B-2 Spirit :Specification

MANUFACTURER:Northrop Grumman Vought (former LTV) (subcontractor) Boeing Advanced Systems (subcontractor)
CREW: 2 (pilot, weapons systems officer)
ENGINES: 4 General Electric F118-GE-100 turbofan
Max power: 19,000 Ib (8,618 kg) static thrust each.

WEIGHTS:
Empty weight: approx 158,000 Ib
(71,668kg)
Max takeoff: 240,000-376,000 Ib
(108,862-170,551 kg)
Maxpayload: 50,000 Ib (22,680 kg)internal

DIMENSIONS:
Wingspan:172 ft (52.42 m)
Length:69ft (21.03m)
Height:17 ft (5.18 m)
Wing area:more than 5,000 ft2
(464.5 m2)speed Mach 0.85

PERFORMANCE:
Operational ceiling:approx 50,000 ft (15,240 m) with weapons load
range (w /weapons)
High altitude: 6,600 nm(7,600 mi; 12,230 km)hi-lo-hi: 4,500 nm (5,182
mi; 8,339 km)hi-lo-hi (optimized):
5,400 nm (6,218 mi;10,006 km)
Armament: 2 internal weapons bays
for up to:16 B83 gravity bombs,
AGM-69A SRAM orAGM-131 SRAM II cruise missiles or 20 smaller nuclear weapons (e.g., B61
gravity bombs) wupto80500-lb (227-kg) bombs or sea mines
Radar: Hughes APQ-181
multimode

B-2 Spirit:Overview

The Advanced Technology Bomber (ATB) is popularly called the Stealth bomber but its official name is B-2 Spirit. Although not operational, this controversial batlike aircraft has flown test missions. The combination of its performance problems, the end of the cold war with the collapse of the Soviet Union, and the high cost of the plane may preclude the B-2 Spirit from joining the active US Air Force.

B-2 Spirit :Characteristics

The B-2 Spirit was designed to complement the B-1 B. It is designed to present the lowest possible visual, radar, acoustic, and infrared signatures. Its original mission was to attack mobile ICBMs and hardened command-and-control installations. After the loss of a structured nuclear threat, the aircraft's mission was redefined to emphasize long-range conventional strike missions.

The B-2 Spirit achieves "invisibility" to radar and infrared sensors for as long as possible by reducing the aircraft's Radar Cross Section (RCS) and decreasing engine exhaust gas temperatures; it also is claimed to be 50% more aerodynamically efficient than the B-l.

The B-2's general design resembles earlier Northrop flying wings (the YB-35 and YB-49 of the 1940s), a configuration that has the smallest head-on and side-view RCS. A further reduction in RCS is attained by using surface skins made of a composite, ferrite-based carbon-fiber honeycomb Radar Absorbent Structure (RAS) over titanium main structural members.

The wing carry-through section was modified in 1984 from single front and rear spars to narrow torque boxes to enable the aircraft to better withstand lowlevel flight and to reduce the wing's weight. The wing is quite rigid, showing only Viath the deflection that the B-52 shows at high load.

The wing's leading edges are swept at approximately 40° to tips that are raked back toward the centerline to decrease the flying wing's tendency to yaw while rolling. The wing's sawtooth trailing edge is unique, designed to cope with a flying wing's natural instability even as it helps to reduce RCS and exhaust heat signature.

At approximately midspan (moving toward the fuselage), the trailing edges turn and head aft to a point just outboard of the engine installations on each side. The two control surfaces are elevens that can also be used as flaps. At this point, the trailing edges again turn almost 90°, heading forward to a point directly aft of the center of the unusual engine exhausts. Finally, the two halves of the flying wing's trailing edge turn aft and meet in a movable fuselage "beavertail," which operates with the elevens for gust alleviation. The hydraulic actuators are the fastaction type and are supported by a 4,000- psi (281.2-kg/cm2) system.

