118-699: The Rockwell B-1 Lancer is a supersonic variable-sweep wing , heavy bomber used by the United States Air Force . It has been nicknamed the "Bone" (from "B-One"). As of 2024, it is one of the United States Air Force's three strategic bombers , along with the B-2 Spirit and the B-52 Stratofortress . Its 75,000-pound (34,000 kg) payload is the heaviest of any U.S. bomber. The B-1 was first envisioned in
236-535: A Global Positioning System (GPS) receiver beginning in 1995. The B-1's defensive electronics include the Eaton AN/ALQ-161A radar warning and defensive jamming equipment, which has three sets of antennas; one at the front base of each wing and the third rear-facing in the tail radome . Also in the tail radome is the AN/ALQ-153 missile approach warning system ( pulse-Doppler radar ). The ALQ-161
354-414: A " swing wing ", is an airplane wing , or set of wings, that may be modified during flight, swept back and then returned to its previous straight position. Because it allows the aircraft's shape to be changed, it is an example of a variable-geometry aircraft. A straight wing is most efficient for low-speed flight, but for an aircraft designed for transonic or supersonic flight it is essential that
472-527: A brochure on the UKVG proposal; various proposals would be issued to cover the use of multiple different engines. The quick production of a demonstrator aircraft, powered by a pair of Rolls-Royce/MAN Turbo RB153 turbofan engines, was also mooted. As solely funding for the UKVG was unrealistic, the British government pursued partners within its fellow NATO members, promoting the concept of developing and procuring
590-509: A combined $ 2.2 billion for the development and production of 100 new B-1 bombers. Numerous changes were made to the design to make it better suited to the now expected missions, resulting in the B-1B . These changes included a reduction in maximum speed, which allowed the variable-aspect intake ramps to be replaced by simpler fixed geometry intake ramps. This reduced the B-1B's radar cross-section which
708-460: A common NATO strike aircraft. In July 1968, a memorandum of understanding was signed between Britain, West Germany , Italy , the Netherlands , Belgium , and Canada . This memorandum eventually led to the launch of the multinational Multi-Role Combat Aircraft (MRCA) project, which successfully produced a variable geometry aircraft for the strike, reconnaissance, and interception missions in
826-579: A complete round of wind tunnel tests, the British Government failed to provide financial backing for the work, allegedly due to budget constraints at the time . Independently from Baynes, British engineer Barnes Wallis was also developing a more radical variable-geometry concept, which he called the wing controlled aerodyne, to maximise the economy of high-speed flight. His first study was the Wild Goose project. Subsequently, Barnes devised
944-561: A configuration for the TFX (Tactical Fighter Experimental) program, which resulted in the development of the General Dynamics F-111 , a sizable twin-engined aircraft intended to perform multiple roles. The F-111 is the first production aircraft to feature a variable-geometry wing and it, along with other systems such as terrain following radar and turbofan engines outfitted with afterburners , were innovative technologies for
1062-428: A long-distance record for the aircraft, which demonstrated its ability to conduct extended mission lengths to strike anywhere in the world and return to base without any stops. The National Aeronautic Association recognized the B-1B for completing one of the 10 most memorable record flights for 1994. The B-1 has been upgraded since production, beginning with the "Conventional Mission Upgrade Program" (CMUP), which added
1180-588: A new MIL-STD-1760 smart-weapons interface to enable the use of precision-guided conventional weapons. CMUP was delivered through a series of upgrades: In 2007, the Sniper XR targeting pod was integrated on the B-1 fleet. The pod is mounted on an external hardpoint at the aircraft's chin near the forward bomb bay. Following accelerated testing, the Sniper pod was fielded in summer 2008. Future precision munitions include
1298-570: A new "super-Foxbat" (almost certainly referring to the MiG-31 ) that had look-down/shoot-down radar in order to attack cruise missiles. This would also make any low-level penetration aircraft "visible" and easy to attack. Given that the B-1's armament suite was similar to the B-52, and it then appeared no more likely to survive Soviet airspace than the B-52, the program was increasingly questioned. In particular, Senator William Proxmire continually derided
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#17327727963221416-582: A new attitude indicator. The IBS upgrades were completed in 2020. In August 2019, the Air Force unveiled a modification to the B-1B to allow it to carry more weapons internally and externally. Using the moveable forward bulkhead, space in the intermediate bay was increased from 180 to 269 in (457 to 683 cm). Expanding the internal bay to make use of the Common Strategic Rotary Launcher (CSRL), as well as utilizing six of
1534-492: A nuclear war broke out. Following inspections and repairs they were returned to duty beginning on 6 February 1991. By 1991, the B-1 had a fledgling conventional capability, forty of them able to drop the 500-pound (230 kg) Mk-82 General Purpose (GP) bomb, although mostly from low altitude. Despite being cleared for this role, the problems with the engines prevented their use in Operation Desert Storm during
1652-499: A number of further studies, including a wing controlled aerodyne in response to OR.346 for a supersonic STOL fighter-bomber, then as BAC two further submissions: the Type 583 to meet Naval ER.206 and Type 584 to meet NATO NBMR.3, both also being V/STOL requirements. In 1960, Maurice Brennan joined Folland Aircraft as its chief engineer and director; he soon set about harnessing his experience of variable-geometry wings. Accordingly, such
1770-531: A percentage of total wingspan ) between the wing pivots. By adopting a wider spacing, this not only reduced the negative aerodynamic effects of changing wing sweep, but also provided a larger fixed wing section which could be used for landing gear or stores pylons . This could, in fact, be adapted to more-or-less existing airframes, which the Soviets accordingly did, such as with the Sukhoi Su-17 (based on
