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184-516: Entering service in 1948, the B-36 was the primary nuclear weapons delivery vehicle of Strategic Air Command (SAC) until it was replaced by the jet-powered Boeing B-52 Stratofortress beginning in 1955. All but four aircraft have been scrapped. The design of the B-36 can be traced to early 1941, prior to the entry of the United States into World War II . At the time, Britain was at risk of falling to

368-513: A Labor Day weekend in 1973, a meeting of about twelve military officers at the Pentagon discussed the creation of a Defense Navigation Satellite System (DNSS) . It was at this meeting that "the real synthesis that became GPS was created." Later that year, the DNSS program was named Navstar , or Navigation System Using Timing and Ranging. During the development of the submarine-launched Polaris missile,

552-484: A nuclear weapon at the position of detonation , on or near its target. Several methods have been developed to carry out this task. Strategic nuclear weapons are used primarily as part of a doctrine of deterrence by threatening large targets, such as cities . Weapons meant for use in limited military maneuvers such as destroying specific military, communications, or infrastructure targets, are known as tactical nuclear weapons . In terms of explosive yields , nowadays

736-506: A 10,000-pound (4,500 kg) payload, while the Model 464-17 was a general purpose bomber with a 9,000-pound (4,100 kg) payload. Due to the cost associated with purchasing two specialized aircraft, the USAAF selected Model 464–17 with the understanding that it could be adapted for nuclear strikes. In June 1947, the military requirements were updated and the Model 464-17 met all of them except for

920-420: A 2,000-hour service life extension to select airframes in 1966–1968, and the extensive Pacer Plank reskinning, completed in 1977. The wet wing introduced on G and H models was even more susceptible to fatigue, experiencing 60% more stress during a flight than the old wing. The wings were modified by 1964 under ECP 1050 . This was followed by a fuselage skin and longeron replacement ( ECP 1185 ) in 1966, and

1104-487: A 5,000-mile (8,000 km) range. In September 1947, the Heavy Bombardment Committee was convened to ascertain performance requirements for a nuclear bomber. Formalized on 8 December 1947, these requirements called for a top speed of 500 miles per hour (430 kn; 800 km/h) and an 8,000-mile (7,000 nmi; 13,000 km) range, far beyond the capabilities of the 464-29. The outright cancellation of

1288-661: A 50/50 blend of Fischer–Tropsch process (FT) synthetic fuel and conventional JP-8 jet fuel, which burned in two of the eight engines. On 15 December 2006, a B-52 took off from Edwards with the synthetic fuel powering all eight engines, the first time a USAF aircraft was entirely powered by the blend. The seven-hour flight was considered a success. This program is part of the Department of Defense Assured Fuel Initiative , which aimed to reduce crude oil usage and obtain half of its aviation fuel from alternative sources by 2016. On 8 August 2007, Air Force Secretary Michael Wynne certified

1472-507: A B-36 crashed in February 1950. Training missions were typically in two parts, a 40-hour flight—followed by time on the ground for refueling and maintenance—and then a 24-hour second flight. With a sufficiently light load, the B-36 could fly at least 10,000 mi (16,000 km) nonstop, and the highest cruising speed of any version, the B-36J-III, was at 230 mph (370 km/h). Engaging

1656-478: A B-36H-20-CF (serial number 51-5712) that had been damaged in a tornado at Carswell AFB on 1 September 1952. This aircraft, redesignated the XB-36H (and later NB-36H ), was modified to carry a 1 MW , air-cooled nuclear reactor in the aft bomb bay, with a four-ton lead disc shield installed in the middle of the aircraft between the reactor and the cockpit. A number of large air intake and exhaust holes were installed in

1840-510: A B-52 to carry twenty-four GBU-38 500-pound guided bombs or twenty GBU-31 2,000-pound bombs, with later phases accommodating the JASSM and MALD family of missiles. In addition to carrying more smart bombs, moving them internally from the wings reduces drag and achieves a 15 percent reduction in fuel consumption. The US Air Force Research Lab is investigating defensive laser weapons for the B-52. The B-52

2024-449: A bomb bay. The GRB-36D would ferry the RF-84K to the vicinity of the objective, whereupon the RF-84K would disconnect and begin its mission. Ten GRB-36Ds and 25 RF-84Ks were built and had limited service in 1955–1956. Projects Tip Tow and Tom-Tom involved docking F-84s to the wingtips of B-29s and B-36s. The hope was that the increased aspect ratio of the combined aircraft would result in

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2208-527: A bomber of truly intercontinental range. The German Reichsluftfahrtministerium 's (RLM) would request the similar ultralong-range Amerikabomber program on 12 May 1942. The USAAC sent out an initial request on 11 April 1941, asking for a 450 mph (720 km/h) top speed, a 275 mph (443 km/h) cruising speed, a service ceiling of 45,000 ft (14,000 m) and a maximum range of 12,000 mi (19,000 km) at 25,000 ft (7,600 m). These requirements were too demanding and far exceeded

2392-459: A combat radius of 3,110 miles (2,700 nmi; 5,010 km), was declared the winner. On 28 June 1946, Boeing was issued a letter of contract for US$ 1.7   million to build a full-scale mockup of the new XB-52 and do preliminary engineering and testing. However, by October 1946, the USAAF began to express concern about the sheer size of the new aircraft and its inability to meet the specified design requirements. In response, Boeing produced

2576-698: A crew of 15. War missions would have been one-way, taking off from forward bases in Alaska or Greenland , overflying the USSR, and landing in Europe, Morocco, or the Middle East. Veteran crews recall feeling confident in their ability to fly the missions, but not to survive weapon delivery, as the aircraft were not fast enough to escape the blast. These concerns were confirmed by the 1954 Operation Castle tests, in which B-36s were flown at combat distances from detonations of bombs in

2760-583: A cruise missile attack. Prior to the development of nuclear-armed submarine-launched ballistic missiles , the United States and the Soviet Union conducted their first at-sea deterrence patrols using modified submarines armed with very large nuclear-armed cruise missiles ; The US operated various diesel-electric submarines armed with the Regulus missile , and the Soviets operated Modified Whiskey -class armed with

2944-471: A digital interface ( MIL-STD-1760 ) and rotary launcher. IWBU is expected to cost roughly US$ 313   million. The 1760 IWBU will allow the B-52 to carry eight JDAM 2,000-pound (910 kg) bombs, AGM-158B JASSM-ER cruise missile and the ADM-160C MALD-J decoy missiles internally. All 1760 IWBUs should be operational by October 2017. Two bombers will have the ability to carry 40 weapons in place of

3128-579: A dry thrust of 10,000 pounds-force (44 kN) which could be increased for short periods to 11,000 pounds-force (49 kN) with water injection . The water was carried in a 360 US gallons (1,400 L) tank in the rear fuselage. B-52B, C, D and E models were equipped with Pratt & Whitney J57-P-29W, J57-P-29WA, or J57-P-19W series engines all rated at 10,500 lbf (47 kN). The B-52F and G models were powered by Pratt & Whitney J57-P-43WB turbojets, each rated at 13,750 pounds-force (61.2 kN) static thrust with water injection. On 9 May 1961,

3312-414: A final attempt to increase range, Boeing created the larger 464-67, stating that once in production, the range could be further increased in subsequent modifications. Following several direct interventions by LeMay, Boeing was awarded a production contract for thirteen B-52As and seventeen detachable reconnaissance pods on 14 February 1951. The last major design change—also at General LeMay's insistence—was

3496-561: A full-pressure test; the resulting explosion severely damaged the trailing edge of the wing, necessitating considerable repairs. The YB-52, the second XB-52 modified with more operational equipment, first flew on 15 April 1952 with "Tex" Johnston as the pilot. A 2-hour, 21-minute proving flight from Boeing Field , near Seattle , Washington, to Larson Air Force Base was undertaken with Boeing test pilot Johnston and USAF Lieutenant Colonel Guy M. Townsend . The XB-52 followed on 2 October 1952. The thorough development, including 670 days in

3680-458: A fuse to initiate detonation. US nuclear weapons that met these criteria are designated by the letter "B" followed, without a hyphen, by the sequential number of the " physics package " it contains. The " B61 ", for example, was the primary bomb in the US arsenal for decades. Various air-dropping techniques exist, including toss bombing , parachute -retarded delivery, and laydown modes, intended to give

3864-544: A golf ball from 45,000 ft (14,000 m) and up to 63,600 ft (19,400 m) away. The first RB-36D (44-92088) made its initial flight on 18 December 1949, six months after the B-36D, but initially flew without turbojets. The 28th Strategic Reconnaissance Wing based at Rapid City AFB (later renamed Ellsworth AFB) , South Dakota , received its first RB-36D on 3 June 1950 but due to severe material shortages, they were not operational until June 1951. The 24th and last RB-36D

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4048-545: A greater range. Project Tip Tow was cancelled when an EF-84D and a specially modified test EB-29A crashed, killing everyone on both aircraft. This accident was attributed to the EF-84D flipping over onto the wing of the EB-29A. Project Tom-Tom, involving RF-84Fs and a GRB-36D from the FICON project (redesignated JRB-36F), continued for a few months after this crash, but was also cancelled due to

