Rockwell B-1 Lancer

The Rockwell B-1 Lancer, colloquially known as the “Bone” (a playful nod to “B-One”), stands as a testament to the evolution of strategic bombing capabilities within the United States Air Force. As of 2024, this aircraft remains a crucial component of the U.S. Air Force’s strategic bomber fleet, alongside the B-2 Spirit and the venerable B-52 Stratofortress. The B-1 Lancer’s impressive payload capacity, capable of carrying up to 75,000 pounds (34,000 kg) of munitions, marks it as the heaviest payload carrier among U.S. bombers, underscoring its significant role in the nation’s defense strategy.

The origins of the B-1 Lancer trace back to the 1960s, a period marked by the United States’ quest for a bomber that could merge the Mach 2 speed of the B-58 Hustler with the extended range and payload capabilities of the B-52, ultimately aiming to replace both aircraft. This ambitious vision led to extensive studies and evaluations, culminating in North American Rockwell, later known as Rockwell International, securing the design contract with their B-1A prototype. This initial iteration of the aircraft was remarkable for its ability to achieve speeds of Mach 2.2 at high altitudes while maintaining long-distance flights at Mach 0.85 at very low altitudes. However, the B-1A program faced a setback in 1977 when it was canceled due to exorbitant costs, the advent of the AGM-86 cruise missile, which offered similar speed and range capabilities, and the early development stages of the B-2 stealth bomber.

In 1981, the B-1 program was resurrected as a stopgap measure due to delays in the B-2 stealth bomber’s development. The original B-1A design underwent significant modifications, resulting in the B-1B variant. These changes included reducing the aircraft’s top speed to Mach 1.25 at high altitudes while enhancing its low-altitude speed to Mach 0.96. The B-1B also featured extensively upgraded electronic components and an enhanced airframe capable of carrying more fuel and weaponry. Deliveries of the B-1B commenced in 1985, and the aircraft officially entered service with the Strategic Air Command (SAC) as a nuclear bomber the following year. By 1988, all 100 aircraft had been delivered.

The strategic role of the B-1B evolved following the disestablishment of SAC and the reassignment of the aircraft to the Air Combat Command in 1992. This transition marked the deactivation of the B-1B’s nuclear capabilities, as it was reconfigured for conventional bombing missions. The B-1B’s first combat deployment occurred during Operation Desert Fox in 1998, and it subsequently played a pivotal role in NATO’s action in Kosovo the following year. Since then, the B-1B has been integral in supporting U.S. and NATO military operations in Afghanistan and Iraq. As of 2021, the Air Force maintained a fleet of 45 B-1Bs, with the Northrop Grumman B-21 Raider slated to begin replacing the B-1B after 2025, leading to the expected retirement of all B-1s by 2036.

The development and history of the B-1 Lancer can be traced back to the mid-1950s when the United States Air Force (USAF) issued requirements for a new bomber that could match the payload and range of the Boeing B-52 Stratofortress while achieving 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 designed to cruise at Mach 3 at high altitudes of 70,000 feet (21,000 meters). During the 1950s, Soviet interceptor aircraft, which were the primary anti-bomber threat, were already incapable of intercepting the high-flying Lockheed U-2. The Valkyrie, with its similar altitude capabilities but significantly higher speeds, was expected to outpace any fighter threats.

However, by the late 1950s, the emergence of anti-aircraft surface-to-air missiles (SAMs) posed a significant threat to high-altitude aircraft, as evidenced by the 1960 downing of Gary Powers’ U-2 spy plane. The USAF’s Strategic Air Command (SAC) had already begun transitioning its bombers to low-level penetration tactics before the U-2 incident. This approach significantly reduced radar detection ranges by utilizing terrain masking techniques, where the bomber would use natural features like hills and valleys to break the line-of-sight from radar installations, rendering them unable to detect the aircraft. Additionally, the radars of that era were plagued by “clutter” from stray returns from the ground and other objects, meaning there was a minimum angle above the horizon where they could detect a target. By flying at low altitudes, bombers could remain below these angles, effectively evading radar detection by keeping their distance from radar sites. This combination of factors rendered SAMs of the time ineffective against low-flying aircraft. Furthermore, low-flying bombers were challenging to detect by interceptors flying at higher altitudes, as their radar systems struggled to distinguish aircraft from ground clutter due to a lack of look-down/shoot-down capability.

