The RB-57D was a high-altitude reconnaissance version of the Martin-built Canberra. It originated in a December 1952 USAF study funded by the Wright Air Development Center for a turbojet-powered special reconnaissance aircraft with a radius of 2000 nautical miles that could operate at altitudes of 65,000 feet. Subsonic performance was considered to be acceptable and it was felt that no defensive armament would be needed. Preliminary specifications were prepared by the Air Force on March 27, 1953. The project was carried out in high secrecy. It was known as Weapon System MX-2147, and the code name was Bald Eagle.
Preliminary design contracts were awarded in April 1953 to Bell, Fairchild, and Martin. On July 1, 1953 these three companies were awarded six-month contracts for further design studies. The Bell Model 67 was a swept-winged aircraft powered by a pair of Pratt & Whitney J57 turbojet engines housed in individual pods slung under the wings. The Fairchild proposal was given the company designation of Model 195. The Martin proposal was an adaptation of the B-57B bomber and was given the company designation of Model 294.
In March of 1954, the Martin and Bell designs were chosen for further development. The Bell design was actually judged to be the more advanced of the two proposals, and Bell was awarded a contract under the designation X-16. The X-16 designation was in the X-for-experimental series, and was assigned to the Bell design in order to conceal its true role. Although Martin's Model 294 design was judged to be somewhat less advanced then the X-16, it was deemed to be less costly and promised to be available earlier. Consequently, the Model 294 was funded as an interim aircraft pending the full development of the Bell design.
A overriding priority was assigned to the Model 294 project by the USAF. The new Martin design was designated B-57D in August of 1954 and then redesignated RB-57D in April of 1955. The USAF had originally intended to carry the high-altitude B-57 on Contract AF 33(600)-22208. However, negotiations for this second contract were complicated by the numerous changes which were affecting the entire B-57 program at that time. After discovering that less than 20 percent of the new aircraft's parts would be in common with the B-57B, the Air Force decided to alter its plans. The number of B-57Bs on order was reduced by 20, and the 20 airframes (completed to the extent components were common to both B and D airframes) were booked against contract AF 300(600)-25825, even though this contract had been purely a paper study.
The RB-57D featured a substantially-altered B-57B fuselage. The fuselage bomb bay was permanently closed off and the fuselage fuel tanks were removed. Four camera windows were installed ahead of the nose wheel well. A large nose and tail radome further lengthened the fuselage. A power-driven rudder and yaw damper were installed. A new 105-foot wing was fitted, which carried all of the internal fuel in the aircraft. The fuel cells were integral with the wing, which was of honeycomb construction--the first time that such a structural feature had been used in a piloted aircraft. Wing spoilers augmented the stubby ailerons. Wing flaps and speed boards were eliminated as a weight saving measure. The J65 engines were replaced by a pair of 10,000 lb.s.t. Pratt & Whitney J57-P-9 turbojets housed in enlarged nacelles and equipped with anti-icing equipment. It was anticipated that the aircraft would be able to operate at altitudes in excess of 70,000 feet.
The first RB-57D flew on November 3, 1955. A total of 20 were built. There were three separate versions.
The first six RB-57Ds were built according to the original Model 294 specification. They were built as single seaters and carried two K-38 and two KC-1 split vertical cameras. Seven Model 744 RB-57Ds followed which were similar to the earlier model but had a midair refuelling capability, with the boom receptacle being installed aft of the canopy.
The next six were known as RB-57D-2 (Martin Model 796) and carried a crew of two. Instead of cameras, they were equipped with ferret electronic countermeasures equipment. The RB-57D-2 featured an AN/APA-69A radar set with an antenna housed inside a belly radome. The RB-57D-2 could often be externally distinguished by the presenced of radomes at the wing tip. Like the previous batch, they had an inflight-refuelling capability.
The third and last version was known as RB-57D-1. It was a single-seater that was equipped with the AN/APQ-56 high-resolution side-looking radar for all-weather radar mapping reconnaissance. There was a nose radome with an antenna for an AN/APN-107(XY-1) antenna, and there was another radome in an extended tailcone. Lengthy sausage-like radomes were faired into the center of the fuselage underneath the wing roots. Only one was built.
