06/30/2010. As the only aircraft of non-US design adopted for operational combat service with the USAF since the end of WW II, the B-57 was unique. It also has a special place in USAF history for its operation, in the RB-57D version, on reconnaissance sorties along and across the Soviet borders. The first of the type to carry USAF insignia, with the s/n 51-17352, was a British-built English Electric Canberra B.Mk.2 (RAF s/n WD932) which was flown to Baltimore, Maryland, USA, on February 21, 1951, becoming the first jet aircraft to complete an unrefueled Atlantic flight in the process.
To establish the production line, the Glenn L. Martin Co. built a preproduction batch of eight B-57As (Martin Model 272) patterned closely on the Canberra B.Mk.2, but with two 7,200 lb (3,269 kg) s.t Wright J65-W-l turbojet engines and engineering changes to suit US production methods. The first B-57A flew at Baltimore on July 20, 1953. With cameras in a bay aft of the bomb-bay, the RB-57A was similar in outward appearance. The first of 67 built had been delivered to Shaw AFB by April 1954, and from the end of that year until 1957 this variant equipped the 363rd Tactical Reconnaissance Wing.
Extensive changes were made in the next version produced, to suit it for a tactical night intruder mission as Weapon System WS307A. The cockpit was re-modeled to seat two in tandem rather than side-by-side, and fixed wing armament of eight 0.50 in (12.7 mm) or four 0.787 (20 mm) guns was introduced. A rotary bomb-door, with the stores mounted on the doors themselves, and wing pylons for HVAR (High Velocity Aircraft Rocket) rockets or bombs, were fitted. Powered by two 7,220 lb (3,275 kg) s.t J65-W-5s, the first B-57B flew on June 28, 1954 and 202 were built, one more than all the other versions put together.
The 461st Bombardment Wing of TAC (Tactical Air Command) received its first B-57B on January 5, 1955, and was fully equipped by the end of the year, followed in 1956 by the 345th Wing. These Wings were inactivated on April 1, 1958, and June 25, 1959, respectively, the B-57B passing out of TAC service on the latter date. It remained in service, however, with the three squadrons of the 3rd Wing of PACAF (Pacific Air Forces), and with Air National Guard units attached to TAC in 1961, which received 48 aircraft including RB-57As and RB-57Bs, the latter being camera-equipped versions of the B-57B. Some were later modified to EB-57B for ECM (Electronic Counter Measures) duties.
To meet the demands of the Vietnam war, several squadrons of B-57Bs were recalled from the ANG in 1964, and operated in the interdiction role until 1969. They were then withdrawn but about 12 were updated to B-57G configuration and resumed combat operations late in 1970. This modification of the B-57B incorporated forward-looking infrared, laser rangefinder and a low-light-level TV installation to improve target acquisition at night and in bad weather.
For use as a transition trainer, the B-57C had dual controls but was otherwise similar to the B-57B. Thirty-eight were built and examples served with all three TAC Wings mentioned above, from early 1955. Some later took the designation TB-57C, and others were modified to RB-57C. The first flight was made on December 30, 1954.
The B-57E was a further variant of the B-57B, equipped as a target tug, and was in fact the first aircraft built for the USAF specifically for this duty. Target containers were fitted on the lower rear fuselage, but the B-57E could be converted to a bomber by removing these containers and the internal cable reels and fittings and cockpit towing controls. In all, 68 B-57Es were built, for service with Tow Target Squadrons, but many were later modified for other roles as TB-57E (training), RB-57E (reconnaissance) and EB-57E (electronic reconnaissance and intercept training).
A major redesign of the B-57 was undertaken to produce a high-altitude reconnaissance version designated RB-57D. The fuselage and tail unit remained basically unchanged, but a new wing of greater span was introduced, and the engines were changed to 11,000 lb (4,990 kg) s.t Pratt & Whitney J57-P-37As. The new wing-span was 106 ft (32.31 m), or 107 ft 6 in (32.77 m) when wing-tip radomes were fitted. Several versions of the RB-57D were included in the batch of 20 built by Martin, including 14 for single-pilot operation, of which eight had provision for air refueling; and six for two-crew operation, also with flight refueling equipment.
The RB-57Ds served in various roles, including aerial policing of the nuclear test-ban treaty and electronic reconnaissance along and possibly across the frontiers of Communist territory. A structural problem in the wing resulted in the RB-57Ds being grounded in 1963, but new wings were manufactured by Martin and some of these aircraft then returned to service as electronic countermeasures targets designated EB-57Ds.
To fill the gap left when the RB-57Ds were grounded, a more advanced high-altitude reconnaissance variant was produced by the General Dynamics' Fort Worth Division, initial delivery being made in July 1964 only nine months after design work started. The new version, designated RB-57F, had an even larger wing, with a span of 122 ft (37.19 m), and new powerplant comprising 18,000 lb (8,165 kg) s.t Pratt & Whitney TF33-P-11 turbofans in the wing nacelles and two 3,300 lb (1,497 kg) s.t J60-P-9 turbojets in under wing pods. The fuselage was lengthened by 40 in (1.02 m) to carry new electronic equipment in the nose.
An initial batch of 17 RB-57Fs was made by General Dynamics, based on
B-57B and RB-57A airframes but with new FY 1963 serial numbers. They entered service in 1964 with the 58th Weather Reconnaissance Squadron. A second batch of four was converted from RB-57Ds to bring the total of this variant to 21. All were redesignated WB-57F in 1968.
The final designation was assigned to sixteen B-57Bs modified as B-57G night intruders, developed by Martin and Westinghouse for use in Vietnam under a project known as Tropic Moon. Installed in a new nose section were a low light level television camera plus a forward-looking infrared (FLIR) set and a laser guidance system. Using 500 lb (227 kg) laser-guided smart bombs the B-57G was one of the first self-contained all-weather night interdiction bombers to serve with the USAF, and was operated from 1969 till 1974.