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Name | B-1 Lancer |
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Caption | A B-1B flying over the Pacific Ocean. |alt=A B-1B with its wings swept forward flying over the Pacific Ocean. |
Type | Supersonic Strategic bomber |
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National origin | United States |
Manufacturer | North American Rockwell/Rockwell International Boeing |
First flight | 23 December 1974 |
Introduction | 1 October 1986 |
Primary user | United States Air Force |
Number built | B-1A: 4 B-1B: 100 |
Status | In service 66 with active duty |
Unit cost | US$283.1 million in 1998 (B-1B) |
The Rockwell (now part of Boeing) B-1 Lancer is a four-engine, variable-sweep wing strategic bomber used by the United States Air Force. First envisioned in the 1960s as a supersonic bomber with sufficient range and payload to replace the Boeing B-52 Stratofortress, it developed primarily into a low-level penetrator with long range and supersonic speed capability.
The bomber's development was delayed multiple times over its history, as the theory of strategic balance changed from flexible response to mutually assured destruction and back again. The initial B-1A version was developed in the early 1970s, but its production was canceled and only four prototypes were built. In 1980, the B-1 resurfaced as the B-1B version with the focus on low-level penetration bombing. The B-1B entered service with the United States Air Force (USAF) in 1986.
The B-1B began service with the USAF Strategic Air Command as a nuclear bomber. In the 1990s, it was converted to conventional bombing use. It was first used in combat during Operation Desert Fox in 1998 and during the NATO action in Kosovo the following year. The B-1B continues to support U.S. and NATO military in Afghanistan and Iraq. The Lancer is the supersonic component of the USAF's long-range bomber force, along with the subsonic B-52 and Northrop Grumman B-2 Spirit. The bomber is commonly called the "Bone" (originally from "B-One"). With the retirement of the General Dynamics/Grumman EF-111A Raven in 1998 and the Grumman F-14 Tomcat in 2006, the B-1B is the U.S. military's only active variable-sweep wing aircraft.
The USAF Strategic Air Command (SAC) began moving its bombers to low-level penetration before the U-2 downing. This tactic greatly reduces radar detection distances by use of terrain masking. 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 the air war environment changed. The B-52's large airframe with internal room allowed the addition of improved electronic countermeasures suites. 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 (27,215 kg), turning it into a powerful tactical aircraft as well. In spite of its flexibility, the B-52 was far from perfect; higher speed would aid even a low-level approach in the strategic role, something the F-111 took advantage of.
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. In mid-1964, the USAF had revised its requirements and retitled the project as Advanced Manned Strategic Aircraft (AMSA), which differed from AMPSS primarily in that it also demanded a high-speed high-altitude capability, albeit slower than the Valkyrie at about Mach 2. Given the lengthy series of design studies, Rockwell engineers joked that the new name actually stood for "America's Most Studied Aircraft".
The arguments that led to the cancellation of the B-70 program had led some to question the need for a new strategic bomber. The Air Force 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 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 mooted the mobility argument, and a newer generation of ICBMs had the accuracy and speed needed to attack any potential target. During this time, ICBMs were seen as a less costly option based on their lower unit cost, but development costs were much higher. and felt a new expensive bomber was not needed.
Program studies continued; IBM and Autonetics were awarded AMSA advanced avionics study contracts in 1968.
President Richard Nixon re-established the 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 the desired range, and recommended that the AMSA design studies be accelerated. In June 1970, North American Rockwell's design was selected and was awarded a 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. Two hundred forty B-1As were planned to be built, with initial operational capability set for 1979.
Rockwell's design featured a number of features common to 1960s U.S. designs. These included the use of variable-sweep wings in order to provide both high lift during takeoff and landing, and low drag during a high-speed dash phase. 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. The first three B-1As featured an 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. The first B-1A prototype (s/n 74-0158) flew on 23 December 1974. Three more B-1A prototypes followed. As the program continued the per-unit cost continued to rise in partly 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.
Given that its armament suite was similar to the B-52, the program was increasingly questioned and remained highly controversial. In particular, Senator William Proxmire continually derided it 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 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 far better avenue of 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 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 just like a bomber, but in much greater numbers at a lower cost. A small number of B-52s could launch hundreds of ALCMs, saturating the defense. A program to improve the B-52 and develop and deploy the ALCM would cost perhaps 20% of the price to deploy the planned 244 B-1As.
Domestically, the reaction to the cancellation was split along partisan lines. The Department of Defense were surprised by the announcement, internal expectations were that the number of B-1s ordered would be cut down to around 150. Congressman Robert Dornan (R-CA) claimed, "They're breaking out the vodka and caviar in Moscow." In contrast, 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."
