An Infrared Search and Track ( IRST ) system (sometimes known as infrared sighting and tracking ) is a method for detecting and tracking objects which give off infrared radiation , such as the infrared signatures of jet aircraft and helicopters .
137-477: The Northrop B-2 Spirit , also known as the Stealth Bomber , is an American heavy strategic bomber , featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses . A subsonic flying wing with a crew of two, the plane was designed by Northrop (later Northrop Grumman ) as the prime contractor, with Boeing , Hughes , and Vought as principal subcontractors, and
274-618: A pulse-Doppler radar also eliminated the AAA-4 IRST receiver and bulge under the nose. The first use of IRST in an Eurasian country was the Mikoyan-Gurevich MiG-23 , which used the (TP-23ML) IRST; later versions used the (26SH1) IRST. The Mikoyan-Gurevich MiG-25 PD was also equipped with a small IRST under the nose. The Swedish Saab J-35F2 Draken (1965) also used an IRST, a Hughes Aircraft Company N71. IRST systems re-appeared on more modern designs starting in
411-690: A $ 2 billion, 10-year-long modernization of the B-2 fleet was to begin. The main area of improvement would be replacement of outdated avionics and equipment. Continued modernization efforts likely have continued in secret, as alluded to by a B-2 commander from Whiteman Air Force Base in April 2021, possibly indicating offensive weapons capability against threatening air defenses and aircraft. He stated: without getting into specifics, and without getting into things that we frankly just don't discuss in open channels, I will tell you that our current bomber fleet, and this
548-403: A $ 5 million specialised air-conditioned hangar to maintain its stealth coating. Every seven years, this coating is carefully washed away with crystallised wheat starch so that the B-2's surfaces can be inspected for any dents or scratches. The B-2's clean, low-drag flying wing configuration not only provides exceptional range but is also beneficial to reducing its radar profile. Reportedly,
685-461: A Texas Instruments AAA-4 infrared seeker under the nose of early production aircraft F-4Bs and F-4Cs. It was not not installed on later F-4Ds due to limited capabilities, but retained the bulge and indeed some F-4Ds had the IRST receiver retrofitted in a modified form. The F-4E eliminated the AAA-4 IRST bulge and received an internal gun mount which took up the area under the nose. The F-4J which had
822-585: A US$ 468 million contract to Northrop Grumman to modernize the B-2 fleet's radars. Changing the radar's frequency was required as the United States Department of Commerce had sold that radio spectrum to another operator. In July 2009, it was reported that the B-2 had successfully passed a major USAF audit. In 2010, it was made public that the Air Force Research Laboratory had developed a new material to be used on
959-409: A combination of reduced acoustic , infrared , visual and radar signatures ( multi-spectral camouflage ) to evade the various detection systems that could be used to detect and be used to direct attacks against an aircraft. The B-2's stealth enables the reduction of supporting aircraft that are required to provide air cover, Suppression of Enemy Air Defenses and electronic countermeasures , making
1096-547: A cost of nearly $ 500 million (~$ 897 million in 2023). In 1995, Northrop made a proposal to the USAF to build 20 additional aircraft with a flyaway cost of $ 566 million each. The program was the subject of public controversy for its cost to American taxpayers. In 1996, the GAO disclosed that the USAF's B-2 bombers "will be, by far, the costliest bombers to operate on a per aircraft basis", costing over three times as much as
1233-590: A few landed safely at RAF bases in Cyprus and some in Turkey, where they were interned. Only 33 were undamaged. Damage to the refineries was soon repaired and oil production actually increased. By October 1942, a new Ford Motor Company plant at Willow Run Michigan was assembling Liberators. Production reached a rate of over one an hour in 1944 helping the B-24 to become the most produced US aircraft of all time. It became
1370-411: A long-time opponent of the bomber, cited five independent studies and offered an amendment to that year's defense authorization bill to cap production of the bombers to the existing 21 aircraft; the amendment was narrowly defeated. Nonetheless, Congress did not approve funding for additional B-2s. Several upgrade packages have been applied to the B-2. In July 2008, the B-2's onboard computing architecture
1507-451: A lot of life left in this platform and up until the B-21 as well on the scene and doing its job, this aircraft will continue to be at the forefront of our country and our nation's defense... and with these, and continued innovative upgrades, and weapons system capabilities we will continue to do that until the last jet flies off the ramp into retirement. It was reported in 2011 that The Pentagon
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#17327837755571644-691: A lot to Sikorsky's ideas; of similar size, it used just two Rolls-Royce Eagle engines and could carry up to 2,000 lb (910 kg) of bombs. The O/100 was designed at the beginning of the war for the Royal Navy specifically to sink the German High Seas Fleet in Kiel: the Navy called for “a bloody paralyser of an aircraft” Entering service in late 1916 and based near Dunkirk in France, it
1781-553: A primary school, and injured 432 in East London. Initially, defence against air attack was poor, but by May 19, 1918, when 38 Gothas attacked London, six were shot down and another crashed on landing. German aircraft companies also built a number of giant bombers, collectively known as the Riesenflugzeug . Most were produced in very small numbers from 1917 onwards and several never entered service. The most numerous were
1918-467: A special branch of the USAF. A former Ford automobile assembly plant in Pico Rivera, California , was acquired and heavily rebuilt; the plant's employees were sworn to secrecy. To avoid suspicion, components were typically purchased through front companies , military officials would visit out of uniform, and staff members were routinely subjected to polygraph examinations. Nearly all information on
2055-515: A squadron of 10 was bombing German positions on the Eastern Front and by summer 1916 there were twenty. It was well-armed with nine machine guns, including a tail gun and initially was immune to German and Austro-Hungarian air attack. The Sikorsky bomber had a wingspan just a few feet shorter than that of a World War II Avro Lancaster , while being able to carry a bomb load of only 3% of the later aircraft. The Handley Page Type O /100 owed
2192-484: A surprise attack. An IRST system may also have a regular magnified optical sight slaved to it, to help the IRST-equipped aircraft identify the target at long range. As opposed to an ordinary forward looking infrared system, an IRST system will actually scan the space around the aircraft similarly to the way in which mechanically (or even electronically) steered radars work. The exception to the scanning technique
2329-490: A switch to conventional warfare missions. One system is the low probability of intercept AN/APQ-181 multi-mode radar, a fully digital navigation system that is integrated with terrain-following radar and Global Positioning System (GPS) guidance, NAS-26 astro-inertial navigation system (first such system tested on the Northrop SM-62 Snark cruise missile) and a Defensive Management System (DMS) to inform
2466-515: 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. The B-2 is highly automated, and one crew member can sleep in a camp bed , use a toilet, or prepare a hot meal while the other monitors the aircraft, unlike most two-seat aircraft. Extensive sleep cycle and fatigue research was conducted to improve crew performance on long sorties. Advanced training
