Boeing B-52 Stratofortress is a long-range strategic bomber, subsonic, and American jet powered. The B-52 is designed and built by Boeing, which continues to provide support and upgrades. It has been operated by the United States Air Force (USAF) since the 1950s. The bomber is capable of carrying up to 70,000 pounds (32,000 kg) of weapons, and has a typical combat range of over 8,800 miles (14,080 km) without air refueling.
Starting with a successful contract offer in June 1946, the B-52's design evolved from a straight wing airplane powered by six turboprop engines to a YB-52 final prototype with eight turbojet engines and swept wings. B-52 took its inaugural flight in April 1952. Built to carry nuclear weapons for the Cold War era prevention mission, B-52 Stratofortress replaces the Convair B-36. A veteran of several wars, the B-52 has dropped only conventional ammunition in battle. The official name B-52 Stratofortress is rarely used; Informally, the aircraft has become commonly referred to as BUFF (Big Ugly Fat Fucker).
B-52 has been active in service with USAF since 1955. In December 2015, 58 are in active service with 18 reserves. The bomber flies under the Strategic Air Command (SAC) until it was disestablished in 1992 and his aircraft was absorbed into Air Combat Command (ACC); in 2010 all B-52 Stratofortresses were transferred from ACC to the newly created Global Air Force Strike Command (AFGSC). Superior performance at high subsonic speeds and relatively low operating costs has kept the B-52 operating despite coming, more advanced aircraft, including the canceled Mach 3 B-70 Valkyrie, variable geometry B-1 Lancer, and stealth B -2 Spirit. B-52 completes sixty years of ongoing services with original operators by 2015. Upgraded between 2013 and 2015, it is expected to serve up to 2050s.
Video Boeing B-52 Stratofortress
Development
Origins
On November 23, 1945, Air Materiel Command (AMC) issued the desired performance characteristics for the new strategic bomber "capable of carrying out strategic missions without dependence on advanced and intermediate bases controlled by other countries". The plane has a crew of five or more turret shooters, and six crew help. Required to sail at 300 mph (260 knots, 480 km/h) at 34,000 feet (10,400 m) with a 5,000 mile combat radius (4,300 nautical miles, 8,000 km). The armament consists of a number of 20mm cannons and 10,000 pounds (4,500 kg) of unspecified bombs. On February 13, 1946, the Air Force issued an offer invitation for this specification, with Boeing, Consolidated Aircraft, and Glenn L. Martin Company submitting a proposal.
On June 5, 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 a 3,110-mile (2,700 nmi, 5.010 km) fighter radius, was declared the winner. On June 28, 1946, Boeing issued a contract worth US $ 1.7 million to build a full-scale mock-up of the new XB-52 and do the initial engineering and testing. However, in October 1946, the air force began to express concern about the size of the new aircraft and its inability to meet the design requirements specified. In response, Boeing produced the Model 464, a four-engine version that was smaller with a gross weight of 230,000 pounds (105,000 kg), which was briefly considered acceptable.
Furthermore, in November 1946, the Deputy Chief of Air Staff for Research and Development, General Curtis LeMay, expressed a desire for 400 mph (345 kn, 645 km/h) cruise speed, which Boeing responded with 300,000 Ã, Â £ (136,000 kg) aircraft. In December 1946, Boeing was asked to turn their design into a four-machine bomber with a top speed of 400 miles per hour, a range of 12,000 miles (10,000 nmi, 19,300 km), and the ability to carry nuclear weapons. ; In total, the plane can weigh up to 480,000 pounds (220,000 kg). Boeing responded with two models supported by the turboprop T35. The 464-16 model is a "nuclear-only" bomber with a payload of 10,000 pounds (4,500 kg), while the Model 464-17 is a general-purpose bomber with a payload of 9,000 pounds (4,000 kg). Due to the costs associated with purchasing two special aircraft, the Air Force chose Model 464-17 with the understanding that it could be adapted for a nuclear strike.
In June 1947, the military requirements were updated and Model 464-17 fulfilled everything except for the range. It becomes clear to the Air Force that, even with the updated performance, the XB-52 will become obsolete by the time it enters production and will offer a slight improvement over the Convair B-36; as a result, the entire project was postponed for six months. During this time, Boeing continued to refine the design, which produced the Model 464-29 with a top speed of 455 miles per hour (395 kn, 730 km/h) and a distance of 5,000 miles. In September 1947, the Heavy Bombing Committee was held to ensure performance requirements for nuclear bombers. Formulated on December 8, 1947, this requirement calls for a top speed of 500 miles per hour (440 kn, 800 km/h) and 8,000 miles (7,000 nmi, 13,000 km) range, far beyond the capability of 464 - 29.
The immediate cancellation of Boeing's contract on December 11, 1947 was repulsed by a request from President William McPherson Allen to Air Force Secretary Stuart Symington. Allen reasoned that the design was able to adapt to new aviation technology and more stringent requirements. In January 1948, Boeing was instructed to explore thoroughly the latest technological innovations, including air refueling and flying wings. Noting the stability and control problems Northrop experienced 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 $ 306 million today) proposal for the design, construction, and testing two models of 464-35 prototypes. Further revisions during 1948 resulted in a plane with a top speed of 513 miles per hour (445 kn, 825 km/h) at 35,000 feet (10.700 m), 6,909 miles (6,005 nmi, 11,125 km), and 280,000 pounds (125,000 kg ) gross weight, including 10,000 pounds (4,500 kg) of bombs and 19,875 US gallons (75,225 liters) of fuel.
Design effort
In May 1948, AMC asked Boeing to include previously disposed jet engines, but is now more fuel-efficient in design. Which resulted in the development of another revision - in July 1948, the Model 464-40 replaced the Westinghouse J40 turbojing aircraft for turboprop. The Air Force project officer reviewing Model 464-40 was impressed, especially since he was already thinking the same line. Nevertheless, the government worried about the high level of fuel consumption of jet engines that day, and pointed that Boeing still uses the Model 464-35 which uses turboprop as a base for XB-52. Although he agrees that turbojet propulsion is the future, General Howard A. Craig, Deputy Chief of Materials Officer, is not particularly interested in the B-52 jet, because he feels that the jet engine has not run enough to allow it. skip the intermediate turboprop stage. However, Boeing is encouraged to continue the turbojet study even without the expected commitment to jet propulsion.
