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101-Northrop-Grumman-B2-Spirit
The Northrop B-2 Spirit, also known as the Stealth Bomber, is an American heavy penetration strategic bomber, featuring low observable stealth technology designed for penetrating dense anti-aircraft defenses; it is a flying wing design with a crew of two. The bomber can deploy both conventional and thermonuclear weapons, such as eighty 500 lb-class JDAM Global Positioning System-guided bombs, or sixteen 2,400 lb B83 nuclear bombs. The B-2 is the only acknowledged aircraft that can carry large air-to-surface standoff weapons in a stealth configuration.

Maximum speed: 1,010 km/h (627.58 mph) Range: 6,897 mi Maiden flight: 17 Jul 1989 Length: 68.90 ft Wingspan: 171.92 ft Cruising speed: 900 km/h (559.23 mph)
When people think of the word “stealth,” this aircraft comes first to mind. Since making its initial flight in 1989, the Northrop Grumman B-2 has been a game changer for stealth aviation. It is the only acknowledged aircraft that can carry large air-to-surface standoff weapons in a stealth configuration. It was also quite costly to operate, and the U.S Congress was concerned about whether they really needed it with the Cold War ending. The B-2 Spirit was developed with the understanding of taking over the U.S. Air Force’s vital penetration missions. It would effectively travel deep into enemy territory and deploy its ordnance. This could include nuclear weapons, of course.
The mid-1970s brought the need to replace the aging Boeing B-52 Stratofortress. Constantly improving anti-aircraft technology was putting pressure on military developers to come up with new ways for aircraft to avoid detection. Planes like the Lockheed SR-71 “Blackbird”  utilized certain components of stealth technology. The Blackbird in particular used a combination of speed, high altitude and composite materials that absorbed radar. By 1979 “stealth” technology had advanced to the point that development could begin on a true stealth bomber.

Originally a Gray Project, meaning that although it was kept secret from the public, some information on it was available to the government, the B-2’s technologies were kept under wraps. So much so that a Northrop employee was arrested in 1984 when he attempted to leak info on the aircraft’s development to the Soviet Union.
After almost a decade in development, the B-2 was first revealed to the public in 1988. Even then, the viewing was tightly restricted and spectators were not allowed to see the rear of the plane (however Aviation Week editors found a way to take photos of the B-2’s rear platform and engine exhaust anyway.)

One of the most important factors contributing to the B-2’s stealth capabilities is the shape of its body. The “flying wing” design introduced with the YB-49 gives the Spirit a very minimal radar profile and its aerodynamics give it a great range of around 6,900 miles. The plane itself is made largely of radar-absorbent materials which make it virtually impossible to detect.

The B-2’s engines are buried within its wings, minimizing their exhaust signature and concealing the engines’ fans. The bottom of the aircraft is covered in anti-reflective paint which blends into the sky at high altitudes making it invisible to both radar and the naked eye. Originally, the white contrail left by the jet engines was eliminated by an added chemical, but later developments did away with this feature in favor of a sensor which alerts the pilot when to change altitude to avoid leaving a trail.

Although the Northrop YB-49 never entered production, it helped lay the groundwork for the design of the B-2 Spirit. The YB-49 was a jet-powered variant based off of Northrop’s piston-powered XB-35 and YB-35 bombers. Only two YB-49s were ever made, and the project was shelved in favor of the more conventional Corvair B-36.
The flying wing design was revolutionary in that it eliminated the need for a tail and fuselage, opting instead to carry its payload in two very large wings. The design proved to be more aerodynamic than the traditional plane but because of expensive development costs and the need for extensive testing the project was put on the back burner until Northrop resurrected it with the B-2 in the 1980s.

The original plan was to build 132 B-2 Spirits, but after the collapse of the Soviet Union in the early 90s, the primary need for the bombers was greatly reduced to the point that President George H. W. Bush announced that production would be limited to 20 aircraft in 1992.

Three years later Northrop made a proposal to build an additional 20 aircraft at a cost of $566 million each. This raised a lot of controversy over Americans’ tax dollars, as it was exposed that the operation costs of these planes were considerably higher than those of other bombers. All in all, the B-2 program saw a price tag of $2.13 billion for every B-2 Spirit made. It was estimated in 2010 that each of these planes cost $135,000 per flight hour to operate, which is double the cost of the B-52 and B-1.

As of right now, no new plans have been released to directly replace the B-2. Focus remains on upgrades and modifications to the existing aircraft.

This number isn’t all that impressive. In fact, the much larger B-52 bomber can carry up to 70,000 lbs of munitions. What makes the B-2 impressive is the accuracy with which it can deploy its bombs and the fact that it can access guarded territory without being detected.
The U.S. military redefined the B-2’s role after the Soviet Union dissolved. Whereas before it was intended to primarily carry nuclear bombs, it was converted into a multi-role bomber capable of carrying conventional bombs as well.