2603-466: A war. This was certainly vindicated by the firebombing of Japanese cities and the two atomic bombs dropped on Hiroshima and Nagasaki in August 1945, as Japan's fragile housing and cottage industry made themselves easily vulnerable to attack, thus completely destroying Japanese industrial production (see Air Raids on Japan ). It was less evident that it held true for the bombing of Germany. During
2740-483: Is a flying wing aircraft, meaning that it has no fuselage or tail. It has significant advantages over previous bombers due to its blend of low-observable technologies with high aerodynamic efficiency and a large payload. Low observability provides greater freedom of action at high altitudes, thus increasing both range and field of view for onboard sensors. The USAF reports its range as approximately 6,000 nautical miles (6,900 mi; 11,000 km). At cruising altitude,
2877-488: Is all of them, we use some pretty innovative ways to integrate modern weapons capabilities to have us both maintain and increase our survivability. And for the B-2 specifically, the expansion of some of our strike capabilities allow us to increase our survivability beyond the fighter escort realm. Now the B-2 fleet is continuing to do that technological advancement, and that's enabled us to expand our strike capabilities, as well. Although we've been around for over 30 years there's
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#17327837755573014-414: Is assumed to share the similar design concept with their system. IRST systems can also be used to detect stealth aircraft, in some cases, outperforming traditional radar. These were fairly simple systems consisting of an infra-red sensor with a horizontally rotating shutter in front of it. The shutter was slaved to a display under the main interception radar display in the cockpit. Any IR light falling on
3151-624: Is capable of carrying 40,000 lb (18,000 kg) of ordnance. Nuclear ordnance includes the B61 and B83 nuclear bombs ; the AGM-129 ACM cruise missile was also intended for use on the B-2 platform. In light of the dissolution of the Soviet Union, it was decided to equip the B-2 for conventional precision attacks as well as for the strategic role of nuclear-strike. The B-2 features a sophisticated GPS-Aided Targeting System (GATS) that uses
3288-552: Is conducted at the USAF Weapons School . In the envisaged Cold War scenario, the B-2 was to perform deep-penetrating nuclear strike missions, making use of its stealthy capabilities to avoid detection and interception throughout the missions. There are two internal bomb bays in which munitions are stored either on a rotary launcher or two bomb-racks; the carriage of the weapons loadouts internally results in less radar visibility than external mounting of munitions. The B-2
3425-637: Is linked with the majority of avionics on the B-2 to continuously monitor the performance and status of thousands of components and consumables; it also provides post-mission servicing instructions for ground crews. In 2008, many of the 136 standalone distributed computers on board the B-2, including the primary flight management computer, were being replaced by a single integrated system. The avionics are controlled by 13 EMP -resistant MIL-STD-1750A computers, which are interconnected through 26 MIL-STD-1553 B- busses ; other system elements are connected via optical fiber . In addition to periodic software upgrades and
3562-453: Is the F-35's DAS, which stares in all directions simultaneously, and automatically detects and declares aircraft and missiles in all directions, without a limit to the number of targets simultaneously tracked. When they find one or more potential targets they will alert the pilot(s) and display the location of each target relative to the aircraft on a screen, much like a radar. Again similarly to
3699-567: The AGM-158 JASSM cruise missile is an upcoming standoff munition to be deployed on the B-2 and other platforms. This is to be followed by the Long Range Standoff Weapon , which may give the B-2 standoff nuclear capability for the first time. To make the B-2 more effective than previous bombers, many advanced and modern avionics systems were integrated into its design; these have been modified and improved following
3836-665: The Allies on August 15, and the Japanese government subsequently signed the official instrument of surrender on September 2, 1945. After World War II, the name strategic bomber came into use, for aircraft that could carry aircraft ordnances over long distances behind enemy lines. They were supplemented by smaller fighter-bombers with less range and lighter bomb load, for tactical strikes. Later these were called strike fighters , attack aircraft and multirole combat aircraft . When North Korea attacked South Korea in 1950
3973-653: The Armistice with Germany). The Vimy's intended use was to bomb industrial and railway targets in western Germany, which it could reach with its range of 900 miles (1,400 km) and a bomb load of just over a ton. The Vickers Vimy is best known as the aircraft that made the first Atlantic crossing from St John's Newfoundland to Clifden in Ireland piloted by the Englishman John Alcock and navigated by Scot Arthur Whitten Brown on June 14, 1919. Between
4110-708: The B-1 , B-52 and B-2 have been retained for the role of carpet bombing in several conflicts. The most prolific example (in terms of total bomb tonnage) is the U.S. Air Force B-52 Stratofortress during the 1960s–early 1970s Vietnam War era, in Operation Menu , Operation Freedom Deal , and Operation Linebacker II . In 1987 the Soviet Tu-160 —the heaviest supersonic bomber/aircraft currently in active service—entered service; it can carry twelve long-range cruise missiles. The 2010 New START agreement between
4247-501: The B-1B (US$ 9.6 million annually) and over four times as much as the B-52H (US$ 6.8 million annually). In September 1997, each hour of B-2 flight necessitated 119 hours of maintenance. Comparable maintenance needs for the B-52 and the B-1B are 53 and 60 hours, respectively, for each hour of flight. A key reason for this cost is the provision of air-conditioned hangars large enough for
Northrop B-2 Spirit - Misplaced Pages Continue
4384-701: The B-29 (1944) delivered payloads in excess of 20,000 pounds (9,100 kg) and had a range of 3,250 miles (5,230 km). By the late 1950s, the jet -powered Boeing B-52 Stratofortress , travelling at speeds of up to 650 miles per hour (1,050 km/h) (more than double that of a Lancaster), could deliver a payload of 70,000 pounds (32,000 kg), over a combat radius of 4,480 miles (7,210 km). During World War II, mass production techniques made available large, long-range heavy bombers in such quantities as to allow strategic bombing campaigns to be developed and employed. This culminated in August 1945, when B-29s of
4521-537: The CBU-97 Sensor Fuzed Weapon . In July 2009, Northrop Grumman reported the B-2 was compatible with the equipment necessary to deploy the 30,000 lb (14,000 kg) Massive Ordnance Penetrator (MOP), which is intended to attack reinforced bunkers ; up to two MOPs could be equipped in the B-2's bomb bays with one per bay, the B-2 is the only platform compatible with the MOP as of 2012. As of 2011,
4658-523: The F-101 Voodoo , F-102 Delta Dagger and F-106 Delta Dart interceptors . The F-106 had an early IRST mounting replaced in 1963 with a production retractable mount. The IRST was also incorporated into the F-8 Crusader (F-8E variant) allowing passive tracking of heat emissions and was similar to the later Texas Instruments AN/AAA-4 installed on early F-4 Phantoms . The F-4 Phantom had
