Everything about B-1 Bomber totally explained
The
B-1 Lancer is a
supersonic strategic bomber with
variable-sweep wings. Its origins began in the 1960s as a supersonic bomber with sufficient range and payload to replace the
B-52 Stratofortress, but developed into a primarily subsonic low-level very long-range penetrator. The B-1B production version has been in service with the
United States Air Force (USAF) since 1986. The Lancer serves as the supersonic-capable component of the USAF's long-range bomber force, along with the subsonic B-52 and
B-2 Spirit. As with official popular names of other aircraft, the
Lancer is commonly called the "Bone" (originally from "B-One") within the USAF. With the retirement of the
EF-111 Raven in 1998 and the
F-14 Tomcat in 2006, the B-1B is the last variable-sweep wing aircraft remaining in U.S. military inventory.
History
The B-1 was conceived as the
Advanced Manned Strategic Aircraft (AMSA) program circa
1965. AMSA was the last in a series of programs through the 1960s that looked at replacing the
B-52 Stratofortress with a multi-role supersonic aircraft capable of long-range bombing and missile launching with nuclear weapons. A series of cancellations led to its service introduction being greatly delayed, until the later half of the 1980s, over twenty years after the program first started.
The Valkyrie
In 1955, the USAF released system requirements for a heavy bomber with the B-52's range and payload capabilities, and the supersonic speed of the
B-58, in order to replace both of these bombers by 1965. The initial requirements called for a Mach 0.9 cruise speed with a Mach 2+ dash capability. The designs that met this specification were considered unrealistically large, requiring new hangars to hold them and reinforced runways to launch them.
During the design phase new fuels and techniques evolved that would allow an aircraft with similar range to cruise all the way to its target at high speeds. The Air Force asked for new proposals based on these advances, and this work would eventually lead to the
B-70 Valkyrie. The Valkyrie was a large six-engine bomber designed to fly at very high altitudes at Mach 3 to avoid defending
interceptors, the only effective anti-bomber weapon at that point in time. Altitude alone was proving so difficult a problem that Soviet interceptors continued to fail to intercept the
Lockheed U-2, running out of fuel before reaching a suitable firing point. Given the speed and altitude of the B-70, the defense would have only a few minutes to respond to an attack, and even small numbers of B-70s attacking simultaneously would ensure that most would fly right by the interceptors, regardless of how much warning time they had.
The introduction of effective
anti-aircraft missiles rendered this mode of operation dangerous. Unlike a manned interceptor that maneuvers within a plane while climbing, missiles flew straight up and could reach the B-70s altitude in a few minutes. The only concern became speed; as long as the target didn't fly out of range before the missile reached it an attack was possible, and a powerful radar giving the operators some "lead time" could easily solve this problem. This was proven in convincing fashion by the
downing of
Gary Powers' U-2 in 1960s.
Redefined role
In response to the missile threat, military planners switched to low-altitude penetration. By carefully selecting the line of approach to a target, and routing the flight path around known anti-aircraft sites, the radar's line-of-sight operation worked in the bomber's advantage by hiding it from view below the landscape. Aircraft speed became much less important. The targets themselves often had defenses located nearby to prevent this sort of approach all the way in, but stand-off weapons such as
cruise missiles and the
AGM-69 SRAM provided an attack capability from outside of the defensive missile's range. Low-altitude flight also made the bombers very difficult to detect from aircraft at higher altitudes, including interceptors, as radar systems of that generation couldn't "look down" due to the clutter that resulted from ground reflections.
Operations at low levels would limit the B-70 to subsonic speed, while dramatically decreasing its range due to much higher fuel requirements. The result would be an aircraft with similar speed but much less range than the B-52 it would have replaced. This wasn't a purely theoretical issue, this exact problem had actually occurred with the B-58, another high-speed aircraft that was forced into the low-level role to avoid missile defenses. The design had "spent" a lot in gaining medium-range Mach 2 performance, but at low altitudes it had strictly subsonic performance and such dramatically reduced range that it limited the selection of targets that could be assigned to it. The "outdated" B-52 outperformed it, as it would have the B-70.
Unsuited for this new role, the viability of the B-70 as a bomber was questioned. Citing high cost, a growing
ICBM force, and poor survivability against missiles, the operational fleet was canceled in 1961 by President
John F. Kennedy, and the program was changed to a supersonic research program.
The B-52 soldiers on
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.
Additionally, no other aircraft had anything close to the B-52's bombload capacity. During the
Vietnam War, B-52s with "big belly" modifications delivered massive loads of high explosive bombs. They proved effective against both industrial targets as well as troop concentrations. With improved coordination with ground spotters, three-plane formations at high altitude had proven to be highly effective ground-attack weapons. The same wouldn't be true of the Valkyrie, which would have had limited uses in the conventional bombing role and featured a much smaller bombload at 25,000 pounds (11,000 kg).