4232-461: A heavier payload enter service. The wings of the B-36 were large even when compared with present-day aircraft, exceeding, for example, those of the C-5 Galaxy, and enabled the B-36 to carry enough fuel to fly the intended long missions without refueling. The maximum thickness of the wing, measured perpendicular to the chord , was 7.5 ft (2.3 m), containing a crawlspace that allowed access to

4416-521: A level partly determined by knowledge of the capability of Soviet air-defense radar . The main Soviet air-defense radar in the 1950s was the American-supplied SCR-270 , or locally made copies, which were only effective up to 40,000 ft (12,000 m) – in theory, and an aircraft cruising above this level likely would remain undetected. The first aircraft to put this theory to

4600-460: A lightweight version of this aircraft, the RB-36-III, could reach 58,000 ft (18,000 m). RB-36s were distinguished by the bright aluminum finish of the camera compartment (contrasting with the dull magnesium of the rest of the fuselage) and by a series of radar domes under the aft fuselage, varying in number and placement. When developed, it was the only American aircraft large enough to carry

4784-547: A navigational fix approximately once per hour. In 1967, the US Navy developed the Timation satellite that proved the ability to place accurate clocks in space, a technology required by the latter Global Positioning System . In the 1970s, the ground-based Omega Navigation System , based on phase comparison of signal transmission from pairs of stations, became the first worldwide radio navigation system. Limitations of these systems drove

4968-677: A neatly bound 33-page proposal and a 14-inch (36 cm) scale model. The aircraft was projected to exceed all design specifications. Although the full-size mock-up inspection in April 1949 was generally favorable, range again became a concern since the J40s and early model J57s had excessive fuel consumption. Despite talk of another revision of specifications or even a full design competition among aircraft manufacturers, General LeMay, now in charge of Strategic Air Command, insisted that performance should not be compromised due to delays in engine development. In

5152-666: A new radio and radar system and the Pratt and Whitney engines were redesigned, adding another 1,000 lb (450 kg). The B-36 was two-thirds longer than the previous "superbomber", the B-29 and its wingspan and height exceeded those of the Soviet Union's 1960s Antonov An-22 , the largest turboprop ever produced. Only with the advent of the Boeing 747 and the Lockheed C-5 Galaxy , both designed two decades later, did aircraft capable of lifting

5336-443: A new strategic bomber "capable of carrying out the strategic mission without dependence upon advanced and intermediate bases controlled by other countries". The aircraft was to have a crew of five or more turret gunners , and a six-man relief crew. It was required to cruise at 300 miles per hour (260 kn; 480 km/h) at 34,000 feet (10,000 m) with a combat radius of 5,000 miles (4,300 nmi; 8,000 km). The armament

5520-453: A prodigious appetite for lubricating oil and each engine required a dedicated 100 US gal (380 L) tank. Normal maintenance consisted of tedious measures, such as changing the 56 spark plugs on each of the six engines which were often fouled by the lead in the 145 octane anti knock fuel required. Thus, each service required changing 336 spark plugs. The B-36 was too large to fit in most hangars . Since even an aircraft with

5704-686: A proposal for a four-engine turbojet bomber. Joined by Ed Wells, Boeing's vice president of engineering, the engineers worked that night in The Hotel Van Cleve in Dayton, Ohio, redesigning Boeing's proposal as a four-engine turbojet bomber. On Friday, Colonel Warden looked over the information and asked for a better design. Returning to the hotel, the Boeing team was joined by Bob Withington and Maynard Pennell, two top Boeing engineers who were in town on other business. By late Friday night, they had laid out what

Convair B-36 Peacemaker - Misplaced Pages Continue

5888-605: A requirement to accurately know the submarine's location was needed to ensure a high circular error probable warhead target accuracy. This led the US to develop the Transit system. In 1959, ARPA (renamed DARPA in 1972) also played a role in Transit. The first satellite navigation system, Transit , used by the United States Navy , was first successfully tested in 1960. It used a constellation of five satellites and could provide

6072-495: A single missile to strike multiple targets, or to inflict maximum damage on a single target by attacking it with multiple warheads. It makes anti-ballistic missile defense even more difficult, and even less economically viable, than before. Missile warheads in the American arsenal are indicated by the letter "W"; for example, the W61 missile warhead would have the same physics package as

6256-495: A switch from the B-47 style tandem seating to a more conventional side-by-side cockpit, which increased the effectiveness of the copilot and reduced crew fatigue. Both XB-52 prototypes featured the original tandem seating arrangement with a framed bubble-type canopy (see above images). Tex Johnston noted, "The B-52, like the B-47, utilized a flexible wing. I saw the wingtip of the B-52 static test airplane travel 32 feet (9.8 m), from

6440-538: A tail turret, or no gunners at all for several years but the development of air-to-air missiles , such as the Soviet K-5 which began test firings in 1951, eliminated remaining justifications for keeping them. In February 1954, the USAF awarded Convair a contract for a new "Featherweight" program, which significantly reduced weight and crew size. The three configurations were: The six turrets eliminated by Featherweight I reduced

6624-465: A tender on 16 October 1941. Consolidated asked for a $ 15 million contract with $ 800,000 for research and development, mockup, and tooling. Two experimental bombers were proposed, the first to be delivered in 30 months, and the second within 36 months. Originally designated Model B-35, the name was changed to B-36 to avoid confusion with the Northrop YB-35 piston-engined flying-wing bomber, against which

6808-423: A three-branched nuclear capability is to significantly reduce the possibility that an enemy could destroy all of a nation's nuclear forces in a first-strike attack; this, in turn, ensures a credible threat of a second strike , and thus increases a nation's nuclear deterrence . Historically the first method of nuclear weapons delivery, and the method used in the twin instances of nuclear warfare in history,

6992-451: A top speed of 513 miles per hour (446 kn; 826 km/h) at 35,000 feet (11,000 m), a range of 6,909 miles (6,004 nmi; 11,119 km), and a 280,000-pound (130,000 kg) gross weight, which included 10,000 pounds (4,500 kg) of bombs and 19,875 US gallons (75,240 L) of fuel. In May 1948, Air Materiel Command asked Boeing to incorporate the previously discarded jet engine, with improvements in fuel efficiency , into

7176-522: A trapeze. The concept was tested using a B-29 carrier, but docking was difficult even for experienced test pilots. Moreover, the XF-85 was no match for contemporary foreign powers' interceptors in development or in service and consequently the project was cancelled. The FICON project was more successful and involving a modified B-36 (a GRB-36D "mothership") and the RF-84K , a fighter modified for reconnaissance , in

7360-471: Is a jet- or rocket-propelled missile that flies aerodynamically at low altitude using an automated guidance system (usually inertial navigation , sometimes supplemented by either GPS or mid-course updates from friendly forces) to make them harder to detect or intercept. Cruise missiles can carry a nuclear warhead. They have a shorter range and smaller payloads than ballistic missiles, so their warheads are smaller and less powerful. The AGM-86 ALCM

7544-645: Is believed that the, in development successor to the nuclear A-135, the A-235 Samolet-M , will dispense with nuclear interception warheads and instead rely on a conventional hit-to-kill capability to destroy its target. Small, two-man portable tactical weapons (erroneously referred to as suitcase bombs ), such as the Special Atomic Demolition Munition , have been developed, although the difficulty to combine sufficient yield with portability limits their military utility. According to an audit by

Convair B-36 Peacemaker - Misplaced Pages Continue

7728-440: Is due to receive a range of upgrades alongside a planned engine retrofit. These upgrades aim to modernize the sensors and displays of the B-52. They include the new APG-79B4 Active electronically scanned array radar, replacing older mechanically scanned arrays, the streamlining of the nose and deletion of blisters housing the forward-looking infrared/electro-optical viewing system. In October 2022 Boeing released new images of what

7912-475: Is officially listed as 50,000 feet (15,000 m), but operational experience shows this is difficult to reach when fully laden with bombs. According to one source: "The optimal altitude for a combat mission was around 43,000 feet (13,000 m), because to exceed that height would rapidly degrade the plane's range." In September 2006, the B-52 became one of the first US military aircraft to fly using alternative fuel. It took off from Edwards Air Force Base with

8096-694: Is the US Air Force 's current nuclear-armed air-launched cruise missile . The ALCM is only carried on the B-52 Stratofortress which can carry 20 missiles. Thus the cruise missiles themselves can be compared with MIRV warheads. The BGM/UGM-109 Tomahawk submarine-launched cruise missile is capable of carrying nuclear warheads, but all nuclear warheads were removed following the Intermediate-Range Nuclear Forces Treaty . Cruise missiles may also be launched from mobile launchers on

8280-497: Is twofold. It results in a tighter target impact circular error probable and therefore by extension, reduces the need for the earlier generation of heavy multi- megaton nuclear warheads, such as the W53 to ensure the target is destroyed. With increased target accuracy, a greater number of lighter, multi-kiloton range warheads can be packed on a given missile , giving a higher number of separate targets that can be hit per missile. During

