A Look Again At All The B-52 Variants As The Iconic Bomber Hits 70

Seventy years since its first flight, the Boeing B-52 Stratofortress stays, remarkably, very a lot on the prime of its sport, as one of many U.S. Air Power’s three strategic bombers, and remains to be making high-profile deployments across the globe. Not solely does it proceed so as to add new weapons and capabilities to make sure its inconceivable service report, however its future is safe, and it’ll outlive the B-1B Lancer and the B-2 Spirit stealth bomber that have been each beforehand anticipated to supersede it. With new engines, in addition to a number of different upgrades already put in or within the pipeline, the mighty ‘BUFF’ will proceed to fly with the Air Power alongside the all-new B-21 Raider, one other stealth bomber. However with this week’s seventieth anniversary of the maiden flight of the prototype YB-52, within the fingers of Boeing take a look at pilot A. M. “Tex” Johnston, it’s price trying again at how the enduring bomber stood the take a look at of time via progressively improved variants that responded to the operational calls for of the altering safety panorama.

Paper Initiatives

What grew to become the B-52 started life with a Boeing response to a November 1945 strategic bomber requirement, though there could be appreciable modifications to the plans earlier than the ‘BUFF’ lastly took its acquainted kind. The unique Mannequin 462 design, for instance, had a straight wing and would have been powered by six Wright XT35 turboprops. In some ways, it mirrored the design philosophy of the corporate’s B-17 and B-29. In June 1946, Boeing gained a growth contract on the again of the Mannequin 462, calling for a full-scale mock-up of what would now be designated the XB-52.

The Mannequin 462 proved short-lived, the-then Military Air Power deciding it provided little benefit over the B-36 Peacemaker. Boeing shortly drafted the marginally smaller Mannequin 464 as an alternative, now with 4 Wright XT35s however with the identical total configuration because the Mannequin 462. The Mannequin 464 additionally gained official help however Gen. Curtis E. LeMay, then the Deputy Chief of Air Employees for Analysis and Improvement wished it greater and heavier, and it was scaled up once more, virtually to Mannequin 462 proportions. Predictably, maybe, the brand new design was once more rejected, amid issues over prices and efficiency shortfalls.

Boeing persevered with the Mannequin 464, nevertheless, refining it by mid-1947 because the Mannequin 464-29, with a brand new wing of elevated space and with 20 levels of sweep on the forefront and un-swept trailing edges. One component that characterizes the B-52 to this present day was added on this iteration: the tandem undercarriage on the fuselage centerline, with outrigger gear below the wings. Nonetheless, the Mannequin 464-29 didn’t meet Air Power necessities and it was virtually canceled altogether, earlier than LeMay stepped in to offer Boeing extra time to remodel it once more.

The Mannequin 464-35 that got here subsequent benefited from the advances in aerial refueling, which now ensured it could meet Air Power vary necessities whereas permitting the plane to be smaller and lighter. The Mannequin 464-35 retained 4 XT35s, however these now featured contrarotating propellers, very similar to the rival Soviet Tu-95. The wing was additionally extra sharply swept, with a sweep on the trailing edges. The tailfin, too, was swept again. Lastly, with a promised vary of over 11,000 miles and a most velocity of 500 mph, the Boeing design may rival the B-36.

The following huge step within the evolution of the B-52 was the Air Power’s resolution in Could 1948 to pursue a turbojet-powered model of the Mannequin 464, which emerged because the Mannequin 464-40, with eight  Westinghouse XJ40 engines in 4 podded pairs slung beneath the wings. With this, one other BUFF trademark was established. The restricted reliability of early jets is mirrored in the truth that the Air Power requested a mock-up and two flying prototypes of the turboprop Mannequin 464-35, as an alternative.

In October 1948 the Boeing XB-52 design group met with the Air Power to debate progress on the Mannequin 464-35 when service officers informed them that they’d modified their minds — turboprops have been now out of the image, attributable to issues with these powerplants mixed with the promise proven by the jet-powered B-47. The day after the October assembly, so it goes, was a Friday. A member of the Boeing group known as the Air Power and informed them they’d have a jet-powered model of the Mannequin 464-35 prepared by Monday.

The Mannequin 464-49, apparently drafted over a weekend in a Dayton lodge room, is what would develop into the XB-52 prototype. The design included eight of the then-new and extremely promising Pratt & Whitney J57 turbojets in podded pairs, a stretched fuselage that in contrast with the Mannequin 464-35, whereas the wing had extra sweep (35 levels) and was mounted additional ahead. The lengthy, fighter-style cockpit cover would later be dropped however it did seem on the XB-52.

