximum speed: Mach 0.79Cruise speed: 476 mph (765 km/h, 414 kn)Stall speed: 124 mph (200 km/h, 108 kn)Combat range: 950 mi (1,530 km, 825 nmi) with 5,250 lb (2,380 kg) of bombsFerry range: 2,720 mi (4,380 km, 2,360 nmi)Service ceiling: 45,100 ft (13,745 m)Rate of climb: 6,180 ft/min (31.4 m/s)Wing loading: 42 lb/sq ft (205 kg/m2)Thrust/weight: 0.36Lift-to-drag ratio: 15.0ArmamentGuns: 4× 20 mm (0.787 in) M39 cannon, 290 rounds/gunBombs:4,500 lb (2,000 kg) in bomb bay, including nuclear bombs2,800 lb (1,300 kg) on four external hardpoints, including unguided rocketsAvionicsAPW-11 Bombing Air Radar Guidance SystemSHORAN bombing systemAPS-54 Radar Warning Receiver#B57canberra #bomber #aircraft