B-58 Program Reendorsement
Development of 13 B-58 test aircraft, and nothing more, was approved by Secretary Talbott on 2 June 1955. The Secretary's approval carried stern, if not unexpected conditions. The Air Force wanted the program's costs to be reduced, and it wanted the aircraft to begin flying before November 1956. Furthermore, ARDC was to plan the aircraft's utilization in light of the Air Force's new objectives. In short, there no longer was any question of producing a high-altitude, manned strategic bomber and reconnaissance weapon system out of the B-58 test-aircraft. The program's only purpose was to promote research and development. SAC was pleased with the decision, but thought a 13-aircraft research and development program was larger than necessary. The Air Force needed to learn more about the aerodynamic problems of sustained supersonic flights at high altitudes, and it needed to test subsystems and components for future weapon systems. There were no delays in satisfying most of Secretary Talbott's demands. AMC had been studying the aircraft's cost problem for several months. An April estimate showed that $554 million would cover 13 B-58s, 31 pods, all engines, other government-furnished equipment and support, as well as Convair's fee. With the aircraft now strictly earmarked for research and development, various items could be deleted. This would save about $50 million and bring total costs close to the Air Force's tentative maximum. Convair seemed unabashed by the cut of its program, believing time would work in its favor. Hence, it went all out to match AMC's cost reductions, while projecting costs for the production of up to 500 aircraft. In mid-June, AMC authorized Convair to resume work on development engineering, tool fabrication, airframe parts, and the like. At month's end, the contractor felt confident it could fly a B-58 by November 1956, which it did. Meanwhile, personnel of the B-58 project office coordinated with representatives of various offices to identify non-essential B-58 subsystems and components, while preserving the development of any B-58 hardware that could benefit other projects. Included in such projects were the B-70, the nuclear-powered aircraft, and a tactical bomber logged as Weapon System 302A.
Scheduled for production in December 1952, an object of indecision in April 1954, practically cancelled 10 months later, and relegated to research and development in June 1955, the B-58 project was yet to undergo another major change. Abruptly, on 22 August 1955, the B-58 weapon system once again emerged as a production candidate. The decision, approved personally by General Wining, climaxed weeks of debates.37 General Putt, now Deputy Chief of Staff for Development, had helped to initiate the program and still professed the B-58 could be "a useful SAC tool." General Irvine, the new Deputy Chief of Staff for Materiel, and others on the Air Force Council shared General Putt's opinion. However, attempts to sway General LeMay failed. This failure most probably accounted for the production directive's unusual wording. The directive of 22 August 1955, calling for a wing of B-58s by mid-1960, was most specific in stressing the need for economy but made no mention of the wing's recipient or of SAC in particular.
Convair's Letter Contract AF33(038)-21250 of February 1951 was superseded in December 1955 by a definitive contract of the cost-plusincentive-fee type. This gave Convair an additional $340 million for 13 aircraft, 31 pods, and all contractor-furnished equipment, bringing the contract's total value to about $540 million. The incentive fees depended on technical performance, weight control, and contractor adherence to cost and to delivery schedule. A second letter contract, AF33(600)-32841, issued on 25 May 1956, provided another $13.6 million to buy long-lead items and to maintain B-58 production at a minimum sustaining rate through October 1956. The Air Force planned to decide in the fall of 1956, if it should buy 17 more upper components (B-58 airframes), 17 powered bomb pods, 12 free fall bomb pods, 3 photo pods, and 3 electromagnetic data (ferret) pods. If it did, an extra $14.9 million of pre-production funds would be needed. This planning was in line with the August 1955 decision to buy a wing of B-58s. As all along understood, this could only be done if there was sufficient evidence that the project was viable.
The initial B/RB-58 made its first flight on 11 November 1956, taking off from the Convair Fort Worth facilities at Carswell AFB, Texas. A second flight on 14 November lasted one hour and was also described as successful. On both occasions, the maximum altitude reached was 30,000 feet, while the maximum speed did not exceed Mach 0.9. Supersonic speeds of Mach 1.6 and Mach 1.35, at altitudes of 35,000 feet, were first reached in a third flight on 4 December. The 3 flights were made by the same plane which, like several subsequent ones, was temporarily identified as a prototype (YB-58). In another departure from the usual, a characteristic that typified the B-58 program from the start, the YB-58 flights of late 1956 and early 1957 proved extremely important. Although testing had just begun, they undoubtedly influenced the Air Force's ensuing decisions.
