Northrop Grumman B-2 Spirit Bomber Aircraft
The Northrop Grumman B-2 Spirit (also known as the Stealth Bomber) is an American strategic bomber, featuring low observable stealth technology designed for penetrating dense anti-aircraft defenses; it is able to deploy both conventional and nuclear weapons. The bomber has a crew of two and can drop up to eighty 500 lb (230 kg)-class JDAM GPS-guided bombs, or sixteen 2,400 lb (1,100 kg) B83 nuclear bombs. The B-2 is the only aircraft that can carry large air to surface standoff weapons in a stealth configuration. Though originally designed primarily as a nuclear bomber, the B-2 was first used in combat to drop conventional bombs on Serbia during the Kosovo War in 1999, and saw continued use during the wars in Iraq and Afghanistan. B-2s were also used during the 2011 Libyan civil war.
The B-2's low-observable, or "stealth", characteristics give it the ability to penetrate an enemy's most sophisticated anti-aircraft defenses to attack its most heavily defended targets. The bomber's stealth comes from a combination of reduced acoustic, infrared, visual and radar signatures, making it difficult for opposition defenses to detect, track and engage the aircraft. Many specific aspects of the low-observability process remain classified. The B-2's composite materials, special coatings and flying wing design, which reduces the number of leading edges, contribute to its stealth characteristics. The Spirit has a radar signature of about 0.1 m2. Each B-2 requires a climate-controlled hangar large enough for its 172-foot (52 m) wingspan to protect the operational integrity of its sophisticated radar absorbent material and coatings. The engines are buried within the wing to conceal the engines' fans and hide their exhaust.
The blending of low-observable technologies with high aerodynamic efficiency and large payload gives the B-2 significant advantages over previous bombers. The U.S. Air Force reports its range as approximately 6,000 nautical miles (6,900 mi; 11,000 km). Also, its low-observation ability provides the B-2 greater freedom of action at high altitudes, thus increasing its range and providing a better field of view for the aircraft's sensors. It combines GPS Aided Targeting System (GATS) with GPS-aided bombs such as Joint Direct Attack Munition (JDAM). This uses its passive electronically scanned array APQ-181 radar to correct GPS errors of targets and gain much better than laser-guided weapon accuracy when "unguided" gravity bombs are equipped with a GPS-aided "smart" guidance tail kit. It can bomb 16 targets in a single pass when equipped with 1,000 or 2,000-pound (450 kg or 900 kg) bombs, or as many as 80 when carrying 500 lb (230 kg) bombs.
The B-2 has a crew of two: a pilot in the left seat, and mission commander in the right. The B-2 has provisions for a third crew member if needed. For comparison, the B-1B has a crew of four and the B-52 has a crew of five. B-2 crews have been used to pioneer sleep cycle research to improve crew performance on long sorties. The B-2 is highly automated, and, unlike two-seat fighters, one crew member can sleep, use a toilet or prepare a hot meal while the other monitors the aircraft.
The prime contractor, responsible for overall system design, integration and support, is Northrop Grumman. Boeing, Raytheon (formerly Hughes Aircraft), G.E. and Vought Aircraft Industries, are subcontractors.
The original B-2 design had tanks for a contrail-inhibiting chemical, but this was replaced in the final design with a contrail sensor from Ophir that alerts the pilot when he should change altitude. Mission planning also considers altitudes where the probability of contrail formation is minimized.