8464-615: The AGM-154 glide bomb and the AGM-158 JASSM missile. The CEM program also introduced new radios, integrated Global Positioning System into the aircraft's navigation system, and replaced the under-nose FLIR with a more modern unit. Forty-seven B-52Hs were modified under the CEM program by 1996, with 19 more by the end of 1999. By around 2010, U.S. Strategic Command stopped assigning B61 and B83 nuclear gravity bombs to B-52, and later listed only

8648-567: The AIR-2 Genie . Further developments of this concept, some with much larger warheads, led to the early anti-ballistic missiles . The United States have largely taken nuclear air-defense weapons out of service with the fall of the Soviet Union in the early 1990s. Russia updated its nuclear armed Soviet era anti-ballistic missile (ABM) system, known as the A-135 anti-ballistic missile system in 1995. It

8832-542: The Air Combat Command (ACC); in 2010, all B-52 Stratofortresses were transferred from the ACC to the new Air Force Global Strike Command (AFGSC). The B-52 completed 60 years of continuous service with its original operator in 2015. After being upgraded between 2013 and 2015, the last airplanes are expected to serve into the 2050s. On 23 November 1945, Air Materiel Command (AMC) issued desired performance characteristics for

9016-464: The B-2 as tasked with delivering strategic nuclear bombs in budget requests. Nuclear gravity bombs were removed from the B-52's capabilities because it is no longer considered survivable enough to penetrate modern air defenses, instead relying on nuclear cruise missiles and focusing on expanding its conventional strike role. The 2019 "Safety Rules for U.S. Strategic Bomber Aircraft" manual subsequently confirmed

9200-508: The B-52 Stability Augmentation and Flight Control program ( ECP 1195 ) in 1967. Fuel leaks due to deteriorating Marman clamps continued to plague all variants of the B-52. To this end, all aircraft variants were subjected to Blue Band (1957), Hard Shell (1958), and finally QuickClip (1958) programs. The latter fitted safety straps that prevented catastrophic loss of fuel in case of clamp failure. The B-52's service ceiling

9384-541: The Brookings Institution , between 1940 and 1996, the US spent $ 11.3 trillion in present-day terms on nuclear weapons programs. 57 percent of which was spent on building delivery mechanisms for nuclear weapons. 6.3 percent of the total, $ 709 billion in present-day terms, was spent on weapon nuclear waste management, for example, cleaning up the Hanford site with environmental remediation , and 7 percent of

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9568-743: The McDonnell Douglas F/A-18 Hornet , the General Dynamics F-16 Fighting Falcon and the McDonnell Douglas AV-8B Harrier II . The ability to carry up to 20 AGM-69 SRAM nuclear missiles was added to G and H models, starting in 1971. To further improve its offensive ability, air-launched cruise missiles (ALCMs) were fitted. After testing of both the USAF-backed Boeing AGM-86 Air Launched Cruise Missile and

9752-562: The Medium Atomic Demolition Munition and the novel Blue Peacock , nuclear depth bombs , and nuclear torpedoes . An 'Atomic Bazooka' was also fielded, designed to be used against large formations of tanks. In the 1950s the US developed small nuclear warheads for air defense use, such as the Nike Hercules . From the 1950s to the 1980s, the United States and Canada fielded a low-yield nuclear armed air-to-air rocket ,

9936-638: The Meteor 1 was launched on 26 March 1969 on the Vostok rocket , a derivative of the R-7 ICBM . WD-40 was first used by Convair to protect the outer skin, and more importantly, the paper thin "balloon tanks" of the Atlas missile from rust and corrosion. These stainless steel fuel tanks were so thin that, when empty, they had to be kept inflated with nitrogen gas to prevent their collapse. In 1953, Dr. S. Donald Stookey of

10120-593: The Nazi "Blitz" attacks , making strategic bombing attacks by the United States Army Air Corps (USAAC) against Germany impossible with the aircraft available. The United States would need a new bomber to reach Europe and return to bases in North America, necessitating a combat range of at least 5,700 mi (9,200 km), the length of a Gander, Newfoundland – Berlin round trip. The USAAC therefore sought

10304-571: The P-5 Пятёрка . These early nuclear-armed SSGs served for a few decades until there were enough SSBNs put in service, after which they were retired. Their spiritual successors, armed with larger amounts of more modern, smaller cruise missiles continue to serve to this day serving in a tactical strike role, although they could be rearmed with nuclear cruise-missiles if need be. Air- or Ground-launched nuclear-armed cruise missiles (sometimes even nuclear-powered ) were considered by both sides early in

10488-707: The Polaris SLBM . The subsequent arms-race culminated in some of the largest submarines ever designed; the Trident-armed 170 meter long Ohio -class submarine armed with 24 x 8 MIRV Trident missiles , and the battlecruiser-sized 48,000 tonne Project 941 Акула , the Typhoon -class submarine , armed with 20 R-39s with 10 MIRVs each. After the Cold War, SSBN and subsequently SLBM development have slowed, but nascent nuclear powers are building novel classes of SSB (N)s, while

10672-584: The Rapid Eight program. The Conventional Enhancement Modification (CEM) program gave the B-52H a more comprehensive conventional weapons capability, adding the modified underwing weapon pylons used by conventional-armed B-52Gs, Harpoon and Have Nap, and the capability to carry new-generation weapons including the Joint Direct Attack Munition (JDAM) and Wind Corrected Munitions Dispenser guided bombs,

10856-594: The SSC-X-9 "Skyfall" (9М730 Буревестник ) was revealed by Russian President Vladimir Putin . It is under development and is slated to enter service sometime in the 2020s . Missiles using a ballistic trajectory deliver a warhead over the horizon; in the case of the most capable of these, classified as intercontinental ballistic missiles (ICBMs) (and submarine-launched ballistic missiles (SLBMs) if transported by submarine ), they can reach distances of nearly tens of thousands of kilometers. Most ballistic missiles exit

11040-540: The Space Shuttle , was the B-52's main computer. In 2007, the LITENING targeting pod was fitted, which increased the effectiveness of the aircraft in the attack of ground targets with a variety of standoff weapons, using laser guidance , a high-resolution forward-looking infrared sensor ( FLIR ), and a CCD camera used to obtain target imagery. LITENING pods have been fitted to a wide variety of other US aircraft, such as

11224-519: The United States Air Force (USAF) since the 1950s, and NASA for nearly 50 years. The bomber can carry up to 70,000 pounds (32,000 kg) of weapons and has a typical combat range of around 8,800 miles (14,200 km) without aerial refueling . Beginning with the successful contract bid in June 1946, the B-52 design evolved from a straight wing aircraft powered by six turboprop engines to

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11408-489: The elevator is also very narrow chord and the B-52 suffers from limited elevator control authority. For long-term pitch trim and airspeed changes the aircraft uses a stabilator (or all-moving tail) with the elevator used for small adjustments within a stabilizer setting. The stabilizer is adjustable through 13 degrees of movement (nine up, four down) and is crucial to operations during takeoff and landing due to large pitch changes induced by flap application. B-52s prior to

11592-414: The flying wing . Noting stability and control problems Northrop Corporation was experiencing with their YB-35 and YB-49 flying wing bombers, Boeing insisted on a conventional aircraft, and in April 1948 presented a US$ 30   million (US$ 380 million today ) proposal for design, construction, and testing of two Model 464-35 prototypes. Further revisions during 1948 resulted in an aircraft with

11776-470: The wind tunnel and 130 days of aerodynamic and aeroelastic testing, paid off with smooth flight testing. Encouraged, the USAF increased its order to 282 B-52s. Only three of the 13 B-52As ordered were built. All were returned to Boeing and used in their test program. On 9 June 1952, the February 1951 contract was updated to order the aircraft under new specifications. The final 10, the first aircraft to enter active service, were completed as B-52Bs. At

11960-469: The 15-megaton range. At distances typical of wartime delivery, aircraft suffered extensive flash and blast damage. The B-36 was employed in a variety of aeronautical experiments throughout its service life. Its immense size, range, and payload capacity lent itself to use in research and development programs. These included nuclear propulsion studies, and "parasite" programs in which the B-36 carried smaller interceptors or reconnaissance aircraft. In May 1946,

12144-413: The 36 that three B-52s can carry. The 1760 IWBU allows precision-guided missiles or bombs to be deployed from inside the weapons bay; the previous aircraft carried these munitions externally on the wing hardpoints . This increases the number of guided weapons ( Joint Direct Attack Munition or JDAM) a B-52 can carry and reduces the need for guided bombs to be carried on the wings. The first phase will allow

12328-552: The AN/ASQ-151 Electro-Optical Viewing System (EVS), which consisted of a low light level television (LLLTV) and a forward looking infrared (FLIR) system mounted in blisters under the noses of B-52Gs and Hs between 1972 and 1976. The navigational capabilities of the B-52 were later augmented with the addition of GPS in the 1980s. The IBM AP-101 , also used on the Rockwell B-1 Lancer bomber and

12512-560: The AN/ASQ-38 bombing navigational computer and the terrain computer. The MADREC (Malfunction Detection and Recording) upgrade fitted to most aircraft by 1965 could detect failures in avionics and weapons computer systems and was essential in monitoring the AGM-28 Hound Dog missiles. The electronic countermeasures capability of the B-52 was expanded with Rivet Rambler (1971) and Rivet Ace (1973). To improve operations at low altitudes,