4795-645: The Have Blue platform had flown and proven the concepts. During the 1980 presidential election campaign in 1979, Ronald Reagan repeatedly stated that Carter was weak on defense and used the B-1 as a prime example. In response, on 22 August 1980 the Carter administration publicly disclosed that the United States Department of Defense was working to develop stealth aircraft, including a bomber. The Advanced Technology Bomber (ATB) program began in 1979. Full development of
4932-1019: The Heinkel He 177 which saw only limited use against the Soviet Union and the United Kingdom ) was published. After Wever's death, Ernst Udet , development director at the Air Ministry steered the Luftwaffe towards dive bombers instead. When Britain and France declared war on Germany in September 1939, the RAF had no heavy bomber yet in service; heavy bomber designs had started in 1936 and ordered in 1938. The Handley Page Halifax and Avro Lancaster both originated as twin-engine "medium" bombers, but were rapidly redesigned for four Rolls-Royce Merlin engines and rushed into service once
5069-538: The Junkers Ju 88 . Heavy bombers still needed defensive armament for protection, even at night. The Stirling's low operational ceiling of just 12,000 ft (3,700 m)—also caused by the thick wing—meant that it was usually picked on by night fighters; within five months, 67 of the 84 aircraft in service had been lost. The bomb bay layout limited the size and types of bombs carried and it was relegated to secondary duties such as tug and paratrooper transport. Due to
5206-477: The Northrop Tacit Blue . Some analysts claim infra-red search and track systems (IRSTs) can be deployed against stealth aircraft, because any aircraft surface heats up due to air friction and with a two channel IRST is a CO 2 (4.3 μm absorption maxima) detection possible, through difference comparing between the low and high channel. Burying engines deep inside the fuselage also minimizes
5343-594: The Supermarine Spitfire had very limited endurance. An early raid on Rouen-Sotteville rail yards in Brittany on August 17, 1942, required four Spitfire squadrons outbound and five more for the return trip. The USAAF chose to attack aircraft factories and component plants. On August 17, 1943, 230 Fortresses attacked a ball-bearing plant in Schweinfurt and again two months later, with 291 bombers, in
5480-694: The U.S. Congress even before the winding down of the Cold War dramatically reduced the desire for a stealth aircraft designed to strike deep in Soviet territory. Consequently, in the late 1980s and 1990s lawmakers shrank the planned purchase of 132 bombers to 21. The B-2 can perform attack missions at altitudes of up to 50,000 feet (15,000 m); it has an unrefueled range of more than 6,000 nautical miles (6,900 mi; 11,000 km) and can fly more than 10,000 nautical miles (12,000 mi; 19,000 km) with one midair refueling . It entered service in 1997 as
5617-732: The United States Army Air Forces dropped atomic bombs over Hiroshima and Nagasaki in Japan. The arrival of nuclear weapons and guided missiles permanently changed the nature of military aviation and strategy . After the 1950s intercontinental ballistic missiles and ballistic missile submarines began to supersede heavy bombers in the strategic nuclear role. Along with the emergence of more accurate precision-guided munitions ("smart bombs") and nuclear -armed missiles , which could be carried and delivered by smaller aircraft, these technological advancements eclipsed
Northrop B-2 Spirit - Misplaced Pages Continue
5754-610: The YB-35 and YB-49 flying wing aircraft. The Northrop design was larger while the Lockheed design included a small tail. In 1979, designer Hal Markarian produced a sketch of the aircraft that bore considerable similarities to the final design. The USAF originally planned to procure 165 ATB bombers. The Northrop team's ATB design was selected over the Lockheed/Rockwell design on 20 October 1981. The Northrop design received
5891-421: The YB-35 and YB-49 were both flying wing bombers that had been canceled in development in the early 1950s, allegedly for political reasons. The resemblance goes as far as B-2 and YB-49 having the same wingspan. The YB-49 also had a small radar cross-section . Approximately 80 pilots fly the B-2. Each aircraft has a crew of two, a pilot in the left seat and mission commander in the right, and has provisions for
6028-468: The Zeppelin-Staaken R.VI of which 13 saw service, bombing Russia and London: four were shot down and six lost on landing. The R.VIs were larger than the standard Luftwaffe bombers of World War II. The Vickers Vimy , a long-range heavy bomber powered by two Rolls-Royce Eagle engines, was delivered to the newly formed Royal Air Force too late to see action (only one was in France at time of
6165-417: The aircraft skin which would also increase the infrared signature. Heavy bomber Heavy bombers are bomber aircraft capable of delivering the largest payload of air-to-ground weaponry (usually bombs ) and longest range ( takeoff to landing ) of their era. Archetypal heavy bombers have therefore usually been among the largest and most powerful military aircraft at any point in time. In
6302-562: The black project followed, funded under the code name " Aurora ". After the evaluations of the companies' proposals, the ATB competition was narrowed to the Northrop/ Boeing and Lockheed/ Rockwell teams with each receiving a study contract for further work. Both teams used flying wing designs. The Northrop proposal was code named "Senior Ice", and the Lockheed proposal code named " Senior Peg ". Northrop had prior experience developing
6439-660: The second raid on Schweinfurt . The works was severely damaged but at a huge cost: 36 aircraft lost in the first raid, 77 in the second. Altogether 850 airmen were killed or captured; only 33 Fortresses returned from the October raid undamaged With the arrival of North American P-51 Mustangs and the fitting of drop tanks to increase the range of the Republic P-47 Thunderbolt for the Big Week offensive, between February 20–25, 1944, bombers were escorted all
6576-512: The 10-ton Grand Slam could be carried. Barnes Wallis , deputy chief aircraft designer at Vickers , spent much time thinking about weapons that might shorten the war. He conceived his “Spherical Bomb, Surface Torpedo” after watching his daughter flip pebbles over water. Two versions of the ' bouncing bomb ' were developed: the smaller Highball was to be used against ships and attracted essential British Admiralty funding for his project. A 1,280 lb (580 kg) flying torpedo, of which half
6713-442: The 1980s with the introduction of 2-D sensors, which cued both horizontal and vertical angle. Sensitivities were also greatly improved, leading to better resolution and range. In more recent years, new systems have entered the market. In 2015, Northrop Grumman introduced its OpenPod IRST pod, which uses a sensor by Leonardo . The United States Air Force is currently incorporating IRST systems for its fighter aircraft fleet, including
6850-894: The Advanced Technology Bomber (ATB) project during the Carter administration , which cancelled the Mach 2-capable B-1A bomber in part because the ATB showed such promise. But development difficulties delayed progress and drove up costs. Ultimately, the program produced 21 B-2s at an average cost of $ 2.13 billion (~$ 4.04 billion in 2023), including development, engineering, testing, production, and procurement. Building each aircraft cost an average of US$ 737 million, while total procurement costs (including production, spare parts , equipment, retrofitting , and software support) averaged $ 929 million (~$ 1.11 billion in 2023) per plane. The project 's considerable capital and operating costs made it controversial in
6987-542: The B-17G model. In order to assemble combat boxes of several aircraft, and later combat wings formed of a number of boxes, assembly ships were used to speed up formation. Even this extra firepower, which increased empty weight by 20% and required more powerful versions of the Wright Cyclone engine, was insufficient to prevent serious losses in daylight. Escort fighters were needed but the RAF interceptors such as
