Rockwell B-1B "Lancer"
Aircraft
Rockwell B-1B "Lancer"
Type
Heavy Bomber
Crew
4
Unit Cost
US$ 283.1 million
Main Operator
United States Air Force
Click here for all pictures of the B-1 currently available

Northrop Grumman B-2 Program Milestones
Maiden Flight
December 23, 1974
Production Start
Late 1970s
Introduction
October 1, 1986
First User
United States Air Force


Rockwell B-1B Aircraft Dimensions
Wing Span Extended
137 feet (41.8 m)
Wing Span Swept
79 feet (24.1 m)
Length
146 feet (44.5 m)
Height
34 feet (10.4 m)
Wing Area
1.950 square feet

Rockwell B-1B Weights
Empty Weight
192,000 lb (87,100 kg)
Loaded
326,000 lb (148,000 kg)
Maximum Take-off Weight
477,000 lb (216,400 kg)

Rockwell B-1B Powerplants
4 x GE F101-GE-102 (Dry)
17,000 lbf
4 x GE F101-GE-102 (AB)
30,780 lbf

Rockwell B-1B Radius & Performance
Range
6,478 nautical miles
Combat Radius
2,993 nautical miles
Service Ceiling
60,000 feet (18 km)
Maximum Speed (Sea Level)
Mach 0.95
Maximum Speed (Altitude)
Mach 1.25
Maximum Rate of Climb
N.A.
Thrust to Weight
0.37
Wing Loading
167 lb/square feet


Number built and status
Total built: 104 / B-1A: 4 / B-1B: 100
Active: 67 / Inactive: 24

Rockwell B-1B Lancer
The Rockwell B-1 has taken a prominent role within the United States Air Force. Although the heavy bomber project seemed like it was headed for extinction in the 1960s, the US Air Force still felt a need for the aircraft, and in the 1970s and 1980s pushed for the development of the B-1 Lancer. In the late 1950s, the US Air Force planned to obtain a large number of Mach 3 North American B-70 aircraft in order to use them as the backbone of their strategic nuclear bombing force. However, improvements to the Sovjet air defense systems and with that the development of US long-range ballistic missiles rendered a high-altitude bomber like the B-70 obsolete. Eventually only two "XB-70s" were completed and were used as high-speed research aircraft.

The Air Force soon began to consider another new bomber as interest still remained. This resulted into many design proposals as studies into a "Subsonic Low Altitude Bomber" started in 1961, studies into an "Extended Range Strike Aircraft" started in 1963, studies into "Advanced Manned Precision Strike System (AMPSS) started in 1964, and finally a study was commenced into an "Advanced Manned Strategic Aircraft (AMSA) in 1965.

Rockwell B-1B Lancer
Rockwell B-1B Lancer
Rockwell B-1B Lancer
Click for a large image
Click for a large image
Click for a large image

Eventually, AMSA led to a request for proposals by the United States Air Force in November 1969. After considering many proposals form Boeing, General Dynamics, and North American Rockwell, the USAF awarded the contract for the B-1 to Rockwell on June 5, 1970. In the meantime, General Electric was awarded a contract on the same day for providing the F101 afterburning turbofan engine that would power the aircraft. Initially the USAF wanted to build two ground-test airframes and five flying prototypes, but the requirement was cut in 1971 to one ground-test airframe and three flying prototypes. Later, a fourth flying prototype was ordered in 1976. In total the United States Air Force wanted to acquire 240 airframes, with the last entering the fleet in 1979.


The Rockwell B-1 flew for the first time on December 23, 1974, followed by the first flight of the third prototype on March 26, 1976. The second prototype had been reserved for ground tests and didn't fly until June 14, 1976. The fourth and last prototype took of for the skies on February 14, 1979. Compared to the previous prototypes, the fourth prototype featured additional test electrics.

Rockwell B-1 Design

The Rockwell B-1B is again a unique aircraft. It is a sleek, dartlike aircraft with "swing wing" capability. Its wings can be extended to full span for take-off, landing, and long-range cruise while in swept back position it allows for high-speed penetration of adversary airspace. Although the swing wing capability does impose a weight penalty, it enables the aircraft to use shorter airstrips. Minimum sweep is 15 degrees and maximum sweep is 67.5 degrees. In order to ensure aerodynamic cleanliness, the junction where the wing sweeps into the wing glove features a so-called seal. The sealing system was derived form that developed for the European swing-wing Panavia Tornado strike fighter, and features an inflatable bag covered with "fingers". Furthermore, the wing has lift-enhancement devices for relatively short take-offs with a full load, including seven-segment full-span leading-edge slats and six-segment trailing-edge Fowler-type flaps. Lateral control is provided by four spoilers on top of each wing which are used for airbraking as well.

The Rockwell B-1 is configured with a conventional tail configuration, with an all-moving horizontal tailplane and a single tailfin. Moreover, the rudder has three sections with the horizontal tailplanes can move in opposite directions to help with lateral control. By turning them to their maximum nose-down position, the horizontal tailplanes act as an airbrake on landings.

The B-1 Lancer is fitted with eight self-sealing fuel tanks, which fill up much of the fuselage and parts of the wing assembly. If necessary, additional fuel tanks can be installed in the weapons bay. All fuel tanks are pressurized with inert nitrogen to reduce fuel explosion hazard. The B-1B's FCGMS (Fuel & Center Of Gravity Management Subsystem) shifts fuel from one tank to another in order to maintain trim when the aircraft changes the sweep of its wings.
Rockwell B-1B Lancer

Just like many other long-range combat aircraft, the B-1B is fitted with a midair refueling socket in the nose, just forward of the wingshield. The position of the socket allows the B-1 bomber's flight crew to keep an eye on the tanker's refueling boom. Moreover, the B-1B is made mostly of aluminum alloys and titanium, with some composite elements. For example, the box supporting the swing wing structure is made entirely of titanium. Furthermore, the aircraft is structurally reinforced in order to withstand the shock of a nuclear blast. The B-1B's fuselage has smooth contours, increasing aerodynamic performance, and uses radar absorbing material (RAM) in order to give it a radar cross section only about one or two percent of that of the B-52, despite the fact that the two different aircraft are roughly the same size.

As said, the B-1B is powered by four General Electric F101-GE-102 afterburning turbofan engines, with each having 17,000 lb of thrust and 30,780 lb of thrust with afterburning. If necessary, the B-1B can fly on only two engines, and can even fly on one if fuel is dumped. Cabin pressurization is distributed throughout the aircraft and is provided by engine bleed. Besides its four engines, the aircraft is fitted with an APU mounted between the engines in each pod, and are used primarily to start the engines and provide ground power. The APUs allow a quick startup of the engines in order to enable it get of the runway very quickly. Switches on the nosewheel gear allow a ground crew man to start the APUs and engines as the crew boards the aircraft. Compared to the B-1A, the B-1B has fixed engine inlets which cuts its speed at high-altitude to Mach 1.25.