1888-503: A powerful tactical aircraft which could be used against ground troops along with strategic targets from high altitudes. The much smaller bomb bay of the B-70 would have made it much less useful in this role. Although effective, the B-52 was not ideal for the low-level role. This led to a number of aircraft designs known as penetrators , which were tuned specifically for long-range low-altitude flight. The first of these designs to see operation
2006-407: A radical aircraft configuration for high-speed flight, which he regarded as distinct from the conventional fixed-wing aeroplane and called it the wing controlled aerodyne. His previous work on the stability of airships had impressed on him the high control forces that could be exerted on the body of an aircraft, through very small deflections. He conceived of a simple ichthyoid (fish-like) fuselage with
2124-661: A safe counterforce option because the bombers could be quickly launched into safe loitering areas where they could not be attacked. However, the introduction of the SLBM made moot the mobility and survivability argument, and a newer generation of ICBMs, such as the Minuteman III , had the accuracy and speed needed to attack point targets. During this time, ICBMs were seen as a less costly option based on their lower unit cost, but development costs were much higher. Secretary of Defense Robert McNamara preferred ICBMs over bombers for
2242-618: A second display aids with threat evasion and targeting, and acts as a back-up display. CITS saw a new diagnostic system installed that allows crew to monitor over 9,000 parameters on the aircraft. Other additions are to replace the two spinning mass gyroscopic inertial navigation system with ring laser gyroscopic systems and a GPS antenna, replacement of the APQ-164 radar with the Scalable Agile Beam Radar – Global Strike ( SABR-GS ) active electronically scanned array , and
2360-609: A six-foot scale model , at speeds of up to Mach 2. However, in 1957, British government decided to withdraw backing from many aeronautical programs, including Wallis' work. Despite this lack of backing, the Swallow attracted international attention for some time. During late 1958, research efforts were temporarily revived through cooperation with the Mutual Weapons Development Programme of NATO , under which all of Wallis' variable geometry research
2478-479: A sliding wing root or larger tail stabiliser, must be incorporated to trim out the changes and maintain level flight. The added weight of the sweep and trim mechanisms eat into the performance gains, while their complexity adds to cost and maintenance. By moving the wing pivots outboard and only sweeping part of the wing, the trim changes are reduced, but so too is the variation in span and accompanying operational flexibility. British engineer Barnes Wallis developed
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#17327727963222596-590: A small angle during flight. This allowed longitudinal trim in the absence of a separate horizontal stabiliser. The concept would later be incorporated in Barnes Wallis's wing-controlled aerodyne. During the Second World War , researchers in Nazi Germany discovered the advantages of the swept wing for transonic flight, and also its disadvantages at lower speeds. The Messerschmitt Me P.1101
2714-438: A variable wing. No other control surfaces were needed. Subtle movements of the wings were able to induce the small deflections which controlled the direction of flight, while trim was maintained by adjusting the angle of sweep to compensate for the varying position of the centre of lift at different speeds. For supersonic flight a delta-planform lifting body is more suitable than a simple ichthyoid. A conflict also arises between
2832-454: A wing was combined with the firm's Folland Gnat light fighter for two different concepts – one tailless and one using with a conventional tail – for a multipurpose fighter/strike/trainer, designated as the Fo. 147. It had a unique mechanism for wing sweep that combined tracks on the fuselage sides and the underside of the wings, which was actuated by hydraulically -driven ball screws positioned at
2950-437: Is Mach 1.25 (about 950 mph or 1,530 km/h at altitude), but its low-level speed increased to Mach 0.92 (700 mph, 1,130 km/h). The speed of the current version of the aircraft is limited by the need to avoid damage to its structure and air intakes. To help lower its radar cross-section, the B-1B uses serpentine air intake ducts (see S-duct ) and fixed intake ramps , which limit its speed compared to
3068-542: Is higher than that of an unswept wing. These tradeoffs are particularly acute for naval carrier-based aircraft . A variable-sweep wing allows the pilot to use the optimum sweep angle for the aircraft's speed at the moment, whether slow or fast. The more efficient sweep angles available offset the weight and volume penalties imposed by the wing's mechanical sweep mechanisms. Its greater complexity and cost make it practical mostly for military aircraft . A number of aircraft, both experimental and production, were introduced between
3186-547: Is linked to a total of eight AN/ALE-49 flare dispensers located on top behind the canopy, which are handled by the AN/ASQ-184 avionics management system. Each AN/ALE-49 dispenser has a capacity of 12 MJU-23A/B flares. The MJU-23A/B flare is one of the world's largest infrared countermeasure flares at a weight of over 3.3 pounds (1.5 kg). The B-1 has also been equipped to carry the ALE-50 towed decoy system . Also aiding
3304-473: Is not necessary to sweep the port and starboard wings in the same sense - one can be swept back and the other forward, as in the oblique wing . Varying the sweep asymmetrically by small amounts was also fundamental to the principle of the wing controlled aerodyne. The earliest use of variable sweep was to trim the aeroplane for level flight. The Westland-Hill Pterodactyl IV of 1931 was a tailless design whose lightly swept wings could vary their sweep through
3422-779: The General Dynamics F-16 Fighting Falcon . It is also the basis for the non- afterburning GE F118 used in the B-2 Spirit and the U-2S . The F101 engine core is also used in the CFM56 civil engine. The nose-gear door is the location for ground-crew control of the auxiliary power unit (APU) which can be used during a scramble for quick-starting the APU. The B-1's main computer is the IBM AP-101 , which
3540-528: The Gulf War . B-1s were primarily reserved for strategic nuclear strike missions at this time, providing the role of airborne nuclear deterrent against the Soviet Union. The B-52 was more suited to the role of conventional warfare and it was used by coalition forces instead. Originally designed strictly for nuclear war, the B-1's development as an effective conventional bomber was delayed. The collapse of
