Northrop B-2 Spirit

The strategic bomber Northrop B-2 Spirit is one of most famous the furtive planes current of the the United States.

Intended for the strategic Bombardment, it is without question the most expensive aircraft of the 20th century with unit costs - Research and development included - estimated between 1,157 billion and 2,2 billion dollars in 1998. However, it is not completely suitable to evoke an unit price for B-2 because of the small number of built specimens. It is delicate to extrapolate without taking account of the equipment and infrastructures, logistics and the formation within the framework of an industrial process of production.

The first flight of the prototype took place the July 17th 1989 and the first operational plane was delivered by the United States Air Force (USAF) at the end of 1993. At the end of 2006, USAF indicates that it should remain in service until 2058.

Design

This apparatus is presented like most powerful of the world in its category by the Armed forces of the United States. Many its characteristics remain top secret and some of those revealed can be of doubtful validity. The Department of Defense of the United States never revealed besides the exact parameters of mass and speed, employing the vague expression “subsonic top” to qualify them.

Origin of the program

As of the end of the Years 1930, the engineer John Knudsen Northrop, founder of the company Northrop was interested by the concept of the hang-gliders. In 1940, after 10 years of research, it exposed its first model called Northrop N-1M and organized a flight of exhibition intended to explore the possible performances of this configuration.

The American army was put to be interested in the project as of the beginning of the Années 1940. The United States Army Air Forces (ancestor of the United States Air Force), fearing the entry of the United States in the Second world war placed order near the aeronautical manufacturers. She asked a bomber with a Passable distance of: 10000 miles to anticipate the problems raised by the capitulation of the the United Kingdom vis-a-vis the Germany. It would be necessary for him to bombard the Europe under domination Nazi since the North America and to strike the Empire of Japan since the bases far away from the theater of operations of the Pacific.

Northrop proposed a plane based on this concept and the October 30th 1941, the preliminary order of the development of B-35 is confirmed.

End 1942, Northrop built the Northrop N-9M, a single-seater airplane being able to go to 400 km/h which was used to carry out XB-35, a bomber with 4 Turbopropulseur S and 8 contrarotating Hélice S of a scale of 52 meters. However, the first apparatus left factory only in 1946 because of problems of stability and spin recovery. Moreover, the appearance of the first jets during this conflict made obsolete the motorization to propeller. 11 of the 13 specimens of Northrop N-9M thus had to be modified by equipping them with 8 turbojets.

It was the project XB-49 of which the first of them flew in 1947. The tests appeared disappointing, an apparatus was lost and a second avoided the crash landing of little. The weak point of such apparatuses was their behavior in unhooking and their instability in vol. Finalement, the Strategic Air Command lately created chooses bombers with more conventional forms like the B-36 “Peacemaker” and the Boeing B-47 Stratojet and the XB-49 were reinforced between 1949 and 1953. The exit of the XB-49 was however glorious with an appearance in the film the war of the worlds left in 1953).

During its in-flight tests, the American soldiers discovered the Furtivité fortuitously; with each time the giant hang-glider approached the aerodrome constituting its destination, its weak equivalent Surface radar made that the Radar S had extremely evil to detect it.

This capacity gave a great interest to the plane during the Cold war because starting from the Années 1970, the anti-aircraft defense of the the USSR was so powerful that the apparatuses then in service in the Armed forces of the United States had little chance to penetrate inside its territory.

The American army then felt the need to have a bomber with minimal signature radar and the hang-glider was essential then as the most effective solution, progress of the Avionique and the use of electric orders of flight making it possible since the beginning of this decade to design naturally unstable planes like the F-16.

The Hang-glider Northrop B-2A Spirit started to be developed starting from 1978 in the greatest secrecy like Bombardier strategic, furtive or undetectable by Radar, with for mission of attacking the strategic targets Soviet with bends S and of the nuclear weapons drawn remotely from safety.

All is made so that it has signatures Infrarouge, electromagnetic , visual acoustics, and radar tiny.

B-2 began its existence in a “black” program, initially known as under the name of “project Senior C.J.” then under name “ATB” (Advanced Technology Bomber).

The project is hidden as well with the public as with the soldiers. Majority of the persons in charge of the US Air Force believer which the bomber B-1B was the priority n° 1, whereas only one handle of them knew the existence of the B-2 project. For the latter, the B-1B was a “temporary” weapon, while waiting for B-2 of which they envisaged to acquire 132 specimens.