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#17327837755577124-418: The B-2 refuels every six hours, taking on up to 50 short tons (45,000 kg) of fuel at a time. The development and construction of the B-2 required pioneering use of computer-aided design and manufacturing technologies due to its complex flight characteristics and design requirements to maintain very low visibility to multiple means of detection. The B-2 bears a resemblance to earlier Northrop aircraft;
7261-485: The B-2 early was made because the small fleet of 20 is considered too expensive per plane to retain, with its position as a stealth bomber being taken over with the introduction of the B-21 Raider starting in the mid-2020s. The B-2 Spirit was developed to take over the USAF's vital penetration missions, allowing it to travel deep into enemy territory to deploy ordnance , which could include nuclear weapons . The B-2
7398-422: The B-2 has a radar cross-section (RCS) of about 0.1 m (1.1 sq ft). The bomber does not always fly stealthily; when nearing air defenses pilots "stealth up" the B-2, a maneuver whose details are secret. The aircraft is stealthy, except briefly when the bomb bay opens. The flying wing design most closely resembles a so-called infinite flat plate (as vertical control surfaces dramatically increase RCS),
7535-423: The B-2's terrain-following/terrain-avoidance radar had difficulty distinguishing rain from other obstacles, rendering the subsystem inoperable during rain. However a subsequent report in October 1996 noted that the USAF had made some progress in resolving the issues with the radar via software fixes and hoped to have these fixes undergoing tests by the spring of 1997. The total "military construction" cost related to
7672-493: The Department of Defense accused Northrop of using faulty components in the flight control system ; it was also found that redesign work was required to reduce the risk of damage to engine fan blades by bird ingestion. In time, several prominent members of Congress began to oppose the program's expansion, including Senator John Kerry (D-MA), who cast votes against the B-2 in 1989, 1991, and 1992. By 1992, Bush had called for
7809-828: The Experimental Survivability Testbed project. Northrop and Lockheed were awarded contracts in the first round of testing. Lockheed received the sole award for the second test round in April 1976 leading to the Have Blue program and eventually the F-117 stealth attack aircraft. Northrop also had a classified technology demonstration aircraft, the Tacit Blue in development in 1979 at Area 51 . It developed stealth technology, LO (low observables), fly-by-wire , curved surfaces, composite materials, electronic intelligence , and Battlefield Surveillance Aircraft Experimental. The stealth technology developed from
7946-507: The F-15, F-16, and F-22. While IRST systems are most common amongst aircraft, land-based, ship and submarine systems are available. The F-35 is equipped with infrared search and track system AN/AAQ-37 Distributed Aperture System (DAS), which consists of six IR sensors around the aircraft for full spherical coverage, providing day/night imaging and acting as an IRST and missile approach warning system. Chengdu J-20 and Shenyang FC-31
8083-669: The House Armed Services Committee trimmed $ 800 million from the B-2 research and development budget, while at the same time staving off a motion to end the project. Opposition in committee and in Congress was mostly broad and bipartisan, with Congressmen Ron Dellums (D-CA), John Kasich (R-OH), and John G. Rowland (R-CT) authorizing the motion to end the project—as well as others in the Senate, including Jim Exon (D-NE) and John McCain (R-AZ) also opposing
8220-499: The Lockheed F-117 program; more people in the federal government knew about the B-2, and more information about the project was available. Both during development and in service, considerable effort has been devoted to maintaining the security of the B-2's design and technologies. Staff working on the B-2 in most, if not all, capacities need a level of special-access clearance and undergo extensive background checks carried out by
8357-709: The Next-Generation Bomber would have an overall cost of $ 55 billion. In 2013, the USAF contracted for the Defensive Management System Modernization (DMS-M) program to replace the antenna system and other electronics to increase the B-2's frequency awareness. The Common Very Low Frequency Receiver upgrade allows the B-2s to use the same very low frequency transmissions as the Ohio -class submarines so as to continue in
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#17327837755578494-623: The Spirit's primary Cold War mission. Under budgetary pressures and Congressional opposition, in his 1992 State of the Union address, President George H. W. Bush announced B-2 production would be limited to 20 aircraft. In 1996, however, the Clinton administration , though originally committed to ending production of the bombers at 20 aircraft, authorized the conversion of a 21st bomber, a prototype test model, to Block 30 fully operational status at
8631-723: The Tirpitz on November 12, 1944. Upkeep, the larger version of the bouncing bomb , was used to destroy the Mohne and Eder dams by Lancasters from the specially recruited and trained No. 617 Squadron RAF , often known as "the Dam Busters", under Wing Commander Guy Gibson . In March and April 1945, as the war in Europe was ending, Lancasters dropped Grand Slams and Tallboys on U-boat pens and railway viaducts across north Germany. At Bielefeld more than 100 yards (91 m) of railway viaduct
8768-431: The USAF previously planned to operate the B-2 until 2058, the FY 2019 budget moved up its retirement to "no later than 2032". It also moved the retirement of the B-1 to 2036 while extending the B-52's service life into the 2050s, because the B-52 has lower maintenance costs, versatile conventional payload, and the ability to carry nuclear cruise missiles (which the B-1 is treaty-prohibited from doing). The decision to retire
8905-442: The USAF responded with daylight bomber raids on supply lines through North Korea. B-29 Superfortresses flew from Japan on behalf of the United Nations , but the supply line for North Korea's army from the Soviet Union was physically and politically out of reach: North Korea for the most part lacked worthwhile strategic targets of its own. The Soviet-backed Northern forces easily routed the South Korean army. The distance to North Korea
9042-430: The USAF to refocus resources away from continued B-2 production and instead begin development of a new bomber, either a new build or a variant of the B-2. In its 1999 bomber roadmap the USAF eschewed the panel's recommendations, believing its current bomber fleet could be maintained until the 2030s. The service believed that development could begin in 2013, in time to replace aging B-2s, B-1s and B-52s around 2037. Although
9179-456: The United States of America and the Russian Federation defined a "heavy bomber" by two characteristics: Some notable heavy bombers are listed below Infrared search and track IRST is a generalized case of Forward Looking Infrared (FLIR), i.e. from forward-looking to all-round situation awareness . Such systems are passive ( thermographic camera ), meaning they do not give out any radiation of their own, unlike radar . This gives them
9316-401: The absence of British heavy bombers, 20 United States Army Air Corps Boeing B-17 Flying Fortresses were lent to the RAF, which during July 1941 commenced daylight attacks on warships and docks at Wilhelmshaven and Brest. These raids were complete failures. After eight aircraft were lost due to combat or breakdown and with many engine failures, the RAF stopped daylight bombing by September. It