3658-557: The Mikoyan-Gurevich MiG-23 fighter and the Sukhoi Su-24 tactical bomber, both of which flew in prototype forms around the end of the 1960s and entering service during the early 1970s. During 1962, Tupolev's design team, recognising room for improvement on the recently introduced Tupolev Tu-22 bomber, begun work on an extensively redesigned derivative that incorporated a variable geometry wing, intended to address
Rockwell B-1 Lancer - Misplaced Pages Continue
3776-745: The Small Diameter Bomb . The USAF commenced the Integrated Battle Station (IBS) modification in 2012 as a combination of three separate upgrades when it realised the benefits of completing them concurrently; the Fully Integrated Data Link (FIDL), Vertical Situational Display Unit (VSDU) and Central Integrated Test System (CITS). FIDL enables electronic data sharing, eliminating the need to enter information between systems by hand. VSDU replaces existing flight instruments with multifunction color displays,
3894-524: The Sukhoi T-4 designs. Designated as the Tupolev Tu-160 , it entered operational service with the 184th Guards Heavy Bomber Regiment located at Pryluky Air Base , Ukrainian SSR , during April 1987. The aircraft is the largest and heaviest combat aircraft, the fastest bomber in use and the largest and heaviest variable-sweep wing airplane to have ever flown as of 2020. A variable-sweep wing
4012-503: The Swallow , a blended wing tailless aircraft, which was envisioned to be capable of making return flights between Europe and Australia within ten hours. Later on, the Swallow was increasingly viewed as a potential supersonic successor to the subsonic Vickers Valiant , one of the RAF's V bombers . During the 1950s, several modes of the Swallow were subjected to promising tests, including
4130-521: The article wizard to submit a draft for review, or request a new article . Search for " Look-down " in existing articles. Look for pages within Misplaced Pages that link to this title . Other reasons this message may be displayed: If a page was recently created here, it may not be visible yet because of a delay in updating the database; wait a few minutes or try the purge function . Titles on Misplaced Pages are case sensitive except for
4248-411: The camber or chord of the wing automatically to adjust to the flight regime; this technique is another form of variable geometry . A straight, unswept wing experiences high drag as it approaches the speed of sound, due to the progressive buildup of sonic shockwaves. Sweeping the wing at an angle, whether backwards or forwards, delays their onset and reduces their overall drag. However it also reduces
4366-556: The 1940s and the 1970s. The majority of production aircraft to be furnished with variable-sweep wings have been strike-oriented aircraft, such as the Mikoyan-Gurevich MiG-27 , Tupolev Tu-22M , and Panavia Tornado . The configuration was also used for a few fighter/ interceptor aircraft , including the Mikoyan-Gurevich MiG-23 , Grumman F-14 Tomcat , and the Panavia Tornado ADV . From the 1980s onwards,
4484-640: The 1960s as a bomber that would combine the Mach 2 speed of the B-58 Hustler with the range and payload of the B-52, ultimately replacing both. After a long series of studies, North American Rockwell (subsequently renamed Rockwell International , B-1 division later acquired by Boeing ) won the design contest for what emerged as the B-1A. Prototypes of this version could fly Mach 2.2 at high altitude and long distances at Mach 0.85 at very low altitudes. The program
4602-675: The 1970s negated many of the disadvantages of a fixed-wing configuration. No new variable-sweep wing aircraft have been built since the Tu-160. In 2015, the Russian Ministry of Defence announced plans to restart Tu-160 production, citing the aging of the current aircraft and likely protracted development of its eventual replacement, the PAK DA project. Production restarted in 2021, marking the first new variable sweep airframes to be produced in 29 years. Look-down From Misplaced Pages,
4720-603: The AFVG, as it was working on two competing in-house projects: the variable geometry Mirage G and the Mirage F1 . According to aviation author Derek Wood, both Dassault and the French Air Force were unenthusiastic participants in the AFVG, the former wanting to pursue its own indigenous variable geometry aircraft, while the latter had determined that the type did not align with its future equipment plans. In June 1967,
4838-450: The ALCM as an "attractive alternative" to the B-1. French General Georges Buis stated "The B-1 is a formidable weapon, but not terribly useful. For the price of one bomber, you can have 200 cruise missiles." Flight tests of the four B-1A prototypes for the B-1A program continued through April 1981. The program included 70 flights totaling 378 hours. A top speed of Mach 2.22 was reached by
Rockwell B-1 Lancer - Misplaced Pages Continue
4956-510: The Air Force portion of the deterrent force and felt a new expensive bomber was not needed. McNamara limited the AMSA program to studies and component development beginning in 1964. Program studies continued; IBM and Autonetics were awarded AMSA advanced avionics study contracts in 1968. McNamara remained opposed to the program in favor of upgrading the existing B-52 fleet and adding nearly 300 FB-111s for shorter range roles then being filled by
5074-467: The B-1 in public, arguing it was an outlandishly expensive dinosaur. During the 1976 federal election campaign, Jimmy Carter made it one of the Democratic Party's platforms, saying "The B-1 bomber is an example of a proposed system which should not be funded and would be wasteful of taxpayers' dollars." When Carter took office in 1977 he ordered a review of the entire program. By this point
5192-506: The B-1's survivability is its relatively low RCS. Although not technically a stealth aircraft, thanks to the aircraft's structure, serpentine intake paths and use of radar-absorbent material its RCS is about 1/50th that of the similar sized B-52. This is approximately 26 ft or 2.4 m, comparable to that of a small fighter aircraft . The B-1 holds 61 FAI world records for speed, payload, distance, and time-to-climb in different aircraft weight classes. In November 1993, three B-1Bs set
5310-612: The B-1A. Vanes in the intake ducts serve to deflect and shield radar returns from the highly reflective engine compressor blades. The B-1A's engine was modified slightly to produce the GE F101-102 for the B-1B, with an emphasis on durability, and increased efficiency. The core from this engine was subsequently used in several other engines, including the GE F110 used in the F-14 Tomcat , F-15K/SG variants and later versions of