The Army 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 U.S. Navy's carrier-based attack aircraft, leaving this role to the Air Force. Although the B-52 had the range to support on-demand global missions, its long runway requirements limited the forward basing possibilities.
During the 1980 presidential campaign, Ronald Reagan campaigned heavily on the platform that Carter was weak on defense, using the cancellation of the B-1 program as a prime 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 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. Air Force studies suggested that the existing B-52 fleet with ALCM would remain a credible threat until 1985, as it was predicted that 75% of the B-52 force would survive to attack its targets. After this period the introduction of the SA-10 missile, MiG-31 interceptor and the first Soviet AWACS systems would make the B-52 increasingly vulnerable.
During 1981, budget funds were given to a new study for a bomber for the 1990s time-frame. These studies led to the Long-Range Combat Aircraft (LRCA) project which compared the B-1, F-111 and ATB as possible solutions. An emphasis was placed on the design being multi-role, as opposed to a purely strategic weapon.
In January 1982 the U.S. Air Force awarded two contracts to Rockwell worth a combined $2.2 billion for the development and production of 100 new B-1 bombers. Numerous changes were made to the design to better fit it to real-world missions, resulting in the new B-1B. High subsonic speeds at low altitude became a focus area for the revised design, In order to deal with the introduction of the MiG-31 and other aircraft with look-down capability, the B-1B's electronic warfare suite was significantly upgraded. 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 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 payload, and that its takeoff performance allowed it to operate with a credible bombload from a much wider variety of airfields. The Air Force spread production subcontracts across many congressional districts, making the aircraft more popular on Capitol Hill. The 100th and final B-1B was delivered on 2 May 1988. The wings of the B-1B originally were cleared for use at settings of 15, 25, 55 and 67.5 degrees. The 45-degree setting was later cleared in 1998–99 timeframe. The B-1's variable-sweep wings and thrust-to-weight ratio provide it with better takeoff performance, allowing it to use more runways than previous bombers. The length of the aircraft presented a flexing problem due to air turbulence at low altitude. To alleviate this, Rockwell included small triangular fin control surfaces or canards near the nose on the B-1. The B-1's Structural Mode Control System rotates the canards automatically to counteract turbulence and smooth out the ride.
Unlike the B-1A, the B-1B made no attempt at Mach 2+ speeds. Its maximum speed 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). Technically, the current version of the aircraft can exceed its speed restriction, but not without risking potential damage to its structure and air intakes. To help lower its radar cross section (RCS), the B-1B uses serpentine air intake ducts and fixed intake ramps, which limit its speed compared to the B-1A. Vanes in the intake ducts serve to deflect and shield radar emissions from the highly reflective engine fan blades.
pass at the Pensacola Beach air show, 2003 |alt=A B-1B makes a high-speed, transonic pass, with the aircraft passing through a shock wave during the Pensacola Beach air show in 2003]]
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 of this engine has since been re-used in several other engine designs, including the GE F110 which has seen use in the F-14 Tomcat, F-15K/SG variants and most recent versions of the 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 nose gear cover door has controls for the auxiliary power units (APUs), main gear doors and nearby entry ladder. Controls there allow for quick starts of the APUs upon order to scramble.
The B-1'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 indicator (MTI), and terrain-following radar modes, Doppler navigation, radar altimeter, and an inertial navigation suite. The B-1B Block D upgrade added 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, has three antennae; one at the front base of each wing and the third rear-facing in the tail radome. The ALQ-161 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 the B-1's survivability is its relatively low radar cross-section (RCS). Although not technically a stealth aircraft in a comprehensive sense, thanks to the aircraft's structure, serpentine intake paths and use of radar-absorbent material its RCS is about 1/50th that of the B-52 (probably about 26 ft² or 2.4 m²), although the Lancer is not substantially smaller in mass than the Stratofortress.
Block D added a "Near Precision Capability" for B-1 aircrews to accurately put bombs on target with improved weapons and targeting systems, and added advanced secure communications capabilities. Block E upgraded the avionics computers and incorporated the Wind Corrected Munitions Dispenser (WCMD), the AGM-154 Joint Standoff Weapon (JSOW) and the AGM-158 JASSM (Joint Air to Surface Standoff Munition), substantially improving the bomber's capability. Upgrades were completed in September 2006. Block F was the Defensive Systems Upgrade Program (DSUP) to improve the aircraft's electronic countermeasures and jamming capabilities, but it was canceled in December 2002 due to cost overruns and schedule slips.