9453-441: The advantage that they are difficult to detect. However, because the atmosphere attenuates infrared to some extent (although not as much as visible light ) and because adverse weather can attenuate it also (again, not as badly as visible systems), their range compared to a radar is limited. Within range, an IRST's angular resolution is better than radar due to the shorter wavelength . The first uses of an IRST system appeared in
9590-443: The aircraft to be unreliable, under-powered and hastened its withdrawal from service. Reaching squadrons early in 1942, the redesigned bomber with four Merlin engines and longer wings was renamed Avro Lancaster ; it could deliver a 14,000 lb (6,400 kg) load of bombs or up to 22,000 lb (10,000 kg) with special modifications. The Lancaster's bomb bay was undivided, so that bombs of extraordinary size and weight such as
9727-499: The aircraft's APQ-181 synthetic aperture radar to map out targets prior to the deployment of GPS -aided bombs ( GAMs ), later superseded by the Joint Direct Attack Munition (JDAM). In the B-2's original configuration, up to 16 GAMs or JDAMs could be deployed; An upgrade program in 2004 raised the maximum carrier capacity to 80 JDAMs. The B-2 has various conventional weapons in its arsenal, including Mark 82 and Mark 84 bombs , CBU-87 Combined Effects Munitions , GATOR mines , and
9864-464: The aircraft's current air speed and angle of attack via pitot -static sensing plates, as opposed to traditional pitot tubes which would impair the aircraft's stealth capabilities. The flight actuation system incorporates both hydraulic and electrical servoactuated components, and it was designed with a high level of redundancy and fault-diagnostic capabilities. Northrop had investigated several means of applying directional control that would infringe on
10001-502: The aircraft's flight envelope, the inner elevons are normally only in use at slow speeds, such as landing. To avoid potential contact damage during takeoff and to provide a nose-down pitching attitude, all of the elevons remain drooped during takeoff until a high enough airspeed has been attained. The B-2's low-observable, or " stealth ", characteristics enable the undetected penetration of sophisticated anti-aircraft defenses and to attack even heavily defended targets. This stealth comes from
10138-416: The aircraft's radar profile as little as possible, eventually settling on a combination of split brake-rudders and differential thrust. Engine thrust became a key element of the B-2's aerodynamic design process early on; thrust not only affects drag and lift but pitching and rolling motions as well. Four pairs of control surfaces are located along the wing's trailing edge; while most surfaces are used throughout
10275-564: The altitude, the less dense the atmosphere and the less infrared radiation it absorbs - especially at longer wavelengths. The effect of reduction in friction between air and aircraft does not compensate for the better transmission of infrared radiation. Therefore, infrared detection ranges are longer at high altitudes. At high altitudes, temperatures range from −30 to −50 °C - which provide better contrast between aircraft temperature and background temperature. The Eurofighter Typhoon's PIRATE IRST can detect subsonic fighters from 50 km from
10412-433: The apparent surface of the target, and target motion analysis (TMA) IRST can calculate the range. The best known modern IRST systems are: Fighter aircraft carry the IRST systems for use instead of radar when the situation warrants it, such as when shadowing other aircraft, under the control of airborne early warning and control (AWACS) aircraft, or executing a ground-controlled interception (GCI), where an external radar
10549-419: The bombardier's clear nose glazing as "cheek" positions, or midway along the rear fuselage sides as "waist" positions. U.S. bombers carried .50 caliber machine gun , and dorsal (spine/top of aircraft) and ventral (belly/bottom of aircraft) guns with powered turrets . All of these machine guns could defend against attack when beyond the range of fighter escort; eventually, a total of 13 machine guns were fitted in
10686-465: The bomber a " force multiplier ". As of September 2013, there have been no instances of a missile being launched at a B-2. To reduce optical visibility during daylight flights, the B-2 is painted in an anti-reflective paint . The undersides are dark because it flies at high altitudes (50,000 ft (15,000 m)), and at that altitude a dark grey painting blends well into the sky. It is speculated to have an upward-facing light sensor which alerts
10823-466: The bomber's 172 ft (52 m) wingspan, which are needed to maintain the aircraft's stealth properties, particularly its "low-observable" stealth skins. Maintenance costs are about $ 3.4 million per month for each aircraft. An August 1995 GAO report disclosed that the B-2 had trouble operating in heavy rain, as rain could damage the aircraft's stealth coating, causing procurement delays until an adequate protective coating could be found. In addition,
10960-659: The bombers were restricted to night interdiction and concentrated on destroying supply routes, including the bridges over the Yalu river into China. By the 1960s, manned heavy bombers could not match the intercontinental ballistic missile in the strategic nuclear role. More accurate precision-guided munitions ("smart bombs"), nuclear -armed missiles or bombs were able to be carried by smaller aircraft such as fighter-bombers and multirole fighters . Despite these technological innovations and new capabilities of other contemporary military aircraft , large strategic bombers such as
11097-597: The bombers were then switched to low-level, nighttime incendiary attacks for which they had not originally been designed (one variant, the B-29B was specially modified for low altitude night missions by removal of armament and other equipment). Japan burned furiously from the B-29 incendiary raids. On August 6, 1945, B-29 Enola Gay dropped an atomic bomb on Hiroshima. Three days later, B-29 Bockscar dropped another on Nagasaki. The war ended when Japan announced its surrender to
11234-645: The cancellation of the B-2 and promised to cut military spending by 30% in the wake of the collapse of the Soviet Union. In October 1995, former Chief of Staff of the United States Air Force , General Mike Ryan , and former chairman of the Joint Chiefs of Staff, General John Shalikashvili , strongly recommended against Congressional action to fund the purchase of any additional B-2s, arguing that to do so would require unacceptable cuts in existing conventional and nuclear-capable aircraft, and that
11371-656: The cost of expended munitions by less than US$ 2 billion in 1995 dollars during the first two weeks of a conflict, in which the USAF predicted bombers would make their greatest contribution; this was a small fraction of the US$ 26.8 billion (in 1995 dollars) life cycle cost that the CBO projected for an additional 20 B-2s. In 1997, as Ranking Member of the House Armed Services Committee and National Security Committee, Congressman Ron Dellums (D-CA),
11508-444: The designation B-2 and the name "Spirit". The bomber's design was changed in the mid-1980s when the mission profile was changed from high-altitude to low-altitude, terrain-following. The redesign delayed the B-2's first flight by two years and added about US$ 1 billion to the program's cost. An estimated US$ 23 billion was secretly spent for research and development on the B-2 by 1989. MIT engineers and scientists helped assess
11645-439: The detection range. With infrared homing or fire-and-forget missiles, the fighter may be able to fire upon the target without having to turn on its radar sets on at all. Otherwise, the fighter can turn the radar on and achieve a lock immediately before firing if desired. The fighter could also close to within cannon range and engage that way. Whether or not they use their radar, the IRST system can still allow them to launch
