Martin B-57 Canberra
General Dynamics WB-57F
The beginning of the Korean conflict on 25 June 1950 and the shortcomings of the Douglas B-26 / A-26, accounted for the urgent procurement of a light tactical bomber.
The new bomber had to be capable of operating from unimproved airfields, at night and in every kind of weather, with conventional or atomic weapons. High altitude reconnaissance was another must. For such purposes, the B-45 was too heavy; the Navy AJ-1, too slow; and the Martin experimental B-51's range too short.
As a result of the outbreak in Korea, the Air Force reached a final decision. The desire for a night intruder was so strong that it took just a few days to set in motion the informal production endorsement of February 1951. Because of its experience with the XB-51, the Glenn L. Martin Company was recognized as the most qualified contractor to assume the domestic production of the British aircraft and to deal with the likely engineering difficulties involved in manufacturing a high-performance tactical bomber.
The new bomber became the Martin B-57, a by-product of the English Electric Canberra, the first British-built jet bomber, initially flown in 1949. Adaptation of a foreign-made aircraft to American mass production methods, as well as the use of different materials and tools, could present many difficulties. Another problem, perhaps more critical, centered on the Wright J65 turbojets, due to replace the Canberra's 2 Rolls Royce Avon turbojet engines. The J65 was the U.S. version of the Sapphire, a British hand-tooled production currently scheduled for manufacturing by the U.S. Curtiss-Wright Corporation. The Air Force was fully aware of these potential pitfalls, but had no better option. It had an immediate requirement for a light jet bomber, with a 40,000-foot service ceiling, a 1,000-nautical mile range, and a maximum speed of 550 knots.
Testing of two imported Canberras revealed design faults that could affect the safety, utility, and maintenance of the future B-57. Then, one of the British planes crashed; Martin's subcontractors could not meet their commitments; and the J65 prototype engines consistently failed to satisfy USAF requirements. 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. Production of the crucial RB-57 was also delayed. The reconnaissance version entered service in mid-1954, after testing again confirmed that the more powerful J65 engines, added equipment, and other improvements had increased the aircraft's weight, in turn reducing the speed, distance, and altitude of both the B-57 and the RB-57.
The program was reduced, but there was no talk of cancellation. In 1955, the B/RB-57s justified their costs when they served overseas pending the B/RB-66 deliveries which, as predicted, had fallen behind schedule. The first Martin B-57A (the name Canberra was retained, though Night Intruder was also used) flew on 20 July 1953. In 1956, much-needed RB-57Ds joined the Strategic Air Command, and various configurations of this model satisfied important special purposes.
The main model (202 built) was the B-57B with a redesigned forward fuselage with a crew of only two seated in tandem under a giant rear-hinged canopy. This attack version introduced a heavier bombload in a rotary-door weapon bay, plus eight pylons under the outer wings and for-ward-firing guns. The B-57B equipped two wings in Tactical Air Command and a wing of PACAF (Pacific Air Forces) but had mainly been passed to Air National Guard units by the early 1960s. Vietnam requirements then demanded aircraft in this class and all available B-57Bs (many had been re built into other models) were rushed to South Vietnam and used very success-fully in the attack role and in particular as FAC (Forward Air Control) aircraft.
Delivered too late for combat in Korea, the RB-57 in May 1963 and the B-57 in February 1965 began to demonstrate under fire in Southeast Asia the basic qualities justifying 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. A total of 16 B-57Bs was rebuilt as B-57G (Tropic Moon) all-weather and night attack aircraft with APQ-139 radar, a FLIR (forward-looking infra-red), low-light TV and laser ranger. The most capable aircraft of its day, the B-57G remained a mere study programme despite brilliant combat re-sults.
The last new-built version was the B-57E multi-role attack/bomber and target tug, all 68 of which were later modified for other tasks.
Finally, WB-57Fs, either modified RB-57Fs or former B-57Bs, were still flying high-altitude radiation sampling missions in 1973. Concurrently, EB-57Es, and related adaptations of the versatile B-57, continued to play significant roles, with no immediate phaseout in sight.
403 were built under licence by Martin (in six variants) as the B-57 and served with the US Air Force from August 1953 until 1982 in various marks and guises. At a later date a number of these were converted by General Dynamics to serve as ultra high-altitude strategic reconnaissance aircraft. These were provided with a wing span of 37.19m, two 80kN Pratt & Whitney TF33-P-11 turbofan engines (replacing the conventional power plant), plus two 14.68kN Pratt & Whitney J60-P-9 turbojets in underwing pods, and many equipment and avionics changes to fit them for their specialised role. The B-57 saw combat over Vietnam beside other Canberras from Australia.
