Besides an increase in gross weight (488,000 instead of 450,000 pounds), major configuration changes characterized the B-52G. A principal distinction was the "wet wing" as it was often called, which contained integral fuel tanks that significantly increased the aircraft's unrefueled range. The B-52G retained the B-52F's new J57-P-43W, but the engine's water injection system was improved in duration by the installation of a single 12,000-gallon tank in the forward fuselage. There were many other changes, some of them quite noticeable. The nose radome was enlarged, the size of the vertical fin reduced, the tail cone modified, and the ailerons eliminated. The B-52G's redesigned wings supported 700-gallon fixed external fuel tanks that replaced the 3,000-gallon auxiliary wing tanks, carried by several preceding B-52 models. While retaining the AN/ASQ-38 bombing navigational system, the B-52G featured the new AN/ASG-15 fire-control system, improved electronic countermeasures technology, a powered stability augmentation system, and emergency ejection seats for the entire crew, including the gunner who was moved to a rearward-facing seat, next to the electronic countermeasures operator(The location of the bombardier and radar navigator was unchanged. They sat forward facing behind and below pilot and co-pilot. Prior to the B-52G, B-52s and their normal crew of 6 only had 5 ejection seats, none for the gunner.). Finally, in addition to its standard bombload, most B-52Gs were in production equipped to carry 2 Hound Dog missiles, 1 on a pylon under each wing between the inboard nacelles and the fuselage. The North American AGM-28 (formerly GAM-77) Hound Dog was an air-to-surface missile powered by a single Pratt & Whitney J52 turbojet. The AGM-28 was equipped with an inertial guidance system and a nuclear warhead. Launched at high altitude and supersonic speed, the AGM-28 could reach a target 500 nautical miles away; at low altitude and subsonic speed, the distance was reduced to 200 nautical miles. Four Quail decoy missiles could also be fitted in the bomb bay. The McDonnell ADM-20 (formerly GAM-72) Quail was a small delta-wing drone, equipped with 1 General Electric J85 turbojet engine. It had a range of several hundred nautical miles, could match the B-52's performance, and accomplish at least 2 turns and 1 speed change. It contained electronic devices that made it look like a B-52 on enemy radar scopes. The Quail was unique among air-launched missiles in that it was the only decoy missile in the United States Air Force.
The B-52G design was officially initiated in June 1956. Yet the roots of the new aircraft can be traced back to January 1955, when Convair's delta-wing B-58 appeared to be heading for trouble. The Air Force's indecision about the future of the costly, high-risk B-58 program meant that the next decade might not bring new bombers to replace or supplement SAC's B-52s. Development of a much more potent version of the original B-52, Air Research and Development Command stated, would prevent a possible technical obsolescence of the strategic force in the 1960s. As envisioned in May 1955, the new aircraft would be a B-52 fuselage with a redesigned wing, J75 engines, and a number of detailed changes. General LeMay at first was unenthusiastic about the proposal, which brought to mind the Lockheed F-84F and its many early production problems. While conceding that the Boeing bomber should be improved "as much as possible" during production, General LeMay argued that the B-52 production schedule should not be disrupted. Although he came to favor the "super B-52" somewhat later, General LeMay noted that if "true meaningful improvement" was to result, the B-52 production schedule would inevitably be slowed down. As urgent as it seemed, the B-52G design did not start until June 1956. Delays in providing $1.2 million for Boeing to complete the necessary study was a factor; another was the Air Staff's continued concern about the B-58 and resulting procrastination in formally approving the Boeing project.
Once the Air Force finally decided to endorse the B-52 model improvement, events moved quickly. In July, the Air Staff shifted $8.8 million to the project, funds which, in any case, had been allocated to support engineering changes. In the same month, Boeing held an initial development engineering inspection at its Seattle plant. The purpose of the inspection was to determine the new configuration of the crew compartment. While the Air Force found no specific faults with the arrangements set up by Boeing, it pointed out that many questions remained unanswered. On 15 August, the contractor submitted for review a model improvement program that was more comprehensive. The Air Staff approved the revised program on 29 August, but specified that its implementation would be only on a "minimum sustaining basis" until more was known about the B-58 program. Possible forthcoming fiscal limitations were another reason for curtailing program's implementation.
The Air Force inspected and approved the crew compartment's mockup for the improved B-52 toward the end of October. The new configuration, based on the so-called "battle-station" concept, placed the defensive crew (the ECM operator and gunner) facing aft on the upper deck, the offensive team (bombing-navigation system operators) facing forward on the lower deck, and the pilot and co-pilot (still sitting side-by-side) facing forward on the flight deck.