5428-414: The B-1B would be less than a decade, being rendered obsolete shortly after the introduction of a much more capable ATB design. The primary argument in favor of the B-1 was its large conventional weapon payload, and that its takeoff performance allowed it to operate with a credible bomb load from a much wider variety of airfields. Production subcontracts were spread across many congressional districts, making
5546-424: The B-52, allowing it to operate from a wider variety of bases. Penetration of the Soviet Union's defenses would take place at supersonic speed , crossing them as quickly as possible before entering the more sparsely defended interior of the country where speeds could be reduced again. The large size and fuel capacity of the design would allow the "dash" portion of the flight to be relatively long. In order to achieve
5664-406: The B-52, but less range. Because of this, and a growing shift to the intercontinental ballistic missile (ICBM) force, the B-70 bomber program was cancelled in 1961 by President John F. Kennedy , and the two XB-70 prototypes were used in a supersonic research program. Although never intended for the low-level role, the B-52's flexibility allowed it to outlast its intended successor as the nature of
5782-520: The B-58. He again vetoed funding for AMSA aircraft development in 1968. President Richard Nixon reestablished the AMSA program after taking office, keeping with his administration's flexible response strategy that required a broad range of options short of general nuclear war . Nixon's Secretary of Defense, Melvin Laird , reviewed the programs and decided to lower the numbers of FB-111s, since they lacked
5900-408: The B-70 program had led some to question the need for a new strategic bomber of any sort. The USAF was adamant about retaining bombers as part of the nuclear triad concept that included bombers, ICBMs, and submarine-launched ballistic missiles (SLBMs) in a combined package that complicated any potential defense. They argued that the bomber was needed to attack hardened military targets and to provide
6018-487: The F-111 and XB-70. It used a crew escape capsule , that ejected as a unit to improve crew survivability if the crew had to abandon the aircraft at high speed. Additionally, the design featured large variable-sweep wings in order to provide both more lift during takeoff and landing, and lower drag during a high-speed dash phase. With the wings set to their widest position the aircraft had a much better airfield performance than
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#17327727963226136-556: The French government announced their withdrawal from the AFVG project ostensibly on the grounds of cost. Despite the AFVG programme's collapse, the design was revamped by BAC into a larger strike-oriented variable geometry aircraft. Holding contracts were issued to BAC to support the project, which had been re-designated as the United Kingdom Variable Geometry (UKVG) aircraft. In November 1967, BAC issued
6254-617: The MiG-31 interceptor and the first effective Soviet Airborne Early Warning and Control (AWACS) systems would make the B-52 increasingly vulnerable. During 1981, funds were allocated to a new study for a bomber for the 1990s time-frame which led to developing the Long-Range Combat Aircraft (LRCA) project. The LRCA evaluated the B-1, F-111, and ATB as possible solutions; an emphasis was placed on multi-role capabilities, as opposed to purely strategic operations. In 1981, it
6372-549: The P.45 light attack/trainer to AST 362. This work fed into a joint Anglo-French programme to develop a variable geometry strike aircraft – the Anglo French Variable Geometry Aircraft (AFVG). This multirole aircraft was to be equipped with a variable geometry wing and was intended to perform the strike , reconnaissance, and interceptor roles. However, as early as 1966, the French aircraft manufacturer Dassault began to actively undermine
6490-430: The Soviet Union had brought the B-1's nuclear role into question, leading to President George H. W. Bush ordering a $ 3 billion conventional refit. On 26 April 1991, ten B-1Bs narrowly avoided being hit by the 1991 Andover tornado while located at McConnell AFB , which took a direct hit. Two of the bombers were equipped with nuclear warheads. Variable-sweep wing A variable-sweep wing , colloquially known as
6608-694: The TSR-2 was terminated during the flight testing phase primarily due to the programme's spiralling costs. To replace the TSR-2, the Air Ministry initially placed an option for the American General Dynamics F-111K ; while the F-111K was promoted as being cheaper, this too was terminated during January 1968 on grounds of cost. Following the TSR-2's cancellation, BAC moved their variable-geometry work to Warton, there submitting
6726-524: The Tu-22's poor handling characteristics more so than bolstering its efficiency at high speeds. As of 2014 more than 100 Tupolev Tu-22M strategic bombers are in use. During the late 1950s and early 1960s, Britain was developing the BAC TSR-2 , a supersonic low-level strategic bomber. Later variants of the type would have been fitted with variable-geometry wings. However, on 1 April 1965, development of
6844-442: The U.S. Air Force. During the 1980 presidential campaign, Ronald Reagan campaigned heavily on the platform that Carter was weak on defense, citing the cancellation of the B-1 program as an example, a theme he continued using into the 1980s. During this time Carter's defense secretary, Harold Brown , announced the stealth bomber project, apparently implying that this was the reason for the B-1 cancellation. On taking office, Reagan
6962-675: The US Navy procured the Grumman F-14 Tomcat to replace the canceled F-111B fleet interceptor during the 1970s. The F-14 was a more nimble fighter than the F-4 Phantom II and, unlike the F-111, its variable-sweep wings automatically adjusted over its speed range, and could be moved even during turns. Furthermore, the wings could be swept forward for tight "bat" turns in close quarters aerial combat, as well as rearwards for dash speeds. Rockwell adopted variable geometry for
7080-451: The USAF equal capability of penetrating Soviet airspace. With a range of 1,500 miles (2,400 km), the ALCM could be launched well outside the range of any Soviet defenses and penetrate at low altitude like a bomber (with a much lower radar cross-section (RCS) due to smaller size), and in much greater numbers at a lower cost. A small number of B-52s could launch hundreds of ALCMs, saturating