On Thursday, October 21, 1948, Boeing George S. Schairer engineers Art Carlsen and Vaughn Blumenthal presented the design of a four-machine turboprop bomber to the head of the bomber's development, Colonel Pete Warden. Warden was disappointed with the projected plane and asked if the Boeing team could submit a proposal for a four-engined turbojet bomber. Joining Ed Wells, vice president of Boeing engineering, engineers working that night at Hotel Van Cleve in Dayton, Ohio, redesigned Boeing's proposal as a four-engined turbojet bomber. On Friday, Colonel Warden checked the information and asked for a better design. Back at the hotel, the Boeing team joins Bob Withington and Maynard Pennell, two of the top Boeing engineers who are in town on another business.
By Friday night, they had compiled what was essentially a new plane. The new design (464-49) is built on the basic layout of the B-47 Stratojet with 35 degree swept wings, eight engines paired in four underwing pods, and a bicycle wheel landing with outrigger wheels on the wingtips. An important feature of landing gear is the ability to rotate the main landing gear up to 20 Â ° from the centerline of the aircraft to improve safety during crosswind landings. After a trip to a hobby shop for supplies, Schairer began working on building a model. The rest of the team focuses on weight and performance data. Wells, who is also a skilled artist, completed the drawing of the plane. On Sunday, a stenographer was hired to type a copy of a clean proposal. On Monday, Schairer presented the Colonel Warden with a neatly bound 33 page proposal and 14-inch scale model. The plane is projected to exceed all design specifications.
Although a full-size mock-up examination in April 1949 was generally advantageous, the range returned to the attention because the J40 and early models of the J57s had excessive fuel consumption. Despite talking about revisions to other specifications or even full design competitions among aircraft manufacturers, General LeMay, who is now in charge of the Strategic Air Command, insisted that performance should not be compromised due to delays in machine development. In a recent effort to increase the range, Boeing created a larger 464-67, stating that once in production, the range could be further enhanced in subsequent modifications. After several direct interventions by LeMay, Boeing was awarded a production contract for thirteen B-52As and seventeen removable reconnaissance pods on 14 February 1951. The last major design change - also at General LeMay's urgency - was the transition from the B-47 tandem sit style to a more conventional side-by-side cockpit, which increases the effectiveness of copilots and reduces crew fatigue. Both XB-52 prototypes feature an original tandem seating arrangement with a framed-bubble canopy.
Pre-production and production
YB-52, the second XB-52 modified with more operational equipment, first flew on 15 April 1952 with "Tex" Johnston as pilot. During ground testing on 29 November 1951, the XB-52 pneumatic system failed during a full pressure test; the resulting explosion is extremely destructive to the trailing edge of the wing, thus requiring much improvement. Two hours, 21 minutes flight proof from Boeing Field, King County, in Seattle, Washington to Larson AFB was conducted with a pilot test of Boeing Johnston and Air Force Colonel Guy M. Townsend. XB-52 was followed on 2 October 1952. Comprehensive development, including 670 days in wind tunnels and 130 days of aerodynamic and aeroelastic testing, paid off with smooth flight testing. Encouraged, the air force increased its order to 282 B-52.
Only three of the 13 B-52As booked were built. All are returned to Boeing, and used in their test programs. On June 9, 1952, the February 1951 contract was renewed to order the aircraft under the new specification. The last 10, the first aircraft to enter active service, were completed as B-52Bs. At the launch ceremony on March 18, 1954, Air Force Chief Gen. Nathan Twining said:
Long rifle is a great weapon of his day...... today B-52 is a long rifle from the air age.
The B-52B is followed by a progressively improved bomber and reconnaissance variant, culminating in the B-52G and B-52H turbofan. To enable fast delivery, the production line was established at Seattle's premier plant and at Wichita's facility in Boeing. More than 5,000 companies are engaged in massive production efforts, with 41% of airframe built by subcontractors. The prototype and all B-52A, B and C models (90 aircraft) were built in Seattle. Testing of aircraft built in Seattle caused problems due to jet noise, which led to the formation of a curfew for machine tests. The aircraft transported 150 miles (240 km) east on their inaugural flight to Larson Air Force Base near Moses Lake, where they were fully tested.
When production B-47 ends, the Wichita plant gradually for B-52D production, with Seattle responsible for 101 D-models and Wichita 69. Both plants continue to build B-52E, with 42 built in Seattle and 58 in Wichita, and B -52F (44 from Seattle and 45 from Wichita). For B-52G, it was decided in 1957 to transfer all production to Wichita, which freed Seattle for other tasks (especially aircraft production). Production ended in 1962 with B-52H, with 742 aircraft built, plus two original prototypes.
Upgrade
A proposed variant of the B-52H is the EB-52H, which will comprise of 16 modified B-52H airframes and supplemented with additional electronic jamming capabilities. This variant will recover the lost USAF air jamming capability when retired from EF-111 Raven. The program was canceled in 2005 after the abolition of funds for jammer stand-off. The program was revived in 2007, and cut again in early 2009.
In July 2013, the Air Force initiated a fleet-wide technological upgrade of the B-52 bomber called Communications Network Technology (CONECT) to modernize electronics, communications, computing and avionics technology on the flight deck. CONECT upgrades include software and hardware such as new computer servers, modems, radios, data links, receivers, and digital workstations for the crew. One of the updates is the ARC-210 Warrior beyond-the-line radio-programmable software that can transmit voice, data, and in-flight information between the B-52 and command and control centers, enabling the transmission and reception of data with updates to intelligence information, mapping, and targeting; a change in the target in the previous flight is required to copy the coordinates. The ARC-210 allows machine-to-machine transfer of data, useful for long-lasting missions where the target may have been moved prior to the arrival of the B-52. The aircraft will be able to receive information via Link-16. CONECT upgrade will cost $ 1.1 billion overall and take several years. Funding has been secured for 30 B-52; The Air Force expects 10 incremental increases per year, but the tariff has not been decided yet.
