Background of The B-1 Lancer
The B-1B is a modified B-1A with major revisions in offensive avionics, defensive
avionics, weapon payload, range, and speed. These modifications were made to incorporate certain technological advances that had occurred between the original B-lA contract award in 1970 and the LRCA competition in 1980. Improvements consist primarily of off-the-shelf technology such as a new radar, new generation computers, expanded ECM capabilities, reduced RCS, and avionics compatibility with the ALCM. The wing sweep is restricted to 60 which limits the maximum speed to just above supersonic. Rockwell also estimated range increases for the modified B-1.
Prior to 1994 B-1B fleet had never achieved its objective of having a
75-percent mission capable rate. In 1992 and 1993 the B-1B mission capable rate averaged about 57 percent. According to the Air Force, a primary reason for the low mission capable rate was the level of funding provided to support the B-1B logistics support system. Concerned about the low mission capable rate, a history of B-1B problems, and the Air Force's plans to spend
$2.4 billion modifying the B-1B to become a conventional bomber, the
Congress directed the Air Force to conduct an Operational Readiness Assessment (ORA) from
June 1, 1994, through November 30, 1994. The purpose of the ORA was to determine whether one B-1B wing was capable of achieving and maintaining its planned 75-percent operational readiness rate for a period of 6 months, if provided the full complement of spare parts, maintenance equipment and manpower, and logistic support equipment. During the ORA the test unit achieved an 84.3-percent mission capable rate during the test period. The ORA demonstrated that, given a full complement of spare parts, equipment, and manpower, the Air Force could achieve and sustain a 75-percent mission capable rate for the B-1B. The Air Force projects that the entire B-1B fleet will reach a 75-percent mission capable rate by 2000 by virtue of numerous on-going and future reliability, maintainability, and management initiatives.
However, as of mid-October 1999 the Air Force wide mission capable rate of the B-1 had fallen to 51.1 percent -- mainly because of maintenance problems and a shortage of parts. Over the previous 12 months, the Kansas Guard had maintained a mission capable rate of 71.1 percent for the 10 usable aircraft assigned to it.
The basis for the projection of useful life of the B-1 is the Aircraft Structural Integrity Program (ASIP). The useful life of the structure is assumed to be the point at which it is more economical to replace the aircraft than to continue structural modifications and repairs necessary to perform the mission. The limiting factor for B-1’s service life is the wing lower surface. At 15,200 hours, based on continued low level usage, the wing’s lower skin will need replacement. Current usage rates, operational procedures, and mishap attrition will place the inventory below the requirement of 89 aircraft in 2018, while the service life attrition will impact around 2038.
On 26 March 1996 it was announced that the 77th Bomb Squadron would return to Ellsworth.
On 1 April 97, the squadron again activated at Ellsworth as the geographically
separated 34th Bomb Squadron completed its transfer to its home at the 366th Wing,
Mountain Home AFB, Idaho. By June 1998, the 77th had six of its B-1Bs out of
the reconstitution reserve. This number ballanced those lost by the 34th BS.
Mission
The B-1B is a long-range strategic bomber, capable of flying intercontinental missions without refueling, then penetrating present and future sophisticated enemy defenses. It can perform a variety of missions, including that of a conventional weapons carrier for theater operations.
The swing-wing design and turbofan engines not only provide greater range and high speed at low levels but they also enhance the bomber's survivability. Wing sweep at the full-forward position allows a short takeoff roll and a fast base-escape profile for airfields under attack. Once airborne, the wings are positioned for maximum cruise distance or high-speed penetration.
The B-1B uses radar and inertial navigation equipment enabling aircrews to globally navigate, update mission profiles and target coordinates in-flight, and precision bomb without the need for ground-based navigation aids. Included in the B-1B offensive avionics are modular electronics that allow maintenance personnel to precisely identify technical difficulties and replace avionics components in a fast, efficient manner on the ground.
The aircraft's defensive avionics is a comprehensive electronic counter-measures package that detects and counters enemy radar threats. It also has the capability to detect and counter missiles attacking from the rear. It defends the aircraft by applying the appropriate counter-measures, such as electronic jamming from the ALE-50 towed decons, or dispensing expendable chaff and flares. Similar to the offensive avionics, the defensive suite has a re-programmable design that allows in-flight changes to be made to counter new or changing threats.
Numerous sustainment and upgrade modifications are ongoing or under study for the B-1B aircraft. Large portions of these modifications that are designed to increase the combat capability are known as the conventional mission upgrade program. This program, with its four blocks, will increase the lethality, survivability and supportability of the B-1B fleet.
Specifications |
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Primary Function: | Long-range, multi-role, heavy bomber |
Builder: | Rockwell International, North American Aircraft |
Operations Air Frame and Integration: | Offensive avionics, Boeing Military Airplane; defensive avionics, AIL Division |
Power Plant: | Four General Electric F-101-GE-102 turbofan engine with afterburner |
Thrust: | 30,000-plus pounds (13,500-plus kilograms) with afterburner, per engine |
Length: | 146 feet (44.5 meters) |
Wingspan: | 137 feet (41.8 meters) extended forward, 79 feet (24.1 meters) swept aft |
Height: | 34 feet (10.4 meters) |
Weight: | Empty, approximately 190,000 pounds (86,183 kilograms) |
Maximum Takeoff Weight: | 477,000 pounds (214,650 kilograms) |
Speed: | 900-plus mph (Mach 1.2 at sea level) |
Range: | Intercontinental, unrefueled |
Ceiling: | Over 30,000 feet (9,000 meters) |
Crew: | Four (aircraft commander, pilot, offensive systems officer and defensive systems officer) |
Armament: | Up to 84 Mark 82 conventional 500-pound bombs and 30 CBU-87/89/97. Also can be reconfigured to carry a wide range of nuclear weapons |
Date Deployed: | June 1985 |
Unit Cost: | $200-plus million per aircraft |
Inventory: | Active force, 50 (PAA) 84 (actual); ANG, 10 PAA (11 actual); Reserve , 0 |