The impact of unforeseen events, international as well as domestic, often played havoc with the best plans. In 1955, B-58 problems worked in favor of producing an improved B-52 (B-52G). In April 1956, the Air Force wanted the B-52 production increased to a monthly rate of 20. In December, the President set the B-52 program at 11 wings and procurement was revamped to provide a greater quantity of improved B-52s (B-52Es). Money from the next fiscal year (FY 58) would cover the procurement changes, and faster production would take place as soon as practicable. But the progress was short-lived. In early 1957, Secretary of Defense Wilson made it known that B-52 monthly production rates would be held at 15. There were several compelling reasons for the Secretary's decision. As explained by Secretary of the Air Force Quarles, progress was being made on the B-58 development, and Mr. Wilson had already indicated that the B-58 would not only merit some production effort, but would definitely get it in due time. Moreover, a slower B-52 output might give the Air Force a larger number of further improved models, this time perhaps fewer B-52Es and more B-52Fs. Other factors bearing on the decision were revised intelligence estimates, particularly the latest information on Soviet Bison and Bear bomber production rates, which seemed to have slowed down. Those, as Mr. Quarles pointed out in Secretary Wilson's words, were "a little different, and it looked like we had more time to do an orderly job." Finally, it was Secretary Wilson's belief that "in many cases we get cheaper production by phasing it out over a longer period of time and getting more expert people to work on it." The Air Force had few grounds for argument, even though SAC pointed out that the endorsed lower production rates would delay its conversion program by almost 1 year. As expected, the decision stood.
Reflecting the evolutionary production process, preceding B-52s were acquired through contracts that covered a variety of models. As a culmination of this process as well as continued developmental efforts, the B-52G was purchased under different conditions. Three procurement contracts were issued-AF33(600)-35992, funded in FY 57; AF33(600)-34670, in FY 58, and AF33(600)-37481, in FY 59. All 3 contracts involved B-52Gs only. The first one, a cost-plus-incentive fee contract with a sliding percentage of 6 percent, was initiated by letter contract on 29 August 1957 and finalized on 15 May 1958. It purchased 53 aircraft. The second and largest one was a fixed-price-incentive-firm (FPIF) contract for 101 B-52Gs. It was started by a letter contract on 14 June 1957, and also finalized on 15 May 1958. The May 1958 contract, as initiated in June 1957, evolved from the President's budget of December 1956, which set the B-52 program at 11 wings and a total of 603 aircraft. The last B-52G contract, started by letter contract in September 1958, and the subsequent procurement of B-52Hs (the last model) were not part of the l I -wing program. They could be viewed as added bonuses, prompted by new dissatisfaction with the B-58 program, concurrent fiscal limitations, and the B-58's high price. The third and last B-52G contract, begun by letter contract on 5 September 1958, was concluded on 28 April 1959. It was a straightforward fixedprice-incentive (FPI) contract for 39 aircraft.
The B-52G entered service with the 5th Bomb Wing at Travis AFB, California. The wing received its first B-52G (Serial No. 47-6478) on 13 February, one day after SAC's last B-36 bomber was retired and the command became an all-jet bomber force. In May 1959, the 42d Bomb Wing also started getting B-52Gs. By the end of June, 41 of the new bombers had been received by SAC. The early B-52Gs and 13 more could not carry the Hound Dog missiles. Boeing could not be faulted for the omission. Because of the complexity and high cost of the Big Four modification package, refinement of the many changes under consideration consumed most of 1959. The Air Staff did not decide until the end of that year which B-52 models would be equipped, either in production or through retrofit, to carry the new missiles. A post-production modification, completed in 1962, accomplished necessary alterations and fitted the 54 aircraft with the equipment required to support as well as fire the new weapons.
B-52Gs, of necessity, played an important role in the Category III testing of both the Hound Dog and Quail missiles. A B-52G crew of the 4135th Strategic Wing accomplished the first SAC launch of a Hound Dog on 29 February 1960. On 8 June, a B-52G crew of the same wing repeated the performance with a Quail decoy. By the end of 1961, a respectable supply of the new missiles-225 Hound Dogs and 400 Quails-had already reached the SAC inventory. However, although the new AGM-28 Hound Dogs had become an important part of the B-52's striking power, the missiles were still highly unreliable. In contrast, the ADM-20 Quail's performance was excellent. In 1963, all Quail decoys were modified for low-level flying. This relatively simple modification added a barometric switch for terrain avoidance and altered the missile's wiring system.