That wasn't to say the B-52 was a perfect solution to these problems. Higher speed would aid even a low-level approach in the strategic role, something the
F-111 was taking advantage of. In the high-load tactical role the aircraft was limited to a small number of airfields due to its very long takeoff roll. By the early 1960s the
state of the art in engine and airframe design had improved considerably, an aircraft designed to the B-52's roles could meet both of these additional requirements. Although the B-52 had proven to be surprisingly adaptable in both the strategic and tactical roles, during the early 1960s a number of studies followed these technical developments in order to design a worthy B-52 replacement.
AMSA
The first such study was known as the
Subsonic Low Altitude Bomber (SLAB), which was completed in 1961. This was followed by the similar
Extended Range Strike Aircraft (ERSA), which added a
Variable-sweep wing planform, something then very much in vogue in the aviation industry. ERSA envisioned a relatively small aircraft with a 10,000 lb (4,500 kg) load and a range of 8,750 nautical miles (16,200 km), with 2,500 nmi (4,600 km) being flown at low altitudes. In August 1963 the similar
Low-Altitude Manned Penetrator (LAMP) design was completed, which called for an aircraft with a 20,000 lb (9,000 kg) load and somewhat shorter range of 7,150 nautical miles (13,200 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. 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. Rockwell engineers joked that the new name actually stood for "America's Most Studied Aircraft", given the lengthy series of design studies.
First cancellation
The ending of the B-70 project had led some to question the need for a newer aircraft in the strategic bombing role at all. The Air Force was adamant about retaining bombers as part of the nuclear "Triad" concept that included bombers,
SLBMs and
ICBMs in a combined package that complicated the defense. But the arguments for keeping the bombers was hotly debated. The original argument was that the bombers could be kept in the air during times of increased defensive posture, where they'd be difficult to attack. Missiles of the era, like the
Atlas and
Redstone, required a lengthy fuelling procedure immediately before launch, and were therefore vulnerable to air attack while still on the ground. They also had low accuracy; enough to attack cities as a strategic deterrent, but not enough to attack hardened military targets. To attack these targets, the bombers were required.
In the early 1960s newer generations of missiles with
solid rocket motors were being introduced that could be launched quickly, even faster than bombers, and were sited in underground silos for protection. Sneak attacks on these weapons would be very difficult for the USSR, which lacked the accuracy in their own weapons and would have to use their bombers in order to be effective against them. US air defenses would have made such an attack extremely unlikely to succeed. Accuracy of the new weapons was so improved that direct attacks against similar weapons in the USSR were a real possibility, and attacks on a military base was now possible. Making matters more troublesome for the Air Force was the introduction and rapid improvement of the U.S. Navy's SLBM force, which had considerably better survivability than either bombers or hardened missile silos. After this period the Air Force used a number of different arguments to make its case for the strategic bomber, including the conventional role and "recall-ability", but these arguments were much less convincing.
One of the biggest critics of the bomber portion of the Triad was
Secretary of Defense Robert McNamara who preferred ICBMs over bombers for the Air Force side of the deterrent force. In testimony before Congress, McNamara said, "
The strategic missile forces for 1967-71 will provide more force than is required for 'Assured Destruction' ... a new advanced strategic aircraft doesn't at this time appear justified." His opposition led to the AMSA program being stopped in 1964. A fourth prototype (76-1074) was ordered in the FY 1976 budget. This fourth aircraft was to be built to production standards. At one time, some 240 B-1As planned to be built, with initial operational capability set for 1979. As the program continued the per-unit cost continued to rise. In 1970, the estimated per-unit price was $40 million, and by 1972, the cost had risen slightly to $45.6 million. By 1975, this figure had climbed to $70 million.
Another cancellation
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 decided that this was a far better avenue of approach than the B-1.
Pentagon officials also stated that the
ALCM launched from the existing B-52 fleet would give the USAF equal capability of penetrating Soviet airspace. With a 1,500 statute mile (2,400 km) range, 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. A small number of B-52 operating outside interception range 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-1A's.
Unsurprisingly, the reaction to the cancellation was split along partisan lines.
Robert Dornan claimed, "They're breaking out the vodka and caviar in Moscow." In contrast, it appears the Soviets were not at all excited by this development, considering a large number of ALCMs represented a much greater threat than a smaller number of B-1s.
Tass commented that "the implementation of these militaristic plans has seriously complicated efforts for the limitation of the strategic arms race."
Shifting priorities
It was during this period that the Soviets, also acting in proxy through
Cuba, started to exert themselves in several new theaters of action, in particular the
Cuban support in
Angola starting in 1975 and the
Soviet invasion of
Afghanistan in 1979. The U.S. strategy to this point was containment and a conventional and nuclear war in Europe, which almost all military planning had been focused on. These newer actions revealed that the military was simply incapable of supporting any sort of effort outside these narrow confines.
