The B-57 Canberra is a by-product of the English Electric Canberra, the first British built jet bomber. The US Air force felt a need for this type of bomber during the Korean conflict as the existing Douglas B-26 could not meet up the requirements.
Although the B-57 was originally procured by the USAF as a night intruder, it has been successfully used in many other roles, including photoreconnaissance and strategic bombing. No distinctive design innovations were incorporated in the purely subsonic B-57; however, its pertinent design parameters were chosen in such a way that the aircraft was readily adaptable to a variety of roles calling for diverse characteristics.
Adopting a foreign made aircraft was not easy for the manufacturer, so it suffered several difficulties. Methods of production were different, so were the materials and tools. Another problem centered around the Wright J65 turbojets, during replacement of the Canberra’s 2 Rolls Royce Avon turbojet engines. Though the US Air Force was completely aware of these potential drawbacks, it had no better option; as an immediate requirement for a light jet bomber was in line, with a 40,000 foot service ceiling, a 1,000 nautical mile range, and a maximum speed of 550 knots.
The US Air Force wanted the new bomber to be capable of operating from unimproved airfields, at night and in every kind of weather with atomic weapons. High altitude reconnaissance was another necessity. The existing B-45 was too heavy; the Navy AJ-1 was too slow; and the Martin experimental B-51’s range was too short; so the emergence of B-57 Canberra became inevitable. The desire for a night intruder was so strong that it took just a few days to endorse the production of it. The Glenn L. Martin Company was recognized as the most qualified contractor for the production of this aircraft and to deal with the likely engineering difficulties involved in manufacturing.
The B-57 was basically considered as a light bomber. The performance characteristics of the B-57B and the B-45C have many similarities. With a gross weight of 53,721 pounds, the B-57B was 2,000 pounds lighter than the Boeing B-17G, one of the standard heavy bombers of World War II. Mission radius of the B-57B was 948 miles with a payload of 5240 pounds, and ferry range was 2722 miles. Maximum speed was 598 miles per hour; Mach 0.79; at 2500 feet and cruising speed was 476 miles per hour. Being about twice as heavy as the B-57B, the B-45C carried nearly twice the payload for approximately the same mission distance.
Even though the USAF did foresee problems with the development of the B-57, the magnitude of it crossed all limits. Testing of two imported Canberras revealed design faults that could affect the safety, utility, and maintenance of the aircraft. Then, one of the British planes crashed; Martin’s subcontractors could not meet their commitments; and the J65 prototype engines consistently failed to satisfy the requirements set by the USAF.
In June 1952, further test flights had to be postponed for a year because of continuing engine and cockpit troubles. As a result, the Korea bound B-57 did not fly before 20 July 1953, just 7 days before the conflict ended.
Later, the manufacturer converted these aircrafts into reconnaissance version. The new RB-57 had more powerful J65 engines and added equipments. These aircrafts entered service in mid 1954. The increased improvements however increased the aircraft’s weight, in turn reducing the speed, distance, and altitude of both the B-57 and the RB-57.
Douglas B/RB-66s was in the horizon but there were no sign that the USAF would cancel the production of the disappointing B/RB-57 program. Steps were taken to ensure that the deficient B/RB-57s would be operational. This turned out to be expensive; later and considerably improved models still carried flaws, but in the long run the program’s retention proved sound. In 1955, the B/RB-57s program justified its cost when it served overseas after the B/RB-66 deliveries fallen behind schedule.
Deliveries of the RB-57 in May 1963 and the B-57 in February 1965 started to show under fire in Southeast Asia and justified the Canberra’s original selection. In 1970, other reactivated and newly equipped B-57s, known as Tropic Moon III B-57Gs, were deployed to Southeast Asia, where they made valuable contributions until April 1972. The WB-57Fs flew in high altitude radiation sampling missions in 1973. At the same time, EB-57Es, and related adaptations of the versatile B-57, continued to play significant roles.
The Canberra B-57 series was deployed in many wars, including in Vietnam and in the undeclared war with Britain in the Falkland Islands.
The B-57 was not easy to fly. Moreover, prior to modification of its longitudinal control and stabilizer systems, the B-57 was uncontrollable if 1 of its 2 engines failed during takeoff or landing. About 47 aircrafts were destroyed in major accidents. The Air Force found out that 50 percent of the major accidents resulted from pilot errors, with 38 percent of the accidents occurring upon landing.
Production of B-57 ended in early 1957.
The US Air Force accepted a total of 403, B-57s, all of which were produced in Baltimore, Maryland. The program comprised 8 B-57As, 202 B-57Bs, 38 B-57Cs, 68 B-57Es, 67 RB-57As, and 20 RB-57Ds. Other B-57s, such as the B-57Gs, RB-57Fs and WB-57Fs, were the result of extensive post production modifications.
B-57 Canberra Technical Specifications
|Manufacturer:||Glen L. Martin|
|Crew:||2 – Pilot and Weapons/Radar Operator|
|Empty Weight:||26,000 lbs|
|Max Weight:||55,000 lbs|
|No. of Engines:||2|
|Powerplant:||Two Wright J65-W-5 engines or
two Buick J65-BW-5 engines
|Thrust (each):||7,200 lbs|
|Cruise Speed:||450 mph|
|Max Speed:||570 mph|
|Service Ceiling:||49,000 ft|
|Guns:||4 – 20mm cannons (or)
8 – .50 caliber machine guns
|Bombs (internal)||5,000 lbs|
|Bombs (external)||4 weapons pylons for bombs or rockets|