11782-476: The flight crew of possible threats. The onboard DMS is capable of automatically assessing the detection capabilities of identified threats and indicated targets. The DMS will be upgraded by 2021 to detect radar emissions from air defenses to allow changes to the auto-router's mission planning information while in-flight so it can receive new data quickly to plan a route that minimizes exposure to dangers. For safety and fault-detection purposes, an on-board test system
11919-487: The frequency wavelength can exceed a certain threshold and cause a resonant effect. RCS reduction as a result of shape had already been observed on the Royal Air Force 's Avro Vulcan strategic bomber, and the USAF's F-117 Nighthawk . The F-117 used flat surfaces ( faceting technique) for controlling radar returns as during its development (see Lockheed Have Blue ) in the early 1970s, technology only allowed for
12056-402: The front and 90 km from the rear - the larger value being the consequence of directly observing the engine exhaust, with an even greater increase being possible if the target uses afterburners . The range at which a target can be identified with sufficient confidence to decide on weapon release is significantly inferior to the detection range - manufacturers have claimed it is about 65% of
12193-556: The heavy bomber's once-central role in strategic warfare by the late 20th century. Heavy bombers have, nevertheless, been used to deliver conventional weapons in several regional conflicts since World War II (for example, B-52s in the Vietnam War ). Heavy bombers are now operated only by the air forces of the United States, Russia and China. They serve in both strategic and tactical bombing roles. The first heavy bomber
12330-468: The infrared spectrum) being released and thus a reduced heat signature. The resulting cooler air is conducted over a surface composed of heat resistant carbon-fiber-reinforced polymer and titanium alloy elements, which disperse the air laterally, to accelerate its cooling. The B-2 lacks afterburners as the hot exhaust would increase the infrared signature; breaking the sound barrier would produce an obvious sonic boom as well as aerodynamic heating of
12467-631: The initial design suitable for bombing and it was first used on a variety of VIP transport and maritime patrol missions. Its long range, however, persuaded the USAAF to send 177 Liberators from Benghazi in Libya to bomb the Romanian oilfields on August 1, 1943, in Operation Tidal Wave . Due to navigational errors and alerted German flak batteries and fighters, only half returned to base although
12604-497: The introduction of new radar-absorbent materials across the fleet, the B-2 has had several major upgrades to its avionics and combat systems. For battlefield communications, both Link-16 and a high frequency satellite link have been installed, compatibility with various new munitions has been undertaken, and the AN/APQ-181 radar's operational frequency was shifted to avoid interference with other operators' equipment. The arrays of
12741-479: The largest radar cross-section of an aircraft that would remain effectively invisible to radars. Initially, Northrop and McDonnell Douglas were selected for further development. Lockheed had experience in this field with the development of the Lockheed A-12 and SR-71 , which included several stealthy features, notably its canted vertical stabilizers, the use of composite materials in key locations, and
12878-556: The logistics (including transport of fuel for the B-29 fleet over the Himalayan range ) of flying from these remote, primitive airfields were complicated and costly. The island of Saipan in the Marianas was assaulted to provide Pacific air bases from which to bomb Japanese cities . Initial high-level, daylight bombing raids using high-explosive bombs on Japanese cities with their wood and paper houses produced disappointing results;
13015-532: The military had greater priorities in spending a limited budget. Some B-2 advocates argued that procuring twenty additional aircraft would save money because B-2s would be able to deeply penetrate anti-aircraft defenses and use low-cost, short-range attack weapons rather than expensive standoff weapons. However, in 1995, the Congressional Budget Office (CBO) and its Director of National Security Analysis found that additional B-2s would reduce
13152-477: The mission effectiveness of the aircraft under a five-year classified contract during the 1980s. Northrop was the B-2's prime contractor; major subcontractors included Boeing , Hughes Aircraft (now Raytheon ), GE , and Vought Aircraft . During its design and development, the Northrop B-2 program was a black project ; all program personnel needed a secret clearance. Still, it was less closely held than
13289-502: The nuclear mission until the Mobile User Objective System is fielded. In 2014, the USAF outlined a series of upgrades including nuclear warfighting, a new integrated processing unit, the ability to carry cruise missiles, and threat warning improvements. Due to ongoing software challenges, DMS-M was canceled by 2020, and the existing work was repurposed for cockpit upgrades. In 1998, a Congressional panel advised
13426-480: The overall surface finish in radar-absorbing paint . A key improvement was the introduction of computer models used to predict the radar reflections from flat surfaces where collected data drove the design of a "faceted" aircraft. Development of the first such designs started in 1975 with the Have Blue , a model Lockheed built to test the concept. Plans were well advanced by the summer of 1975, when DARPA started
13563-575: The part of the wing trailing edge subject to engine exhaust, replacing existing material that quickly degraded. In July 2010, political analyst Rebecca Grant speculated that when the B-2 becomes unable to reliably penetrate enemy defenses, the Lockheed Martin F-35 Lightning II may take on its strike/ interdiction mission, carrying B61 nuclear bombs as a tactical bomber. However, in March 2012, The Pentagon announced that
13700-576: The perfect stealth shape, as it would lack angles to reflect back radar waves (initially, the shape of the Northrop ATB concept was flatter; it gradually increased in volume according to specific military requirements). Without vertical surfaces to reflect radar laterally, side aspect radar cross section is also reduced. Radars operating at a lower frequency band (S or L band) are able to detect and track certain stealth aircraft that have multiple control surfaces, like canards or vertical stabilizers, where
13837-400: The pilot to increase or reduce altitude to match the changing illuminance of the sky. The original design had tanks for a contrail -inhibiting chemical, but this was replaced in production aircraft by a contrail sensor that alerts the crew when they should change altitude. The B-2 is vulnerable to visual interception at ranges of 20 nmi (23 mi; 37 km) or less. The B-2 is stored in
13974-514: The powerplant seriously delayed the B-29's operational service debut. The aircraft had four remotely operated twin-gun turrets on its fuselage , controlled through an analog computer sighting system; the operator could use any of a trio of Perspex ball stations. Only the tail gunner manually controlled his gun turret station in the rear of the airplane. B-29s were initially deployed to bases in India and China, from which they could reach Japan; but
14111-469: The presentation area and took aerial photographs of the aircraft's secret rear section with suppressed engine exhausts. The B-2's (s/n 82-1066 / AV-1) first public flight was on 17 July 1989 from Palmdale to Edwards Air Force Base . In 1984, Northrop employee Thomas Patrick Cavanagh was arrested for attempting to sell classified information from the Pico Rivera factory to the Soviet Union . Cavanagh