When seen from ahead, the fuselage is thickest through the center, with the cross section tapering out to the outer panels. Over the center section are two low engine intakes, one on each side of a shallow, rounded cockpit section that has large window panels. The windshield is designed to be a load-bearing structure and has an integral metal mesh designed to prevent strong returns from the glazing or emission leakage from flight deck instruments or systems.

The two four-wheel, main-landing-gear bogies retract inward while the wheels are stowed close to the centerline. The two wheel nose gear retracts to the rear. The aircraft is able to use any runway that will support a Boeing 727 jet transport. Each engine intake feeds two of the four GE nonafterburning turbofan engines that are in the wing. Each engine intake has two rear-hinged auxiliary inlet doors that face forward and are angled off the centerline. These doors are open at low speeds to provide sufficient airflow to the engines. In October 1990, Northrop was contracted to convert the B-2's fuel system from JP-4 fuel, which requires pressurization, to JP-8, which has a higher flash point.

The two-man cockpit has control sticks linked to a computer-controlled, quadruple- redundant Stability Augmentation System (SAS) produced by General Electric. Honeywell is developing the Radar Altimeter Set (RAS) and GEC Avionics (formerly Kearfott) is responsible for the advanced Inertial Navigation System (INS). The aircraft has two flat-plate antennas for the Hughes AN/APQ-181 multimode phased-array radar. Multifunction Displays (MFD) provide instrumentation, navigation, and attack information.

Nuclear weapons such as gravity bombs and Short-Range Attack Missiles (SRAM) are carried in side-by-side internal weapons bays. Up to 16 B83 gravity bombs, AGM-69A SRAM or AGM-131 SRAM II cruise missiles, or 20 smaller nuclear weapons could be stowed; alternative loads include up to 80 conventional 500-lb (227-kg) bombs or sea mines.

B-2 Spirit :Development

The B-2 Spirit first flight had originally been planned for late 1987, but a $1- billion design modification to permit low-level flight delayed the program. After high- and low-speed taxi tests, the first flight took place on July 17, 1989, at Edwards AFB, California. First flight of the second aircraft came on October 19, 1990; this aircraft (AV-2) is the only one of the six test aircraft not to be refitted as an operational bomber.

The planned total number of aircraft has been reduced first from 132 to 75 aircraft and then to 20. The initial operational capability is currently planned for the mid-1990s. When the 20 B-2 bombers are properly equipped near the turn of the century, they could drop 160 tons of bombs a day in a war area, compared to the 146 tons/day dropped by 20 B-52 bombers in Operations Desert Shield/ Desert Storm.

B-2 Spirit :Combat Experience

The B-2 Spirit was derided by many as being too expensive to risk in combat. However, the aircraft has seen service in three separate campaigns. Its debut was during the Kosovo War in 1999. The B-2 Spirit first introduced the satellite guided JDAM in combat use. Since then, the aircraft has operated over Afghanistan in Operation Enduring Freedom and Iraq in Operation Iraqi Freedom. The raids on Afghanistan saw a first for the aircraft. After flying bombing missions over Afghanistan, the aircraft landed at Diego Garcia, were refueled and had a crew change before another sortie. This was taken a step further during the Iraq campaign when B-2's were based at Diego Garcia. Later missions to Iraq came from Whiteman AFB in Missouri. This resulted in missions lasting over 30 hours and one mission of over 50 hours. The B-2 is highly automated, and unlike single-seat fighters, one crewmember can sleep, use a flush toilet or prepare a hot meal while the other monitors the aircraft. The Pentagon's Operational Test and Evaluation 2003 Annual Report noted that the B-2's serviceability for FY03 was still inadequate, mainly due to maintenance on the B-2's Low Observable materials, the Evaluation also noted that the Defensive Avionics suite also had shortcomings in warning of pop-up threats. Despite these problems the B-2 Spirit was declared to be in full operational capability in December of 2003. The B-2 Spirit maintained high serviceability for Operation Iraqi Freedom, dropping 583 JDAMs during the war.