With the Mannequin 464-49, the Boeing group had lastly gained the Air Power over and it was a call that the service wouldn’t remorse.

XB-52: A Delayed Begin

The XB-52, as the primary flying prototype, adopted the final configuration of the Mannequin 464-49 design, however was nonetheless not a certainty for amount manufacturing, with varied rivals lining up, together with the Convair YB-60, a jet-powered model of the B-36. With LeMay’s backing, Boeing had additional tweaked the Mannequin 464-49 to provide the Mannequin 464-67, on which the XB-52 was truly primarily based. Above all, efforts have been made to extend the plane’s vary to satisfy SAC necessities. The fuselage was stretched once more, to spice up the gasoline load, for a fight radius of three,070 nautical miles unrefueled, whereas the general weight rose to 390,000 kilos. One other new characteristic that may be discovered on early-model BUFFs was the tall, narrow-chord swept fin.

Just one XB-52 was accomplished, to Mannequin 464-67 specs, however it was the second of the sort to fly, in October 1952, preceded by the YB-52. The six-month delay was the results of repairs after a failure of the pneumatic system throughout floor exams. In March 1953, the Air Power accepted the XB-52 however, just like the YB-52, this historic airframe was later scrapped.

YB-52: First In The Air

Initially, the Air Power contracted for 2 flying prototype XB-52s and the rationale for one in every of these being accomplished as a YB-52 — indicating a pre-production take a look at plane — just isn’t completely clear. It could nicely have been a budgetary transfer, and the variations between the 2 prototypes have been minor.

The YB-52 was the primary BUFF to fly, from Boeing’s Seattle plant, on April 15, 1952, touchdown at Larson Air Power Base, Washington, after a flight of two hours quarter-hour.

“I’m satisfied that this isn’t solely a great airplane, it’s a hell of a great airplane,” take a look at pilot “Tex” Johnston informed reporters after the flight.

B-52A: Three For Luck

Buoyed by the promise of the XB-52 and YB-52, and with conflict raging in Korea, the Air Power in early 1951 issued a primary manufacturing contract for the BUFF, to interchange the B-36. This coated a batch of 13 B-52As, which might differ from the prototypes of their revised cockpit sections. With one other LeMay intervention, the fighter-style cockpit cover was eliminated, the pilot and co-pilot now sitting facet by facet. The digital warfare officer was behind them, dealing with aft, with the navigator and bombardier beneath them on a decrease deck.

Different modifications included one more fuselage stretch, uprated J57-P-9W engines, and rear-fuselage water tanks for water injection, boosting energy on takeoff. The tempo of this system was such that, though the B-52A was completely sound, the contract was swiftly modified to only three plane, whereas the others could be accomplished as RB-52Bs. The primary B-52A flew in August 1954 and all three have been used solely for exams, together with the four-gun tail turret, first fitted on this variant. Essentially the most well-known of the take a look at BUFFs was additionally a former B-52A, the NB-52A being completely transformed as a mothership for the X-15 high-speed analysis plane program. It continued on this distinctive function till 1969.

RB-52B: Recce Intermission

The primary of the operational variants was the RB-52B, the designation and twin function reflecting the truth that the Air Power Headquarters, initially at the very least, wished the brand new plane to focus on reconnaissance missions. This ran counter to SAC concepts, which proposed pod-mounted cameras to be fitted solely as required.

In October 1951, nevertheless, the Air Employees declared that each one B-52s would, in the intervening time, be accomplished as reconnaissance plane that might be tailored for bombing.

Finally, nevertheless, solely the primary 27 plane have been accomplished to the convertible reconnaissance/bomber customary, earlier than additional manufacturing of ‘straight’ bombers, recognized to the Air Power as B-52Bs.

For the reconnaissance function, the RB-52 was fitted with an gear capsule that contained two devoted crewmen (supplied with downward-firing ejection seats) plus varied mission packages, together with optical cameras, digital intelligence (ELINT) sensors, or completely different surveillance radars.

The precise missions flown by the RB-52s stay mysterious and the Air Power pretty shortly did away with the RB-52 designation altogether.

After a primary flight in January 1955, the primary RB-52 was delivered to the 93rd Bombardment Wing at Citadel Air Power Base, California, in 1955.

Whereas the primary RB-52s retained the four-gun tail turret of the B-52A, with 50-cal machine weapons, the rest launched the brand new turret with a pair of 20-mm cannons.

