Rockwell B-1 Lancer

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The Rockwell (now part of [Vous devez être inscrit et connecté pour voir ce lien]) B-1 Lancer^{[Vous devez être inscrit et connecté pour voir ce lien]} is a four-engine [Vous devez être inscrit et connecté pour voir ce lien] used by the [Vous devez être inscrit et connecté pour voir ce lien] (USAF).

First envisioned in the 1960s as a [Vous devez être inscrit et connecté pour voir ce lien] bomber with sufficient [Vous devez être inscrit et connecté pour voir ce lien] and payload to replace the [Vous devez être inscrit et connecté pour voir ce lien], it developed primarily into a low-level penetrator with long range and supersonic speed capability at high altitude.

Designed by [Vous devez être inscrit et connecté pour voir ce lien], the bomber's development was delayed multiple times over its history, as the theory of strategic balance changed from [Vous devez être inscrit et connecté pour voir ce lien] to [Vous devez être inscrit et connecté pour voir ce lien] and back again.

This change in stance repeatedly demanded then ignored the 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 [Vous devez être inscrit et connecté pour voir ce lien] was promising an aircraft of dramatically improved capability.

Production went ahead as the B-1B would be operational before these "Advanced Technology Bomber" concepts, during a period when the B-52 would be increasingly vulnerable.

It entered service in 1986 with the USAF [Vous devez être inscrit et connecté pour voir ce lien] as a nuclear bomber.

In the 1990s, the B-1B was converted to conventional bombing use.

It first served in combat during [Vous devez être inscrit et connecté pour voir ce lien] in 1998 and again during the [Vous devez être inscrit et connecté pour voir ce lien] the following year.

The B-1B continues to support U.S. and [Vous devez être inscrit et connecté pour voir ce lien] military forces in [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien].

The Lancer is the supersonic component of the USAF's long-range bomber force, along with the subsonic B-52 and [Vous devez être inscrit et connecté pour voir ce lien].

The bomber is commonly called the "Bone" (originally from "B-One"). With the retirement of the [Vous devez être inscrit et connecté pour voir ce lien] in 1998 and the [Vous devez être inscrit et connecté pour voir ce lien] in 2006, the B-1B is the U.S. military's only active variable-sweep wing aircraft.

The B-1B is expected to continue to serve into the 2020s, when it is to be supplemented by the [Vous devez être inscrit et connecté pour voir ce lien].

Development


Background


In December 1957, the U.S. Air Force selected [Vous devez être inscrit et connecté pour voir ce lien]'s proposal to replace the Boeing B-52 Stratofortress with the [Vous devez être inscrit et connecté pour voir ce lien].

The Valkyrie was a six-engine bomber that could reach [Vous devez être inscrit et connecté pour voir ce lien] 3 speeds at high altitude (70,000 feet / 21,000 m) to avoid [Vous devez être inscrit et connecté pour voir ce lien], the only effective anti-bomber weapon in the 1950s.

Soviet interceptors were already unable to intercept the high-flying [Vous devez être inscrit et connecté pour voir ce lien]; and the Valkyrie would fly at similar altitudes and much higher speeds.

By the late 1950s, however, anti-aircraft [Vous devez être inscrit et connecté pour voir ce lien] (SAMs) could threaten high-altitude aircraft, as demonstrated by the [Vous devez être inscrit et connecté pour voir ce lien] of [Vous devez être inscrit et connecté pour voir ce lien]'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 [Vous devez être inscrit et connecté pour voir ce lien].

At that time SAMs were ineffective against low-flying aircraft.

Also during this era, low flying aircraft were difficult to detect by higher flying interceptors since their radar systems could not readily pick out opposing aircraft against the radar clutter from ground reflections.

Planners outlined a series of low-level profiles for the B-70, but higher drag at low level limited the B-70 to subsonic speed while dramatically decreasing its range.

The result would be an aircraft with similar speed but less range than the B-52 it was meant to replace.

Unsuited for this new role and because of a growing [Vous devez être inscrit et connecté pour voir ce lien] (ICBM) force, the B-70 bomber program was canceled in 1961 by President [Vous devez être inscrit et connecté pour voir ce lien], and the two XB-70 prototypes were used in a supersonic research program.

Penetrator concept


The [Vous devez être inscrit et connecté pour voir ce lien], designed to requirements essentially calling for a shorter-range B-70, demonstrated these problems in practice.

Like the B-70, the B-58 had been designed to overfly the Soviet Union at high altitudes and Mach 2 speeds, delivering a single weapon from an external store.

When forced into the low-level role, the aircraft had severely limited range, greatly limiting the selection of targets it could attack. It was also a hugely expensive aircraft to purchase and operate.

In June 1960 the Air Force released SOR 183 calling for a new aircraft dedicated to the low-level role.

This emerged in 1965 as the [Vous devez être inscrit et connecté pour voir ce lien], a smaller and less expensive aircraft than the B-58 which offered roughly equal performance in strategic terms, yet was much more survivable and had considerable multi-purpose capabilities.

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 large airframe with internal room allowed the addition of improved [Vous devez être inscrit et connecté pour voir ce lien] suites.

During the [Vous devez être inscrit et connecté pour voir ce lien] 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 (27,215 kg), turning it into a powerful tactical aircraft as well.

A combination of these features in a penetrator design was an obvious development.

Design studies and delays

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 [Vous devez être inscrit et connecté pour voir ce lien],
something 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 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) bomb load and somewhat shorter range of 7,150 nmi (13,200 km).

These all culminated in the October 1963 Advanced Manned Precision Strike System (AMPSS), which led to industry studies at [Vous devez être inscrit et connecté pour voir ce lien], [Vous devez être inscrit et connecté pour voir ce lien], and [Vous devez être inscrit et connecté pour voir ce lien].

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.

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 [Vous devez être inscrit et connecté pour voir ce lien] 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 [Vous devez être inscrit et connecté pour voir ce lien] concept that included bombers, ICBMs, and [Vous devez être inscrit et connecté pour voir ce lien] (SLBMs) 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 [Vous devez être inscrit et connecté pour voir ce lien]
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 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.

[Vous devez être inscrit et connecté pour voir ce lien] 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; [Vous devez être inscrit et connecté pour voir ce lien] and [Vous devez être inscrit et connecté pour voir ce lien] were awarded AMSA advanced avionics study contracts in 1968.

McNamara remained opposed to the program in favor of upgrading the existing [Vous devez être inscrit et connecté pour voir ce lien] fleet and adding nearly 300 [Vous devez être inscrit et connecté pour voir ce lien] for shorter range roles then being filled by the [Vous devez être inscrit et connecté pour voir ce lien].

He again vetoed funding for AMSA aircraft development in 1968.