The weapon upgrades include the 1760 Internal Weapons Bay Upgrade (IWBU), which provides a 66 percent increase in weapon load using a digital interface and a rotating launcher. IWBU is estimated to cost about $ 313 million. 1760 IWBU will allow the B-52 to carry JASSM-ER AGM-158B cruise missiles and ADM-160C MALD-J missile controls. All 1760 IWBUs will be operational by October 2017. Two bombers will have the ability to carry 40 weapons replacing 36 that can be carried by three B-52s. 1760 IWBU allows guided missiles or precision-guided bombs to be deployed from within the armory space; the previous aircraft carried this ammunition externally on the wing peg. This increases the number of guided weapons that B-52 can carry and reduces the need for guided bombs to be carried on the wings. The first phase will allow B-52 to carry twenty-four JDAM-guided bombs of 500-pound or twenty 2,000 pounds of JDAM, with subsequent phases that accommodate the JASSM and MALD missile families. In addition to bringing more smart bombs, moving them internally from the wing reduces the barriers and achieves a 15 percent reduction in fuel consumption.
Air Force scientists are working to arm B-52s with defensive laser weapons capable of burning air-to-air or surface-to-air missiles.
Maps Boeing B-52 Stratofortress
Design
Overview
The B-52 shares many of the technological similarities with the previous Boeing B-47 Stratojet strategic bomber. Both aircraft use the same basic design, such as swept wings and podded jet engines, and cabins include a crew ejection system. In B-52D, pilots and electronic countermeasures (EDM) are ejected upward, while the lower deck crew is dropped down; until B-52G, the shooter must throw the tail gun to save.
Structural fatigue is accelerated at least by a factor of eight in the low altitude flight profile at high flying altitudes, requiring costly repairs to extend service life. In the early 1960s, the three-phase High Stress program was launched to fight structural fatigue, registering aircraft at 2,000 flight hours. Follow-up programs were undertaken, such as a 2,000-hour service life extension to choose airframes in 1966-1968, and extensive Pacer Plank reskinning, completed in 1977. Wet wings introduced on G and H models were even more prone to fatigue, experiencing 60% more stress during flight than the old wing. The wings were modified in 1964 under ECP 1050 . This was followed by the skin of the aircraft and the longer replacement ( ECP 1185 ) in 1966, and the B-52 Stability Augmentation and Flight Control program ( ECP 1195 i) in 1967. Leakage of fuel due to the worsening of Marman clamps continues to disrupt all B-52 variants. For this purpose, the aircraft were subjected to the Blue Band (1957), Hard Shell (1958), and finally the QuickClip (1958) program. The last installed safety strap that prevents catastrophic fuel loss in case of a clamp failure. The B-52 service ceiling is officially listed as 50,000 feet, but operational experience shows it is difficult to reach when it is bomb-filled. According to one source: "The optimal height for the combat mission is about 43,000 feet, because to exceed that height it will quickly decrease the range of the aircraft."
In September 2006, the B-52 became one of the first US military aircraft to fly using alternative fuels. The aircraft takes off from Edwards Air Force Base with a 50/50 synthesis of Fischer-Tropsch process (FT) and conventional JP-8 jet fuel, which is burned in two of the eight engines. On December 15, 2006, the B-52 took off from Edwards with synthetic fuel powering eight engines, the first ever air force aircraft fully supported by the mix. A seven-hour flight is considered a success. This program is part of the Department of Defense Assured Fuel Initiative, which aims to reduce the use of crude oil and obtain half of its aviation fuel from alternative sources by 2016. On August 8, 2007, Air Force Secretary Michael Wynne certified B-52H fully approved for use FT mix.
Flight control
Because of the B-52 mission parameters, only simple maneuvers are required without the need for round recovery. This aircraft has a relatively small and narrow chord steering, thus limiting the yaw control authority. Initially all moving vertical stabilizers will be used, but left out due to doubts about the reliability of hydraulic actuators. Since the plane has eight engines, the asymmetrical impulse due to the loss of the engine in flight will be minimal and can be fixed with a narrow steering wheel. To help with takeoff and wind landings, the main landing gear can be rotated 20 degrees to either side of the neutral. The adjustable crosswind landing gear will be set by the crew according to ground-based wind observations.
The elevator is also very narrow as is the steering wheel, and the B-52 suffers from limited elevator control authority. For long pitch pitch and air velocity change, the plane uses a moving tail with an elevator that is used for minor adjustments in the stabilizer setting. Stabilizers can be adjusted through 13 degrees of movement (nine up, four down) and are essential for operation during takeoff and landing due to large pitch changes caused by flap applications.
B-52s before G models have very small ailerons with short ranges that are roughly the same as their chords. These "palpable aillers" are used to provide feedback power for control of the yoke control and to fine-tune the axis of the roll during delicate maneuvers such as air refueling. Because the main wing turns are thin, the conventional outboard aegypes will lose authority and therefore can not be used. In other words, aileron activation will cause the wing to twist, lowering the roll control. Six spoilerons on each wing are responsible for most of the roll controls. The late B-52G model removes the aileron altogether and adds extra spoilerons to each wing. Partly due to the lack of ailerons, the B-52G and H models are more susceptible to Dutch scrolls.
Avionics
An ongoing problem with the avionics system is discussed in the Jolly Well program, completed in 1964, which enhanced the components of the AN/ASQ-38 bombing and terrain computer navigation. The upgraded MADREC (Malfunction Detection and Recording) installed on most aircraft in 1965 could detect failures in computer systems of avionics and weapons, and was essential in monitoring Hound Dog missiles. The B-52's electronic control capability was expanded with Rivet Rambler <1971> and Rivet Ace (1973).
To improve operation at low altitudes, the AN/ASQ-151 Electro-Optical Viewing System (EVS), consisting of Low Light Level Television (LLLTV) and Forward looking infrared (FLIR) systems installed in blisters under the B -52Gs nose and Hs between 1972 and 1976. The B-52's navigation capability was supplemented by the addition of GPS in the 1980s. The IBM AP-101, also used on the Rockwell B-1 Lancer and Space Shuttle bombers, is the main B-52 computer.