The B-2 has two rotary launchers capable of releasing “dumb” bombs, which simply fall on the target, as well as precision guided bombs. The bomber is equipped with GPS targeting which allows it to attack its target swiftly and with precision.

Since the B-2 was so complex and required such attention to detail to ensure its stealth characteristics, the use of early computer technologies was instrumental in the aircraft’s design and manufacturing process. While the plane’s shape had many advantages, one particular disadvantage was in the stability department. Without a tail or fuselage, the B-2 lacked the backbone to keep it stable during rough weather, which limited its in-flight capabilities. The lack of adequate design technology is one reason why it took so long for the flying wing design to be properly utilized by the U.S. Air Force.

There’s a lot of controversy surrounding the United States military’s fleet of bombers, most of which are getting shockingly long in the tooth. The current fleet contains 160 heavy bombers, including six B-52 Stratofortresses (last made in 1962), 63 B-1 Lancers (last made in 1988), and 20 B-2 Spirits (last made in 1993). That’s an average age of 33 years per plane.

To make matters worse, the Air Force plans to keep on using their B-1s and B-52s until 2040 and the B-2s until 2060. There is already worry that these aircraft are quickly becoming (or have long been) technologically obsolete with regard to other countries’ military weapons. Their vulnerability to attack only increases with their age, and the U.S. appears to have no replacements on the horizon.

Although it was never used in the function it was designed for (dropping nuclear bombs during the Cold War), the B-2 entered action for the first time in 1999, dropping conventional munitions in the Kosovo War. It was responsible for 33% of the targets destroyed and its GPS targeting system proved highly effective compared to the carpet bombing techniques used previously by other bombers. B-2s have since dropped bombs during missions in Afghanistan, Iraq and Libya.

While maintenance and operating costs have proven to be astronomically high for the planes, they are efficient when it comes to the crew members needed to fly them. The B-2 is highly automated and requires only two crew members to operate it in flight (the B1-B requires four and the B-52 requires five.) The B-2’s crew includes a pilot (left seat) and a mission commander (right seat) and has place for a third crew member should the need arise.

Extensive research was done on pilot fatigue and sleep cycles for the B-2’s operation, and it’s one of very few two-seat aircraft that allows one member to sleep, prepare meals or use the washroom while the other flies the plane.       
(Courtesy: Robert Flis 05.13.15 Most Influential )
General characteristics
Crew: 2: pilot (left seat) and mission commander (right seat)
Length: 69 ft (21.0 m)
Wingspan: 172 ft (52.4 m)
Height: 17 ft (5.18 m)
Wing area: 5,140 ft² (478 m²)
Empty weight: 158,000 lb (71,700 kg)
Loaded weight: 336,500 lb (152,200 kg)
Max. takeoff weight: 376,000 lb (170,600 kg)
Fuel Capacity: 167,000 pounds (75,750 kg)
Powerplant: 4 × General Electric F118-GE-100 non-afterburning turbofans, 17,300 lbf (77 kN) each

Performance
Maximum speed: Mach 0.95 (550 knots, 630 mph, 1,010 km/h) at 40,000 ft altitude / Mach 0.95 at sea level
Cruise speed: Mach 0.85 (487 knots, 560 mph, 900 km/h) at 40,000 ft altitude
Range: 6,000 nmi (11,100 km (6,900 mi))
Service ceiling: 50,000 ft (15,200 m)
Wing loading: 67.3 lb/ft² (329 kg/m²)
Thrust/weight: 0.205

Armament
2 internal bays for ordnance and payload with an official limit of 40,000 lb (18,000 kg); maximum estimated limit is 50,000 lb (23,000 kg).
80× 500 lb class bombs (Mk-82, GBU-38) mounted on Bomb Rack Assembly (BRA)
36× 750 lb CBU class bombs on BRA
16× 2,000 lb class bombs (Mk-84, GBU-31) mounted on Rotary Launcher Assembly (RLA)
16× B61 or B83 nuclear bombs on RLA (strategic mission)
Standoff weapon: AGM-154 Joint Standoff Weapon (JSOW) and AGM-158 Joint Air-to-Surface Standoff Missile (JASSM)
Role:Strategic stealth bomber
National origin: United States
Manufacturer: Northrop Corporation
                         Northrop Grumman
First flight: 17 July 1989
Introduction: April 1997
Status: In service
Primary user: United States Air Force
Produced: 1987-2000
Number built: 21
Program cost: US$44.75 billion (through 2004)
Unit cost: $737 million (1997 approx. flyaway cost)
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