Intensive structural testing, conducted by Boeing and the Air Force in 1960, again confirmed that hard usage shortened the structural life of the B-52 aircraft. The B-52Gs and B-52Hs differed significantly from predecessor models, but design changes incorporated in the new bombers made them even more susceptible to fatigue damage. Briefly stated, the changes had been made to extend the aircraft's range, which essentially meant that while the B-52G and B-52H bombers were lighter than preceding B-52s, their fuel loads had been increased. Moreover, the overall decrease in structural weight had been achieved primarily by using an aluminum alloy in the aircraft's wings. While testing did not question the intrinsic strength of the wing, it pinpointed areas of fatigue. No one could forecast accurately when the wing failures would happen, but low-level flying and the structural strains that occurred during air refueling were expected to speed up fatigue considerably. It was estimated that under fairly similar circumstances, the operating stress placed on the new wing was approximately 60 percent higher than the stress inflicted on the wing of preceding B-52s. The anticipated problem appeared serious enough for SAC to impose stringent flying restrictions on the new aircraft, pending approval of necessary modifications. In May 1961, the Air Staff endorsed a $219 million modification program for all B-52G and B-52H wing structures. The wing structural improvement program, carried out as ECP 1050, replaced the wing box beam with a modified wing box that used thicker aluminum. It also installed stronger steel taper lock fasteners in lieu of the existing titanium fasteners; it added brackets and clamps to the wing skins, added wing panel stiffeners, and made at least a dozen other changes. Finally, a new protective coating was applied to the interior structure of the wing integral fuel tanks. The program provided for Boeing to retrofit the modified wings during the airplanes' regular IRAN schedule, except for the last 18 B-52Hs, which would get their modified wings on the Wichita production lines. Started in February 1962, the program was completed by September 1964, as scheduled.
While ECP 1050 had strengthened the wings of the B-52Gs and B-52Hs by September 1964, as already noted, ECP 1128, a major engineering change proposal approved in the same year for the entire B-52 fleet, had just begun. Shortly before the beginning of ECP 1128, the Air Force had directed that the tail section of all B-52s be reinforced in order to withstand turbulence during low-level penetration tactics. Started in September 1963, this engineering modification (ECP 1124-2) was due to spread over several years. Concurrently, MADREC, a previously described improvement program that also covered most B-52s, was in progress. In addition, various modifications, addressed to specific B-52 models, were either underway or about to start. In spite of such projects, the Air Force believed that major efforts would still be required in the ensuing years to keep extending the structural life of the critically needed B-52G and B-52H bombers. Hence, the Air Staff in October 1967 approved ECP 1195, an engineering change studied by SAC since 1965. Eventually known as the B-52 Stability Augmentation and Flight Control program, the $69 million modifications installed a number of new devices in the bombers. Necessary kits, contracted for in December 1967, began reaching the Air Force in mid-1969, and their installation required 2 years. Meanwhile, ECP 1185, due to cost about $50 million and actually initiated in May 1966, had started to replace thdpircraft's fuselage side skin, crown skin fasteners, and upper longerbns. Completion of these latest engineering changes, accomplished as usual during the aircraft's regular IRAN schedule, was expected to ensure the structural safety of the B-52G and B-52H airframes through the 1980s.
In line with current plants to retain the B-52Gs and B-52Hs for years to come, the Air Force in 1970 decided to equip these bombers with the Boeing-developed AGM-69A nuclear-tipped short-range attack missile (SRAM). The 2,300-pound AGM-69A SRAM measured 14 feet in length and 18 inches in diameter. The internally guided, solid-propellant missile could be flown at supersonic or subsonic speeds and set to follow either a high-altitude semi-ballistic trajectory or a low-altitude profile. It could strike targets ahead of the launch aircraft or turn in flight to hit installations to the side or behind the bomber. Required modifications and the addition of necessary equipment, such as wing pylons, launch gear, rotary launchers, and new avionics would be accomplished by 2 air materiel areas. Oklahoma City would modify all B-52Gs; San Antonio, all B-52Hs. This long-term, $400 million retrofit program began on 15 October 1971, when 1 B-52G entered the Oklahoma City modification center. In March 1972, a SRAM-equipped B-52G was delivered to the 42d Bomb Wing at Loring AFB, Maine. The 42d became SRAM-operational in August, the first of 19 wings programmed to acquire the versatile missiles. SAC's 2 wings of FB-111As would also be equipped with the new missiles, at an estimated cost of $43 million. Each modified B-52G and H bomber could carry up to 20 SRAMs, 12 externally and 8 inside the rear of the bomb bay.
As SAC strove to preserve the might of its primary bombers, the war in Southeast Asia continued unabated. Since 1965, when the B-52Fs had first arrived in Southeast Asia, B-52 conventional bombing operations had increased from year to year. The purpose of the bombing was not always the same, the theaters of operation also varied, but the task always grew. B-52Gs did not enter the war before mid-1972; yet, their short-lived participation did not prove easy. On 18 December, as ordered by President Nixon, B-52Gs and the older B-52Ds began to bomb military targets in the Hanoi and Haiphong areas of North Vietnam. The bombing operation, nicknamed Linebacker II, ended on 29 December, after a Christmas pause of 24 hours. SAC B-52s terminated over 8 years of conventional bombing operations in Southeast Asia on 15 August 1973, when all U.S. bombing of targets in Cambodia ceased. In this attack on Haiphong and Hanoi, the B-52s encountered awesome defenses. In 11 days, 15 B-52s were shot down by surfaceto-air missiles.