Development and characteristics

Being based largely on designs of preceding hang-gliders like YB-49 conceived during the Years 1940 with the Fuselage included in the aerofoil, Northrop profited from the powerful support of Boeing (which carried out part of the principal structural components, the external wing, the fuel system, the system of delivery of armament and the Gear landing), Vought and General Electric, using a system of design and manufacture 3D computer-assisted to conceive the single shape of the wing in “W” of B-2. More: 100000 images of equivalent surfaces radar of models of B-2 and their components were analyzed to evaluate their characteristics of furtivity, then: 550000 hours of tests in Soufflerie were carried out. The program required the development of 900 new methods of design-manufacture, including new composite Materials high temperature and high strength and especially of the Radar Absorb Materials, of the tools of cutting ic Ultrason, of the tools to numerical control controlled by database 3D and of the systems Laser of detection of splits.

An experimental plane, the Northrop Tacit Blue, was built at the request of USAF and the Defense Advanced Research Projects Agency (DARPA) to test furtive technologies. It flew for the first time in February 1982 and accumulated 135 flights until 1985. It made it possible to collect many data which appeared very useful for the settling of B-2.

Northrop is responsible for the construction of the nose section and of the Cockpit, Boeing of the part power station-before and of the external section, and Vought produced the median section of the fuselage and the parts in Aluminum, Titane and composite materials.

Approximately 80% of the mass of B-2 make use of composite materials, in particular epoxy Graphite/in its structure in honeycomb intended to absorb the waves radar, carried out by the American subsidiary company of the company Saint-Gobain. To reduce its infra-red signature, the exhaust fumes of the 4 Turboréacteur S General Electric Aircraft Engines F118-GE-100 (derivatives of those equipping the B-1B, F-14, F-15 and F-16) is evacuated by conduits in the shapes of “V” assembled above and in withdrawal to mask these thermal sources with the terrestrial detectors. Acid chlorofluorosulphonic, derived from the Sulfonic acid , is injected into the wake of exhaust to prevent the formation of trails of Condensation. The leading edge out of arrow (33 °) and the trailing edge in tooth of saw trap the waves radar. Other passive countermeasures of detection include intakes air curved in form of “S” and furtive dielectric panels recover the Radar with synthesis of opening AN/APQ-181 Active Electronically Scanned Array (AESA) with operative passive electronic sweeping in Bande Ku (an improvement tested as from 2004 of radar AN/APQ-181 of origin and in front of being operational on all the fleet in 2010) and preventing its antenna from reflecting the enemy waves radar while allowing a normal functioning.

B-2 was initially considered as an apparatus of penetration to high-altitude but when its final design was fixed in 1983, one allotted to him an operational mission at low altitude. The integration of this new mission to original design ATB involved the displacement of the Cockpit and the air intake of the engines, the addition of elevon S interns (which gave him its distinctive profile in “W”), the modification of the leading edges and the important internal changes.

The cockpit is equipped for 2 pilot, with ejector seats Douglas/upwards evacuating Weber ACES II, and has sufficient space for a third team member or “a bag bed for the long missions” according to USAF. The pilot controls the Ordinateur mission which manages the designation of the targets (or their redesignation in flight). The navigation and the shooting of the armament are the responsibility for the officer system of weapons (WSO), sitted on the right seat. The 2 flight compartments lay out of 4 multifunction screens color. The aircraft is equipped with a quadruple system of numerical electric controls of flight controlling the control surfaces of trailing edge of the wings, combining the functions of aileron, of shutter and elevator which accounts for 15% of the surface of the wing. An embryo of horizontal Empennage is used as compensation of depth as well as shock absorber of gusts in co-operation with the ailerons.

To readjust the position of the objective at the last minute, the B-2A briefly activates its Radar with synthesis of opening Raytheon APG-181 equipped with electronic countermeasures and having 21 operating processes of which a mode of follow-up of lighting ground a minimal zone before launching its attack. It is equipped with an electronic system of Guerre integrating the detector of emissions radar AN/APR-50 (ZSR-63) of IBM Federals Systems and the secret system of defensive assistances ZSR-42. In 2002, it was decided to accelerate the programme of improvement of maintenance, of electronics as well as the capacity of carrying of new armaments. A contract was signed in 2004 to modernize its Avionique and to face the Obsolescence of sound Informatique and to equip it with a Liaison 16 .

During their service in the US Air Force which considers their potential structural at: 40000 hours of flight, the responsibility for the maintenance of B-2 is ensured by the Oklahoma City Air Logistics Center , of the base of Tinker AFB, for the electronic systems, by the Odgen Air Logistics Center , of Hill AFB) for the landing gear and by Northrop-Grumman, with Palmdale, for periodic maintenances.