The Army responded by accelerating its
Rapid Deployment Force concept, but suffered from major problems with airlift and sealift capability. While gaming a USSR-led invasion of
Iran from Afghanistan, then considered (incorrectly) to be a major Soviet goal, it was discovered that only small numbers of units could be in the field in anything close to a week. In order to slow an advance while this happened they relied on air power, but critically the Iran-Afghanistan border was outside the
U.S. Navy's range, leaving this role to the Air Force. They, in turn, had limited capability to offer ground support in many areas that were outside of the range of friendly airbases. Although the B-52 had the range to support on-demand global missions, the B-52's long runway requirements dramatically limited the forward basing possibilities. In real-world scenarios the capabilities of this force against any given potential target was limited, something the B-1 would be better prepared to handle due to its better takeoff performance and range.
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. Brown later denied this claim, stating Carter was simply opposed to any military buildup. Although Reagan's primary attack on Carter's decision was now rendered moot, he immediately changed his complaint saying that Carter was giving away secrets and politicizing The Pentagon, charges that led to a round of sparring between Brown and Reagan in the press. Interestingly, it was Brown that had led the original AMSA program, but later came to prefer the cruise missile after taking the job of Defense Secretary in 1977.
B-1B program
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. He decided to do both. 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 them increasingly vulnerable.
During the FY81 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. This left the B-1B with the capability for speeds of about Mach 1.25 "at altitude," a reduction from the B-1A's Mach 2 performance. 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. These changes, along with the rampant
inflation of the U.S. economy during the time, dramatically increased the
nominal price to about $200 million total projected
lifetime cost per completed airframe.
Opposition to the plan was widespread within Congress. Critics pointed out that many of the original problems with the concept remained. In particular it seemed the B-52 fit 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 introduction by the 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 debate remained rancorous. But the Air Force very astutely spread production subcontracts across many congressional districts, making the aircraft more popular on
Capitol Hill. Crews, who generally felt the "Lancer" moniker was unappealing, quickly latched onto the "Bone" nickname.
Design
The B-1 has a
blended wing body configuration, with
variable-sweep wing, triangular fin control surfaces and four
turbofan engines, to improve range and speed with enhanced
survivability. Forward swept wing settings are used for
takeoff,
landings and high-altitude maximum
cruise. Aft swept wing settings are used in high subsonic and supersonic flight. 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 length of the aircraft presented a serious flexing problem due to air turbulence at low altitude. To alleviate this, Rockwell included small canards near the nose on the B-1. An accelerometer would actuate 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 at altitude is Mach 1.25 (about 950 mph or 1,530 km/h), 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. The B-1A's engine was modified slightly to produce the
F101-102, 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
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
F118 used in the B-2 Spirit bomber and the
U-2S. However its greatest success was forming the core of the extremely popular
CFM56 civil engine, which can be found on some versions of practically every small-to-medium sized airliner. It includes with an "Alert Start" panel on the nosegear, which quickly activated the engines 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. From 1995 on, the B-1B Block D upgrade added a
Global Positioning System receiver.
The B-1's defensive electronics include the
Eaton AN/ALQ-161 radar warning and defensive
jamming equipment, 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. The AN/ALE-49 dispenser has a capacity of 12 MJU-23A/B flares each. The MJU-23A/B flare is one of the world's largest infrared countermeasure flares having a gross weight of ~1170 g. The cylindrical
Magnesium/Teflon/Viton pellet has a net weight of ~1470 g. The Plans for a defensive systems upgrade program (DSUP) were cancelled for budgetary reasons. The B-1 has also been equipped to carry the
ALE-50 Towed Decoy System. The Lancer has an additional
Doppler tail-warning radar to detect aircraft or missiles approaching from the rear.
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 ft²/2.4 m²), although the Lancer isn't substantially smaller in mass than the Stratofortress.
The B-1 has been upgraded since production through the "Conventional Mission Upgrade Program". This multi-stage program added a new
MIL-STD-1760 smart-weapons interface that enables the use of the
Joint Direct Attack Munition and other precision-guided conventional weapons, such as the
Wind Corrected Munitions Dispenser (WCMD), the
AGM-154 Joint Standoff Weapon (JSOW), and the
AGM-158 JASSM (Joint Air to Surface Standoff Munition). Future precision munitions include the
GBU-39 Small Diameter Bomb. These and other improvements are intended to ensure that the B-1 will be viable through approximately 2020. In addition, the Air Force has recently announced a program to keep the aircraft flying until at least 2040.
Operational history
The USAF
Strategic Air Command (SAC) had B-1 Lancers in service from 1986 through 1992, when SAC was re-organized out of existence. During that time the "Bone" was on limited alert, and the backbone of SAC's alert bombers remained B-52H models. 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. Aircraft were placed on "limited alert", meaning they were grounded unless a nuclear war broke out. They were returned to duty one-at-a-time starting in January 1991 as they were inspected and repaired. It wasn't until mid-April that the fleet was once again declared airworthy.