The shift from high-altitude to low-altitude flight profiles had a profound impact on the B-70, which was optimized for high-altitude performance. The increased aerodynamic drag at lower altitudes limited the B-70 to subsonic speeds, significantly reducing its range. Consequently, the B-70 would have offered only slightly higher subsonic speed than the B-52 but with less range. These limitations, coupled with a growing emphasis on intercontinental ballistic missiles (ICBMs), led to the cancellation of the B-70 bomber program in 1961 by President John F. Kennedy. The two XB-70 prototypes were subsequently used for supersonic research purposes.

Despite never being intended for low-level operations, the B-52’s versatility allowed it to outlast its intended successor as the nature of aerial warfare evolved. The B-52’s substantial fuel capacity enabled it to operate at lower altitudes for extended periods, while its large airframe facilitated the integration of advanced radar jamming and deception systems to counter enemy radars. During the Vietnam War, the notion that future conflicts would be exclusively nuclear was challenged, and the “big belly” modifications increased the B-52’s bomb load to 60,000 pounds (27,000 kg), transforming it into a formidable tactical aircraft capable of engaging ground targets in addition to strategic objectives from high altitudes. The B-70’s much smaller bomb bay would have limited its effectiveness in this role.

Although the B-52 proved effective, it was not ideally suited for low-level missions. This led to the development of various aircraft designs known as penetrators, specifically optimized for long-range, low-altitude flight. The first of these designs to enter service was the supersonic F-111 fighter-bomber, which employed variable-sweep wings for tactical missions. A series of studies followed, exploring the development of a strategic-range counterpart.

The first strategic penetrator study after the B-70 was the Subsonic Low-Altitude Bomber (SLAB) project, completed in 1961. This design resembled an airliner more than a bomber, featuring a large swept wing, T-tail, and high-bypass engines. It was succeeded by the Extended Range Strike Aircraft (ERSA) study, which incorporated a variable-sweep wing, a design feature gaining popularity in the aviation industry at the time. 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 Low-Altitude Manned Penetrator design was completed, calling for an aircraft with a 20,000-pound (9,100 kg) bomb load and a somewhat shorter range of 8,230 miles (13,240 km).

These studies 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). By mid-1964, the USAF had revised its requirements and rebranded the project as the Advanced Manned Strategic Aircraft (AMSA), which differed from AMPSS primarily in its demand for a high-speed, high-altitude capability similar to that of the existing Mach 2-class F-111. Given the extensive series of design studies, North American Rockwell engineers humorously referred to the new name as “America’s Most Studied Aircraft.”

The arguments that led to the cancellation of the B-70 program had prompted some to question the need for a new strategic bomber altogether. However, the USAF remained committed to retaining bombers as part of the nuclear triad concept, which included bombers, ICBMs, and submarine-launched ballistic missiles (SLBMs) in a combined package that complicated any potential defense strategy. They argued that bombers were essential for targeting hardened military installations and providing a safe counterforce option, as they could be quickly launched into safe loitering areas where they would be less vulnerable to attack. Nevertheless, the introduction of SLBMs diminished the mobility and survivability argument, and a newer generation of ICBMs, such as the Minuteman III, possessed the accuracy and speed necessary to strike point targets. During this period, ICBMs were perceived as a more cost-effective option based on their lower unit cost, although their development costs were significantly higher. Secretary of Defense Robert McNamara favored ICBMs over bombers for the Air Force’s deterrent force and believed that an expensive new bomber was unnecessary. Consequently, McNamara limited the AMSA program to studies and component development beginning in 1964.

Despite McNamara’s opposition, program studies continued, with IBM and Autonetics awarded AMSA advanced avionics study contracts in 1968. However, McNamara remained steadfast in his preference for upgrading the existing B-52 fleet and adding nearly 300 FB-111s for shorter-range roles previously filled by the B-58. He once again vetoed funding for AMSA aircraft development in 1968.