B-2 lacking vertical surfaces for the marks of identification, those are registered on the trap doors of the principal landing gear which carry the code of the base, the serial number and at least on the 88-0329 the legends “ Spirit off Missouri ” and “ Follow Us ” (“Follow us”).

In-flight tests

With the general surprise, USAF, in April 1988, revealed a sight of artist of the apparatus which had been up to that point kept in the greatest secrecy. 6 prototype S (5 for USAF) were financed in 1982. The November 22nd 1988, the first apparatus (registered 82-1066) left the factory Air Force Seedling 42 of Palmdale, California. Northrop had organized an inaugural ceremony and had took great care to dissimulate the principal characteristics of the design of the wing, being arranged so that them: 2500 guests only see the apparatus before and since the ground, an air was especially made up for the occasion ( Stealth Fanfare ). A Photographe astute discovered that one had not prohibited the overflight of the factory and could obtain the first complete Photographie S of the plane thanks to a fast overflight in Cessna.

The inaugural flight took place July 17th 1989 (initially envisaged in 1987), when this apparatus (also indicated AV1/Air Vehicle One), was delivered to USAF with the bases Edwards to begin its test routine; the Test pilot chief of Northrop, the Lieutenant-colonel Bruce Hinds in station of 1982 to 1991 was with the orders. Envisaged the 15, this event was delayed by a failure of the fuel system. It was preceded by a series by tests wheelers at high-speed with a short lift-off by the caster by tail. October 19th, the 82-1067 joined the AV-1.

A test routine of: 3600 hours of flight was fixed, initial with 16 flights (67 hours) of certification and tests of handiness. Finished mid-June 1990, these tests also included/understood the first in-flight refueling with a KC-10 has, on November 8th, 1989.

A second series of tests began in October 1990, relating mainly to the furtive characteristics in real size. One could thus discover that furtive B-2 did not hold its promises exactly. In July 1991, the defects of furtivity were revealed, and it was admitted that it could be detected by radars on the ground of detection advanced with high power and the Russia affirmed that it would be vulnerable to the systems of ground-to-air missiles new generation such S-300PMU (SA-10/A “Grumble”) and S-300V-9M82/83 (SA-12A/B “Gladiator”). The following flights were stopped to carry out modifications on 82-1066 such whole of “treatments” on the leading edges and the airfoils to reduce the signature of the apparatus in certain frequency bands.

The tests of furtivity continued in 1993, while the 82-1067 carried out bearing tests and performances. The third apparatus (82-1068) accomplished its first flight on June 18th, 1991 and was the first model with being completely equipped with the new system avionics including the radar Hughes AN/APQ-181 LPI (with weak probability of interception).

The first dropping of weapons was carried out by the fourth apparatus (82-1069) which had taken the air for the first time on April 17th, 1992. September 4th, 1992, it released only one inert bomb Mk 84 of 908 kg. Intended to receive others weapons and to carry out climatic tests and of furtivity, fifth B-2 (82-1070) took its take-off on October 5th, 1992, followed by the 82-1071 on February 2nd, 1993. At the end of this year, the program had accumulated: 1500 hours of vol.

In February 1994, the apparatus was officially named Spirit (“Spirit”). This same year saw fusion between the companies Northrop and Grumman, another company which produced famous planes like the Grumman F-14 Tomcat.

With the end of the year 1997, them: 40000 hours of flight which were programmed were accomplished.

Financing

The problems of performances of B-2 did not help it in its fight for the financing in front of the Congrès of the United States.

The initial budget counted on a fleet of 132 units, including the prototypes, but in 1991, this figure had been tiny room to 76.

After the first six planes ordered in 1982, three others could be financed when B-2 was still a “black” project. In 1989, funds were resolved for three other units, then two in 1990 and finally two others in 1991. The Congress blocked then acquisitions with these 16 (15 for USAF) apparatuses.

USAF affirmed whereas it could not guarantee an effective operational capacity with less than twenty apparatuses. Thus in 1993 was approved the financing of five B-2 additional. This authorization of the financing was matched condition that the problems of Furtivité are solved so that the production can begin. The cost by plane (ready with the flight) was then of: 2220 million dollars.

Cost of the program

In 1987, the initial estimates of the program for 75 planes rose with a total of: 64700 million American dollars; In 1996, the US General Accounting Office estimates that the cost of the program with the 21 apparatuses built is of 44,785 billion dollars (value in 1996) it is not impossible that certain parts of the colossal budget of B-2 were devoted to other secret projects.

The maintenance in condition of the 21 apparatuses and their modernization costs on average nearly 700 million dollars per annum.

Each machine is worth between two and three times its mass in Or.