14248-586: The program was kept from the Government Accountability Office (GAO) and members of Congress until the mid-1980s. The B-2 was first publicly displayed on 22 November 1988 at United States Air Force Plant 42 in Palmdale, California , where it was assembled. This viewing was heavily restricted, and guests were not allowed to see the rear of the B-2. However, Aviation Week editors found that there were no airspace restrictions above
14385-435: The program was later incorporated into other operational aircraft designs, including the B-2 stealth bomber. By 1976, these programs had progressed to a position in which a long-range strategic stealth bomber appeared viable. President Jimmy Carter became aware of these developments during 1977, and it appears to have been one of the major reasons the B-1 was canceled. Further studies were ordered in early 1978, by which point
14522-448: The program was projected to be US$ 553.6 million in 1997 dollars. The cost to procure each B-2 was US$ 737 million in 1997 dollars (equivalent to US$ 1.3 billion in 2021), based only on a fleet cost of US$ 15.48 billion. The procurement cost per aircraft, as detailed in GAO reports, which include spare parts and software support, was $ 929 million per aircraft in 1997 dollars. The total program cost projected through 2004
14659-576: The project. Dellums and Kasich, in particular, worked together from 1989 through the early 1990s to limit production to 21 aircraft and were ultimately successful. The escalating cost of the B-2 program and evidence of flaws in the aircraft's ability to elude detection by radar were among factors that drove opposition to continue the program. At the peak production period specified in 1989, the schedule called for spending US$ 7 billion to $ 8 billion per year in 1989 dollars, something Committee Chair Les Aspin (D-WI) said "won't fly financially". In 1990,
14796-589: The second aircraft designed with advanced stealth technology, after the Lockheed F-117 Nighthawk attack aircraft. Primarily designed as a nuclear bomber, the B-2 was first used in combat to drop conventional, non-nuclear ordnance in the Kosovo War in 1999. It was later used in Iraq , Afghanistan , Libya and Yemen . The United States Air Force has nineteen B-2s in service as of 2024; one
14933-412: The second half of the 20th century, heavy bombers were largely superseded by strategic bombers , which were often even larger in size, had much longer ranges and were capable of delivering nuclear bombs . Because of advances in aircraft design and engineering — especially in powerplants and aerodynamics — the size of payloads carried by heavy bombers has increased at rates greater than increases in
15070-581: The sensor would generate a "pip" on the display, in a fashion similar to the B-scopes used on early radars. The display was primarily intended to allow the radar operator to manually turn the radar to the approximate angle of the target, in an era when radar systems had to be "locked on" by hand. The system was considered to be of limited utility, and with the introduction of more automated radars they disappeared from fighter designs for some time. Detection range varies with external factors such as The higher
15207-411: The simulation of radar reflections on simple, flat surfaces; computing advances in the 1980s made it possible to simulate radar returns on more complex curved surfaces. The B-2 is composed of many curved and rounded surfaces across its exposed airframe to deflect radar beams. This technique, known as continuous curvature , was made possible by advances in computational fluid dynamics , and first tested on
15344-587: The size of their airframes. The largest bombers of World War I , the Zeppelin-Staaken Riesenflugzeuge of Germany, could carry a payload of up to 4,400 pounds (2,000 kg) of bombs; by the latter half of World War II , the Avro Lancaster (introduced in 1942) routinely delivered payloads of 14,000 pounds (6,400 kg) (and sometimes up to 22,000 lb (10,000 kg)) and had a range of 2,530 miles (4,070 km), while
15481-625: The standard heavy bomber in the Pacific and the only one used by the RAAF. The SAAF used Liberators to drop weapons and ammunition during the Warsaw Uprising in 1944. The Avro Manchester was a twin-engine bomber powered by the ambitious 24-cylinder Rolls-Royce Vulture , but was rapidly redesigned for four Rolls-Royce Merlin engines due to technical problems with the Vulture which caused
15618-665: The technical problems of the larger Rolls-Royce Vulture emerged in the Avro Manchester . The Halifax joined squadrons in November 1940 and flew its first raid against Le Havre on the night of 11–12 March 1941. British heavy bomber designs often had three gun turrets with a total of 8 machine guns . In January 1941, the Short Stirling reached operational status and first combat missions were flown in February. It
15755-607: The thermal visibility or infrared signature of the exhaust. At the engine intake, cold air from the boundary layer below the main inlet enters the fuselage ( boundary layer suction , first tested on the Northrop X-21 ) and is mixed with hot exhaust air just before the nozzles (similar to the Ryan AQM-91 Firefly ). According to the Stefan–Boltzmann law , this results in less energy ( thermal radiation in
15892-655: The upgraded radar features were entirely replaced to make the AN/APQ-181 into an active electronically scanned array (AESA) radar. Due to the B-2's composite structure, it is required to stay 40 miles (64 km) away from thunderstorms , to avoid static discharge and lightning strikes . To address the inherent flight instability of a flying wing aircraft, the B-2 uses a complex quadruplex computer-controlled fly-by-wire flight control system that can automatically manipulate flight surfaces and settings without direct pilot inputs to maintain aircraft stability. The flight computer receives information on external conditions such as
16029-530: The war, German industrial production actually increased , despite a sustained Allied bombing campaign. As the German Luftwaffe 's main task was to support the army, it never developed a successful heavy bomber. The prime proponent of strategic bombing, Luftwaffe Chief of Staff General Walther Wever , died in an air crash in 1936 on the very day that the specification for the Ural bomber (later won by
16166-469: The war, bombers continually managed to strike their targets, but suffered unacceptable losses in the absence of careful planning and escort fighters . Only the later de Havilland Mosquito light bomber was fast enough to evade fighters. Heavy bombers needed defensive armament for protection, which reduced their effective bomb payload. The second tenet was that strategic bombing of industrial capacity, power generation, oil refineries, and coal mines could win
16303-512: The wars, aviation opinion fixed on two tenets. The first was that “ the bomber will always get through .” The speed advantage of biplane fighters over bombers was insignificant, and it was believed that they would never catch them. Furthermore, there was no effective method of detecting incoming bombers at sufficiently long range to scramble fighters on an interception course. In practice, a combination of new radar technology and advances in monoplane fighter design eroded this disadvantage. Throughout
16440-489: The way a radar works, the operator can tell the IRST to track a particular target of interest, once it has been identified, or scan in a particular direction if a target is believed to be there (for example, because of an advisory from AWACS or another aircraft). IRST systems can incorporate laser rangefinders in order to provide full fire-control solutions for cannon fire or launching missiles ( Optronique Secteur Frontal ). The combination of an atmospheric propagation model,