7198-627: The USAF issued requirements for a new bomber combining the payload and range of the Boeing B-52 Stratofortress with the Mach ;2 maximum speed of the Convair B-58 Hustler . In December 1957, the USAF selected North American Aviation 's B-70 Valkyrie for this role, a six-engine bomber that could cruise at Mach 3 at high altitude (70,000 ft or 21,000 m). Soviet Union interceptor aircraft ,
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#17327727963227316-512: The air war environment changed. The B-52's huge fuel load allowed it to operate at lower altitudes for longer times, and the large airframe allowed the addition of improved radar jamming and deception suites to deal with radars. During the Vietnam War , the concept that all future wars would be nuclear was turned on its head, and the "big belly" modifications increased the B-52's total bomb load to 60,000 pounds (27,000 kg), turning it into
7434-579: The aircraft more popular on Capitol Hill . B-1A No. 1 was disassembled and used for radar testing at the Rome Air Development Center in the former Griffiss Air Force Base , New York . B-1As No. 2 and No. 4 were then modified to include B-1B systems. The first B-1B was completed and began flight testing in March 1983. The first production B-1B was rolled out on 4 September 1984 and first flew on 18 October 1984. The 100th and final B-1B
7552-410: The aircraft presented a flexing problem due to air turbulence at low altitude. To alleviate this, Rockwell included small triangular fin control surfaces or vanes near the nose on the B-1. The B-1's Structural Mode Control System moves the vanes, and lower rudder, to counteract the effects of turbulence and smooth out the ride. Unlike the B-1A, the B-1B cannot reach Mach 2+ speeds; its maximum speed
7670-476: The airframe to carry more fuel and weapons. Dubbed the B-1B, deliveries of the new variant began in 1985; the plane formally entered service with Strategic Air Command (SAC) as a nuclear bomber the following year. By 1988, all 100 aircraft had been delivered. With the disestablishment of SAC and its reassignment to the Air Combat Command in 1992, the B-1B's nuclear capabilities were disabled and it
7788-453: The bomber has been commonly called the "Bone"; a nickname that appears to stem from an early newspaper article on the aircraft wherein its name was phonetically spelled out as "B-ONE" with the hyphen inadvertently omitted. In late 1990, engine fires in two Lancers led to a grounding of the fleet. The cause was traced back to problems in the first-stage fan, and the aircraft were placed on "limited alert"; in other words, they were grounded unless
7906-465: The bomber which, combining both internal and external weapon carriage, could conceivably bring the total number of hypersonic weapons to 31. The second B-1B, "The Star of Abilene", was the first B-1B delivered to SAC in June 1985. Initial operational capability was reached on 1 October 1986 and the B-1B was placed on nuclear alert status. The B-1 received the official name "Lancer" on 15 March 1990. However,
8024-421: The clutter from ground reflections (lack of look-down/shoot-down capability). The switch from high-altitude to low-altitude flight profiles severely affected the B-70, the design of which was tuned for high-altitude performance. Higher aerodynamic drag at low level limited the B-70 to subsonic speed while dramatically decreasing its range. The result would be an aircraft with somewhat higher subsonic speed than
8142-403: The defense. A program to improve the B-52 and develop and deploy the ALCM would cost at least 20% less than the planned 244 B-1As. On 30 June 1977, Carter announced that the B-1A would be canceled in favor of ICBMs, SLBMs, and a fleet of modernized B-52s armed with ALCMs. Carter called it "one of the most difficult decisions that I've made since I've been in office." No mention of the stealth work
8260-462: The design and manufacturing quality. The F-111B, intended for the US Navy , was cancelled in 1968 due the aircraft's weight and performance issues, as well as its inadequacies for the service's fighter requirements. Several variants, such as the FB-111A strategic bomber model, featured elongated wings to give a greater range and load-carrying capability. The F-111's wing featured pivoting pylons (two under each wing) which automatically adjusted to
8378-535: The design due to failures to meet specifications and desired improvements for ease of maintenance and operation. The first B-1A prototype (Air Force serial no. 74–0158) flew on 23 December 1974. As the program continued the per-unit cost continued to rise in part because of high inflation during that period. In 1970, the estimated unit cost was $ 40 million, and by 1975, this figure had climbed to $ 70 million. In 1976, Soviet pilot Viktor Belenko defected to Japan with his MiG-25 "Foxbat" . During debriefing he described
8496-580: The desired range, and recommended that the AMSA design studies be accelerated. In April 1969, the program officially became the B-1A . This was the first entry in the new bomber designation series , created in 1962. The Air Force issued a request for proposals in November 1969. Proposals were submitted by Boeing, General Dynamics and North American Rockwell in January 1970. In June 1970, North American Rockwell
8614-400: The development of such aircraft were curtailed by advances in flight control technology and structural materials which have allowed designers to closely tailor the aerodynamics and structure of aircraft, removing the need for variable sweep angle to achieve the required performance; instead, wings are given computer-controlled flaps on both leading and trailing edges that increase or decrease
8732-419: The earlier swept wing Sukhoi Su-7 ). The limitation of the wide spacing, however, was that it reduced the benefits of variable geometry as much as it reduced their technical difficulties. As such, producing new, "clean-sheet" Soviet designs remained desirable. For this, TsAGI devised a more narrowly-spaced arrangement somewhat similar to that of the F-111. This design was used, albeit at different scales, for
8850-577: The eight external hardpoints that had been previously out of use to keep in line with the New START Treaty, would increase the B-1B's weapon load from 24 to 40. The configuration also enables it to carry heavier weapons in the 5,000 lb (2,300 kg) range, such as hypersonic missiles; the AGM-183 ARRW is planned for integration onto the bomber. In the future the HAWC could be used by