SAC lost 7 B-52Gs in Southeast Asia, all of them during 1972. B-52Gs had been lost years before in highly publicized accidents. The first occurred on 17 January 1966, when a B-52G collided with a KC-135 tanker during a high-altitude refueling operation and both aircraft crashed near Palomares, Spain. The release of some radioactive material required removal of some 1,400 tons of slightly contaminated soil and vegetation to the the United States for disposal. A lost nuclear weapon, finally located by a U.S. Navy submarine about 5 miles from the shore and approximately 2,500 feet under water, was recovered intact on 7 April. Then, on 22 January 1968, a B-52G with 4 nuclear weapons aboard crashed and burned on the ice of North Star Bay, while attempting an emergency landing at nearby Thule Air Base, Greenland. An extensive clean-up operation to remove all possible traces of radioactive material was completed on 13 September. Six of the planes were hit by enemy surface-to-air missiles over North Vietnam, with 4 of them going down around Hanoi and the other 2 crashing in Thailand. The seventh B-52G loss was only indirectly caused by the war. The plane, after taking off from Andersen AFB, Guam, crashed into the ocean, presumably because of materiel failure.
Ensuring the durability of an airframe was a difficult and costly problem; a worse one, on both counts, was to cope with the enemy's technological developments. In the early seventies, many improvements in electronic countermeasures, initially limited to the Southeast Asiacommitted B-52Ds, were extended to the B-52Gs and B-52Hs. These various projects centered essentially on the installation of more efficient jammers to ease the penetration of enemy defenses. One project, Rivet Rambler, was a 2-phase modification accomplished on all B-521)s by 1971 and specifically directed against the SA-2 radars. In 1973 the Rivet Rambler modification of the B-52G and H bombers was almost completed, but the resulting improvements soon would be nearing obsolescence. Because of the experience gained in Southeast Asia, particularly as a result of the Linebacker II strikes against heavily defended targets, SAC wanted more than ever to equip the B-52Gs and B-52Hs with truly advanced ECM transmitters and jammers. An improved warning system was also needed: one that could detect threats from surface-to-air missiles, anti-aircraft artillery, and airborne interceptors. The Air Staff had already endorsed most of SAC's new requirements. Modification 2525, due to provide more efficient airborne early warning countermeasures, had been approved in June 1971; modification 2519, known as Rivet Ace and due to upgrade the aircraft's radar warning receivers, was approved in December of the same year. However, none of these projects would start before mid-1973, and all were scheduled to take several years. There were many reasons for the implementation delays. Uchnical difficulties had to be worked out, unexpected requirements were likely to materialize, and new components had to be tested for quality as well as compatibility within any given avionics system. An example was Rivet Ace. Within the span of 2 short years, this fairly unsophisticated modification had become a very ambitious endeavor. In mid-1973, although the transformed modification project was about to start, serious problems remained. Components, due to be added to the aircraft's radar warning receivers, had been tested with success, but the system's new surface-to-air missile detection equipment was still defective. Meanwhile, other projects fared well. B-52s were being modified to carry the SRAM, as scheduled, even though a new modification was being done simultaneously. This additional project would give the aircraft an electrooptical viewing system, which made use of forward-looking infrared and low-light-level television sensors. The new system would make low-level flying much easier, and a B-52H, modified by the San Antonio Air Materiel Area, had already been returned to operational duty by mid-1973. Another improvement considered in mid-1973 consisted of fitting the B-52's bombing and navigation system with automated offset units. Such devices, SAC believed, would ease significantly the synchronized bombing of several targets.
B-52G production ended in early 1961. The Air Force accepted the last 2 aircraft in February. The B-52G was the major production model of the B-52 series. All 193 aircraft were built at the Wichita plant. Fifty B-52Gs were accepted in FY 59 (between October 1958 and June 1959); 106 in FY 60 (between July 1959 and June 1960); 37 in FY 61 (between July 1960 and February 1961). Cost per aircraft was: $7.69 million: Airframe, $5,351,819; engines (installed), $1,427,611; electronics, $66,374; ordnance, $6,809; armament (and others), $840,000.
The Air Force in July 1973 retained 175 of 193 B-52Gs, purchased almost 15 years before. These efficient bombers were undergoing modification, with more changes to come in the future.
On 14 December 1960, a B-52G of the 5th Bomb Wing, Travis AFB, California, completed a world record-breaking flight of 10,078.84 miles without refueling. The flight lasted 19 hours and 44 minutes. The previous closed course record, established in 1947 by a B-29, covered only 8,854 miles.
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