16577-605: The way to the target and back. Losses were reduced to 247 out of 3,500 sorties, still devastating but accepted at the time. The Consolidated B-24 Liberator and later version of the Fortress carried even more extensive defensive armament fitted into Sperry ball turrets . This was a superb defensive weapon that rotated a full 360 degrees horizontally with a 90-degree elevation. Its twin M2 Browning machine guns had an effective range of 1,000 yards (910 m). The Liberator
16714-511: Was Torpex torpedo explosive, it was developed specifically to sink the Tirpitz which was moored in Trondheim fjord behind torpedo nets. Development delays in the 'bouncing bomb' meant that another Barnes Wallis invention, the 5-ton Tallboy was deployed instead; two Tallboys dropped by Avro Lancasters from 25,000 ft (7,600 m) altitude hit at near- supersonic speed and capsized
16851-413: Was US$ 44.75 billion in 1997 dollars (equivalent to US$ 79 billion in 2021). This includes development, procurement, facilities, construction, and spare parts. The total program cost averaged US$ 2.13 billion per aircraft. The B-2 may cost up to $ 135,000 per flight hour to operate in 2010, which is about twice that of the B-52 and B-1. In its consideration of the fiscal year 1990 defense budget,
16988-544: Was based on the successful Short Sunderland flying boat and shared its Bristol Hercules radial engines, wing, and cockpit with a new fuselage. It carried up to 14,000 lb (6,400 kg) of bombs—almost twice the load of a Boeing B-17 Flying Fortress —but over just a 300-mile (480 km) radius. Due to its thick, short wing it was able to out-turn the main German night fighters, the Messerschmitt Bf 110 and
17125-745: Was clear that the B-17C model was not combat ready and that its five machine guns provided inadequate protection. Combat feedback enabled Boeing engineers to improve the aircraft; when the first model B-17E began operating from English airfields in July 1942, it had many more defensive gun positions including a vitally important tail gunner. Eventually, U.S. heavy bomber designs, optimized for formation flying, had 10 or more machine guns and/or cannons in both powered turrets and manually operated flexible mounts to deliver protective arcs of fire. These guns were located in tail turrets , side gun ports either just behind
17262-678: Was designed as an airliner . Igor Sikorsky , an engineer educated in St Petersburg, but born in Kiev of Polish-Russian ancestry designed the Sikorsky Ilya Muromets to fly between his birthplace and his new home. It did so briefly until August 1914, when the Russo-Balt wagon factory converted to a bomber version, with British Sunbeam Crusader V8 engines in place of the German ones in the passenger plane. By December 1914
17399-447: Was destroyed by Grand Slams creating an earthquake effect, which shook the foundations. The Boeing B-29 Superfortress was a development of the Fortress, but a larger design with four Wright R-3350 Duplex-Cyclone engines of much greater power, enabling it to fly higher, faster, further and with a bigger bomb load. The mammoth new Wright radial engines were susceptible to overheating if anything malfunctioned, and technical problems with
17536-511: Was destroyed in a 2008 crash and another one damaged in a crash in 2022 was retired from service likely on account of the cost and duration of a potential repair. The Air Force plans to operate the B-2s until 2032, when the Northrop Grumman B-21 Raider is to replace them. By the mid-1970s, military aircraft designers had learned of a new method to avoid missiles and interceptors, known today as " stealth ". The concept
17673-490: Was evaluating an unmanned stealth bomber, characterized as a "mini-B-2", as a potential replacement in the near future. In 2012, USAF Chief of Staff General Norton Schwartz stated the B-2's 1980s-era stealth technologies would make it less survivable in future contested airspaces, so the USAF is to proceed with the Next-Generation Bomber despite overall budget cuts. In 2012 projections, it was estimated that
17810-559: Was extensively redesigned; it now incorporates a new integrated processing unit that communicates with systems throughout the aircraft via a newly installed fiber optic network; a new version of the operational flight program software was also developed, with legacy code converted from the JOVIAL programming language to standard C . Updates were also made to the weapon control systems to enable strikes upon moving targets, such as ground vehicles. On 29 December 2008, USAF officials awarded
17947-406: Was produced from 1987 to 2000. The bomber can drop conventional and thermonuclear weapons , such as up to eighty 500-pound class (230 kg) Mk 82 JDAM GPS -guided bombs, or sixteen 2,400-pound (1,100 kg) B83 nuclear bombs . The B-2 is the only acknowledged in-service aircraft that can carry large air-to-surface standoff weapons in a stealth configuration. Development began under
18084-447: Was sentenced to life in prison in 1985 but released on parole in 2001. In October 2005, Noshir Gowadia , a design engineer who worked on the B-2's propulsion system, was arrested for selling classified information to China. Gowadia was convicted and sentenced to 32 years in prison. A procurement of 132 aircraft was planned in the mid-1980s but was later reduced to 75. By the early 1990s the Soviet Union dissolved , effectively eliminating
18221-461: Was the result of a proposal to assemble Fortresses in Consolidated plants, with the company returning with its own design of a longer-range, faster and higher-flying aircraft that could carry an extra ton of bombs. Early orders were for France (delivered to the RAF after the fall of France) and Britain, already at war, with just a batch of 36 for the USAAF. Neither the USAAF nor the RAF judged
18358-642: Was to build an aircraft with an airframe that deflected or absorbed radar signals so that little was reflected back to the radar unit. An aircraft having radar stealth characteristics would be able to fly nearly undetected and could be attacked only by weapons and systems not relying on radar. Although other detection measures existed, such as human observation, infrared scanners , and acoustic locators , their relatively short detection range or poorly developed technology allowed most aircraft to fly undetected, or at least untracked, especially at night. In 1974, DARPA requested information from U.S. aviation firms about
18495-537: Was too great for fighter escorts based in Japan, so the B-29s flew alone. In November, Mikoyan-Gurevich MiG-15s flown by Soviet pilots started to intercept the US bombers over North Korea. The MiG-15 was specifically designed to destroy US heavy bombers; it could out-perform any fighter deployed by United Nations air forces until the capable F-86 Sabre was produced in greater numbers and brought to Korea. After 28 B-29s were lost,
18632-457: Was used for daylight raids on naval targets, damaging a German destroyer. But after one was lost, the O/100 switched to night attacks. The uprated Handley Page Type O /400 could carry a 1,650 lb (750 kg) bomb, and wings of up to 40 were used by the newly formed, independent Royal Air Force from April 1918 to make strategic raids on German railway and industrial targets. A single O/400
18769-659: Was used to support T. E. Lawrence 's Sinai and Palestine Campaign . The Imperial German Air Service operated the Gotha bomber, which developed a series of marques. The Gotha G.IV operated from occupied Belgium from the Spring of 1917. It mounted several raids on London beginning in May 1917. Some reached no further than Folkestone or Sheerness on the Kent Coast. But on June 13, Gothas killed 162 civilians, including 18 children in
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