The first RB-57D flew on November 3, 1955. A total of 20 were built. The first deliveries were in April 1956 to the 4025th Strategic Reconnaissance Squadron of the 4080th Strategic Reconnaissance Wing, which was a part of the Strategic Air Command (SAC). Initially, the planes were to be based at Lockbourne AFB in Ohio, but they were soon relocated to Turner AFB in Georgia. The Westinghouse autopilots and some of the more complex electronic components did not always function properly. In addition, the new enlarged wing was a source of problems. It suffered from frequent failures, and on several occasions the wing literally broke off upon landing, leading to several groundings. The main wing spar had to be strengthened as did sections of the wing panels. The Martin-developed honeycomb wing surfaces were subject to water seepage and wing stress.
Following operational training, RB-57D detachments were sent to Yokota AB in Japan and to Eielson AFB in Alaska. The Alaskan detachment carried out ELINT operations around the Kamchatka Peninsula. The Japanese-based RB-57Ds gathered electronic intelligence on Soviet naval and air force operations in the Far East and monitored airborne radiation samples from Soviet nuclear tests. Some sorties were flown over Mainland China, the RB-57D's operational ceiling being well above that of Chinese MiG-15s.
In early 1956, the 4080th SR Wing moved to Laughlin AFB in Texas.
Several RB-57D crews participated in support of atomic bomb tests at Eniwetok Atoll in the Marshall Islands during 1958.
Midair-refuelling capable RB-57Ds were deployed in 1957 to Rhine Main air base in Germany to support USAFE operations. All RB-57D operations were under heavy security and very little information ever leaked out about their early operations. They presumably carried out ELINT/SIGINT missions along the East German border and over the Baltic. Since the missions were carried out under an atmosphere of high secrecy, RB-57s returning from missions over the Baltic were often intercepted by RAF Hunters just to make sure that they were not Soviet aircraft.
In 1958, the Central Intelligence Agency started sponsoring a program known as Diamond Lil, in which Chinese Nationalist pilots were trained to fly RB-57Ds. In early 1959, two (not three as some sources claim) RB-57Ds were ferried to Taoyuan AB on Taiwan. During early 1959, they carried out deep penetration reconnaissance flights over the Mainland. They flew in Nationalist Chinese markings, being painted white on top and black on the bottom with lettering stenciled in red. RB-57D "5643" piloted by Capt Ying-Chin Wang was shot down and killed on October 7, 1959 by a People's Liberation Army SA-2 missile, which was incidentally the first (or among the first) kills ever achieved by a SAM. It seems that the pilot had made a premature descent while returning to Taiwan. The program ended around 1964, when fatigue problems with the wing spars forced the retirement of the surviving aircraft, which was returned to the USA. They were replaced by four Lockheed U-2s, all of which were subsequently lost in operations over the Chinese mainland.
Wing failures gradually took their toll, and these had caused SAC to place several RB-57Ds into storage by early 1959. The 4025th SRS was deactivated in June of 1959, and the Rhein-Main based RB-57Ds were reassigned to a new unit, the 7407th Support Squadron, which continued to carry out some ELINT/SIGINT missions. Some of the RB-57Ds that had been operating with the 4025th SRS were adapted to other specialist roles. Some were used by NASA for high-altitude flight testing and terrain mapping, whereas four were assigned to the 4677th Radar Evaluation Squadron for calibration duties. Six more RB-57Ds were used to monitor the last series of American atmospheric nuclear tests which took place in 1962. Three RB-57Ds were assigned to the 1211th Test Squadron (Sampling) of the USAF Weather Service at Kirtland AFB in New Mexico and were re-designated WB-57D.
In 1964, an RB-57D 53-3973 which was operating on test flights out of Wright-Patterson AFB, lost its wing at high altitude over Dayton, Ohio and crashed into a schoolyard at Beavercreek High School. Fortunately, noone was injured and the pilot was able to eject safely. This mishap finally forced all the surviving RB-57Ds to be withdrawn from service and grounded. However, a few were rebuilt as RB-57Fs.
However, this was not yet to be the end of the line for the RB-57D. In 1966, Martin received a contract to rebuild the wings of eight stored RB-57Ds. These aircraft were fitted with electronic countermeasures equipment and were assigned to the 4677th Defense Systems Evaluation Squadron at Hill AFB, Utah for use in the training of jet interceptor crews. When fitted with ECM gear, they were redesignated EB-57D. However, their service was destined to be brief. They were once again placed in storage in 1970, this time for good. Most of them were scrapped. One RB-57D is on display at the Pima Air Museum in Tucson, Arizona.
The Bell X-16, the RB-57D's early rival, was never actually produced. Clarence "Kelly" Johnson of Lockheed had gotten wind of the Bald Eagle project, and submitted an unsolicited proposal on his own which eventually edged out the Bell design, resulting in the famous U-2.
53-3963/3982 Martin RB-57D-MA