12696-401: The Air Force began the Nuclear Energy for the Propulsion of Aircraft project, which was followed in May 1951 by the Aircraft Nuclear Propulsion (ANP) program. The ANP program used modified B-36s to study shielding requirements for an airborne reactor to determine whether a nuclear-powered aircraft was feasible. Convair modified two B-36s under the MX-1589 project. The Nuclear Test Aircraft was

12880-442: The B-36 and the carburetor was in front of the engine, where it would not benefit from engine heat and made more existing carburetor heat systems unsuitable. Hence, when intake air was cold and humid, ice gradually obstructed the carburetor intake, which increased the air/fuel mixture richness until unburned fuel in the exhaust caught fire. Three engine fires of this nature led to the first loss of an American nuclear weapon when

13064-434: The B-36 ceased in 1954. Due to problems that occurred with the B-36 in its early stages of testing, development, and later in service, some critics referred to the aircraft as a "billion-dollar blunder". In particular, the United States Navy saw it as a costly bungle, diverting congressional funding and interest from naval aviation and aircraft carriers in general, and carrier–based nuclear bombers in particular. In 1947,

13248-404: The B-36 could match what was arguably its approximate Soviet counterpart, the later Tu-95 . Until the B-52 became operational, the B-36 was the only means of delivering the first generation Mark 17 hydrogen bomb , 25 ft (7.6 m) long, 5 ft (1.5 m) in diameter, and weighing 42,000 lb (19,000 kg), the heaviest and bulkiest American aerial nuclear bomb. The Mark 17 took up

13432-542: The B-36 to USS United States . The Air Force successfully defended the B-36 project, and United States was cancelled by Secretary of Defense Louis A. Johnson in a cost-cutting move over the objections of both Secretary of the Navy John L. Sullivan and the Navy's senior leadership. Sullivan resigned in protest and was replaced as Secretary of the Navy by Francis P. Matthews , who had limited familiarity with defense issues, but

13616-406: The B-36 was believed to have "an ace up its sleeve": a phenomenal cruising altitude for a piston-driven aircraft, made possible by its huge wing area and six engines, putting it out of range of most interceptors, as well as ground-based anti-aircraft guns . Consolidated Vultee Aircraft Corporation (later Convair) and Boeing Aircraft Company took part in the competition, with Consolidated winning

13800-407: The B-36 was meant to compete for a production contract. Throughout its development, the B-36 program encountered delays. When the United States entered World War II, Consolidated was ordered to slow B-36 development to greatly increase Consolidated B-24 Liberator production. The first mockup was inspected on 20 July 1942, following six months of refinements. A month after the inspection, the project

13984-473: The B-36, thanks to its ability to operate at more than 50,000 ft (15,000 m). Later, the new Secretary of Defense, Louis A. Johnson , who considered the U.S. Navy and naval aviation essentially obsolete in favor of the USAF and SAC, forbade putting the Navy's claim to the test. The propulsion system of the B-36 was unique, with six 28-cylinder Pratt & Whitney R-4360 Wasp Major radial engines mounted in an unusual pusher configuration , rather than

14168-606: The B-47 came to an end, the Wichita factory was phased in for B-52D production, with Seattle responsible for 101 D-models and Wichita 69. Both plants continued to build the B-52E, with 42 built at Seattle and 58 at Wichita, and the B-52F (44 from Seattle and 45 from Wichita). For the B-52G, Boeing decided in 1957 to transfer all production to Wichita, which freed up Seattle for other tasks, in particular,

14352-450: The B-52's 70,000 pounds (32,000 kg), the bombers are rarely able to carry their full loads. The most the B-52 carries is a full load of AGM-86Bs totaling 62,660 pounds (28,420 kg). The B-1 has the internal weapons bay space to carry more GBU-31 JDAMs and JASSMs, but the B-52 upgraded with the conventional rotary launcher can carry more of other JDAM variants. The AGM-183A Air-Launched Rapid Response (ARRW) hypersonic missile and

14536-462: The B-52H as fully approved to use the FT blend. Because of the B-52's mission parameters, only modest maneuvers would be required with no need for spin recovery. The aircraft has a relatively small, narrow chord rudder , giving it limited yaw control authority. Originally an all-moving vertical stabilizer was to be used but was abandoned because of doubts about hydraulic actuator reliability. Because

14720-591: The B-52H began to be delivered to the USAF with cleaner burning and quieter Pratt & Whitney TF33-P-3 turbofans with a maximum thrust of 17,100 pounds-force (76 kN). In a study for the USAF in the mid-1970s, Boeing investigated replacing the engines, changing to a new wing, and other improvements to upgrade B-52G/H aircraft as an alternative to the B-1A, then in development. In 1996, Rolls-Royce and Boeing jointly proposed fitting each B-52 with four leased Rolls-Royce RB211 engines. This would have involved replacing

14904-446: The B61 gravity bomb described above, but it would have different environmental requirements, and different safety requirements since it would not be crew-tended after launch and remain atop a missile for a great length of time. While the first modern ballistic missile designed is the basis of contemporary rocket- and missilery, it never carried a nuclear warhead. The first ICBM ever designed

15088-534: The Boeing contract on 11 December 1947 was staved off by a plea from its president William McPherson Allen to the Secretary of the Air Force Stuart Symington . Allen reasoned that the design was capable of being adapted to new aviation technology and more stringent requirements. In January 1948, Boeing was instructed to thoroughly explore recent technological innovations, including aerial refueling and

15272-452: The Cold War, but both concluded that it was impractical with the technology of the time. Nuclear-powered aircraft were considered due to the nascent aeronautical and rocketry technology of the time, especially when considering the temperamental and inefficient nature of early jet engines , which limited the range and use cases of strategic bombers and cruise missiles. Later on in the Cold War both disciplines had advanced far enough that it

15456-775: The Corning Research and Development Division invented Pyroceram , a white glass-ceramic material capable of withstanding a thermal shock (sudden temperature change) of up to 450 °C (840 °F). It evolved from materials originally developed for a US ballistic missile program, and Stookey's research involved heat-resistant material for nose cones . Precise navigation would enable United States submarines to get an accurate fix of their positions before they launched their SLBMs, this spurred development of triangulation methods that ultimately culminated in GPS . The motivation for having accurate launch position fixes, and missile velocities,

15640-529: The Earth's atmosphere and re-enter it in their sub-orbital spaceflight . Ballistic missiles aren't always nuclear armed, but the conspicuous and alarming nature of their launch often precludes arming ICBMs and SLBMs, the most capable classes of ballistic missiles, with conventional warheads . Placement of nuclear missiles on the low Earth orbit has been banned by the Outer Space Treaty as early as 1967. Also,

15824-454: The G models had very small ailerons with a short span that was approximately equal to their chord. These "feeler ailerons" were used to provide feedback forces to the pilot's control yoke and to fine-tune the roll axes during delicate maneuvers such as aerial refueling. Due to twisting of the thin main wing, conventional outboard flap-type ailerons would lose authority and therefore could not be used. In other words, aileron activation would cause

16008-683: The Germans' Amerikabomber proposals, and the same day that the German firm Heinkel began design on a six-engined bomber of their own. The USAAF submitted a "letter of intent" to Convair for an initial production run of 100 , even before testing of the two prototypes was complete. The first delivery was due in August 1945, and the last in October 1946, but Consolidated (by now renamed Convair after merging with Vultee Aircraft ) delayed delivery. Three months after V-E Day

16192-554: The Model 464, a smaller four-engine version with a 230,000-pound (100,000 kg) gross weight, which was briefly deemed acceptable. Subsequently, in November 1946, the Deputy Chief of Air Staff for Research and Development, General Curtis LeMay , expressed the desire for a cruising speed of 400 miles per hour (350 kn; 640 km/h), to which Boeing responded with a 300,000-pound (140,000 kg) aircraft. In December 1946, Boeing

16376-515: The Navy attacked congressional funding for the B-36, alleging it failed to meet Pentagon requirements. The Navy held to the pre-eminence of the aircraft carrier in the Pacific during World War II, presuming carrier-based aircraft would be decisive in future wars. To this end, the Navy designed USS  United States , a " supercarrier " capable of launching huge fleets of tactical aircraft or nuclear bombers. It then pushed to have funding transferred from

16560-680: The Navy-backed General Dynamics AGM-109 Tomahawk , the AGM-86B was selected for operation by the B-52 (and ultimately by the B-1 Lancer). A total of 194 B-52Gs and Hs were modified to carry AGM-86s, carrying 12 missiles on underwing pylons, with 82 B-52Hs further modified to carry another eight missiles on a rotary launcher fitted in the bomb bay. To conform with SALT II Treaty requirements that cruise missile-capable aircraft be readily identifiable by reconnaissance satellites,

16744-725: The R-7 is still in use as the launch vehicle for the Russian Federation, in the form of the Soyuz spacecraft . The first true weather satellite , the TIROS-1 was launched on the Thor-Able launch vehicle in April 1960. The PGM-17 Thor was the first operational IRBM (intermediate ballistic missile) deployed by the US Air Force ( USAF ). The Soviet Union 's first fully operational weather satellite,