In 2007, LITENING targeting pods were installed, which increased the effectiveness of aircraft in ground target attacks with various deadlock weapons, using laser guides, high resolution infrared sensors (FLIRs), and CCD cameras used to obtain target images. LITENING Pods have been fitted to other US aircraft, such as the McDonnell Douglas F/A-18 Hornet, the General Dynamics F-16 Fighting Falcon and the McDonnell Douglas AV-8B Harrier II.
Armament
The ability to carry up to 20 SRAM-SRAM nuclear missiles was added to G and H models, beginning in 1971. To further enhance its offensive capabilities, airborne launch missiles were launched (ALCMs) installed. After good testing supported by Air Force Boeing AGM-86 and General Dynamics AGM-109 supported by Navy, Tomahawk, AGM-86B was chosen to be operated by B-52 (and ultimately by B-1 Lancer). A total of 194 B-52Gs and Hs were modified to carry AGM-86, carrying 12 missiles on underwing poles, with 82 B-52H further modified to carry eight other missiles at rotary launchers mounted on bomb-bay. In order to comply with the terms of the SALT II Agreement which can explore missile-capable aircraft identified by surveillance satellites, cruise missiles armed with B-52Gs are modified with typical wing root fairing. Since all B-52Hs are assumed to have been modified, no visual modifications are needed from this aircraft. In 1990, AGM-129 ACM cruise missiles entered service; although intended to replace AGM-86, the high cost and end of the Cold War led to only 450 produced; unlike AGM-86, no conventional (non-nuclear) version is built. B-52 has been modified to use North Carolina AGM-137 TSSAM weapons; However, the missile was canceled due to development costs.
Those B-52Gs were not converted as cruise missile operators underwent a series of modifications to improve conventional bombing. They are equipped with New Integrated Conventional Store Management System (ICSMS) and new underwater poles that can accommodate larger bombs or other shops than external poles. Thirty B-52Gs were further modified to carry up to 12 AGP Harpoon anti-ship missiles respectively, while 12 B-52Gs were installed to carry air-to-ground missiles from AGM-142 Have Nap. When the B-52G retired in 1994, an urgent scheme was launched to restore the capabilities while Harpoon and Have Nap, four aircraft modified to bring Harpoon and four to bring Have Nap under the Rapid Eight program.
The Conventional Enhancement Modification Program (CEM) provides B-52H with more conventional weapons capability, adding modified underwing pylton weapons used by B-52G, Harpoon and Conventional Nap, and the ability to carry new-generation weapons including Direct Attack Bombs and Corrected Wind of Munitions Guided bomb dispensers, AGM-154 bombs and JASSM AGM-158 missiles. The CEM program also introduces a new radio, Global Positioning System integrated into the aircraft navigation system and replaces the FLIR under the nose with a more modern unit. Forty-seven B-52Hs were modified under the CEM program in 1996, with 19 more by the end of 1999.
Beginning in 2016, Boeing will upgrade its internal rotary launchers to the MIL-STD-1760 interface to allow internal smart bomb trains, previously only available on the wings.
While the B-1 Lancer technically has a larger theoretical charge of 75,000 lb compared to the 70,000 B-52 charge, the aircraft is almost never really able to carry their full payload, most B-52 carrying into full-load AGM -86Bs with total 62,660 lb. The B-1 has an internal weapons space to carry more GBU-31 JDAM and JASSMs, but the B-52 enhanced with conventional rotary launchers can carry more in other JDAM variants.
Machine
Eight B-52 engines are paired in pods and suspended by four poles below and forwards from the front wing. The careful pylon arrangement also allows them to work as a wing fence and delay the start of the stall. The first two prototypes, XB-52 and YB-52, are both supported by Pratt & amp; Whitney YJ57-P-3 turbojet engine of 8,700 lbf (38.70 kN) of static thrust respectively.
Model B-52A comes with Pratt & amp; Whitney J57-P-1W turbojets, providing a dry thrust of 10,000 lbf (44.48 kN) which can be upgraded for short periods to 11,000 lbf (48.93 kN) with water injection. Water is carried in a 360 gallon tank on the back of the body.
The B-52B, C, D and E models are equipped with Pratt & amp; Whitney J57-P-29W, J57-P-29WA, or J57-P-19W series engine all rated at 10,500 lbf (46,71 kN). The B-52F and G models are supported by Pratt & amp; Whitney J57-P-43WB turbojets, each rated at 13,750 lbf (61.16 kN) static thrust with water injection.
On May 9, 1961, the B-52H began shipping to the Air Force with cleaner burning and quieter Pratt & amp; Whitney TF33-P-3 turbofans with maximum thrust of 17,100 lbf (76.06 kN).
Retrofit engine
For US Air Force research in the mid-1970s, Boeing investigated machine replacements, transformed into new wings, and other improvements to upgrade the B-52G/H aircraft as an alternative to B-1A, later in development.
In 1982, Pratt & amp; Whitney studied B-52 retrofit with four Pratt & amp; Whitney PW2000 (F117) engine, but this was not done, as all B-52s had to be replaced by B-1 and B-2 in the late 1990s. In 1996, Rolls-Royce and Boeing jointly proposed to customize the B-52 with four Rolls-Royce RB211-535 machines that were leased, but this plan failed because of the Air Force's resistance to the chartering of combat assets and the negative economic analysis of the Air Force later disputed as a flaw.
This will involve replacing eight Pratt & amp; Whitney TF33 engine (total thrust of 8 × 17,000 Â £) with four RB211 engines (total thrust 4 ÃÆ'â € 37,400 lb), which will increase range and reduce fuel consumption, at a cost of approximately US $ 2.56 billion for the entire fleet (71 aircraft for $ 36 million each). However, an Air Force analysis in 1997 concluded that Boeing's estimated savings of US $ 4.7 billion would not be realized and that rework would cost US $ 1.3 billion rather than maintaining existing machinery, citing significant advance procurement and performing spending tools, as well as higher RB211 maintenance costs.