The B-1A program emerged under the administration of President Richard Nixon, who reinstated the Advanced Manned Strategic Aircraft (AMSA) initiative to align with his administration’s flexible response strategy. This strategic doctrine emphasized the need for a broad range of military options beyond general nuclear warfare. Nixon’s Secretary of Defense, Melvin Laird, conducted a thorough review of existing military programs and concluded that the FB-111 fleet should be reduced due to its insufficient range, while the AMSA design studies should be expedited. Consequently, in April 1969, the program officially transitioned into the B-1A, marking the first entry in the new bomber designation series established in 1962. The Air Force subsequently issued a request for proposals in November 1969.

By January 1970, major aerospace companies, including Boeing, General Dynamics, and North American Rockwell, had submitted their proposals. In June 1970, North American Rockwell was awarded the contract to develop the B-1A. The original program plan called for the construction of two test airframes, five flyable aircraft, and 40 engines. However, in 1971, the scope was reduced to one ground test and three flight test aircraft. In 1973, the company rebranded itself as Rockwell International, with its aircraft division being renamed North American Aircraft Operations. A fourth prototype, built to production standards, was later added to the fiscal year 1976 budget, with plans for a total of 240 B-1As to be produced, achieving initial operational capability by 1979.

The design of the B-1A incorporated several features reminiscent of the F-111 and XB-70 aircraft. It included a crew escape capsule that ejected as a unit, enhancing crew survivability in high-speed emergency situations. Additionally, the B-1A featured large variable-sweep wings, which provided increased lift during takeoff and landing and reduced drag during high-speed dash phases. With its wings extended to their widest position, the B-1A demonstrated superior airfield performance compared to the B-52, enabling it to operate from a broader range of bases. The aircraft’s mission profile involved penetrating Soviet defenses at supersonic speeds to cross them swiftly before reducing speed in the less-defended interior of the country. Its large size and fuel capacity allowed for an extended “dash” portion of the flight.

The B-1A was designed to achieve the required Mach 2 performance at high altitudes through the use of variable exhaust nozzles and air intake ramps. Initially, it was anticipated that the aircraft could reach Mach 1.2 at low altitudes, necessitating the use of titanium in critical areas of the fuselage and wing structure. However, the low-altitude performance requirement was later reduced to Mach 0.85, resulting in decreased titanium usage and lower costs. To ensure a smoother ride at low altitudes, small vanes near the nose were integrated as part of an active vibration damping system. The first three B-1A prototypes featured the escape capsule, while the fourth prototype was equipped with conventional ejection seats for each crew member.

In late October 1971, a mockup review of the B-1A took place, resulting in 297 requests for design alterations to address specification failures and improve maintenance and operational ease. The first B-1A prototype, with the Air Force serial number 74–0158, took to the skies on December 23, 1974. However, as the program progressed, the per-unit cost continued to escalate, partly due to high inflation during that period. In 1970, the estimated unit cost was $40 million, but by 1975, this figure had risen to $70 million.

In 1976, the defection of Soviet pilot Viktor Belenko to Japan with his MiG-25 “Foxbat” aircraft revealed the existence of a new “super-Foxbat,” likely referring to the MiG-31, which featured look-down/shoot-down radar capabilities. This development raised concerns about the effectiveness of low-level penetration aircraft like the B-1A, as they would become more visible and vulnerable to attack. Given that the B-1A’s armament was similar to that of the B-52, doubts about its survivability in Soviet airspace began to surface. Senator William Proxmire was a vocal critic, labeling the B-1 as an excessively expensive and outdated dinosaur. During the 1976 federal election campaign, Jimmy Carter made the cancellation of the B-1 bomber a key platform of the Democratic Party, arguing that funding the program would be a waste of taxpayers’ dollars.

Upon assuming office in 1977, President Carter ordered a comprehensive review of the B-1 program. By this time, the projected cost of the program had exceeded $100 million per aircraft, although this figure accounted for lifetime costs over 20 years. Carter was informed of ongoing research into stealth technology, which had commenced in 1975, and he concluded that this was a more promising approach than the B-1. Pentagon officials also pointed out that the AGM-86 Air-Launched Cruise Missile (ALCM), deployed from the existing B-52 fleet, could provide the USAF with equivalent capabilities for penetrating Soviet airspace. With a range of 1,500 miles (2,400 km), the ALCM could be launched well beyond the reach of Soviet defenses and penetrate at low altitudes, benefiting from a much smaller radar cross-section due to its reduced size. A small number of B-52s could launch hundreds of ALCMs, overwhelming enemy defenses. A program to upgrade the B-52 and develop and deploy the ALCM was estimated to cost at least 20% less than the planned 244 B-1As.

