B-58 Initial Requirements
Concurrent with the elimination of flaws from the initial MX-1626 configuration, the Air Force further defined what would be generally expected of the future Supersonic Aircraft Bomber (SAB). USAF planning culminated on 1 February 1952 with the publication of General Operational Requirement (GOR) SAB-51 (This actually was GOR No. 8 (SAB-51). It added reconnaissance to the requirements embodied in a December 1951 GOR, which only called for a strategic bombardment system). This highly ambitious document called for a versatile, mufti-mission strategic reconnaissance bomber capable of carrying 10,000 pounds of bombs, and of operating in daylight or darkness under "all-weather" conditions. Production should take place within 5 years.
There were many other sophisticated requirements. The aircraft had to be able to cover almost 5,000 miles (4,000 nautical miles) both ways, with a single outbound inflight refueling; about half that distance without refueling. It also needed supersonic speed at altitudes of 50,000 feet or more, and high subsonic speeds when flying at low levels. It was to be easy to fly, highly reliable, and should require few personnel for operation and maintenance. Although due to feature the best electronic countermeasures systems, "economy from the standpoint of cost to our national resources" was a must. The GOR also emphasized that the future aircraft should be small, a specification apparently suggested in a recent Rand Corporation study which stressed that by minimizing size, one reduced the radar reflectivity of the vehicle and the probabilities of interception by surface-to-air missiles. As it turned out, this "small size" requirement was to influence greatly subsequent decisions.
As customary, the GOR of February 1952 led to a development directive. Also, detailed military characteristics were issued for the benefit of interested contractors. There was a significant change, however. The directive (No. 34, published on 26 February 1952) created a precedent in that it sharply curtailed the general requirements formulated earlier in the month. The revision, formalized on 1 September 1952 by GOR No. 1 (SAB-52-1), stood to reason. As pointed out by Gen. Donald N. Yates, Director of Research and Development, Office of the Deputy Chief of Staff for Development, it was unrealistic to expect the rapid development of a high-altitude, long-range, supersonic reconnaissance bomber that could also be used for low-level missions requiring high subsonic speeds.
Some aeronautical engineers argued this could be done with the proper technological efforts and plenty of money, but many in the Air Staff were not convinced. Following discussions with members of the Air Council and representatives of Air Research and Development Command (ARDC), SAC, the Rand Corporation, and the Scientific Advisory Board, the Air Force endorsed General Yates' recommendation. Directive No. 34, as finally worded, only called for the development of a high-altitude, long-range supersonic strategic reconnaissance bomber. However, a low-altitude strategic bomber was still needed. Even though this would be costly, the Air Force issued a separate directive for development of such an aircraft, insisting in both cases that the 2 airplanes should be available by 1957 (The Martin Company won the competition that ensued with a design featuring a delta-wing plantform, but the Air Force cancelled the project in 1957. SAC's confidence that the B-47 was rugged enough for low-level bombing accounted in part for the cancellation. Another factor was the Air Force's anticipation that modified B-52s would eventually fulfill the requirements wanted in a low-altitude bomber).
If refining and slimming down requirements were not an easy matter, financing the Phase I development of 2 parallel projects was even more difficult during a period of austerity. Boeing's MX-1712 benefited to some extent from the XB-55 cancellation and did not seem to face a serious money problem, but the financial support of Convair's MX-1626 was another story. 'Ib begin with, although the 2 letter contracts of February 1951 were fairly similar, Convair's document failed to provide sufficient funds to carry the MX-1626 through the mockup stage. Complicating the situation further, confusing events began to emerge in early 1952. In January, the Air Staff asked Convair to prepare package program costs for specific numbers of airplanes (25, 50, and 100). Estimates were to cover all development and production costs, except for the engines which were to be furnished by the government. Tentative delivery schedules also were required.