16928-618: The SAC. Convair touted the B-36 as the "aluminum overcast", a so-called " long rifle ", giving SAC truly global reach. During General Curtis LeMay 's tenure as head of SAC (1949–57), the B-36 formed the heart of the Strategic Air Command. Its maximum payload was more than four times that of the B-29 and exceeded that of the later B-52. The B-36 was slow and could not refuel in midair, but could fly missions to targets 3,400 mi (5,500 km) away and stay aloft as long as 40 hours. Moreover,

17112-587: The USAF released its request for proposals for 608 commercial engines plus spares and support equipment, with the plan to award the contract in May 2021. This Commercial Engine Reengining Program (CERP) saw General Electric propose its CF34-10 and Passport turbofans, Pratt & Whitney its PW800 , and the Rolls-Royce BR725 to be designated F130 . On 24 September 2021, the USAF selected the Rolls-Royce F130 as

17296-451: The USSR. The modification to allow the use of larger atomic weapons on the B-36 was called the "Grand Slam Installation". The B-36 was obsolete from the outset, while it now faced the widespread introduction of opposing jet fighters. The Boeing B-47 Stratojet , its jet engined counterpart, did not become fully operational until 1953, and lacked the range to attack the Soviet Union from North America without aerial refueling and could not carry

17480-694: The XB-36 was restricted to Carswell Field adjacent to the factory in Texas, Eglin Field in Florida, and Fairfield-Suisun Field in California. The single-wheel gear was soon replaced by a four-wheeled bogie . At one point, a tank-like tracked landing gear was also tried on the XB-36, but it proved heavy and noisy and was soon abandoned. The four bomb bays could carry up to 87,200 lb (39,600 kg) of bombs, more than 10 times

17664-472: The YB-36, flew on 4 December 1947. It had a redesigned, high-visibility, yet still heavily framed greenhouse dome-shaped canopy, which was later adopted for production, and the engines used on the YB-36 were more powerful and more efficient. Altogether, the YB-36 was much closer to the production aircraft. The first 21 B-36As were delivered in 1948 as interim airframes intended for crew training. No defensive armament

17848-632: The aircraft has become commonly referred to as the BUFF ( Big Ugly Fat Fucker / Fella ). There are 76 aircraft in inventory as of 2024 ; 58 operated by active forces ( 2nd Bomb Wing and 5th Bomb Wing ), 18 by reserve forces ( 307th Bomb Wing ), and about 12 in long-term storage at the Davis-Monthan AFB Boneyard . The bombers flew under the Strategic Air Command (SAC) until it was disestablished in 1992 and its aircraft absorbed into

18032-410: The aircraft has eight engines, asymmetrical thrust due to the loss of an engine in flight would be minimal and correctable with the narrow rudder. To assist with crosswind takeoffs and landings the main landing gear can be pivoted 20 degrees to either side from neutral. The crew would preset the yaw adjustable crosswind landing gear according to wind observations made on the ground. Like the rudder,

18216-414: The aircraft to "crab" or roll with a sideways slip angle down the runway). After a trip to a hobby shop for supplies, Schairer set to work building a model. The rest of the team focused on weight and performance data. Wells, who was also a skilled artist, completed the aircraft drawings. On Sunday, a stenographer was hired to type a clean copy of the proposal. On Monday, Schairer presented Colonel Warden with

18400-581: The aircraft was unveiled on 20 August 1945 , and flew for the first time on 8 August 1946. After the start of the Cold War with the 1948 Berlin Airlift , and the 1949 atmospheric test of the first Soviet atomic bomb , American military planners sought bombers capable of delivering the very large and heavy first-generation atomic bombs. The B-36 was the only American aircraft with the range and payload to carry such bombs from airfields on American soil to targets in

18584-494: The aircraft's electrical wiring to jar loose or the vacuum tube electronics to malfunction, leading to failure of the aircraft controls and navigation equipment, which contributed to the crash of B-36B 44-92035 on 22 November 1950. The Convair B-36 was the only aircraft capable of carrying the T-12 Cloudmaker , a gravity bomb weighing 43,600 lb (19,800 kg) and designed to produce an earthquake bomb effect. Part of

18768-479: The aircraft's two aft bomb bays, while the forward bay could hold a Mark 6 atomic weapon. The defensive armament consisted of six retractable gun turrets, with side-by-side turrets mounted in forward dorsal, aft dorsal and ventral positions, aft dorsal and non-retractable tail and nose turrets. Each turret was fitted with two 20 mm (0.79 in) cannon , for a total of 16, and all turrets were remote controlled. Recoil vibration from gunnery practice often caused

18952-431: The arrival of the B-52. The aircraft will be able to receive information through Link-16 . CONECT upgrades will cost US$ 1.1   billion overall and take several years. Funding has been secured for 30 B-52s; the USAF hopes for 10 CONECT upgrades per year, but the rate has yet to be decided. Weapons upgrades include the 1760 Internal Weapons Bay Upgrade (IWBU), which gives a 66 percent increase in weapons payload using

19136-488: The bulky, high-resolution cameras of the day. The standard RB-36D carried up to 23 cameras, primarily K-17C, K-22A, K-38, and K-40 cameras. A special 240 in (6,100 mm) focal length camera (known as the Boston Camera after the university where it was designed) was tested on 44-92088, the aircraft being redesignated ERB-36D. The long focal length was achieved by using a two-mirror reflection system and could resolve

19320-471: The cabin included the crew ejection systems. On the B-52D, the pilots and electronic countermeasures (ECM) operator ejected upwards, while the lower deck crew ejected downwards; until the B-52G, the gunner had to jettison the tail gun to bail out . The tail gunner in early model B-52s was located in the traditional location in the tail of the plane, with both visual and radar gun laying systems; in later models,

19504-487: The conclusions of a separate Congress-funded study conducted in 2003. Criticizing the USAF cost analysis, the DSB found that among other things, the USAF failed to account for the cost of aerial refueling; the DSB estimated that aerial refueling cost $ 17.50 per US gallon ($ 4.62/L), whereas the USAF had failed to account for the cost of delivering the fuel and so had only priced fuel at $ 1.20 per US gallon ($ 0.32/L). On 23 April 2020,

19688-485: The conventional tractor propeller layout of other heavy bombers . The prototypes six R-4360s delivered 18,000 hp (13,000 kW) which resulted in early B-36s needing long takeoff runs, which was ameliorated when power was boosted to 22,800 hp (17,000 kW). Each engine drove a three-bladed propeller, 19 ft (5.8 m) in diameter, mounted in a pusher configuration. This unusual configuration prevented propeller turbulence from interfering with airflow over

19872-420: The crew from 15 to 9. Featherweight III had a longer range and an operating ceiling of at least 47,000 ft (14,000 m), especially valuable for reconnaissance missions. The B-36J-III configuration (the last 14 made) had a single radar-aimed tail turret, extra fuel tanks in the outer wings, and landing gear allowing the maximum gross weight to be increased to 410,000 lb (190,000 kg). Production of

20056-573: The crew. One update is the AN/ARC-210 Warrior beyond-line-of-sight software programmable radio able to transmit voice, data, and information in-flight between B-52s and ground command and control centers, allowing the transmission and reception of data with updated intelligence, mapping, and targeting information; previous in-flight target changes required copying down coordinates. The ARC-210 allows machine-to-machine transfer of data, useful on long-endurance missions where targets may have moved before

20240-463: The cruise missile-armed B-52Gs were modified with a distinctive wing root fairing . As all B-52Hs were assumed modified, no visual modification of these aircraft was required. In 1990, the stealthy AGM-129 ACM cruise missile entered service; although intended to replace the AGM-86, the high cost and the Cold War's end led to only 450 being produced; unlike the AGM-86, no conventional, non-nuclear version

20424-456: The day, and directed Boeing to use the turboprop-powered Model 464–35 as the basis for the XB-52. Although he agreed that turbojet propulsion was the future, General Howard A. Craig, Deputy Chief of Staff for Materiel, was not very enthusiastic about a jet-powered B-52 since he felt that the jet engine had not yet progressed sufficiently to permit skipping an intermediate turboprop stage. However, Boeing

20608-456: The design. That resulted in the development of yet another revision—in July 1948, Model 464-40 substituted Westinghouse J40 turbojets for the turboprops. The USAF project officer who reviewed the Model 464-40 was favorably impressed, especially since he had already been thinking along similar lines. Nevertheless, the government was concerned about the high fuel consumption rate of the jet engines of

20792-450: The development of more advanced strategic bombers, such as the Mach 2+ Convair B-58 Hustler , the canceled Mach 3 North American XB-70 Valkyrie , the variable-geometry Rockwell B-1 Lancer , and the stealth Northrop Grumman B-2 Spirit . A veteran of several wars, the B-52 has dropped only conventional munitions in combat. The B-52's official name Stratofortress is rarely used; informally,

20976-479: The dropping aircraft time to escape the ensuing blast. The earliest gravity nuclear bombs ( Little Boy and Fat Man ) of the United States could only be carried, during the era of their creation, by the special Silverplate limited production (65 airframes by 1947) version of the B-29 Superfortress . The next generation of weapons were still so big and heavy that they could only be carried by bombers such as