B-52B: The First True Bomber BUFF

After 27 RB-52Bs, the remaining 23 B-models have been pure bombers, with no provision for the reconnaissance capsules. First flown in July 1955, the B-52B initially used the dual 20-mm cannon tail turret, though the final seven plane reverted to the 4 50-cal machine weapons.

Just like the RB-52Bs, the B-52Bs have been primarily used for crew coaching, a task wherein they served till the mid-Sixties. One other former B-model was transformed because the NB-52B, to help the NASA NB-52A on the X-15 program. This plane, referred to as Balls 8, additionally served as a mothership to different air-launched autos, together with the NASA Lighting Physique sequence, the X-43 hypersonic take a look at car, and others, till lastly retired in 2004.

B-52C: A Raft Of Enhancements

Though solely 35 examples of the B-52C have been constructed, this variant proved that the essential plane had vital potential for additional growth, a incontrovertible fact that has stored the BUFF on the entrance line ever since.

These plane have been heavier than their predecessors, powered by up-rated J57-P-19W or J57-P-29WA engines and had the identical four-gun tail turret because the final B-52Bs. By the point manufacturing ended, the C-model was additionally fitted with a much-improved MD-9 fire-control system. Whereas underwing gasoline tanks have been discovered on the B-52A and B, the B-52C was in a position to carry a lot bigger auxiliary tanks, every of three,000 gallons reasonably than 1,000 gallons. Different new gear included the AN/ASB-15 navigation/bombing system. The choice to suit the reconnaissance capsule of the RB-52 was retained.

The primary B-52Cs started to be issued to the forty second and 99th Bomb Wings starting in December 1956. Latterly, the sort served as trainers.

B-52D: BUFFs In Large Numbers

The primary variant to be inbuilt giant numbers — 170 in all — was the B-52D and the manufacturing effort required two factories: the principle plant in Seattle, plus Wichita in Kansas.

First flown in Could 1956, the B-52D was similar to the B-52C, with the identical J57-P-19W or J57-P-29WA engines and MD-9 fire-control system for the tail turret. The key distinction was the removing of the choice to suit the reconnaissance capsule.

In a while, modifications have been made to optimize the B-52D for the low-level function, with tail clearance radar, Doppler, and low-altitude radar altimeters. On the similar time, structural modifications ensured the plane was in a position to function ‘down within the weeds.’

With the conflict in Vietnam, the B-52D was additional modified, receiving the ‘Large Stomach’ improve that elevated its capability to hold typical ordnance via the introduction of high-density clips of bombs. Whereas unmodified B-52Ds may carry 27 500-pound or 750-pound bombs, the Large Stomach variant may carry 84 500-pound or 42 750-pound bombs.

Finally, the B-52D proved very helpful, not solely in Southeast Asia, and the Air Power ended up prolonging its service life, via the Pacer Plank improve, with the ultimate operational examples being retired solely in October 1983.

B-52E: BUFF On A Price range

Superficially much like the B-52D, the E-model was equally inbuilt Seattle and Wichita, to the tune of 100 examples. A key benefit of the B-52E was its lowered price ticket, a pre-inflation amortized unit price of $1.4 million.

For that, the client obtained all of the options of the B-52D but additionally a number of new additions, together with a low-altitude functionality built-in from the beginning, the power to make use of the GAM-77 (later AGM-28) Hound Canine nuclear-tipped standoff missile, and the GAM-72 (later ADM-20) Quail decoy.

With a strategic-only tasking, the B-52E was by no means utilized in Vietnam, the final of those variations being retired from service by 1970.

B-52F: The Sizzling Rod

The final of the ‘tall-tail’ BUFFs, the B-52F was additionally the final mannequin inbuilt Seattle and Wichita. These 89 plane differed primarily from their predecessors in having a brand new powerplant, with completely different sub-variants of the J57-P-43 providing elevated energy for a helpful efficiency enhance.

First flown in Could 1958, the B-52F started to be delivered to the Air Power in early 1959. As soon as in service, it acquired a traditional munitions enhance, below Venture South Bay, which added an extra 24 750-pound bombs on underwing pylons, along with the 27 that might be carried within the bomb bay. Regardless of this, the B-52F was overshadowed by the B-52D within the typical bombing function in Southeast Asia, so most have been returned to strategic duties, together with as Hound Canine missile carriers. The final B-52F was withdrawn from service in December 1978.