The Air Force's 1997 re-engining denial was subsequently debated in the Council of Defense Science (DSB) report in 2003. The DSB urged the Air Force to re-engine the aircraft without delay, saying it would not only create significant cost savings, but reduce the GHG emissions glass and increase aircraft coverage and resistance; This conclusion is in line with the conclusion of a separate congregation-funded study conducted in 2003. Criticizing the analysis of Air Force costs, the DSB found that among other things, the Air Force failed to take into account the cost of refueling air; The DSB estimates that refueling in the air costs $ 17.50 per gallon, while the Air Force has failed to take into account the cost of shipping fuel and so does the fuel price of only $ 1.20 per gallon.
As the cost of TF33 overhaul tripled in a decade, the 2003 Boeing/USAF joint study recommends a $ 4-4.7 billion rework, enabling cost savings of $ 11-15 billion while increasing B-52H combat range by 22% and time triple winding at the station, proposing a competition between RB211, PW2000, and eight CFM56 engines financed by the Energy Saving Performance Contract.
In 2014, the US Air Force is reviewing the industry study of machine replacement. By 2014, retrofit machines have not been approved. By the end of 2014, it was reported that DOD and an unnamed private company were exploring a rental program in which private rental companies would buy a new machine and lease it to the USAF. The DOD fee will be determined by depreciation and actual usage without advance mortar payment.
Cost
Operational history
Introduction
Although the B-52A is the first production variant, this aircraft is only used in testing. The first operational version is the B-52B which has been developed in parallel with the prototype since 1951. The first flight in December 1954, B-52B, AF Serial Number 52-8711, entered operational service with 93th Heavy Bombardment Wing (93rd BW) at Castle Air Force Base, California, on June 29, 1955. The wing began operations on March 12, 1956. The training for the B-52 crew consisted of five weeks of elementary school and four weeks of flying, collecting 35 to 50 hours in the air. The new B-52B replaces the B-36 operation one-to-one.
The initial operation is problematic; in addition to supply problems, there are also technical issues. Ramps and taxiways deteriorate under the weight of aircraft, fuel systems are vulnerable to leaks and ice sheets, and bombing and fire control computers are unreliable. The split level cockpit presents the problem of temperature control - the pilot cockpit is heated by sunlight while the observer and navigator on the lower deck sit on a cold floor. Thus, a comfortable temperature setting for the pilot causes the other crew members to freeze, while a comfortable temperature for the lower crew causes the pilot to overheat. The J57 engine proved unreliable. Alternator failure caused the first fatal B-52 accident in February 1956; as a result, the fleet landed quickly. In July, fuel and hydraulic issues eased B-52 again. In response to maintenance issues, the air force formed a team of "Sky Speed" from 50 contractors on each B-52 basis for routine maintenance and inspections, averaging one week per plane.
On May 21, 1956, B-52B (52-0013) dropped the Mk-15 nuclear bomb above the Bikini Atoll in a test code called Cherokee. It was the first thermonuclear weapon dropped in the air. The aircraft is now on display at the National Museum of Nuclear Science and History in Albuquerque, NM. From 24 to 25 November 1956, four B-52Bs from 93rd BW and four B-52Cs from 42nd BW flew endlessly around North America in Operation Quick Kick, covering 15,530 miles (13,500 million, 25,000 km) within 31 hours, 30 minutes. SAC recorded flight time can be reduced to 5 to 6 hours if four times the refueling has been done by a jet-powered tanker faster than Boeing KC-97 Stratofreighters propelled propeller. In the B-52 global range demonstration, from 16 to 18 January 1957, three B-52Bs made non-stop flights around the world during Operation Power Flite during 24.325 miles (21,145 Ã, nmi, 39,165Ã , Km) closed within 45 hours 19 minutes (536.8 smph) with some in-flight refueling by KC-97.
B-52 set many records over the next few years. On September 26, 1958, the B-52D set a world speed record of 560,705 miles per hour (487 kn, 902 km/h) over 10,000 km (5,400 nmi, 6,210 mi) of uncluttered closed circuits. On the same day, the other B-52D set a world speed record of 597,675 miles per hour (519 kn, 962 km/h) over a closed circuit 5,000 kilometers (2,700 nmi, 3,105 mi) without charge. On December 14, 1960, the B-52G set a world distance record by flying not wasted for 10,078.84 miles (8,762 nmi, 16,227 km); The flight lasts 19 hours 44 minutes (510.75 mph). From 10 to 11 January 1962, the B-52H (60-0040) set the world distance record by flying unabated, surpassing the previous B-52 record set two years earlier, from Kadena Air Base, Okinawa Prefecture, Japan to TorrejÃÆ'³n Air Base , Spain, which covers 12,532.28 miles (10,895 nmi, 20,177 km). Flights pass through Seattle, Fort Worth and the Azores.
Cold War
When the B-52 began its operation, the Strategic Air Command (SAC) was intended to use it to deter and ward off the vast and modern Soviet army. When the Soviet Union improves its nuclear capability, it destroys or "fights" the forces that will send nuclear strikes (bombers, missiles, etc.) to be very strategic. Eisenhower's government supports this switch in focus; The president in 1954 declared a preference for military targets over civilians, a principle reinforced in the Single Integrated Operation Plan (SIOP), an action plan in case of a cracked nuclear war.
Throughout the Cold War, B-52s and other US strategic bombers patrolled airborne codes such as Head Start , Chrome Dome , Hard Head , Round Robin , and Giant Lance . The bombers roam at high altitudes near the borders of the Soviet Union to provide quick attacks or quick revenge abilities in the event of a nuclear war. This air patrol forms a component of the US nuclear deterrent, which will act to prevent the outbreak of a large-scale war between the US and the Soviet Union under the concept of Degrading Responsibility.
Due to the threat of the late-1950s-to-air era (SAM) era that could threaten the height of the aircraft, seen in practice in the 1960 U-2 incident, the intended use of B-52 was altered to serve as a low-penetration bomber during a forecast attack against the Union Soviet, because the field masking provides an effective method of avoiding radar and thus the threat from SAM. Though never intended for low-level roles, the B-52's versatility makes it possible to outlast some of the successors that are intended as the nature of air-altered warfare. The large B-52 airframe allows the addition of various design improvements, new equipment, and other adaptations during its service life.