In late February, however, the MX-1626 project was nearly canceled. The emergency transfer of $100,000 provided some relief, but the MX-1626 status remained precarious until 15 May, when a supplemental agreement to the deficient letter contract assured the MX-1626's General Phase I Development Program of $2,800,000. Meanwhile, the Air Force faced another dilemma. Back in 1951, although reasonably sure that Convair and Boeing offered the best hopes to secure quickly the urgently needed supersonic bomber, AMC had requested informal proposals from other aircraft producers including Douglas, Lockheed, Martin, and North American. The field narrowed, when only 2 of the last 4 contractors submitted proposals. Moreover, the problem was resolving itself since these last proposals did not amuse any special interest. Nevertheless, now that the requirements were changed, the Air Force considered whether the entire aeronautical industry should again be queried.
Early in 1952, the Air Force agreed with Brig. Gen. John W. Sessums, ARDC Deputy for Development, that it would be better to forego additional competition along traditional lines. Time and money would be saved in selecting contractors on the basis of experience, facilities, and the intrinsic value of the proposals already submitted. Shortly thereafter, the Wright Air Development Center was given permission to eliminate or reorient current projects. In short, Boeing and Convair were instructed to stop their present investigations and to begin new Phase I designs of their respective projects (MX-1712 and MX-1626), as dictated by Directive 34. Maj. Gen. Donald L. Putt, the newly appointed Wright Air Development Center Commander, also informed the 2 contractors that contracts would be issued in the fall of 1952 for the detailed design and mockup of each supersonic bomber. Evaluation and selection of the winning design would follow in February or March 1953, which clearly indicated that obtaining production aircraft by 1957 would never be feasible. Assuming all went well, Wright Air Development Center officials speculated, a prototype might perhaps fly in 1957.
Meanwhile, events were determining the shape of the program. To begin with, Development Directive 34 strongly reemphasized the Supersonic Aircraft Bomber design priorities of minimum size and high performance (altitude and speed), already specified by the GOR of February 1952. Secondly, both GOR and the directive called for the application of the weapon system concept, an objective with which Convair was familiar. The so-called "1954 Interceptor;' an upshot of the Convair XF-92, soon symbolized the difficulties involved. It marked the first attempt to apply the weapon system concept, and the concept's practical defeat. Yet, it eventually led to Convair's production of the F-102 and F-106, 2 most-effective and long-lasting fighter-interceptors. This concept, in essence, acknowledged that the increasing complexity of weapons no longer permitted the isolated and compartmented development of equipment and components which, when put together in a structural shell, formed an aircraft or a missile. It integrated the design of the entire weapon system, making each component compatible with the others, and put heavy responsibilities on the prime contractor. The weapon system concept coincided with a significant deviation from previous practices. Instead of accepting technology as the determining factor against which a mission could be fitted, the Air Force had decided that mission objectives now should come first and technology could be made to satisfy them.
In any case, other events occurred in mid-1952, which also seemed to favor the delta-wing configuration. By that time, the 2 contractors had made considerable progress in their efforts to conform with the requirements set forth in Directive 34. In the process, Convair's former MX-1626 had become project MX-1964, while Boeing's MX-1712 was now known as the MX-1965. Wright Air Development Center's analysis of both designs in the summer of 1952 yielded no startling discoveries. The center tentatively concluded that the 2 designs appeared to meet performance and size requirements, but that extensive development work would be needed to give either configuration the necessary engines and the required integrated electronic system. Soon afterwards, the center's Weapons Systems Division proposed that recent plans be changed. The division's officials felt that selecting 1 of the 2 contractors before design and mockup completion would be advantageous to the Air Force. It would eliminate the many problems created by simultaneous development programs, as well as the need to develop costly electronic and control systems for 2 aircraft. Moreover, an earlier selection would save additional time and money,' thereby allowing a more extensive development of the selected system. Since Project MX-1965 was lagging slightly behind the Convair MX-1964, such recommendations could hardly be expected to help Boeing's prospects.
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