B-52G: ‘Tremendous B-52’

Boeing initially started work on a ‘Tremendous B-52’ as a substitute for the supersonic B-58 Hustler, however the resultant B-52G would show way more long-lived. The B-52G was designed round an all-new wing and was as soon as meant to be powered by eight non-afterburning variations of the Pratt & Whitney J75 as used within the F-105 and F-106. In any occasion, the B-52G retained the J57-P-43WA, though elevated water capability was supplied for a longer-duration takeoff enhance.

Different refinements included a program of weight-saving measures, additional bettering total efficiency. The brand new wing additionally contained further gasoline capability, permitting the exterior wing tanks to get replaced by smaller and lighter examples. The obvious visible change affected the tail, which was now lowered in peak by 91 inches. In the meantime, the defensive gunner was relocated from their place within the tail to the principle cockpit, seated alongside the digital warfare officer.

Finally, the lighter construction of the B-52G and its elevated gasoline capability led to structural issues and a brand new wing field beam needed to be retrofitted, work additionally addressing the sooner B-52Hs, which have been equally affected.

With 193 examples constructed, the B-52G was probably the most quite a few BUFF model, all of them being accomplished in Wichita. Service entry was with the fifth Bomb Wing at Citadel Air Power Base in February 1959.

The calls for of the Vietnam Warfare noticed B-52Gs pressed into service as typical bombers, though in 1970 this model was chosen to obtain AGM-69 Brief-Vary Assault Missiles (SRAM) to supersede the Hound Canine. You may learn all about how B-52s would have employed this weapon in this earlier story.

One other main in-service improve added the AN/AQS-151 Electro-optical Viewing System (EVS) with sensors in nostril fairings that supplied an improved view for the crew throughout low-level flight at night time.

Earlier than the tip of the B-52G’s profession, it had traded the SRAM for the way more versatile AGM-86B Air-Launched Cruise Missile (ALCM), 12 of which might be carried on exterior pylons, whereas a part of the pressure later added the AGM-86C Typical Air-Launched Cruise Missile (CALCM), which it utilized in fight over Iraq throughout Operation Desert Storm.

Retirement of the B-52G started in 1989 and was lastly accomplished in Could 1994.

B-52H: Final BUFF

The one Stratofortress variant nonetheless in service, the B-52H emerged as a by-product of the B-52G, with the identical fundamental airframe, however allied with new Pratt & Whitney TF33 turbofan engines. All H-models have been inbuilt Wichita, the plant producing 102. One other change, in comparison with the B-52G, was a brand new tail turret, armed with a single M61A1 Vulcan 20-mm rotary cannon.

The primary B-52H flew in July 1960 and deliveries started in Could 1961, initially to the 379th Bombardment Wing at Wurtsmith Air Power Base, Michigan.

One other deliberate distinction was to have addressed the B-52H’s most important armament, however the GAM-87 Skybolt air-launched ballistic missile was canceled, leaving the 2 underwing pylons for various shops.

A low-level-optimized avionics suite was included from the nineteenth manufacturing plane, together with Superior Functionality Radar (ACR) with terrain-following operate.

Thereafter, the B-52H, like different BUFF variants, has been successively upgraded, with a few of the most important current efforts having been undertaken to broaden the sort’s weapons choices. In spite of everything, till the tip of the Chilly Warfare, the B-52H was dedicated virtually solely to the nuclear function.

Starting with the Typical Enhancement Modification in 1994, the B-52H had its typical weapons choices elevated, finally including varied precision-guided munitions together with laser-guided bombs and Joint Direct Assault Munitions (JDAM).

It was because of its new and increasing typical arsenal that the B-52H may first go to conflict, in September 1996, when the sort launched CALCMs towards Iraqi targets. That started a long-running marketing campaign of fight operations in each the Center East and Afghanistan, throughout which the B-52H excelled in a shut air help function that could not have been extra completely different from the airborne nuclear alert mission wherein the sort had begun its service.

But extra modifications are actually deliberate, together with long-awaited new engines, as nicely as an AESA radar, a partial glass cockpit, and main enhancements to its communications and defensive suites. It’s attainable that each one these upgrades may result in one other new BUFF designation. That might be the B-52J, though earlier ideas for a standoff jammer model of the B-52 casually used it as an unofficial designation.

Within the meantime, nevertheless, with the way forward for the B-52 seemingly safe till at the very least 2050, the number of weapons that it might probably carry is just going to extend. Chief amongst these is a brand new breed of hypersonic weapons, for which the Stratofortress has been recognized because the excellent launch platform. Already, the B-52H is getting used to check experimental examples of those weapons, with operational variations of some trying set to supply one more new lease of life for the extraordinary bomber.

Contact the creator: thomas@thedrive.com