In November 1959, to improve the combat capability of the aircraft in a changing strategic environment, SAC started the Big Four modification program (also known as Modification 1000 ) for all operational B-52s except early B models. The program was completed in 1963. The four modifications are the ability to launch the Hound Dog Hoff-28 nuclear missile and Quail ADM-20 feed, a series of advanced electronic countermeasures (ECM), and upgrades for all-weather, low-altitude interdiction missions ( below 500 feet or 150 m) in the face of advanced Soviet-based air defense missiles.
In the 1960s, there were concerns over the age that the fleet could afford. Some projects outside the B-52, Convair B-58 Hustler and North American XB-70 Valkyrie, have been canceled or proved disappointing given the changing requirements, which make the B-52 older as the main bomber as opposed to the model of the planned plane in a row. On 19 February 1965, General Curtis E. LeMay testified to Congress that the lack of a follow-up bomber project to the B-52 posed a danger that, "B-52 will collapse on us before we can get a replacement for it." Other aircraft, such as General Dynamics F-111 Aardvark, then equipping the B-52 in the role of the aircraft was not capable, such as missions involving high speed, low penetration rates.
Vietnam War
With the escalating situation in Southeast Asia, 28 B-52Fs equipped with external shelves for bombs 24ÃÆ'â € "750Ã, Â £ (340 kg) under the South Bay project in June 1964; an additional 46 aircraft received similar modifications under the Sun Bath project. In March 1965, the United States started the Rolling Thunder Operation. The first combat mission, Operation Light Arc, was flown by B-52F on June 18, 1965, when 30 bombers from the Bombing Squadron 9 and 441 attacked a communist base near the B'n CÃÆ'¡t District in South Vietnam. The first bomber waves arrived too early at the specified meeting point, and when maneuvering to defend the station, two B-52s collided, resulting in the loss of both bombers and eight crew members. The remaining bombers, minus one more turning around because of mechanical problems, continue toward the target. Twenty-seven Stratofortresses were dropped on a one-mile target box with two miles from between 19,000 and 22,000 feet, slightly more than 50% of the bombs falling within the target zone. The troops return to Andersen AFB except for one bomber with a recovered electrical problem to Clark AFB, the mission has lasted 13 hours. The post-strike assessment by South Vietnamese troop teams with American advisers found evidence that the Viet Cong had left the area before the attack, and it is suspected that southern troop infiltration might have guided the north as the South Vietnamese Army forces were involved in post-strike checks.
Beginning in late 1965, a number of B-52Ds were modified to Big Belly to increase bomb capacity for carpet bombing. While the external charge remains at 24 bombs of 500 pounds (227 kg) or 750 pounds (340 kg), the internal capacity increases from 27 to 84 for a 500 pound bomb, or 27-42 for a 750 pound bomb. The modifications created enough capacity for a total of £ 60,000 (27,215 kg) using 108 bombs. Thus modified, B-52Ds can carry 22,000 pounds (9,980 kg) over B-52Fs. Designed to replace the B-52F, the modified B-52D entered the battle in April 1966 from Andersen Air Force Base, Guam. Each bombing mission lasts 10 to 12 hours and includes air refueling by KC-135 Stratotankers. In the spring of 1967, the B-52 began flying from U Tapao Airfield in Thailand so no refueling was required.
On November 22, 1972, B-52D (55-0110) from U-Tapao was hit by surface-to-air missiles (SAM) during an attack on Vinh. The crew was forced to abandon the damaged aircraft over Thailand. This is the first B-52 that was destroyed by enemy fire. In total, 31 B-52s were lost during the war, which included 10 B-52s shot down in North Vietnam.
The peak of the B-52 attack in Vietnam was Linebacker II Operation (sometimes called Christmas Bombing), performed from 18 to 29 December 1972, consisting of B-52 waves (mostly D models, but some Gs without jamming equipment and with smaller bomb loads). For 12 days, the B-52 flew 729 attacks and dropped 15,237 tonnes of bombs in Hanoi, Haiphong, and other targets. Initially 42 B-52 committed to war; However, that number is often twice this number. During Linebacker II operations, fifteen B-52s were shot down, five severely damaged (one fell in Laos), and five suffered moderate damage. A total of 25 crew were killed in this loss. North Vietnam claimed 34 B-52s were shot down.
Air-to-air battles
During the Vietnam War, the b-52D tail shooter was credited with shooting down two MiG-21 "Fishbeds". On December 18, 1972, the tail shooter Sergeant Samuel O. Turner B-52 had just completed a bomb operation for Operation Linebacker II and was turned away, as the North Vietnamese MiG-21 Air Force approached. MiG and B-52 lock each other. When the fighter flew within range, Turner fired his quad (four guns on one pair).50 caliber machine guns. MiG explodes behind the bomber, as confirmed by Sgt Master Louis E. Le Blanc, tail shooter at the nearby Stratofortress. Turner accepts Silver Star for his actions. The B-52, tail number 56-0676, is maintained on display with signs of air-to-air killing at Fairchild AFB in Spokane, Washington.
On December 24, 1972, during the same bombing campaign, B-52 Diamond Lil was heading to bomb the Nguyen Van Nguyen railway yard when Airman First Class's tail shooter Albert E. Moore spotted a fast approaching. MiG-21. Moore fired a shot with a.50 caliber rifle at 4,000 ms (3,700 m), and continued firing until the plane disappeared from its scope. Technical Sergeant Clarence W. Chute, a tail shooter over another Stratofortress, watched MiG burn and fall; this is not confirmed by VPAF. Diamond Lil is stored on-screen at the United States Air Force Academy in Colorado. Moore is the last bomber shooter believed to shoot down enemy aircraft with machine guns in aerial combat.
However, two B-52 tail gunner kills were not confirmed by the VPAF, and they admitted losing only three MiGs, all by F-4 Vietnamese sources had attributed air-to-air victories to the B-52, a MiG-21 shot down on 16 April 1972 This victory makes the B-52 the largest aircraft credited with air-to-air killing. The last Arc Light missions without combat escort took place on August 15, 1973, when US military action in Southeast Asia ended.
Postal Service Vietnam
B-52Bs reached the end of their structural service life in the mid-1960s and all retired in June 1966, followed by the last B-52C on 29 September 1971; except for NASA B-52B "008" which eventually retired in 2004 at Edwards AFB, California. Another Model B, "005" is on display at Wings Over the Rockies Air and Space Museum in Denver, Colorado.