On June 30, 1977, Carter announced the cancellation of the B-1A program in favor of ICBMs, SLBMs, and a fleet of modernized B-52s armed with ALCMs. Carter described the decision as “one of the most difficult” he had made since taking office. The stealth work, being top secret, was not publicly disclosed at the time, but it is now known that in early 1978, Carter authorized the Advanced Technology Bomber (ATB) project, which eventually led to the development of the B-2 Spirit.

Domestically, the cancellation of the B-1A program elicited mixed reactions along partisan lines. The Department of Defense was surprised by the announcement, as it had anticipated a reduction in the number of B-1s ordered to around 150. Congressman Robert Dornan (R-CA) claimed that the Soviets were celebrating the decision. However, it appears that the Soviets were more concerned about the proliferation of ALCMs, which posed a greater threat than a smaller number of B-1s. The Soviet news agency TASS commented that the implementation of these militaristic plans had complicated efforts to limit the strategic arms race. Western military leaders generally supported the decision. NATO commander Alexander Haig described the ALCM as an attractive alternative to the B-1, while French General Georges Buis noted that for the price of one bomber, 200 cruise missiles could be acquired.

Despite the cancellation, flight tests of the four B-1A prototypes continued through April 1981, encompassing 70 flights and totaling 378 hours. The second B-1A achieved a top speed of Mach 2.22 during these tests. Engine testing also continued, with the YF101 engines accumulating nearly 7,600 hours of testing.

During this period, the geopolitical landscape was shifting, with the Soviet Union asserting itself in new theaters of action, notably through Cuban proxies during the Angolan Civil War starting in 1975 and the Soviet invasion of Afghanistan in 1979. U.S. military strategy had primarily focused on containing Communism and preparing for potential conflict in Europe. However, these new Soviet actions underscored the military’s lack of capability outside these narrow confines.

In response, the U.S. Department of Defense accelerated its Rapid Deployment Forces concept, although it faced significant challenges with airlift and sealift capabilities. To slow enemy invasions of other countries, air power became critical. However, the key Iran-Afghanistan border was beyond the range of the United States Navy’s carrier-based attack aircraft, leaving this role to the U.S. Air Force.

During the 1980 presidential campaign, Ronald Reagan capitalized on the perception that Carter was weak on defense, using the cancellation of the B-1 program as a prime example. This theme continued into the 1980s, as Carter’s defense secretary, Harold Brown, announced the stealth bomber project, subtly implying that this was the rationale behind the B-1 cancellation.

Upon taking office, President Ronald Reagan faced a similar decision to that of his predecessor, Jimmy Carter: whether to proceed with the B-1 bomber as an interim solution or to await the development of the Advanced Technology Bomber (ATB), which promised to be a more advanced aircraft. Studies conducted during this period suggested that the existing B-52 fleet, equipped with Air-Launched Cruise Missiles (ALCMs), would remain a credible deterrent until 1985, with projections indicating that 75% of the B-52 force would survive to strike their targets. However, beyond 1985, the introduction of the Soviet SA-10 missile, the MiG-31 interceptor, and the first effective Soviet Airborne Early Warning and Control (AWACS) systems were expected to increase the vulnerability of the B-52.

In light of these developments, funds were allocated in 1981 for a new study to develop a bomber for the 1990s, leading to the Long-Range Combat Aircraft (LRCA) project. The LRCA evaluated the B-1, F-111, and ATB as potential solutions, with a particular emphasis on multi-role capabilities rather than purely strategic operations. It was believed that the B-1 could be operational before the ATB, thus covering the transitional period between the B-52’s growing vulnerability and the ATB’s eventual deployment. Reagan concluded that procuring both the B-1 and ATB was the optimal solution, and on October 2, 1981, he announced an order for 100 B-1 bombers to fulfill the LRCA role.