8968-548: The end of the conflict, the partially complete P.1101 was recovered and transported to the United States , where it was studied in depth by Bell Aircraft . However, due to a lack of documentation as well as some structural damage sustained, Bell decided against completing the aircraft itself. Instead, a close copy, known as the Bell X-5 , was constructed with wings that enabled the sweep angle to be altered mid-flight. As
9086-565: The era were subject to " clutter " from stray returns from the ground and other objects, which meant a minimum angle existed above the horizon where they could detect a target. Bombers flying at low altitudes could remain under these angles simply by keeping their distance from the radar sites. This combination of effects made SAMs of the era ineffective against low-flying aircraft. The same effects also meant that low-flying aircraft were difficult to detect by higher-flying interceptors, since their radar systems could not readily pick out aircraft against
9204-459: The era. Despite this head start in the field, development of the F-111 was protracted; flight testing of the F-111A model only ended in 1973. During 1968, cracks were discovered in the F-111's wing attach points , the issue also has been attributed with the loss of an F-111 in the following year. Accordingly, the attach points were structurally redesigned and subject to intensive testing of both
9322-736: The form of the Panavia Tornado. Following the AFVG effort, Dassault Aviation constructed a prototype fighter, the Mirage G, completing two aircraft, the Mirage G4 and G8, in 1968. Furthermore, Dassault also worked in cooperation with the American manufacturing interest Ling-Temco-Vought to develop the LTV V-507 , which was submitted for US Navy's VFX project . From the VFX submissions,
9440-895: The 💕 Look for Look-down on one of Misplaced Pages's sister projects : [REDACTED] Wiktionary (dictionary) [REDACTED] Wikibooks (textbooks) [REDACTED] Wikiquote (quotations) [REDACTED] Wikisource (library) [REDACTED] Wikiversity (learning resources) [REDACTED] Commons (media) [REDACTED] Wikivoyage (travel guide) [REDACTED] Wikinews (news source) [REDACTED] Wikidata (linked database) [REDACTED] Wikispecies (species directory) Misplaced Pages does not have an article with this exact name. Please search for Look-down in Misplaced Pages to check for alternative titles or spellings. You need to log in or create an account and be autoconfirmed to create new articles. Alternatively, you can use
9558-519: The military lacked capability outside these narrow confines. The U.S. Department of Defense responded by accelerating its Rapid Deployment Forces concept but suffered from major problems with airlift and sealift capability. In order to slow an enemy invasion of other countries, air power was critical; however the key Iran-Afghanistan border was outside the range of the United States Navy 's carrier-based attack aircraft, leaving this role to
9676-470: The much larger Advanced Manned Strategic Bomber (AMSA) program that produced the B-1 Lancer bomber, intended to provide an optimum combination of high-speed cruising efficiency and fast, supersonic penetration speeds at extremely low level. The B-1's variable-sweep wings provide a relatively high level of lift during takeoff and landing, while also generating little drag during a high-speed dash. When
9794-412: The nose are part of an active vibration damping system that smooths out the otherwise bumpy low-altitude ride. The first three B-1As featured the escape capsule that ejected the cockpit with all four crew members inside. The fourth B-1A was equipped with a conventional ejection seat for each crew member. The B-1A mockup review occurred in late October 1971; this resulted in 297 requests for alteration to
9912-504: The only effective anti-bomber weapon in the 1950s, were already unable to intercept the high-flying Lockheed U-2 ; the Valkyrie would fly at similar altitudes, but much higher speeds, and was expected to fly right by the fighters. By the late 1950s, however, anti-aircraft surface-to-air missiles (SAMs) could threaten high-altitude aircraft, as demonstrated by the 1960 downing of Gary Powers ' U-2. The USAF Strategic Air Command (SAC)
10030-438: The overall span of a given wing, leading to poor cruise efficiency and high takeoff and landing speeds. A fixed wing must be a compromise between these two requirements. Varying the sweep in flight allows it to be optimised for each phase of flight, offering a smaller aircraft with higher performance. However it has disadvantages which must be allowed for. As the wing sweeps its centre of lift moves with it. Some mechanism, such as
10148-452: The pivot mechanism he had developed, NASA also insisted on implementing a conventional horizontal stabiliser to ease the issues of trim and manoeuvrability. Although it was no longer the wing-controlled aerodyne that Wallis envisaged, it would prove a more practical solution than either his or Bell's. Swallow research led to several new configurations, including the adoption of a compact folding tail section and canards . Barnes' work inspired
10266-418: The project as Advanced Manned Strategic Aircraft (AMSA), which differed from AMPSS primarily in that it also demanded a high-speed high-altitude capability, similar to that of the existing Mach 2-class F-111. Given the lengthy series of design studies, North American Rockwell engineers joked that the new name actually stood for "America's Most Studied Aircraft". The arguments that led to the cancellation of
10384-502: The projected cost of the program had risen to over $ 100 million per aircraft, although this was lifetime cost over 20 years. He was informed of the relatively new work on stealth aircraft that had started in 1975, and he decided that this was a better approach than the B-1. Pentagon officials also stated that the AGM-86 Air-Launched Cruise Missile (ALCM) launched from the existing B-52 fleet would give
10502-471: The required Mach 2 performance at high altitudes, the exhaust nozzles and air intake ramps were variable. Initially, it had been expected that a Mach 1.2 performance could be achieved at low altitude, which required that titanium be used in critical areas in the fuselage and wing structure. The low altitude performance requirement was later lowered to Mach 0.85, reducing the amount of titanium and therefore cost. A pair of small vanes mounted near