Some of the time-expired E models had retired in 1967 and 1968, but most (82) had retired between May 1969 and March 1970. Most of the F models also retired between 1967 and 1973, but 23 survived as coaches until the end of 1978. The D model fleet serving longer; 80 D models were extensively overhauled under the Pacer Plank Program during the mid-1970s. Skinning on the lower wing and fuselage is replaced, and various structural components are updated. The D model fleet remained intact until the end of 1978, when 37 had not been upgraded, Ds had retired. The remainder were retired between 1982 and 1983.
The remaining G and H models are used for nuclear standby ("idle") tasks as part of the nuclear triad of the United States, a combination of nuclear-based ground missiles, submarine-based missiles, and manned bombers. The B-1, intended to replace the B-52, replaces the old and supersonic model FB-111. In 1991, the B-52s quit the SAC's 24-hour duty.
After Vietnam, operating experience in a hostile air defense environment is taken into account. Because this B-52 is modernized with new weapons, equipment and both offensive and defensive avionics. This and the use of low-level tactics marks a major change in the B-52 utility. Improvements are:
- Supersonic short-range nuclear missiles: Model G and H modified to carry up to 20 SRAM missiles replacing existing gravity bombs. Eight SRAMs are performed internally on special rotary launchers and 12 SRAMs mounted on two pylon wings. With SRAM, B-52 can attack highly sustained targets without entering the terminal's defenses.
- New countermeasures: ECM Stage VI modification is the sixth major ECM program for B-52. It enhances the aircraft's self-protection capability in a dense Soviet air defense environment. New equipment extends the range of signals, enhanced threat warnings, provides new countermeasures and increases the quantity of expenditure. Phase VI power requirements ECM also spends most of its excess capacity on the B-52G. B-52G and Hs are also modified with an electro-optical view system (EVS) that makes low-level operation and field avoidance much easier and safer. The EVS system contains low light-level television cameras (LLTV) and infrared cameras forward (FLIR) to display the information required for penetration at lower altitudes.
- Subsonic-cruise unoyed decoy: SCUD is similar to B-52 on radar. As an active feed, it brings ECM and other devices, and has a range of several hundred miles. Although the SCUD has never been used operationally, this concept was developed, becoming known as a launched airborne missile (ALCM-A).
This modification increases the weight of nearly 24,000 pounds, and decreases the operational range by 8-11%. This is considered acceptable for capacity building.
After the fall of the Soviet Union, all remaining B-52Gs in service were destroyed in accordance with the terms of the Strategic Arms Reduction Treaty (START). The Aerospace Maintenance and Regeneration Center (AMRC) cut 365 B-52s into sections. Completion of duties of vandalism verified by Russia through satellite and first person inspection at AMARC facility.
Gulf War and then
B-52 strikes are an essential part of Operation Desert Storm. Beginning on January 16, 1991, the B-52G flight flew from Barksdale AFB, Louisiana, refueled in the air on the way, struck targets in Iraq, and returned home - 35 hours and 14,000 miles (23,000 km) record for long-distance combat missions, breaking records previously held by RAF Vulcan bomber in 1982; However, this is achieved by refueling forward. The seventh B-52s flew the first fight fighter Operation Desert Storm, fired 35 missiles from AGC-86C CALCMs and successfully destroyed 85-95 percent of their targets. B-52G operates from King Abdullah Air Base in Jeddah, Saudi Arabia, RAF Fairford in the United Kingdom, Moria Air Base, Spain, and the island of Diego Garcia in the British Indian Ocean Region flew the bombing mission to Iraq, initially at a low point. height. After the first three nights, the B-52 moved to a high-altitude mission instead, which reduced their effectiveness and psychological impact compared to the low-altitude role that was originally played.
The conventional strike was carried out by three bombers, which fell to 153 bombs of 750 pounds over an area 1.5 times 1 mile (2.4 times 1.6 km). The bombing demoralized the surviving Iraqi forces, many of whom surrendered after the attack. In 1999, the science and technology magazine Popular Mechanics described the role of B-52 in the conflict: "Buff's value was made clear during the Gulf War and the Fox Desert." The B-52 changed the lights in Baghdad. "During Operation Desert Storm , The B-52 flew about 1,620 attacks, and sent 40% of the weapons dropped by coalition forces.
During the conflict, several claims of Iraqi air-to-air success were made, including an Iraqi pilot, Khudai Hijab, who allegedly fired Vympel R-27R missiles from MIG-29 and damaged the B-52G on the opening night of the Gulf War. However, the US Air Force denied this claim, saying the bomber was actually hit by a friendly fire, a high-speed, AGM-88 Missile Radiation (HARM) mounted on a fire-control radar from a B-52 tail gun; the jet was later renamed to In HARM's Way . Shortly after this incident, General George Lee Butler announced that the shooter's position in the B-52 crew would be eliminated, and the weapons towers were permanently disabled, starting on October 1, 1991.
Since the mid-1990s, B-52H is the only remaining variant in military service; currently placed at:
- Minot Air Force Base, NDÃ, - 5 Bomb Wing
- Barksdale Air Force Base, LAÃ, - 2nd Bomb Wing (Active Air Force) and 307 Bomb Wing (Air Force Reserve Command)
- One B-52H was assigned to Edwards Air Force Base and used by the Air Force Material Command at the Air Force Flight Test Center.
- One additional B-52H was used by NASA at Dryden Flight Research Center, California as part of the Weight Lifting Air Launch program.
From 2 to 3 September 1996, two B-52H bombers performed missions as part of Operation Desert Desert. The B-52s struck Baghdad's power plant and communications facility with 13 conventional air-cruise missiles AGM-86C (CALCM) during a 34-hour round trip, 16,000 miles from Andersen AFB, Guam - the longest distance ever for combat missions.
On March 24, 1999, when Operation Allied Forces began, the B-52 bomber bombarded Serbian targets throughout the Federal Republic of Yugoslavia, including during the Battle of Kosare.