By virtue of the weapon system concept adopted for the highly complex B/RB-58, the core of the testing program was altered. Also, the Air Force's insistence in 1952 that technological developments fit requirements inevitably affected testing. The Air Force decision of 1952 was one of the many difficulties and momentary contradictions that plagued the B-58. A few years before, when the GEBO study was initiated, USAF engineers asked for more realistic military characteristics and advocated state-of-the-art design compromises. As a result of such innovations, the flight testing program, an always thorough undertaking, acquired a new, time-consuming, and occasionally frustrating dimension. By chance, this coincided with the end of the 8-phase concept of testing, under which a new aircraft was designed, built, and tested first by the contractor, then at various ARDC centers, and finally transferred to a major Air Force command for operational utilization. The new testing program, although counting only 3 categories, did not degrade in any way the former program's scope. The Category I tests, begun by the contractor in November 1956, accounted for almost 3,000 hours of flight tests by March 1962, and the destruction of 1 aircraft (the fifth YB-58, Serial No. 55-664) in November 1959. Furthermore, pod drops, aerial refueling, and a few other special tests, properly part of Category I, were completed under the Category II program, which did not officially start before March 1959.
While the production decision of 22 August 1955 failed to indicate which command would use the new aircraft, it soon again became obvious that the B-58 lay in SAC's future. General LeMay's lack of enthusiasm for the B-58 put the aircraft within the reach of the Tactical Air Command. It was a fact, however, that the Convair project had been geared from the start to meet SAC's performance criteria, that the recently flown YB-58 basically remained a SAC-configured aircraft, one that would require the time-consuming incorporation of many costly changes if it were to fulfill the Tactical Air Command mission. In early 1957, Gen. Otto P Weyland, who headed the command, wanted a minimum of 2 B-58 wings, but the Air Staff disagreed. As technological difficulties increasingly impaired the B-70 development, the command became more involved with the B-58. Willing to believe in the B-58's potential for improvement, SAC in late 1956 was actually preparing to participate in the aircraft's forthcoming test program. In the spring of 1957, imminent budget decisions affecting SAC aircraft nearly shattered the command's fragile cooperation. By that time, the B-58 had established itself as the world's fastest jet bomber. The Mach 2 speed success of the B-58, cited as one of the reasons for decreasing the B-52 production rate, did not satisfy General LeMay. He quickly reasserted his early 1955 position that no B-58s were needed. New studies, General LeMay explained, showed that the B-52G with its programmed penetration aids would be superior to the production-improved B-58 and to any "better" B-58, such as the new B-58B configuration proposed by Convair. This was particularly true from the standpoints of cost effectiveness and availability. As for the B-70, General LeMay added, there was no doubt that it would provide substantial improvements over the B-52G. Therefore, "the B-58 should be limited to a test program. Funding for procurement or model improvement testing should not be provided." The Air Staff bluntly disagreed with General LeMay, stating that it was "most desirable" that SAC get a supersonic bomber at an early date and that the decision had been made to buy a limited quantity of B-58s for the SAC inventory. In a mollifying gesture, the Air Staff underlined that the United States had to protect its technological lead over the Soviets as well as the money already invested in the B-38 program. Also, the B-38 would improve through normal growth, and the program's funding requirements would not affect the B-70's prospects. Indeed, the proposed B-70 fell under a different time period. Nevertheless, by focusing attention on cost, the enormously expensive B-58 program did not help the cause of future high-performance manned bombers.
Flight testing of the first 3 YB-38s, while accounting for some spectacular achievements,43 brought to light several problems. By the end of 1957, the YB-58s had attained a maximum speed of Mach 2.11 at altitudes over 30,000 feet; made 2 successful pod drops from 42,000 feet at Mach 2 speeds; maintained a speed of more than Mach 1.13 during 91 minutes, and zoomed without pod from a speed of Mach 2 at 50,000 feet to a speed of Mach 1.13 at 68,000 feet. The J79-GE-1 prototype engines, installed on the YB-38s pending certification of the J79-GE-3s, had a number of flaws ( Even though General Electric's progress had negated the temporary use of Pratt & Whitney J57s, the J79-5's 150-hour preliminary flight rating test was not expected before year's end). Malfunctions in the fuel system sloshed the fuel around when the YB-58 accelerated or slowed down, impairing the aircraft's stability. Afterburner problems caused intermittent yawing at supersonic speeds. Of greater concern were already noted acoustical and sonic fatigue problems as well as excess vibration in the YJ79-GE-1 engines. The acoustical and sonic fatigue difficulties affected the aft area of the fuselage and would cause testing restrictions unless promptly solved. Fatigue created cracks along the rivet lines in the forward section of the fuselage. Since the cracks appeared after less than 30 hours of flight, replacing the YJ79-1 engine by the J79-3 would worsen the problem because the more powerful J79-3 would increase the sound level 10 decibels above the level induced by the YJ79-1. The engine vibrations also might affect components of the electronic equipment, installed in the fuselage'.s aft section and in the aft portion of the various droppable pods that were programmed for the aircraft. There were other difficulties of varying importance. The brake system was not satisfactory. Because of inadequate heat dissipation after braking, tire failures were frequent following landing at high gross weights and high-speed taxi runs. The upward-type of ejection seat put in the aircraft was unsafe at high speed, due to insufficient thrust. Convair tests of a more powerful, rocket-type catapult seat identified problems of another kind. Other sorts of ejection seats were being considered, with misgivings. The Air Force and the B-58 contractor greatly favored a capsule-type escape system, under development by both the Martin Company and the Goodyear Tire and Rubber Company, but time was of the essence. Finally, slippage in the bombing-navigation subsystem development program portended a serious delay in the delivery of the initial equipment. This would retard the B-58 flight-test program, as would shortages of spares for both the YJ79-1 and -5 engines.