In January 1982, the U.S. Air Force awarded Rockwell two contracts totaling $2.2 billion for the development and production of 100 new B-1 bombers. Numerous modifications were made to the original design to better suit the anticipated mission profiles, resulting in the B-1B variant. These changes included a reduction in maximum speed, which allowed for the replacement of the variable-aspect intake ramps with simpler fixed geometry intake ramps. This alteration reduced the B-1B’s radar cross-section, which was deemed an advantageous trade-off for the decreased speed. The revised design focused on achieving high subsonic speeds at low altitudes, with low-level speeds increased from approximately Mach 0.85 to Mach 0.92. The B-1B’s maximum speed at higher altitudes was set at Mach 1.25.

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) to accommodate a full internal fuel load and the carriage of external weapons. Rockwell engineers reinforced critical areas of the airframe while lightening non-critical areas, resulting in minimal increases in empty weight. To counter the threat posed by the MiG-31 equipped with the Zaslon radar system and other aircraft with look-down capability, the B-1B’s electronic warfare suite received significant upgrades.

Despite widespread opposition within Congress, many of the original performance and expense issues persisted. Critics argued that the B-52, equipped with similar electronics to the B-1B, would be equally capable of avoiding interception, as the B-1’s speed advantage was now minimal. Additionally, it appeared that the “interim” period served by the B-1B would be relatively short, as it would likely become obsolete shortly after the introduction of the more advanced ATB design. However, the primary argument in favor of the B-1 was its substantial conventional weapon payload and its ability to operate with a credible bomb load from a wider variety of airfields. Production subcontracts were distributed across numerous congressional districts, bolstering the aircraft’s popularity on Capitol Hill.

The first B-1B was completed and began flight testing in March 1983. The first production B-1B was rolled out on September 4, 1984, and made its first flight on October 18, 1984. The 100th and final B-1B was delivered on May 2, 1988. However, 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 to serve as the primary contractor for the B‑1 as of 2024.

The B-1 boasts a blended wing body configuration with variable-sweep wings, four turbofan engines, triangular ride-control fins, and a cruciform tail. The wings can sweep from 15 degrees to 67.5 degrees (full forward to full sweep), with forward-swept settings used for takeoff, landings, and high-altitude economical cruise, and aft-swept settings for high subsonic and supersonic flight. The B-1’s variable-sweep wings and thrust-to-weight ratio enhance its takeoff performance, allowing it to use shorter runways than its predecessors. To address the flexing issues caused by air turbulence at low altitudes, Rockwell incorporated small triangular fin control surfaces or vanes near the nose of the B-1. The Structural Mode Control System moves these vanes and the lower rudder to counteract turbulence effects and smooth out the ride.

The B-1B cannot reach the Mach 2+ speeds of the B-1A; its maximum speed is Mach 1.25 (approximately 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 limitation of the current version of the aircraft is due to the need to avoid damage to its structure and air intakes. To reduce its radar cross-section, the B-1B employs serpentine air intake ducts and fixed intake ramps, which limit its speed compared to the B-1A. Vanes in the intake ducts deflect and shield radar returns from the reflective engine compressor blades.

The B-1B’s engine, the GE F101-102, was slightly modified from the B-1A’s engine to emphasize durability and increased efficiency. The core of this engine was later used in several other engines, including the GE F110 used in the F-14 Tomcat, F-15K/SG variants, and later versions of the General Dynamics F-16 Fighting Falcon. It also serves as the basis for the non-afterburning GE F118 used in the B-2 Spirit and the U-2S, as well as the CFM56 civil engine.

The nose-gear door houses the ground-crew control for the auxiliary power unit (APU), which can be used for quick-starting the APU during a scramble.

The B-1’s main computer is the IBM AP-101, also used on the Space Shuttle orbiter and the B-52 bomber. The computer is programmed using 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, synthetic aperture radar, ground moving target indication, and terrain-following radar modes, as well as Doppler navigation, a 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 a third rear-facing in the tail radome. The tail radome also houses the AN/ALQ-153 missile approach warning system (pulse-Doppler radar). The ALQ-161 is linked to eight AN/ALE-49 flare dispensers located behind the canopy, managed by the AN/ASQ-184 avionics management system. Each AN/ALE-49 dispenser can hold 12 MJU-23A/B flares, which are among the world’s largest infrared countermeasure flares. The B-1 has also been equipped with the ALE-50 towed decoy system.