21160-428: The eight Pratt & Whitney TF33 engines (total thrust 136,000 lbf (600 kN)) with four RB211-535E4 engines (total thrust 172,400 lbf (767 kN)), which would increase range and reduce fuel consumption. However, a USAF analysis in 1997 concluded that Boeing's estimated savings of US$ 4.7   billion would not be realized and that reengining would instead cost US$ 1.3   billion more than keeping

21344-416: The end of each wing which were also retrofitted to surviving B-36Bs. Consequently, the B-36 was configured to have 10 engines, six radial propeller engines and four jet engines, leading to the B-36 slogan of "six turnin' and four burnin ' ". The B-36 had more engines than any other mass-produced aircraft. The jet pods greatly improved takeoff performance and dash speed over the target. In normal cruising flight,

21528-571: The engines. The wing area permitted cruising altitudes well above the operating ceiling of any 1940s-era fighters, at over 40,000 ft (12,000 m). In 1954, the turrets and other nonessential equipment were stripped out (not unlike the earlier Silverplate program for the atomic bomb-carrying "specialist" B-29s), resulting in a "featherweight" configuration that increased top speed to 423 mph (681 km/h), and cruise at 50,000 ft (15,000 m) and dash at over 55,000 ft (17,000 m), perhaps even higher. The large wing area, with

21712-618: The established powers, all members of the United Nations Security Council , are plotting the next - generation of nuclear-powered nuclear-armed ballistic missile submarines. Hypersonically-Gliding Warheads are a novel form of warhead to arm ballistic missiles. These maneuverable devices threaten to obsolate current forms of ABM defences, thus various nascent and established nuclear powers are racing to field examples of such systems . Other delivery methods included nuclear artillery shells, mines such as

21896-456: The event of a surprise attack. Early ballistic missiles carried a single warhead , often of megaton -range yield. Because of the limited accuracy of the missiles, this kind of high yield was considered necessary in order to ensure a particular target's destruction. Since the 1970s modern ballistic weapons have seen the development of far more accurate targeting technologies, particularly due to improvements in inertial guidance systems . This set

22080-580: The eventual Soviet Fractional Orbital Bombardment System (FOBS) that served a similar purpose—it was just deliberately designed to deorbit before completing a full circle—was phased out in January 1983 in compliance with the SALT II treaty. An ICBM is more than 20 times as fast as a bomber and more than 10 times as fast as a fighter plane , and also flying at a much higher altitude , and therefore more difficult to defend against. ICBMs can also be fired quickly in

22264-442: The evolution of US human spaceflight. The Atlas vehicle sent John Glenn , the first American into orbit. Similarly in the Soviet Union it was the R-7 ICBM / launch vehicle that placed the first artificial satellite in space, Sputnik , on 4 October 1957, and the first human spaceflight in history was accomplished on a derivative of the R-7, the Vostok , on 12 April 1961 , by cosmonaut Yuri Gagarin . A modernized version of

22448-531: The existence of the United States was the one need that did justify this cost in the view of the United States Congress. This deterrent effect is why GPS was funded. The nuclear triad consisted of the United States Navy's submarine-launched ballistic missiles (SLBMs) along with United States Air Force (USAF) strategic bombers and intercontinental ballistic missiles (ICBMs). Considered vital to

22632-454: The existing engines, citing significant up-front procurement and re-tooling expenditure. The USAF's 1997 rejection of reengining was subsequently disputed in a Defense Science Board (DSB) report in 2003. The DSB urged the USAF to re-engine the aircraft without delay, saying doing so would not only create significant cost savings but reduce greenhouse gas emissions and increase aircraft range and endurance; these conclusions were in line with

22816-481: The external pylons could. Thirty B-52Gs were further modified to carry up to 12 AGM-84 Harpoon anti-ship missiles each, while 12 B-52Gs were fitted to carry the AGM-142 Have Nap stand-off air-to-ground missile. When the B-52G was retired in 1994, an urgent scheme was launched to restore an interim Harpoon and Have Nap capability, the four aircraft being modified to carry Harpoon and four to carry Have Nap under

23000-429: The film. The second bomb bay contained up to 80 T-86 photoflash bombs , while the third bay could carry an extra 11,000 L (3,000 US gal) droppable fuel tank. The fourth bomb bay carried electronic countermeasure equipment. The full defensive armament was retained. The extra fuel tanks increased the flight endurance to up to 50 hours and it had an operational ceiling of 50,000 ft (15,000 m). Later,

23184-589: The final prototype YB-52 with eight turbojet engines and swept wings . The B-52 took its maiden flight in April 1952. The B-52 has been in service with the USAF since 1955, and NASA from 1959 to 2007. Built to carry nuclear weapons for Cold War –era deterrence missions, the B-52 Stratofortress replaced the Convair B-36 Peacemaker . Superior performance at high subsonic speeds and relatively low operating costs have kept them in service despite

23368-489: The form of missiles. Gravity bombs are designed to be dropped from planes, which requires that the weapon be able to withstand vibrations and changes in air temperature and pressure during the course of a flight. Early weapons often had a removable core for safety, known as in flight insertion (IFI) cores, being inserted or assembled by the air crew during flight. They had to meet safety conditions, to prevent accidental detonation or dropping. A variety of types also had to have

23552-558: The former have much larger yield than the latter, even though it is not a rule. The bombs that destroyed Hiroshima and Nagasaki in 1945 (with TNT equivalents between 15 and 22 kilotons ) were weaker than many of today's tactical weapons, yet they achieved the desired effect when used strategically. A nuclear triad refers to a strategic nuclear arsenal which consists of three components, traditionally strategic bombers , intercontinental ballistic missiles (ICBMs), and submarine-launched ballistic missiles (SLBMs). The purpose of having

23736-422: The four jet engines supplementing the piston engines in later versions gave the B-36 a wide margin between stall speed ( V S ) and maximum speed ( V max ) at these altitudes. This made the B-36 more maneuverable at high altitude than most jet interceptors of the day, which could not maneuver effectively above 40,000 ft (12,000 m). However, the U.S. Navy McDonnell F2H Banshee fighter could intercept

23920-448: The fuselage to carry spare engines between bases. Each pod could airlift two engines. When the pods were empty, they were removed and carried in the bomb bays. No record exists of the pods being used. As engine fires occurred with the B-36's radial engines, some crews humorously changed the aircraft's slogan from "six turning, four burning" into "two turning, two burning, two smoking, two choking and two more unaccounted for". This problem

24104-648: The future Long Range Stand Off (LRSO) nuclear -armed air-launched cruise missile will join the B-52 inventory in the future. The eight engines of the B-52 are paired in pods and suspended by four pylons beneath and forward of the wings' leading edge . The careful arrangement of the pylons also allowed them to work as wing fences and delay the onset of stall . The first two prototypes, XB-52 and YB-52, were both powered by experimental Pratt & Whitney YJ57-P-3 turbojet engines with 8,700 pounds-force (39 kN) of static thrust each. The B-52A models were equipped with Pratt & Whitney J57-P-1W turbojets, providing

24288-675: The ground , and from naval ships. There is no letter change in the US arsenal to distinguish the warheads of cruise missiles from those for ballistic missiles. Cruise missiles, even with their lower payload, speed, and thus readiness, have a number of advantages over ballistic missiles for the purposes of delivering nuclear strikes: However, cruise missiles are vulnerable to typical air-defence means as they are essentially one-use unmanned aircraft ; strategies such as combat flights of fighter aircraft , or an integrated air-defence system comprising both CAP and ground-based elements, such as surface-air missiles (SAM) , can be used to defend against

24472-570: The gunner was moved to the front of the fuselage, with gun laying carried out by radar alone, much like the B-58 Hustler's tail gun system. Structural fatigue was accelerated by at least a factor of eight in a low-altitude flight profile over that of high-altitude flying, requiring costly repairs to extend service life. In the early 1960s, the three-phase High Stress program was launched to counter structural fatigue, enrolling aircraft at 2,000 flying hours. Follow-up programs were conducted, such as

24656-539: The huge Mark 16 hydrogen bomb . The other American piston bombers of the day, the Boeing B-29 Superfortress and Boeing B-50 Superfortress , were also too limited in range. Intercontinental ballistic missiles did not become sufficiently reliable until the early 1960s. Until the Boeing B-52 Stratofortress became operational in 1955, the B-36 was the primary nuclear weapons delivery vehicle of

24840-517: The huge production effort, with 41% of the airframe being built by subcontractors. The prototypes and all B-52A, B and C models (90 aircraft) were built at Seattle. Testing of aircraft built in Seattle caused problems due to jet noise, which led to the establishment of curfews for engine tests. Aircraft were ferried 150 miles (240 km) east on their maiden flights to Larson Air Force Base near Moses Lake , where they were fully tested. As production of

25024-455: The jet engines could raise the cruising speed to over 400 mph (640 km/h). Hence, a 40-hour mission, with the jets used only for takeoff and climbing, flew about 9,200 mi (14,800 km). Due to its size, the B-36 was never sprightly or agile. Lieutenant General James Edmundson likened it to "sitting on your front porch and flying your house around". Crew compartments were nonetheless cramped, especially when occupied for 24 hours by