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. Although cleared for this role, the problems with the engines precluded their use in
Operation Desert Storm. Also, B-1s were reserved for strategic nuclear strike missions at this time.
After the absorption of Strategic Air Command (SAC) into
Air Combat Command in 1992, the B-1 began to truly develop conventionally. A key part of this development was the start-up of the B-1 Weapons School Division, also in 1992. 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. This development has continued through the present.
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. In both conflicts, the B-1 employed its full array of conventional weapons, most notably the GBU-31, 2,000 lb (900 kg)
Joint Direct Attack Munition (JDAM). During OEF, the B-1 improved its mission capable rate to 79%. The
National Aeronautic Association recognized the B-1B for completing one of the 10 most memorable record flights for 1994. As of 2008, the B-1 is being used in Iraq in close support of ground troops by delivering precision-guided bombs.
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 in a flight over Texas and New Mexico. The B-1B is undergoing flight testing using a 50/50 mix of synthetic and petroleum fuel as part of an ongoing Air Force testing program.
Variants
B-1A/B
The B-1A was original B-1 design with variable engine intakes and Mach 2.2 top speed. Four prototypes were built.
The B-1B is the improved B-1 design with reduced radar signature and a top speed of Mach 1.25. A total of 100 B-1Bs were produced.
B-1R
The B-1R is a proposed replacement for the B-1B fleet. Boeing's director of global strike integration, Rich Parke, was first quoted about the "B-1R" bomber in
Air Force Magazine. Parke said the B-1R (R stands for "regional") would be a Lancer with advanced radars, air-to-air missiles, and
Pratt & Whitney F119 engines (originally developed for the
F-22 Raptor).
- Block A: Standard design of the B-1B with the capability to deliver non-precision Mk-82 500 lb gravity bombs. Before CMUP all B-1Bs were designated as "Block A" models.
- Block B: Improved Synthetic Aperture Radar, as well as some upgrades to the Defensive Countermeasures System. This upgrade reached the field in 1995.
- Block C: "Enhanced Capability" provided for delivery of up to 30 Cluster Bomb Units (CBUs) per sortie. The upgrade consists of modification for B-1B bomb module from the original configuration of 28 x 500 lb bombs per unit to 10 x 1,000 lb cluster bombs per bomb rack. The modifications were made to 50 bomb racks. This capability was completed in August 1997.
- Block D: "Near Precision Capability" gives B-1 aircrews increased abilities to accurately put bombs on target with improved weapons and targeting systems, as well as giving them advanced secure communications capabilities. The first part of the electronic countermeasures upgrade, addition of Joint Direct Attack Munitions (JDAM), ALE-50 Towed Decoy System, and anti-jam radios are also included.
- Block E: This upgrade covers improvements to the avionics computers. This package also incorporates the Wind-Corrected Munitions Dispenser (WCMD), the Joint Standoff Weapon (JSOW) and the Joint Air-to-Surface Standoff Missile (JASSM), substantially improving the bomber's capability. Upgrades were completed in Sept. 2006.
- Block F: The Defensive Systems Upgrade Program (DSUP) improves the aircraft's electronic countermeasures and jamming capabilities. This includes the Towed Decoy System (TDS). Upgrades were canceled in December 2002 due to cost overruns and schedule slips.
After the CMUP program, upgrades will provide for better network centric capability. A program was begun in 2005 to provide integrated data linking and upgraded crew station displays. Integration of a targeting pod will follow. An interim targeting pod modification is to be fielded in mid-2008.
Operators
Popular culture
The B-1 and B-52 bombers have been featured frequently in author Dale Brown's books. A B-1 carries the President to NORAD, during an alien invasion in the Larry Niven and Jerry Pournelle science fiction novel Footfall.
The unofficial 1983 James Bond film Never Say Never Again features a cruise missile launch from a B-1 (although a sequence in which cruise missiles are loaded onto the B-1 was filmed with a Concorde SST substituting for the B-1's undercarriage). In the 1985 film Real Genius, the laser weapon that's developed by Chris Knight is mounted in a B-1's bomb bay.
Gallery
image:B1A160wingsmuseum.JPG|B-1A nose section with ejection capsule denoted
image:B1BtailWingsMus.JPG|Tail section.
image:B1ArearWingsMus.JPG|Rear section with pointed radome.
image:B1ArudderWingsMus.JPG|Rudder and tail.
image:B1AmaingearWingsMus.JPG|Main gear.
image:B1AnosegearWingsMus.JPG|Nose gear.
image:B1AswingWingsMus.JPG|Top view of swing wing.
image:B1AbayWingsMus.JPG|Bomb bay.
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