The USAF bought 21 WB-57F aircraft, which were built by General Dynamics from existing B-57Bs and RB-57Ds. The airplanes’ ability to reach altitudes over 65,000 feet, carry payloads in excess of 4,000 lbs, and its triple spar wings made it a very capable high-altitude platform. Missions included everything from weather reconnaissance for Apollo space launches to sampling radiation in nuclear weapon test plumes.
In the late 1960s and early 1970s the Air Force decided to ground the WB-57F and depend exclusively on the U-2 for high-altitude support. The mission of monitoring nuclear test bans was better done by the WB-57F than the U-2, however. That mission was important enough that three aircraft were given to NASA to keep that capability alive, which were designated N925N, N926NA, and N928NA.
When N925N was retired and put on display at Pima Air & Space Museum in Tucson, Arizona, it that left NASA with two WB-57Fs. Another airframe joined the fleet in 2011 after been taken out of the 309th Aerospace Maintenance and Regeneration Group, (AMARG), better known as the “Bone Yard,” at Davis-Monthan Air Force Base, Arizona. The aircraft, designated N927NA, began as a B-57B, and then was one of 21 aircraft rebuilt as an RB-57F in 1964. As an RB-57F the aircraft had its wingspan increased to 122 feet and the original Wright J65 turbojets were replaced by Pratt & Whitney TF-33 turbofans, doubling both the wingspan and thrust.
N927 had been retired in June 1972 and remained on “celebrity row” at the Bone Yard until May 2011 when it was dismantled and trucked to Sierra Nevada Corporation at Centennial Airport, Colorado. After being refurbished to flying condition it was flown to Ellington AFB in August 2013.
The aircraft had been in storage for over 40 years and made its first flight in 41 years in the summer of 2013, setting a record for the longest an aircraft had sat in the Bone Yard before returning to flying status.
Based at Ellington Field near NASA’s Johnson Space Center in Houston, Texas, the WB-57F operates in NASA’s High Altitude Research Program. The aircraft provides unique, high-altitude (up to 70,000 feet MSL) airborne platforms to United States government agencies and other customers for scientific research, advanced technology development, and testing around the world.
Since 2000, the unique performance capabilities of the WB-57F aircraft and increasing costs associated with the ER-2 program have resulted in NASA allowing multiple customers to use the WB-57Fs for atmospheric and satellite sensor research. The DOD programs have gotten much broader, and N928 (and sometimes N926) have multiple customers asking us to help them develop satellite sensors.
Both aircraft were enjoying multiple customers. By June 2014, both aircraft were upgraded with global positioning satellite navigation systems, F-15 main landing gear and brakes, and the gross weight capability of both aircraft was certified from 63,000 pounds to 72,000 pounds. Ongoing upgrades to the aircraft include installation of the ACES II ejection seat system and installation of an improved, modern autopilot.
Engines: two 3,275-kg (7,220-lb) thrust Wright J65-W-5 turbojets.
Maximum speed 937 km/h (582 mph) at 12190 m (40,000 ft).
Service ceiling 14630 m (48,000 ft).
Range 3700 km (2,300 miles).
Weights: empty 11793 kg (26,000 lb)
Maximum take-off 24948 kg (55,000 lb)
Wing span 19.51 m (64 ft 0 in)
Length 19.96 m (65 ft 6 in)
Height: 4.75 m (15 ft 7 in)
Wing area: 89.18 m (960 sq ft).
Armament: eight 12.7-mm (0, 5-in) or four 20-mm guns; up to 2722 kg (6,000 lb), 16 underwing rockets or mixed rocket/ bomb/napalm loads.
Night intruder bomber
Engines: 2 x Wright J65-W-3 Sapphire turbojets, 7,500lb thrust
Wingspan: 64 ft
Length: 65 ft. 6 in
Loaded weight: 46,000 lb.
Max speed: over 600 m.p.h.
Ceiling: over 45,000 ft.
Max range: 3,000 miles.
Armament: 8x.50 in. machine-guns
Bombload: 6,000 lb; 8x5-in. rockets
Engines: 2 x Pratt & Whitney TF33-P-11 turbofan, 18,000 lb (8,165 kg) st, and 2 x P&W J60-P-9 auxiliary turbojets, 3,300 lb (1,500 kg) st.
Wing span: 122 ft 5 in (37.32 m)
Length: 69 ft 0 in (21.03 m).
Height: 5.8 m / 19 ft 0 in
Max take-off weight: 20360 kg / 44886 lb
Empty weight: 13600 kg / 29983 lb
Max. speed: 880 km/h / 547 mph
Ceiling: 25000 m / 82000 ft
Range w/max.fuel: 6440 km / 4002 miles
Typical endurance: Over 10 hr
Martin B-57 Intruder