25208-415: The jet engines were shut down to conserve fuel. When the jet engines were shut down, louvers closed off the front of the pods to reduce drag. The two pods with four turbojets and the six piston engines combined gave the B-36 a total of 40,000 hp (30,000 kW) for short periods of time. The B-36 had a crew of 15. As with the B-29 and B-50, the pressurized flight deck and crew compartment were linked to

25392-501: The late 1940s, strategic intelligence on Soviet capabilities and intentions was scarce. Before the development of the Lockheed U-2 high-altitude spy plane and Corona orbital reconnaissance satellites, technology and politics limited American reconnaissance efforts to the borders, of the Soviet Union. One of the essential criteria of the early postwar reconnaissance aircraft was the ability to cruise above 40,000 ft (12,000 m),

25576-512: The load carried by the World War II Boeing B-17 Flying Fortress . The B-36 was not designed with nuclear weapons in mind, because the existence of such weapons was top secret during the period when the B-36 was conceived and designed, and the initial B-36A was not capable of accommodating them. Nevertheless, the B-36 stepped into its nuclear delivery role immediately upon becoming operational. In all respects except speed,

25760-523: The location. Special shelters were built to provide the maintenance crews a modicum of protection. Ground crews were at risk of slipping and falling from icy wings. The wing roots were thick enough, at 7 ft (2.1 m), to enable a flight engineer to access the backs of the engines and the landing gear during flight by crawling through the wings but was only possible at lower altitudes. In 1950, Consolidated-Vultee developed streamlined pods that looked like large drop tanks that mounted on each side of

25944-508: The maximum effective altitude of most of Nazi Germany 's anti-aircraft guns. In the Pacific, the USAAF needed a bomber capable of reaching Japan from bases in Hawaii , and the development of the B-36 became a priority. Secretary of War Henry L. Stimson , in discussions with high-ranking officers of the USAAF, decided to waive normal army procurement procedures, and on 23 July 1943, 15 months after

26128-404: The need for a more universal navigation solution with greater accuracy. While there were wide needs for accurate navigation in military and civilian sectors, almost none of those was seen as justification for the billions of dollars it would cost in research, development, deployment, and operation for a constellation of navigation satellites. During the Cold War arms race , the nuclear threat to

26312-402: The negative 1-G load position to the positive 4-G load position." The flexible structure allowed "...the wing to flex during gust and maneuvering loads, thus relieving high-stress areas and providing a smoother ride." During a 3.5-G pullup, "The wingtips appeared about 35 degrees above level flight position." During ground testing on 29 November 1951, the XB-52's pneumatic system failed during

26496-504: The nuclear-deterrence posture, accurate determination of the SLBM launch position was a force multiplier . Precise navigation would enable United States submarines to get an accurate fix of their positions before they launched their SLBMs. The USAF, with two-thirds of the nuclear triad, also had requirements for a more accurate and reliable navigation system. The Navy and Air Force were developing their own technologies in parallel to solve what

26680-531: The production of airliners. Production ended in 1962 with the B-52H, with 742 aircraft built, plus the original two prototypes. A proposed variant of the B-52H was the EB-52H, which would have consisted of 16 modified and augmented B-52H airframes with additional electronic jamming capabilities. This variant would have restored USAF airborne jamming capability that it lost on retiring the EF-111 Raven . The program

26864-484: The range of the B-36 needed to be stationed as close to enemy targets as possible, this meant the plane was largely based in the extreme weather locations of the northern continental United States, Alaska, and the Arctic . Since the maintenance had to be performed outdoors, the crews were largely exposed to the elements, with temperatures of −60 °F (−51 °C) in winters and 100 °F (38 °C) in summers, depending on

27048-450: The range. It was becoming obvious to the USAAF that, even with the updated performance, the XB-52 would be obsolete by the time it entered production and would offer little improvement over the Convair B-36 Peacemaker ; as a result, the entire project was postponed for six months. During this time, Boeing continued to perfect the design, which resulted in the Model 464–29 with a top speed of 455 miles per hour (395 kn; 732 km/h) and

27232-608: The rear compartment by a pressurized tunnel through the bomb bay. In the B-36, movement through the tunnel was on a wheeled trolley, pulling on a rope. The rear compartment featured six bunks and a dining galley and led to the tail turret. The tricycle landing gear of the XB-36 featured a single-wheel main landing gear whose tires were the largest ever manufactured up to that time: 9 ft 2 in (2.79 m) tall, 3 ft (0.91 m) wide, and weighing 1,320 lb (600 kg), with enough rubber for 60 automobile tires. These tires placed so much ground pressure on runways that

27416-517: The removal of B61-7 and B83-1 gravity bombs from the B-52H's approved weapons configuration. Starting in 2016, Boeing is to upgrade the internal rotary launchers to the MIL-STD-1760 interface to enable the internal carriage of smart bombs, which previously could be carried only on the wings. While the B-1 Lancer has a larger theoretical maximum payload of 75,000 pounds (34,000 kg) compared to

27600-509: The roll-out ceremony on 18 March 1954, Air Force Chief of Staff General Nathan Twining said: The long rifle was the great weapon of its day.   ... today this B-52 is the long rifle of the air age. The B-52B was followed by progressively improved bomber and reconnaissance variants, culminating in the B-52G and turbofan B-52H. To allow rapid delivery, production lines were set up both at its main Seattle factory and at Boeing's Wichita facility. More than 5,000 companies were involved in

27784-446: The satellite transponder in orbit. A fourth ground-based station, at an undetermined position, could then use those signals to fix its location precisely. The last SECOR satellite was launched in 1969. Decades later, during the early years of GPS, civilian surveying became one of the first fields to make use of the new technology, because surveyors could reap benefits of signals from the less-than-complete GPS constellation years before it

27968-902: The serving Chief of Naval Operations (CNO), Admiral Louis E. Denfeld , following Denfeld's testimony before the House Armed Services Committee . The congressional and media furor over the firing of Admiral Denfeld, as well as the significant use of aircraft carriers in the Korean War , resulted in the Truman administration subsequently ousting both Johnson and Matthews, and procuring Forrestal -class supercarriers, which were similar in size to United States , but geared towards multirole use with air wings of fighter, attack, reconnaissance, electronic warfare , early warning and antisubmarine-warfare aircraft. Simultaneously, heavy manned bombers for SAC were also deemed crucial to national defense and

28152-414: The sides and bottom of the aircraft's rear fuselage to cool the reactor in flight. On the ground, a crane would be used to remove the 35,000 lb (16,000 kg) reactor from the aircraft. To protect the crew, the highly modified cockpit was encased in lead and rubber, with a 1 ft-thick (30 cm) leaded glass windshield . The reactor was operational, but did not power the aircraft as its purpose

28336-446: The six/ten-engined, seventy-meter wingspan B-36 Peacemaker , the eight jet-engined B-52 Stratofortress , and jet-powered British RAF V bombers , but by the mid-1950s smaller weapons had been developed that could be carried and deployed by fighter-bombers . Modern nuclear gravity bombs are so small that they can be carried by (relatively) small multirole fighter aircraft , such as the single-engined F-16 and F-35 . A cruise missile

28520-450: The stage for smaller warheads in the hundreds-of- kilotons -range yield, and consequently for ICBMs having multiple independently targetable reentry vehicles (MIRV). Advances in technology have enabled a single missile to launch a payload containing several warheads; the number of which depended on the missile's and payload bus' design. MIRVs has a number of advantages over a missile with a single warhead. With few additional costs, it allows

28704-407: The technology of the day, so on 19 August 1941, they were reduced, to a maximum range of 10,000 mi (16,000 km), an effective combat radius of 4,000 mi (6,400 km) with a 10,000 lb (4,500 kg) bomb-load, a cruising speed between 240 and 300 mph (390 and 480 km/h), and a service ceiling of 40,000 ft (12,000 m) The ceiling in both cases was chosen to exceed

28888-503: The test was the RB-36D specialized photo-reconnaissance version of the B-36D . It was outwardly identical to the standard B-36D, but carried a crew of 22 rather than 15, the additional crew members being needed to operate the reconnaissance equipment carried. The forward bomb bay was filled with a pressurized, manned compartment with 14 cameras and a darkroom , where a photo technician would develop

29072-470: The testing process involved dropping two of them in a single flight, one from 30,000 ft (9,100 m) and the second from 40,000 ft (12,000 m). The first prototype XB-36 flew on 8 August 1946. The speed and range of the prototype failed to meet the standards set out by the USAAC in 1941. This was expected, as the Pratt & Whitney R-4360 engines required were not yet available. A second aircraft,

29256-462: The third one in 1974 carrying the first atomic clock into orbit. Another important predecessor to GPS came from a different branch of the United States military. In 1964, the United States Army orbited its first Sequential Collation of Range ( SECOR ) satellite used for geodetic surveying. The SECOR system included three ground-based transmitters from known locations that would send signals to

29440-535: The total, $ 795 billion was spent on the manufacturing of nuclear weapons themselves. Strictly speaking however not all this 57 percent was spent solely on "weapons programs" delivery systems. For example, two such delivery mechanisms , the Atlas ICBM and Titan II , were re-purposed as human launch vehicles for human spaceflight , both were used in the civilian Project Mercury and Project Gemini programs respectively, which are regarded as stepping stones in