B-52 contributed to Operation Enduring Freedom in 2001 (Afghanistan/Southeast Asia), providing the ability to roam high over the battlefield and provide Near Air Support (CAS) through the use of precision guided ammunition, a mission which had previously been restricted to combat aircraft and ground attacks. By the end of 2001, ten B-52s dropped a third of the bomb tonnage in Afghanistan. B-52 also played a part in Operation Iraqi Freedom, which began on March 20, 2003 (Iraq/Southwest Asia). On the night of March 21, 2003, B-52H launched at least one AGM-86C CALCM on target in Iraq.
Latest service
In August 2007, a B-52H transported AGM-129 ACM cruise missiles from Minot Air Force Base to Barksdale Air Force Base for faulty dismantling was loaded with six missiles with their nuclear warheads. The weapons did not leave the USAF detainees and were secured in Barksdale.
Four of the 18 B-52Hs from Barksdale AFB have retired and are at "boneyard" 309 AMARG at Davis-Monthan AFB as of September 8, 2008.
In January 2013, 78 original 744 B-52 aircraft operated in the US Air Force.
B-52 is regularly updated at USAF maintenance depots such as Tinker Air Force Base, Oklahoma. Even when the air force is working on a new bomber, it intends to keep the B-52H in service until 2045, almost 90 years after the first B-52 entry service, a service unprecedented for any aircraft, civil or military.
USAF continues to rely on the B-52 for remaining an effective and economical heavy bomber without sophisticated air defense, especially in the type of mission that has been carried out since the end of the Cold War against countries with limited defense capabilities. B-52 also continues to operate because there has been no reliable replacement. The B-52 has the capacity to "roam" for a long time, and can provide deadlocks of precision and fire ammunition directly from a distance, in addition to the live bombing. It has been a valuable asset in support of ground operations during conflicts such as Operation Iraqi Freedom. The B-52 has the highest missionary capability of the three heavy bomber types operated by USAF in the 2000-2001 period. B-1 average 53.7% ready, Northrop Grumman B-2 Spirit reaches 30.3%, while B-52 averages 80.5%. The $ 72,000 B-52 per hour flight cost is greater than the B-1B cost of $ 63,000 per hour, but less than the B-2's $ 135,000 per hour.
The Long Range Strike Bomber program is intended to produce hidden routers for B-52 and B-1 that will start operating in the 2020s; is intended to produce 80 to 100 aircraft. Two competitors, Northrop Grumman and joint team Boeing and Lockheed Martin, submitted a proposal in 2014; Northrop Grumman was awarded a contract in October 2015.
On November 12, 2015, the B-52 initiated the freedom of navigation operation in the South China Sea in response to the Chinese-made island in the region. Chinese troops, claiming jurisdiction within the 12-mile exclusion zone of the islands, ordered the bombers to leave the area, but they refused, disowned the jurisdiction. On January 10, 2016, the B-52 split over parts of South Korea escorted by the F-15K and F-16s of the South in response to a North Korean hydrogen bomb test.
On April 9, 2016, an undisclosed number of B-52s arrived at Al Udeid Air Base in Qatar as part of Operation Inherent Resolve, part of a military intervention against ISIL. The B-52 took over the big bombing after the B-1 Lancers who had carried out air strikes were driven out of the territory in January 2016. In April 2016, the B-52 arrived in Afghanistan to take part in the War in Afghanistan (2015-present) and began operations in July, proving its flexibility and precision in carrying out its short-range support missions.
According to a statement by the US military, undisclosed amounts of B-52 participated in the US attack on pro-government forces in eastern Syria on February 7, 2018.
Variant
B-52 experienced several design changes and variants for 10 years of production.
- XB-52
- Two prototype aircraft with limited operational equipment, used for aerodynamic tests and handling
- YB-52
- One XB-52 modified with some operational equipment and reset
- B-52A
- Only three of the first production versions, B-52A, were built, all lent to Boeing for flight testing. The first production of the B-52A differs from the prototype in having a redesigned front fuselage. Bubble canopies and tandem seating are replaced by side-by-side arrangements and the deep 21-nose extension (53 cm) accommodates more avionics and new sixth crew members. At the rear of the plane, the tail tower with four 0.50 (12.7 mm) machine guns with a fire-control system, and a water injection system to add engine power to a 360 Â ° US (1,363 liter) water tank was added. The aircraft also carries an external fuel tank of 1,000 gallons (3,785 liters) beneath each wing. The tanks shook the wings vibrating and also kept the wingtips close to the ground for easy maintenance.
- NB-52A The last B-52A (series 52-0003) was modified and redesigned NB-52A in 1959 to bring X-15 North America. The pylon is mounted under the right wing between the fuselage and the engine inside with a 6 foot x 8 foot (1.8 m x 2.4 m) section which is released from the right wing to fit the X-15 tail. Liquid oxygen tank and hydrogen peroxide installed in bomb bay to refuel X-15 before launch. His first flight with the X-15 was on 19 March 1959, with the first launch on June 8, 1959. The NB-52A, named "The High and Mighty One" carried X-15 on 93 of the 199 flight programs.
- B-52B/RB-52B
United States Air Force 76 aircraft in service in February 2015
- Air Combat Command
- 57th Wing - Nellis AFB, Nevada
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- 340th Weapons Squadron (Barksdale)
- Global Air Force Strike Order
- 2d Bomb Wing - Barksdale AFB, Louisiana
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- Bom Squadron 11
- 20th Bomb Squadron
- 96th Bomber Squadron
- Bomb 5 Wing - Minot AFB, North Dakota
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- 23d Bomb Squadron
- 69th Bomb Squadron
- Air Force Command Materials
- 412 Wing Test - Edwards AFB, California
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- 419 Flying Test Squadron
- Air Force Reserve Command
- Bomb wing 307 - Barksdale AFB, LA
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- The 93d Bomb Squadron
- 343d Bomb Squadron
The famous crash
On January 10, 1957, the B-52 who returned to Loring Air Force Base from a routine instrument training mission broke out in the air and crashed near Morrell, New Brunswick, Canada, killing eight of the nine crew. Co-pilot Captain Joseph L. The church was deployed to a safe place. The accident is believed to be caused by excessive wing and/or fuselage pressure during exercises designed to test pilot reflexes. This is the fourth accident involving B-52 in 11 months.Source of the article : Wikipedia
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