The Bone
Nicknamed “The Bone,” the B-1B Lancer is a long-range, multi-mission conventional bomber, which has served the United States Air Force since 1985. Originally designed for nuclear capabilities, the B-1 switched to an exclusively conventional combat role in the mid 1990’s. In 1999, during Operation Allied Force, six B-1s flew 2 percent of the strike missions, yet dropped 20 percent of the ordnance. The B-1 has been nearly continuously deployed in combat operations over Afghanistan and Iraq since 2001.
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Function
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Long-range, multi-role, heavy bomber
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Power plant
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Four General Electric F101-GE-102
turbofan engine with afterburner
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Thrust
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30,000-plus pounds with afterburner, per
engine
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Wingspan
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137 ft (41.8 m) extended forward, 79 ft
(24.1 m) swept aft
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Length
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146 ft (44.5 meters)
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Height
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34 ft (10.4 meters)
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Weight
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Approximately 190,000 lbs (86,183 kg)
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Max Takeoff Weight
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477,000 lbs (216,634 kg)
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Fuel Capacity
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265,274 lbs (120,326 kg)
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Payload
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75,000 lbs internal (34,019 kg), 50,000
lbs (22,679 kg)
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Speed
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900-plus mph (Mach 1.2 at sea level)
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Range
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Intercontinental
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Ceiling
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More than 30,000 ft (9,144 m)
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Crew
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4 (aircraft commander, copilot, and two
weapon systems officers)
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Inventory
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66
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B-1B Lancer Milestones
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April 30 2015
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Jan 22 2014
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July 20 2012
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April 09 2012
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Feb 27 2012
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B-1B Lancer Customer
Since the U.S. Air Force received its first B-1B in 1984, the bomber has served the country as both a conventional and nuclear strike option. Over four years, 100 B-1Bs left Boeing’s factories, and 66 continue in operation today.
The Rockwell B-1 Lancer[N 1] is a four-engine supersonic variable-sweep wing, jet-powered heavy strategic bomber used by the United States Air Force (USAF). It was first envisioned in the 1960s as a supersonic bomber with Mach 2 speed, and sufficient range and payload to replace the Boeing B-52 Stratofortress. It was developed into the B-1B, primarily a low-level penetrator with long range and Mach 1.25 speed capability at high altitude. It is commonly called the "Bone" (originally from "B-One").
Designed by Rockwell International (now part of Boeing), development was delayed multiple times over its history due to changes in the perceived need for manned bombers. The initial B-1A version was developed in the early 1970s, but its production was canceled, and only four prototypes were built. The need for a new platform once again surfaced in the early 1980s, and the aircraft resurfaced as the B-1B version with the focus on low-level penetration bombing. However, by this point, development of stealth technology was promising an aircraft of dramatically improved capability. Production went ahead as the B version would be operational before the "Advanced Technology Bomber" (which became the B-2 Spirit), during a period when the B-52 would be increasingly vulnerable. The B-1B entered service in 1986 with the USAF Strategic Air Command (SAC) as a nuclear bomber.
In the early 1990s, following the Gulf War and concurrent with the disestablishment of SAC and its reassignment to the newly formed Air Combat Command (ACC), the B-1B was converted to conventional bombing use. 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. The B-1B is expected to continue to serve into the 2030s, with the Long Range Strike Bomber to start supplementing the B-1B in 2030.
Background
In 1955 the U.S. Air Force 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 U.S. Air Force selected North American Aviation's proposal to replace the B-52 with the B-70 Valkyrie. The Valkyrie was a six-engine bomber that could reach Mach 3 speeds at high altitude (70,000 ft or 21,000 m) to avoid interceptor aircraft, the only effective anti-bomber weapon in the 1950s. Soviet aircraft were already unable to intercept the high-flying Lockheed U-2; the Valkyrie would fly at similar altitudes but much higher speeds. In combat, the B-70 was expected to simply fly right by the defenders.
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's U-2. The USAF Strategic Air Command (SAC) were aware of these developments and had begun moving its bombers to low-level penetration even before the U-2 downing. This tactic greatly reduces radar detection distances by 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 the target. Even at somewhat higher altitudes, radar systems of the era were subject to "clutter" from stray returns from the ground and other objects, requiring a minimum angle above the ground to be effective. 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 interceptor aircraft, since their radar systems could not readily pick out opposing aircraft against 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, whose design was highly tuned to provide the desired high-altitude performance. Planners outlined a series of low-level profiles for the B-70, but 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, but less range than the B-52 it was meant to replace. Unsuited for the new low-altitude role, and because of a growing shift to the intercontinental ballistic missile (ICBM) force, the B-70 bomber program was canceled 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 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 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.
The B-1 has a blended wing body configuration, with variable-sweep wing, four turbofan engines, triangular fin control surfaces 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 maximum 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 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 vanes near the nose on the B-1. The B-1's Structural Mode Control System rotates the vanes automatically to counteract turbulence and smooth out the ride.
A rear view of a B-1B at Royal International Air Tattoo air show in 2004
Rear view of B-1B in flight, 2004
Unlike the B-1A, the B-1B cannot reach 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). 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 (RCS), the B-1B uses serpentine air intake ducts (see S-duct) 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 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 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 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 was the basis for the core of the extremely popular CFM56 civil engine, which can be found on some versions of practically every small-to-medium-sized airliner. The nose gear cover door has controls for the auxiliary power units (APUs), which allow for quick starts of the APUs upon order to scramble.
The B-1's main computer is the IBM AP-101, which is 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 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 (Pulse-Doppler radar). 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 of the similar sized B-52's RCS; this is about 26 ft² or 2.4 m², roughly equivalent to the RCS of a small fighter aircraft.
Variants
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.
B-1R
The B-1R is a proposed upgrade of existing B-1B aircraft. The B-1R (R for "regional") would be fitted with advanced radars, air-to-air missiles, and new Pratt & Whitney F119 engines. This variant would have a top speed of Mach 2.2, but with 20% shorter range.
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 currently capable of sustained speeds over Mach 2.
Accidents and incidents
Ten B-1s have been lost due to accidents. Between 1984 and 2001, 17 crew members and people on board have been killed in B-1 accidents.
Bombs:
84× Mk-82 Air inflatable retarder (AIR) general purpose (GP) bombs
81× Mk-82 low drag general purpose (LDGP) bombs
84× Mk-62 Quickstrike sea mines
24× Mk-84 general purpose bombs
24× Mk-65 naval mines
30× CBU-87/89/CBU-97 Cluster Bomb Units (CBU)
30× CBU-103/104/105 Wind Corrected Munitions Dispenser (WCMD) CBUs
24× GBU-31 JDAM GPS guided bombs (Mk-84 GP or BLU-109 warhead)
15× GBU-38 JDAM GPS guided bombs (Mk-82 GP warhead)
48x GBU-38 JDAM (using rotary launcher mounted multiple ejector racks)
48x GBU-54 LaserJDAM (using rotary launcher mounted multiple ejector racks)
24× AGM-154 Joint Standoff Weapon (JSOW)
96× or 144× GBU-39 Small Diameter Bomb GPS guided bombs (not fielded on B-1 yet)
24× AGM-158 Joint Air to Surface Standoff Missile (JASSM)
24× B61 or B83 nuclear bombs (no longer carried)
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