29624-487: The two systems would never again be in competition for funding. The B-36, including its GRB-36, RB-36, and XC-99 variants, was in USAF service as part of the SAC from 1948 to 1959. The RB-36 variants of the B-36 were used for reconnaissance during the Cold War with the Soviet Union and the B-36 bomber variants conducted training and test operations and stood ground and airborne alert, but were never flown offensively as bombers against hostile forces. The Wasp Major engines had

29808-408: The upgrade would look like. The upgrades will also include improved communication systems, new pylons, new cockpit displays and the deletion of one crew station. The changes will carry the designation B-52J. The B-52 shared many technological similarities with the preceding B-47 Stratojet strategic bomber. The two aircraft used the same basic design, such as swept wings and podded jet engines, and

29992-432: The violent turbulence induced by the wingtip vortices of the B-36. One of the SAC's initial missions was to plan strategic aerial reconnaissance on a global scale. The first efforts were in photo-reconnaissance and mapping. Along with the photo-reconnaissance mission, a small electronic intelligence cadre operated. Weather reconnaissance was part of the effort, as was long-range detection of Soviet atomic explosions. In

30176-513: The wing to twist, undermining roll control. Six spoilerons on each wing are responsible for the majority of roll control. The late B-52G models eliminated the ailerons altogether and added an extra spoileron to each wing. Partly because of the lack of ailerons, the B-52G and H models were more susceptible to Dutch roll . Ongoing problems with avionics systems were addressed in the Jolly Well program, completed in 1964, which improved components of

30360-436: The wing, but led to engine overheating due to insufficient airflow around the engines, resulting in inflight engine fires . The large, slow-turning propellers interacted with the high-pressure airflow behind the wings to produce an easily recognizable very-low-frequency pulse at ground level that betrayed approaching flights. Beginning with the B-36D, Convair added a pair of General Electric J47 -19 jet engines suspended near

30544-501: The winner and announced plans to purchase 650 engines (608 direct replacements and 42 spares), for US$ 2.6   billion. Unlike the previous re-engine proposal which also involved reducing the number of engines from eight to four, the F130 re-engine program maintains eight engines on the B-52. Although four-engine operation would be more efficient, retrofitting the airframe to operate with only four engines would involve additional changes to

30728-455: Was a gravity bomb dropped by a plane . In the years leading up to the development and deployment of nuclear-armed missiles, nuclear bombs represented the most practical means of nuclear weapons delivery; even today, and especially with the decommissioning of nuclear missiles , aerial bombing remains the primary means of offensive nuclear weapons delivery, and the majority of US nuclear warheads are represented in bombs, although some are in

30912-531: Was a close friend of Johnson. Several high-level Navy officials questioned the government's decision in cancelling the United States to fund the B-36, alleging a conflict of interest because Johnson had once served on Convair's board of directors. The uproar following the cancellation of United States in 1949 was nicknamed the " Revolt of the Admirals ", during which time Matthews dismissed and forced into retirement

31096-473: Was an essentially new airplane. The new design (464-49) built upon the basic layout of the B-47 Stratojet with 35-degree swept wings , eight engines paired in four underwing pods , and bicycle landing gear with wingtip outrigger wheels. A notable feature was the ability to pivot both fore and aft main landing gear up to 20° from the aircraft centerline to increase safety during crosswind landings (allowing

31280-413: Was asked to change their design to a four-engine bomber with a top speed of 400 miles per hour (350 kn; 640 km/h), range of 12,000 miles (10,000 nmi; 19,000 km), and the ability to carry a nuclear weapon ; in total, the aircraft could weigh up to 480,000 pounds (220,000 kg). Boeing responded with two models powered by T35 turboprops. The Model 464-16 was a "nuclear only" bomber with

31464-448: Was built. The B-52 was to have been modified to utilize Northrop Grumman 's AGM-137 TSSAM weapon; however, the missile was canceled due to development costs. Those B-52Gs not converted as cruise missile carriers underwent a series of modifications to improve conventional bombing. They were fitted with a new Integrated Conventional Stores Management System (ICSMS) and new underwing pylons that could hold larger bombs or other stores than

31648-523: Was canceled in 2005 following the removal of funds for the stand-off jammer. The program was revived in 2007 and cut again in early 2009. In July 2013, the USAF began a fleet-wide technological upgrade of its B-52 bombers called Combat Network Communications Technology (CONECT) to modernize electronics, communications technology, computing, and avionics on the flight deck. CONECT upgrades include software and hardware such as new computer servers, modems, radios, data-links, receivers, and digital workstations for

31832-468: Was declared operational. GPS can be thought of as an evolution of the SECOR system where the ground-based transmitters have been migrated into orbit. Boeing B-52 Stratofortress The Boeing B-52 Stratofortress is an American long-range, subsonic , jet-powered strategic bomber . The B-52 was designed and built by Boeing , which has continued to provide support and upgrades. It has been operated by

32016-405: Was delivered in May 1951. Some RB-36Ds were later modified to the featherweight configuration, in which all but the tail guns were removed and the crew reduced from 22 to 19. These aircraft were redesignated as RB-36D-III. Modifications were carried out by Convair from February to November 1954. Nuclear weapons delivery Nuclear weapons delivery is the technology and systems used to place

32200-414: Was encouraged to continue turbojet studies even without any expected commitment to jet propulsion. On Thursday, 21 October 1948, Boeing engineers George S. Schairer , Art Carlsen, and Vaughn Blumenthal presented the design of a four-engine turboprop bomber to the chief of bomber development, Colonel Pete Warden . Warden was disappointed by the projected aircraft and asked if the Boeing team could produce

32384-489: Was essentially the same problem. To increase the survivability of ICBMs, there was a proposal to use mobile launch platforms (such as Russian SS-24 and SS-25 ) and so the need to fix the launch position had similarity to the SLBM situation. In 1960, the Air Force proposed a radio-navigation system called MOSAIC (MObile System for Accurate ICBM Control) that was essentially a 3-D  LORAN . A follow-on study, Project 57,

32568-498: Was exacerbated by the propellers' pusher configuration, which increased carburetor icing . The design of the R-4360 engine tacitly assumed that it would be mounted in the conventional tractor configuration with the air flowing in the order of propeller/air intake/cylinders and to the carburetor. In this configuration, the carburetor is bathed in warm air flowing past the engine, so is unlikely to ice up. However, they were mounted backwards in

32752-420: Was feasible to create both reliable long-ranged cruise missiles and the strategic bombers able to launch them. Another arms-race began which produced contemporary post-Cold War cruise missiles and launch systems; VLS technology also allowed for surface ships to be armed with nuclear-armed cruise missiles while concealing their true payload. In 2018, the first operational nuclear-powered strategic cruise missile,

32936-653: Was fitted, since none was ready. All surviving B-36As were converted to RB-36E reconnaissance models once later models became available. Deliveries began in November 1948 of the combat-capable B-36B, which finally met the 1941 requirements, but had serious engine reliability and maintenance problems (changing the 336 spark plugs was a task dreaded by ground crews) and with the availability of weapons and spares. Later models had more powerful R-4360 engines, improved radar, and redesigned crew compartments. The jet engines increased fuel consumption and reduced range. Gun turrets were already recognized as obsolete, and newer bombers had only

33120-420: Was moved from San Diego, California, to Fort Worth, Texas, which set back development several months. Consolidated changed the tail from a twin-tail to a single, thereby saving 3,850 lb (1,750 kg), but this change delayed delivery by a further 120 days. Changes in the USAAF requirements added back the weight saved in redesigns, and cost more time. A new antenna system needed to be designed to accommodate

33304-540: Was the Soviet R-7 . The first SLBM-carrying submarine was also Soviet; the prototype Modified Zulu -class and the mass-produced Golf -class ballistic missile submarines carried their SLBMs in their sails, but these pioneering designs had to surface to launch their ballistic missiles. The Americans responded with the first "modern design" of ballistic missile subs; the George Washington -class , which launched

33488-540: Was to consist of an unspecified number of 20 mm cannons and 10,000 pounds (4,500 kg) of bombs. On 13 February 1946, the USAAF issued bid invitations for these specifications, with Boeing, Consolidated Aircraft , and Glenn L. Martin Company submitting proposals. On 5 June 1946, Boeing's Model 462, a straight-wing aircraft powered by six Wright T35 turboprops with a gross weight of 360,000 pounds (160,000 kg) and

33672-484: Was to investigate the effect of radiation. Between 1955 and 1957, the NB-36H completed 47 test flights and 215 hours of flight time, during 89 of which the reactor was critical. Other experiments involved providing the B-36 with its own fighter defense in the form of parasite aircraft carried partially or wholly in a bomb bay. One parasite aircraft was the diminutive football-shaped McDonnell XF-85 Goblin , which docked using

33856-500: Was worked in 1963 and it was "in this study that the GPS concept was born". That same year, the concept was pursued as Project 621B, which had "many of the attributes that you now see in GPS" and promised increased accuracy for Air Force bombers as well as ICBMs. Updates from the Navy Transit system were too slow for the high speeds of Air Force operation. The Navy Research Laboratory continued advancements with their Timation (Time Navigation) satellites, first launched in 1967, and with

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