The B-1’s relatively low radar cross-section (RCS) enhances its survivability. Although not a stealth aircraft, its structure, serpentine intake paths, and radar-absorbent materials give it an RCS approximately 1/50th that of the similarly sized B-52, 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 various aircraft weight classes. In November 1993, three B-1Bs set a long-distance record, demonstrating the aircraft’s ability to conduct extended missions globally and return to base without stops. The National Aeronautic Association recognized the B-1B for completing one of the 10 most memorable record flights in 1994.

The B-1 has undergone multiple upgrades since its production, beginning with the “Conventional Mission Upgrade Program” (CMUP), which added a new MIL-STD-1760 smart-weapons interface to enable the use of precision-guided conventional weapons. The CMUP was delivered through a series of upgrades:

Block A was the standard B-1B with the capability to deliver non-precision gravity bombs.

Block B introduced an improved Synthetic Aperture Radar and upgrades to the Defensive Countermeasures System, fielded in 1995.

Block C provided an “enhanced capability” for delivering up to 30 cluster bomb units (CBUs) per sortie, with modifications made to 50 bomb racks.

Block D added a “Near Precision Capability” through improved weapons and targeting systems and advanced secure communications capabilities. It also included the Joint Direct Attack Munition (JDAM), ALE-50 towed decoy system, and anti-jam radios.

Block E upgraded the avionics computers and integrated the Wind Corrected Munitions Dispenser (WCMD), the AGM-154 Joint Standoff Weapon (JSOW), and the AGM-158 JASSM (Joint Air to Surface Standoff Munition), significantly enhancing the bomber’s capabilities. These upgrades were completed in September 2006.

Block F was the Defensive Systems Upgrade Program (DSUP) aimed at improving the aircraft’s electronic countermeasures and jamming capabilities, but it was canceled in December 2002 due to cost overruns and delays.

In 2007, the Sniper XR targeting pod was integrated into the B-1 fleet, mounted on an external hardpoint near the forward bomb bay. Following accelerated testing, the Sniper pod was fielded in the summer of 2008. Future precision munitions include the Small Diameter Bomb.

The USAF initiated the Integrated Battle Station (IBS) modification in 2012, combining three separate upgrades: 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 for manual data entry between systems. VSDU replaces existing flight instruments with multifunction color displays, aiding threat evasion and targeting while serving as a backup display. CITS introduced a new diagnostic system that allows the crew to monitor over 9,000 parameters on the aircraft. Additional upgrades include replacing the spinning mass gyroscopic inertial navigation system with ring laser gyroscopic systems and a GPS antenna, replacing the APQ-164 radar with the Scalable Agile Beam Radar – Global Strike (SABR-GS) active electronically scanned array, and installing 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 increase its internal and external weapon capacity. By expanding the internal bay and utilizing six of the eight external hardpoints previously unused to comply with the New START Treaty, the B-1B’s weapon load increased from 24 to 40. This configuration also allows 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, and in the future, the HAWC could be used, potentially bringing the total number of hypersonic weapons to 31.

The B-1 has seen several variants throughout its history:

B-1A: The original B-1 design with variable engine intakes and a Mach 2.2 top speed. Four prototypes were built, but no production units were manufactured.

B-1B: A revised B-1 design with a reduced radar signature and a top speed of Mach 1.25, optimized for low-level penetration. A total of 100 B-1Bs were produced.

B-1R: A 2004 proposed upgrade of existing B-1B aircraft. The B-1R (R for “regional”) would have been fitted with advanced radars, air-to-air missiles, and new Pratt & Whitney F119 engines (from the Lockheed Martin F-22 Raptor). This variant would have had a top speed of Mach 2.2 but with 20% shorter range. Existing external hardpoints would have been modified to carry multiple conventional weapons, increasing overall loadout. An active electronically scanned array (AESA) radar would have been added for air-to-air defense, with some existing hardpoints modified to carry air-to-air missiles.