-based B-1 |alt=A B-1B with a Sniper XR pod mounted on its chin ]]
The Sniper XR targeting pod is being 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 the GBU-39 Small Diameter Bomb.
Subsequent upgrades will provide for better network-centric capability. A program was begun in 2005 to provide integrated data linking and upgraded crew station displays. A B-1 equipped with the Fully Integrated Data Link (FIDL) first flew on 29 July 2009. The FIDL allows for electronic data sharing so the crew will no longer have to enter information between systems by hand. The USAF is expected to place a contract to have FIDL installed in the entire fleet by the end of 2010.
Despite upgrades, the B-1 has repair and cost issues resulting from its age. For every flight hour it needs 48.4 hours of repair. The fuel, repairs and other needs for a 12-hour mission costs $720,000 as of 2010.
In late 1990 engine fires in two Lancers caused the grounding of the fleet. The cause was traced back to problems in the first-stage fan, the aircraft were placed on "limited alert"; in other words, they were grounded unless a nuclear war broke out. They were returned to duty following inspection and repairs, and the fleet was declared airworthy in April 1991.
Originally designed strictly for nuclear war, the B-1's development as an effective conventional bomber was delayed until the 1990s. By 1991, the B-1 had a fledgling conventional capability, forty of them able to drop the 500 lb (230 kg) Mk-82 General Purpose (GP) bomb, although mostly from low altitude. Despite being cleared for this role, the problems with the engines precluded their use in Operation Desert Storm. The B-52 was more suited to the role of conventional warfare and it was used by coalition forces instead. In 1994, two additional B-1 bomb wings were also created in the Air National Guard, with former fighter wings in the Kansas Air National Guard and the Georgia Air National Guard converting to the aircraft. By the mid-1990s, the B-1 could employ GP weapons as well as various CBUs. By the end of the 1990s, with the advent of the "Block D" upgrade, the B-1 boasted a full array of guided and unguided munitions. The B-1B no longer carries nuclear weapons;
Operationally, the B-1 was first used in combat in support of operations against Iraq during Operation Desert Fox in December 1998, employing unguided GP weapons. B-1s have been subsequently used in Operation Allied Force (Kosovo) and most notably in Operation Enduring Freedom in Afghanistan and the 2003 invasion of Iraq. At the height of the Iraq War a B-1 was permanently airborne to provide rapid precision bombardment upon important targets as intelligence identified them.
During Operation Enduring Freedom, the B-1 was able to raise its mission capable rate to 79%. In November 1983 three B-1Bs set a long distance record for the aircraft, which demonstrated its ability to conduct extended mission lengths to strike anywhere in the world and return back 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. in 2004 a new appropriations bill called for some of the retired aircraft to return to service. In 2004 the USAF returned seven of the mothballed bombers to service, giving a total force of 67 aircraft.
On 14 July 2007, the Associated Press reported on the growing USAF presence in Iraq as a result of "surge" in forces. Also mentioned is the reintroduction of B-1Bs to be a close-at-hand "platform" to support Coalition ground forces. B-1s have been used in Iraq and Afghanistan. Since 2008 B-1s have been used there in an "armed overwatch" role. They loiter over the region maintaining surveillance, ready to deliver guided bombs in support of ground troops if contacted.
The B-1B underwent a series of flight tests using a 50/50 mix of synthetic and petroleum fuel; on 19 March 2008 a B-1B from Dyess Air Force Base, Texas, became the first US Air Force aircraft to fly at supersonic speed using a synthetic fuel during a flight over Texas and New Mexico. This was conducted as part of an ongoing Air Force testing and certification program to reduce reliance on traditional oil sources. On 4 August 2008, a B-1B flew the first Sniper Advanced Targeting Pod equipped combat sortie where the crew successfully targeted enemy ground forces and dropped a GBU-38 guided bomb in Afghanistan.
With upgrades to keep the B-1 viable, the Air Force may keep the bomber in service until approximately 2038. However, in June 2010 senior U.S. Air Force officials met to consider retiring the entire fleet to meet budget cuts.
;B-1A The B-1A was the original B-1 design with variable engine intakes and Mach 2.2 top speed. Four prototypes were built; no production units were manufactured. ;B-1B The B-1B is a revised B-1 design with reduced radar signature and a top speed of Mach 1.25. It was otherwise optimized for low-level penetration. A total of 100 B-1Bs were produced. The B-1R (R for "regional") would be a Lancer with advanced radars, air-to-air missiles, and Pratt & Whitney F119 engines. Compared to the B-1B, the B-1R would have a higher top speed of Mach 2.2, but its range would be 20% less.