In 1958, the B-58 program came under renewed scrutiny. The YB-58 could fly fast and high, but its range remained poor. With 1 refueling, the aircraft had a radius of 3,800 nautical miles; without refueling, the distance dropped by almost 40 percent. In addition, limited testing had already uncovered far too many problems. Configuration changes worked out between Convair and an 85-man team from ARDC, AMC, and SAC, would probably help a lot. Yet, changes were always costly. In August 1958, General Power, who had been heading SAC for over a year,45 told the Air Staff that the B-58's deficiencies were exaggerated, a common occurrence, he remarked, when a program was expensive and it became difficult to obtain financial support. Believing that a mixed force of B-52s and B-58s was the best way to replace the B-47s, General Power pointed out that the B-58's bombing and navigation system, already late, might become available sooner than expected since performance of the system's doppler radar was getting better (General LeMay, although acknowledging in November 1957 that the mixed force concept was apparently in the offing, continued to question the wisdom of the proposed combination. The cost, from the standpoint of refueling operations alone, did not favor the B-58. It would take 1 tanker to refuel 1 of the new bombers, while 2 tankers could take care of 3 B-52s. Among the members of the Air Force Council, General LeMay stood alone in his opinion.). Agreeing with General Power that the B-58's early difficulties had been taken out of perspective, General White nevertheless cautioned that, should the program survive, the quantity of aircraft to be purchased in fiscal year 1959 would have to be reduced. The money thereby saved would pay for the most important changes and inevitable cost increases. By the end of December, photo reconnaissance, one of the B-58 program's initial requirements, was deleted. ME-1 pods and ground photo processing equipment, under contracts but yet to be delivered, were canceled, as were 45 ALD-4 ferret pods. On the positive side, the MB-1 free fall bomb pod was exchanged for a 2-component bomb and fuel pod. The new 2-component bomb and fuel pod had special merits. After the fuel had been used, the bomb and integral tankage would be dropped on a target, making the aircraft lighter for its return flight. Other approved changes included improved communications equipment (singleside band/high frequency and emergency ultra-high frequency radios), encapsulated crew ejection seats (another new development), tactical air navigation (TACAN) electronics, and various minor improvements. However, as indicated by General White, one-third of the fiscal year 1959 B-58 procurement was cancelled. Letter Contract AF33(600)-36700, issued on 1 November 1957, called for 47 B-58s, bringing forecast procurement to a total of 77-30 so-called prototypes and 47 aircraft for the operational inventory. But the letter contract of November 1957 remained to be finalized, and its 47 aircraft were reduced to 33 on 26 September 1958.
Officially initiated in March 1959, but actually started on 15 February 1958, the Category II tests first assumed some of the flight testing normally conducted under Category I. This variance was primarily due to the November 1957 decision to consolidate the B-58 flight test program under the direction of the weapon system office. While the ARDC testing role was not changed significantly, the proposed using command (SAC, as already confirmed) was to participate in all testing, which was unusual. In another departure from past procedures, testing would be carried out as close as possible to the contractor facilities, which made Carswell AFB the obvious location. The Air Force believed that, among other advantages, this arrangement should reduce costs for logistical training and for support of the Convair technicians. As to the consolidated testing program, it should help to discover and solve development problems quicker. SAC's 3958th Operational Employment 'Ii'sting and Evaluation Squadron was activated on 1 March 1958, too late to monitor the beginning of the Category I tests. Nevertheless, the 3958th, its ARDC counterpart (the 6592d Test Squadron), and representatives from AMC and Convair soon were in place, constituting the test force that took care effectively of the Air Force Category II and III tests. The Category II tests were completed on 30 June 1960, after accumulating 1,216 flight hours that were reached in 256 sorties. Except for a few authorized deviations and some unexpected delays, the Category II testing progressed as planned. Tivo YB-58As, undergoing stability and control evaluation, were flight tested from Edwards AFB, California, and from Convair's Fort Worth airfield. Another test-aircraft, earmarked for climatic hangar evaluation, went directly from Fort Worth to Eglin AFB, Florida. Finally, the accelerated service test of the J79-GE-5 engine, after 330 flight hours under Category II, was completed under Category III, when SAC crews accumulated 170 additional hours of flight. From the practical standpoint, the Category II tests proved invaluable. Yet, they probably accounted in part for the program's last near-cancellation and final reduction. Seven test-aircraft were lost between December 1958 and June 1960, including 1 which disintegrated in flight on 7 November 1959.
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