Rockwell B-1 Lancer
The Rockwell B-1 Lancer is a supersonic variable-sweep wing, heavy bomber used by the United States Air Force. It has been nicknamed the "Bone"., it is one of the U.S. Air Force's three strategic bomber types, along with the B-2 Spirit and the B-52 Stratofortress. It carries up to a 75,000-pound payload.
The B-1 was first envisioned in the 1960s as a bomber that would combine the Mach 2 speed of the B-58 Hustler with the range and payload of the B-52, ultimately replacing both. After a long series of studies, North American Rockwell won the design contest for what emerged as the B-1A. Prototypes of this version could fly Mach 2.2 at high altitude and long distances and at Mach 0.85 at very low altitudes. The program was canceled in 1977 due to its high cost, the introduction of the AGM-86 cruise missile that flew the same basic speed and distance, and early work on the B-2 stealth bomber.
The program was restarted in 1981, largely as an interim measure due to delays in the B-2 stealth bomber program. The B-1A design was altered, reducing top speed to Mach 1.25 at high altitude, increasing low-altitude speed to Mach 0.92, extensively improving electronic components, and upgrading the airframe to carry more fuel and weapons. Named the B-1B, deliveries of the new variant began in 1985; the plane formally entered service with Strategic Air Command as a nuclear bomber the following year. By 1988, all 100 aircraft had been delivered.
The B-1B was reassigned to Air Combat Command in 1992 and it was outfitted for conventional bombing, with its nuclear mission eliminated in 1994 per the START I treaty. It first served in combat during the 1998 bombing of Iraq and again during the 1999 NATO bombing of Yugoslavia the following year. The B-1B has supported U.S. and NATO military forces in the wars in Afghanistan and Iraq, as well as strikes in Libya, Syria and Venezuela. As of 2025, the Air Force operates 45 B-1Bs bombers, with many retired units in the Boneyard. The Northrop Grumman B-21 Raider is to begin replacing the B-1B after 2025; all B-1s are planned to be retired by 2036, replaced by the B-21.
Development
Background
In 1955, the USAF issued requirements for a new bomber combining the payload and range of the Boeing B-52 Stratofortress with the Mach 2 maximum speed of the Convair B-58 Hustler. In December 1957, the USAF selected North American Aviation's B-70 Valkyrie for this role, a six-engine bomber that could cruise at Mach 3 at high altitude. Soviet Union interceptor aircraft, the only effective anti-bomber weapon in the 1950s, were already unable to intercept the high-flying Lockheed U-2; the Valkyrie would fly at similar altitudes, but much higher speeds, and was expected to fly right by the fighters.By the late 1950s, however, anti-aircraft surface-to-air missiles could threaten high-altitude aircraft, as demonstrated by the 1960 downing of Gary Powers' U-2. The USAF Strategic Air Command was aware of these developments and had begun moving its bombers to low-level penetration even before the U-2 incident. This tactic greatly reduces radar detection distances through the use of terrain masking; using features of the terrain like hills and valleys, the line-of-sight from the radar to the bomber can be broken, rendering the radar incapable of seeing it. Additionally, radars of the era were subject to "clutter" from stray returns from the ground and other objects, which meant a minimum angle existed above the horizon where they could detect a target. Bombers flying at low altitudes could remain under these angles simply by keeping their distance from the radar sites. This combination of effects made SAMs of the era ineffective against low-flying aircraft. The same effects also meant that low-flying aircraft were difficult to detect by higher-flying interceptors, since their radar systems could not readily pick out aircraft against the clutter from ground reflections.
The switch from high-altitude to low-altitude flight profiles severely affected the B-70, the design of which was tuned for high-altitude performance. Higher aerodynamic drag at low level limited the B-70 to subsonic speed while dramatically decreasing its range. The result would be an aircraft with somewhat higher subsonic speed than the B-52, but less range. Because of this, and a growing shift to the intercontinental ballistic missile force, the B-70 bomber program was cancelled in 1961 by President John F. Kennedy, and the two XB-70 prototypes were used in a supersonic research program.
Although never intended for the low-level role, the B-52's flexibility allowed it to outlast its intended successor as the nature of 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, 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.
