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Rockwell 1:144 B-1 Lancer

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Rockwell 1:144 B-1 Lancer

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Rockwell 1:144 B-1 Lancer

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Development

 

In 1955 the U.S. Air Force issued requirements for a new bomber combining the payload and range of the Boeing B-52 Strat fortress 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,[7] as demonstrated by the 1960 downing of Gary Powers's U-2. 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; 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.[9] Even at somewhat higher altitudes, radar systems of the era were subject to "clutter (radar)" 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 flying around 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 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 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.

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. Similar aircraft also emerged for other users as well, notably the BAC TSR-2, and later, Panavia Tornado and Sukhoi Su-24. 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 (SLAB), 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 (ERSA), which added a variable-sweep wing planform, then in vogue in the aviation industry. ERSA envisioned a relatively small aircraft with a 10,000 pounds (4,500 kg) payload and a range of 8,750 nautical miles (16,200 kilometres), with 2,500 mi. (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 pounds (9,100 kg) bomb load and somewhat shorter range of 7,150 mi. (13,240 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, similar to that of the existing Mach 2 class Convair B-58 Hustler. 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 of any sort. 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 defence. 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 and survivability argument, and a newer generation of ICBMs (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 Defence Robert McNamara preferred ICBMs over bombers for the Air Force portion of the deterrent force[25] 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-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. 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, the introduction of the SA-10 missile, the MiG-31 interceptor and the first Soviet Airborne Early Warning and Control (AWACS) systems would make the B-52 increasingly vulnerable. During 1981, funds were allocated to a new study for a bomber for the 1990s time-frame, this led to the Long-Range Combat Aircraft (LRCA) project. The LRCA evaluated the B-1, F-111 and ATB as possible solutions; an emphasis was placed on multi-role capabilities, as opposed to purely strategic operations.

In 1981, it was believed the B-1 could be in operation before the ATB, covering the transitionary period between the B-52's increasing vulnerability and the ATB's introduction. Reagan decided the best solution was to procure both the B-1 and ATB, and on 2 October 1981 Reagan announced that 100 B-1s were to be ordered to fill the LRCA role.

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 make it better suited to the now expected missions, resulting in the new B-1B. These changes included a reduction in maximum speed, which allowed the variable-aspect intake ramps to be replaced by simpler fixed geometry intake ramps in the newer design. This reduced the B version's radar signature; the reduction in radar cross-section was seen as a good trade off for the speed decrease. High subsonic speeds at low altitude became a focus area for the revised design, and low-level speeds were increased from about Mach 0.85 to 0.92. The B-1B has a maximum speed of Mach 1.25 at higher altitudes.

The B-1B's maximum take-off weight was increased to 477,000 pounds (216,000 kg) from the B-1A's 395,000 pounds (179,000 kg). The weight increase was to allow for take-off with a full internal fuel load and for external weapons to be carried. Rockwell engineers were able to reinforce critical areas and lighten non-critical areas of the airframe, so the increase in empty weight was minimal. In order to deal with the introduction of the MiG-31 and other aircraft with look-down capability (which reduced the B-1s low-flying advantage), the B-1B's electronic warfare suite was significantly upgraded.

Opposition to the plan was widespread within Congress. Critics pointed out that many of the original problems remained in both areas of performance and expense. 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 favour of the B-1 was its large conventional weapon payload, and that its take-off 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.

B-1A #1 was disassembled and used for radar testing at the Rome Air Development Centre at the former Griffiss Air Force Base, New York. B-1As #2 and #4 were modified to include B-1B systems. The first B-1B was completed and began flight testing in March 1983. The first production B-1B was rolled out on 4 September 1984 and first flew on 18 October 1984. The 100th and final B-1B was delivered on 2 May 1988; before the last B-1B was delivered, the air force had determined that the aircraft was vulnerable to Soviet air defences.

 

Design

 

Overview

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 take-off, 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 take-off 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.

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.

 

Avionics

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.[80] 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.

 

Operational history

 

Strategic Air Command

The second B-1B, "The Star of Abilene", was the first B-1B delivered to the USAF Strategic Air Command (SAC) in June 1985. Initial operational capability was reached on 1 October 1986 and the B-1B was placed on nuclear alert status. The B-1 received the official name "Lancer" on 15 March 1990. However, the bomber has been commonly called the "Bone"; a nickname that appears to stem from an early newspaper article on the aircraft wherein its name was phonetically spelled out as "B-ONE" with the hyphen inadvertently omitted.

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. Following inspections and repairs they were returned to duty beginning on 6 February 1991. Due to the engine problems, the B-1B was effectively sidelined in the Gulf War.

Originally designed strictly for nuclear war, the B-1's development as an effective conventional bomber was delayed until the 1990s. The collapse of the Soviet Union had brought the B-1's nuclear role into question, leading to President George H. W. Bush ordering a $3 billion conventional refit. By 1991, the B-1 had a fledgling conventional capability, forty of them able to drop the 500 pounds (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.[114] B-1s were primarily reserved for strategic nuclear strike missions at this time, providing the role of airborne nuclear deterrent against the Soviet Union. The B-52 was more suited to the role of conventional warfare and it was used by coalition forces instead.

After the inactivation of Strategic Air Command (SAC) and the establishment of the Air Combat Command (ACC) in 1992, the B-1 developed a greater conventional weapons capability. Part of this development was the start-up of the U.S. Air Force Weapons School B-1 Division. 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; its nuclear capability was disabled by 1995 with the removal of nuclear arming and fuzzing hardware.

Additional Information

Show on Homepage Diecast
Diecast Toy Manufacturer Dragon Wings
Manufacturer No
Country United States
Scale 1:144
Type Jet Aircraft
Series No
Color Multi-Colored