Existing external hardpoints would be modified to allow multiple conventional weapons to be carried, increasing overall loadout. For air-to-air defense, an Active Electronically Scanned Array (AESA) radar would be added and some existing hardpoints modified to carry air-to-air missiles. If needed the B-1R could escape from unfavorable air-to-air encounters with its Mach 2+ speed. Few aircraft are capable of over Mach 2 speeds, and those that are can maintain these speeds for only very short periods of time. The third B-1A (s/n 74-0160) is on display at Wings Over the Rockies Museum at the former Lowry Air Force Base in Denver, Colorado. The fourth and last B-1A (s/n 74-0174) was on display at the National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio for many years before moving to the Strategic Air and Space Museum near Offutt AFB in Ashland, Nebraska. This aircraft has conventional ejection seats and other features distinctive to the B-1B variant instead of the B-1A. B-1B (s/n 83-0065) is on display at the Dyess Linear Air Park at Dyess Air Force Base, Texas. This was the first aircraft delivered to the Air Force and is named "The Star of Abilene". Dyess AFB is home to one of two Regular Air Force B-1B wings.
*In September 1987, B-1B (s/n 84-0052) from the 96th Bomb Wing, 338th Bomb Squadron, Dyess AFB crashed near La Junta, Colorado while flying on a low-level training route. This was the only B-1B crash to occur with six crew members aboard. The two crew members in jump seats, and one of the four crew members in ejection seats perished. The root cause of the accident was thought to be a bird strike on a wing's leading edge during the low-level flight. The impact was severe enough to sever fuel and hydraulic lines on one side of the aircraft, the other side's engines functioned long enough to allow for ejection. The B-1B fleet was later modified to protect these supply lines.
*In November 1988, B-1B (s/n 85-0063) from the 96th Bomb Wing, 337th Bomb Squadron, Dyess AFB crashed near Tye, Texas after a fire broke out above the left engines. All four crew members successfully ejected from the aircraft. The review board found that the bomber struck the ground while performing a defensive maneuver.
*On 18 February 1998, B-1B (s/n 84-0057) from the 7th Bomb Wing, Dyess AFB, Texas crashed near Marion, Kentucky when a fire detected by a cockpit instrument panel shut down the aircraft's power. All four crew members were able to eject and were rescued safely.
*In December 2001, B-1B (s/n 86-0114) from the 28th Bomb Wing, 37th Bomb Squadron, Ellsworth AFB, South Dakota, was lost over the Indian Ocean. All four crew members successfully ejected and were rescued. The bomber was flying en route to a long-range combat mission over Afghanistan when the crew declared an in-flight emergency. The pilot, Capt. William Steele, attributed the crash to "multiple malfunctions" causing the bomber to go "out of control". Because of the water's depth, the structural data collector (SDC) or "Black Box" was not recovered and the cause was not positively determined. The aircraft had recently returned from Ellsworth AFB from a routine Phase Inspection, and was on its first combat mission after returning to the island of Diego Garcia in the British Indian Ocean Territory. This was the first B-1B to be lost in combat operations since the model became operational in 1986.
*On 4 April 2008, B-1B (s/n 86-0116) lost hydraulic power while taxiing, then crashed into a concrete barrier and caught fire at Al Udeid AB, Qatar. The crew safely evacuated the aircraft. The B-1B was carrying multiple bombs at the time, all but two of which detonated during the fire. The aircraft was a total loss.
*In October 1990, while flying a training route in eastern Colorado, B-1B (s/n 86-0128) from the 384th Bomb Wing, 28th Bomb Squadron, McConnell AFB, experienced an explosion as the engines reached full power without afterburners. Fire on the aircraft's left was spotted. The #1 engine was shut down and its fire extinguisher was activated. The accident investigation determined that the engine had suffered catastrophic failure, in which engine blades cut through the engine mounts, causing the engine to detach from the aircraft.
*On 8 May 2006, B-1B (s/n 86-0132) from the 7th Bomb Wing, 9th Bomb Squadron, Dyess AFB, Texas, landed "gear-up" during recovery from an 11-hour ferry flight to the island of Diego Garcia. A resulting fire was quickly extinguished and the crew escaped through the top hatch with only a minor back injury to the co-pilot. The Air Force investigation concluded that the pilots disabled the aural tone generator circuit breaker which creates audible warning signals and then "forgot to lower the landing gear". The B-1B impacted and slid on the runway, causing approximately $8 million of damage to the aircraft and runway. Four days later the aircraft was raised and its landing gear deployed. The B-1B returned to normal service in 2007.
B-1B Lancer Category:Rockwell aircraft Category:United States bomber aircraft 1970-1979 Category:Variable-sweep wing
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