10620-729: The second B-1A. Engine testing also continued during this time with the YF101 engines totaling almost 7,600 hours. It was during this period that the Soviets started to assert themselves in several new theaters of action, in particular through Cuban proxies during the Angolan Civil War starting in 1975 and the Soviet invasion of Afghanistan in 1979. U.S. strategy to this point had been focused on containing Communism and preparation for war in Europe. The new Soviet actions revealed that
10738-591: The sweep angle. Subsequent swing-wing aircraft, such as the Panavia Tornado and Sukhoi Su-24 , would also be similarly equipped. In the Soviet Union , military planners had also formulated similar requirements, which led to TsAGI , the Soviet aerodynamics bureau, performing extensive studies into variable geometry wings. TsAGI evolved two distinct designs, differing mainly in the distance (expressed as
10856-413: The variable sweep wing. He devised a method of varying the tail geometry as well in order to stabilise the centre of lift; no sliding mechanism was necessary, instead, the wing wake interacted with the variable tail to effect the necessary trim changes. During 1949 and 1951, Baynes filed patent applications associated with this work. While the design reached the physical modelling stage and was subject to
10974-507: The vodka and caviar in Moscow." However, it appears the Soviets were more concerned by large numbers of ALCMs representing a much greater threat than a smaller number of B-1s. Soviet news agency TASS commented that "the implementation of these militaristic plans has seriously complicated efforts for the limitation of the strategic arms race." Western military leaders were generally happy with the decision. NATO commander Alexander Haig described
11092-444: The wing be swept. Most aircraft that travel at those speeds usually have wings (either swept wing or delta wing ) with a fixed sweep angle. These are simple and efficient wing designs for high speed flight, but there are performance tradeoffs. One is that the stalling speed is increased, necessitating long runways (unless complex high-lift wing devices are built in). Another is that the aircraft's fuel consumption during subsonic cruise
11210-434: The wing sweep angle necessary for trim and the optimal angle for supersonic cruise. Wallis resolved this by moving mass, typically the engines, out to the wing tips and swivelling them as the wing swept in order to maintain the thrust line. In the asymmetric engine-out condition, the remaining engines could be swivelled to divert the thrust line closer to the centre of pressure and reduce the asymmetry to manageable levels. It
11328-494: The wing swept back, the root also slid forwards, maintaining the centre of lift in a constant position. A variable-sweep wing of this sliding type was flown on the prototype Grumman XF10F Jaguar in 1952. However, flight testing of the F10F proved to be unacceptable, albeit for other factors such as a lack of engine power and considerable controllability issues. During the late 1940s, British engineer L. E. Baynes started studying
11446-424: The wing's inner ends. The wings could be swept from 20 degrees to 70 degrees; at the 70-degree position, longitudinal control was maintained by wing tip-mounted elevons , while this was provided by a retractable canard arrangement when swept at the 20-degree position, using full auto- stabilisation . By providing trimming functionality via the canard, the necessity of a large tailplane was eliminated. The Fo. 147
11564-533: The wings were set to their widest position the aircraft had considerably better lift and power than the B-52, allowing the B-1 to operate from a much wider variety of bases. Rockwell submitted its proposal in January 1970, competing against bids by Boeing and General Dynamics. The B-1's development was authorised in October 1981 as a stopgap between the increasingly vulnerable B-52 and the more capable Advanced Technology Bomber (ATB). Initial operational capability
11682-800: Was also used on the Space Shuttle orbiter and the B-52 bomber. The computer is programmed with the JOVIAL programming language . The Lancer's offensive avionics include the Westinghouse (now Northrop Grumman ) AN/APQ-164 forward-looking offensive passive electronically scanned array radar set with electronic beam steering (and a fixed antenna pointed downward for reduced radar observability), synthetic aperture radar , ground moving target indication (GMTI), and terrain-following radar modes, Doppler navigation , radar altimeter , and an inertial navigation suite. The B-1B Block D upgrade added
11800-481: Was an experimental jet fighter which was, in part, developed to investigate the benefits of varying wing sweep. Its sweep angle mechanism, which could only be adjusted on the ground between three separate positions of 30, 40, and 45 degrees, was intended for testing only, and was unsuitable for combat operations. However, by Victory in Europe Day , the sole prototype was only 80 per cent complete. Following
11918-558: Was awarded the development contract. The original program called for two test airframes, five flyable aircraft, and 40 engines. This was cut in 1971 to one ground and three flight test aircraft. The company changed its name to Rockwell International and named its aircraft division North American Aircraft Operations in 1973. A fourth prototype, built to production standards, was ordered in the fiscal year 1976 budget. Plans called for 240 B-1As to be built, with initial operational capability set for 1979. Rockwell's design had features common to
12036-466: Was aware of these developments and had begun moving its bombers to low-level penetration even before the U-2 incident. This tactic greatly reduces radar detection distances through the use of terrain masking ; using features of the terrain like hills and valleys, the line-of-sight from the radar to the bomber can be broken, rendering the radar (and human observers) incapable of seeing it. Additionally, radars of
12154-502: Was believed the B-1 could be in operation before the ATB, covering the transitional period between the B-52's increasing vulnerability and the ATB's introduction. Reagan decided the best solution was to procure both the B-1 and ATB, and on 2 October 1981 he announced that 100 B-1s were to be ordered to fill the LRCA role. In January 1982, the U.S. Air Force awarded two contracts to Rockwell worth
12272-630: Was canceled in 1977 due to its high cost, the introduction of the AGM-86 cruise missile that flew the same basic speed and distance, and early work on the B-2 stealth bomber. The program was restarted in 1981, largely as an interim measure due to delays in the B-2 stealth bomber program. The B-1A design was altered, reducing top speed to Mach 1.25 at high altitude , increasing low-altitude speed to Mach 0.96, extensively improving electronic components, and upgrading