Design studies and delays
Although effective, the B-52 was not ideal for the low-level role. This led to a number of aircraft designs known as penetrators, which were tuned specifically for long-range low-altitude flight. The first of these designs to see operation was the supersonic F-111 fighter-bomber, which used variable-sweep wings for tactical missions. A number of studies on a strategic-range counterpart followed.The first post-B-70 strategic penetrator study was known as the Subsonic Low-Altitude Bomber, which was completed in 1961. This produced a design that looked more like an airliner than a bomber, with a large swept wing, T-tail, and large high-bypass engines. This was followed by the similar Extended Range Strike Aircraft, which added a variable-sweep wing, then en vogue in the aviation industry. ERSA envisioned a relatively small aircraft with a payload and a range of including flown at low altitudes. In August 1963, the similar Low-Altitude Manned Penetrator design was completed, which called for an aircraft with a bomb load and somewhat shorter range of.
These all culminated in the October 1963 Advanced Manned Precision Strike System, 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, which differed from AMPSS primarily in that it also demanded a high-speed high-altitude capability, similar to that of the existing Mach 2-class F-111. Given the lengthy series of design studies, North American Rockwell engineers joked that the new name actually stood for "America's Most Studied Aircraft".
The arguments that led to the cancellation of the B-70 program had led some to question the need for a new strategic bomber of any sort. The USAF was adamant about retaining bombers as part of the nuclear triad concept that included bombers, ICBMs, and submarine-launched ballistic missiles 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 made moot the mobility and survivability argument, and a newer generation of ICBMs, such as the Minuteman III, had the accuracy and speed needed to attack point targets. During this time, ICBMs were seen as a less costly option based on their lower unit cost, but development costs were much higher. Secretary of Defense Robert McNamara preferred ICBMs over bombers for the Air Force portion of the deterrent force and felt a new expensive bomber was not needed. McNamara limited the AMSA program to studies and component development beginning in 1964.
Program studies continued; IBM and Autonetics were awarded AMSA advanced avionics study contracts in 1968. McNamara remained opposed to the program in favor of upgrading the existing B-52 fleet and adding nearly 300 FB-111s for shorter range roles then being filled by the B-58. He again vetoed funding for AMSA aircraft development in 1968.
B-1A program
President Richard Nixon reestablished the AMSA program after taking office, keeping with his administration's flexible response strategy that required a broad range of options short of general nuclear war. Nixon's Secretary of Defense, Melvin Laird, reviewed the programs and decided to lower the numbers of FB-111s, since they lacked the desired range, and recommended that the AMSA design studies be accelerated. In April 1969, the program officially became the B-1A. This was the first entry in the new bomber designation series, created in 1962. The Air Force issued a request for proposals in November 1969.Proposals were submitted by Boeing, General Dynamics and North American Rockwell in January 1970. In June 1970, North American Rockwell was awarded the development contract. The original program called for two test airframes, five flyable aircraft, and 40 engines. This was cut in 1971 to one ground and three flight test aircraft. The company changed its name to Rockwell International and named its aircraft division North American Aircraft Operations in 1973. A fourth prototype, built to production standards, was ordered in the fiscal year 1976 budget. Plans called for 240 B-1As to be built, with initial operational capability set for 1979.
Rockwell's design had features common to the F-111 and XB-70. It used a crew escape capsule, that ejected as a unit to improve crew survivability if the crew had to abandon the aircraft at high speed. Additionally, the design featured large variable-sweep wings in order to provide both more lift during takeoff and landing, and lower drag during a high-speed dash phase. With the wings set to their widest position the aircraft had a much better airfield performance than the B-52, allowing it to operate from a wider variety of bases. Penetration of the Soviet Union's defenses would take place at supersonic speed, crossing them as quickly as possible before entering the more sparsely defended interior of the country where speeds could be reduced again. The large size and fuel capacity of the design would allow the "dash" portion of the flight to be relatively long.
In order to achieve the required Mach 2 performance at high altitudes, the exhaust nozzles and air intake ramps were variable. Initially, it had been expected that a Mach 1.2 performance could be achieved at low altitude, which required that titanium be used in critical areas in the fuselage and wing structure. The low altitude performance requirement was later lowered to Mach 0.85, reducing the amount of titanium and therefore cost. A pair of small vanes mounted near the nose are part of an active vibration damping system that smooths out the otherwise bumpy low-altitude ride. The first three B-1As featured the escape capsule that ejected the cockpit with all four crew members inside. The fourth B-1A was equipped with a conventional ejection seat for each crew member.
The B-1A mockup review occurred in late October 1971; this resulted in 297 requests for alteration to the design due to failures to meet specifications and desired improvements for ease of maintenance and operation. The first B-1A prototype flew on 23 December 1974. As the program continued the per-unit cost continued to rise in part because of high inflation during that period. In 1970, the estimated unit cost was $40 million, and by 1975, this figure had climbed to $70 million.