12390-474: Was claimed to have been capable of speeds in excess of Mach 2, being limited by the heat buildup generated by high speed flight. Ultimately, the concept would not be developed to the prototype stage while the RAF showed little interest the prospective variable geometry trainer. During the 1960s, the first programmes to produce mass production variable-sweep aircraft commenced. In the United States, such
12508-424: Was completed, which called for an aircraft with a 20,000-pound (9,100 kg) bomb load and somewhat shorter range of 8,230 miles (13,240 km). These all culminated in the October 1963 Advanced Manned Precision Strike System (AMPSS), which led to industry studies at Boeing , General Dynamics , and North American (later North American Rockwell ). In mid-1964, the USAF had revised its requirements and retitled
12626-955: Was delivered on 2 May 1988; before the last B-1B was delivered, the USAF had determined that the aircraft was vulnerable to Soviet air defenses. In 1996, Rockwell International sold most of its space and defense operations to Boeing, which continues as the primary contractor for the B‑;1 as of 2024. The B-1 has a blended wing body configuration, with variable-sweep wing , four turbofan engines , triangular ride-control fins and cruciform tail . The wings can sweep from 15 degrees to 67.5 degrees (full forward to full sweep). Forward-swept wing settings are used for takeoff , landings and high-altitude economical cruise . Aft-swept wing settings are used in high subsonic and supersonic flight. The B-1's variable-sweep wings and thrust-to-weight ratio provide it with improved takeoff performance, allowing it to use shorter runways than previous bombers. The length of
12744-462: Was faced with the same decision as Carter before: whether to continue with the B-1 for the short term, or to wait for the development of the ATB, a much more advanced aircraft. Studies suggested that the existing B-52 fleet with ALCM would remain a credible threat until 1985. It was predicted that 75% of the B-52 force would survive to attack its targets. After 1985, the introduction of the SA-10 missile,
12862-404: Was followed by the similar Extended Range Strike Aircraft (ERSA), which added a variable-sweep wing , then en vogue in the aviation industry. ERSA envisioned a relatively small aircraft with a 10,000-pound (4,500 kg) payload and a range of 10,070 miles (16,210 km) including 2,900 miles (4,700 km) flown at low altitudes. In August 1963, the similar Low-Altitude Manned Penetrator design
12980-558: Was made public with the program being top secret , but it is now known that in early 1978 he authorized the Advanced Technology Bomber (ATB) project, which eventually led to the B-2 Spirit . Domestically, the reaction to the cancellation was split along partisan lines. The Department of Defense was surprised by the announcement; it expected that the number of B-1s ordered would be reduced to around 150. Congressman Robert Dornan (R-CA) claimed, "They're breaking out
13098-586: Was outfitted for conventional bombing. It first served in combat during Operation Desert Fox in 1998 and again during the NATO action in Kosovo the following year. The B-1B has supported U.S. and NATO military forces in Afghanistan and Iraq . As of 2021 the Air Force has 45 B-1Bs. The Northrop Grumman B-21 Raider is to begin replacing the B-1B after 2025; all B-1s are planned to be retired by 2036. In 1955,
13216-529: Was reached on 1 October 1986 and the B-1B was placed on nuclear alert status. The Soviet Union also opted to develop a large strategic bomber equipped with variable geometry wings. During the early 1970s, Tupolev's design, which was initially designated Aircraft 160M , featured a lengthened blended wing layout and incorporated some elements of the Tu-144 , competed against the Myasishchev M-18 and
13334-428: Was seen as a good trade off for the speed decrease. High subsonic speeds at low altitude became a focus area for the revised design, and low-level speeds were increased from about Mach 0.85 to 0.92. The B-1B has a maximum speed of Mach 1.25 at higher altitudes. The B-1B's maximum takeoff weight was increased to 477,000 pounds (216,000 kg) from the B-1A's 395,000 pounds (179,000 kg). The weight increase
13452-547: Was selected as the winning design used by Boeing 's entry in the FAA 's study for a supersonic transport , the 2707 . However it evolved through several configurations during the design stage, finally adding a canard, and it eventually became clear that the design would be so heavy that it would be lacking sufficient payload for the fuel needed. The design was later abandoned in favor of a more conventional tailed delta wing . The advent of relaxed stability flight control systems in
13570-546: Was shared with the Americans. According to aviation author James R. Hansen, American aerospace engineer John Stack was enthusiastic on the concept, as were numerous engineers at NASA ; however, the United States Department of Defense was opposed to committing any resources to the project. Wallis collaborated with NASA's Langley Laboratory on a design study for a variable-sweep fighter. Although it used
13688-476: Was significantly upgraded. Opposition to the plan was widespread within Congress. Critics pointed out that many of the original problems remained in both areas of performance and expense. In particular it seemed the B-52 fitted with electronics similar to the B-1B would be equally able to avoid interception, as the speed advantage of the B-1 was now minimal. It also appeared that the "interim" time frame served by
13806-520: Was the supersonic F-111 fighter-bomber, which used variable-sweep wings for tactical missions. A number of studies on a strategic-range counterpart followed. The first post-B-70 strategic penetrator study was known as the Subsonic Low-Altitude Bomber (SLAB), which was completed in 1961. This produced a design that looked more like an airliner than a bomber, with a large swept wing, T-tail , and large high-bypass engines . This
13924-422: Was to allow for takeoff with a full internal fuel load and for external weapons to be carried. Rockwell engineers were able to reinforce critical areas and lighten non-critical areas of the airframe, so the increase in empty weight was minimal. To deal with the introduction of the MiG-31 equipped with the new Zaslon radar system, and other aircraft with look-down capability, the B-1B's electronic warfare suite
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