Options of Arme lies

B-2 is built around two large Soute S of armament placed side by side in the lower part of its central part. In front of each bay, small Spoiler S drops to produce swirls guaranteeing a good separation of the air-to-ground ammunition during the dropping.

Rotary launchers in the two compartments can receive a theoretical load of: 34020 kg, but it is limited in practice to: 18000 kg and according to the American regulation of the nuclear war (Before SIOP, Individual Integrated Operational Plan renamed OPLAN 8044, Plane Operational 8044 since March 2003), no nuclear load must exceed: 9072 kg.

It is able to carry to 80 traditional bombs Mk 82 of 227 kg, but it is too invaluable to be used like simple “truck with bombs”.

A exercise implying the dropping on the only one way 22 second old of 80 bends S of 227 kg “intelligent” JDAM guided by GPS on a zone extended with an accuracy of 10 meters to take place the September 10th 2003 successfully to Hill Air Force Bases, in the Utah. Such a mission of bombardment means that only one apparatus can from now on neutralize, for example, a Régiment mechanized with the stop in only one raid.

For the strategic missions with armament drawn remotely from safety, it carries 16 missiles of croières AGM-129A or AGM-158 JASSM. Its schedule of conditions of origin provided that it could also carry AGM-69A SRAM II withdrawn in 1990 before its startup or the AGM-137 TSSAM furtive whose program was stopped in 1994.

It can also carry 16 smooth nuclear bombs B61 and B63, is 16 conventional bombs Mk84 of 908 kg or 80 Mk82 bombs of 227 kg or 80 mines marinades Mk62 or of the GBU-37 of: 4700 kg, known as Bunker buster , destructors of bunker S as various others Ammunition S such bomb MOP ( Massive Ordnance Penetrator ) in the course of integration in 2007 which weighs 13,5 T and makes it possible to treat hardened objectives. It will be able to transport two bombs MOP in its side compartments. But it is to be provided that its autonomy will be reduced when it is armed with these gigantic bombs.

Other characteristics

Several specialists estimate that B-2 would use also active furtive techniques based on the électroaérodynamique one of which here the principle:

The leading edges are charged with positive electricity while flows of combustion of the Tuyère S are negatively charged. B-2 would thus transform into a condensing with a potential difference which would reach 15 million volts. The leading edges which are thus positively charged, cause a Ionization Air.

The resistance of the decreasing air, the performances of B-2 (speed, range operating, capacity of carryings) would increase. This cloud of plasma would create a electromagnetic Camouflage thus.

It is necessary to also note the Théorie of the plot of Jean-Pierre Petit (ex-director of research to the CNRS and specialist in this type of propulsion) which thinks that the “official” fleet of B-2 is used as screen with bombers hypersonic with very large operating range, able to fly to 60 km of altitude and to: 10000 km/h without creating shock waves.

See also: Magnetohydrodynamic, Magnétoaérodynamique

Engagement

Operational career

The 21 operational apparatuses depend on the 509th Bomb Wing (the squadron which carried out the two bombardments nuclear on Japan in 1945) based with Whiteman Air Force Bases (State of the Missouri) which is the single group of the US Air Force to being equipped with B-2. This one is composed of 2 escadrilles, the 325th and 393rd Bomb squadron. B-2 at least is constantly in California to be used as testing ground.

The first operational bomber was the Spirit off Missouri , delivered on the basis of Whiteman the December 17th 1993, the 90e birthday of the first flight of the Frères Wright.

The squadron was operational after the delivery of these 20 planes in April 1997.

USAF announces that some 50 hours missions would be possible, with however a good preparation and several in-flight refueling, which wants to say that these apparatuses can strike any point of planet.

The pilots of B-2 steal on supersonic planes of drive T-38 Talon to maintain the hours of flight necessary to answer their requirements of mission.

The black spot of B-2 is the fact that it is not easily spreadable because of the brittleness of its anti-radar coating, which prohibits to him to station outside its hangars too a long time. Known Hangar S dismountable pressurized under the name of B-2 Shelter System Extra Broad Spreadable Aircraft Hangar Systems were created to overcome this difficulty as from 1999; they cost between 2 and 2,5 million dollars part and require 29 exits of C-130 for their transport.

Its current Maintenance was a long time impossible apart from its single base of Whiteman because of the very specific logistical supports which it requires and which were available only on this basis until the creation of these dismountable hangars and construction on the basis of Andersen Air Force Bases on the island of Guam in the Pacific Ocean, of Diego Garcia in the Indian Ocean and of the base of the Royal Air Force of RAF Fairford in England of buildings which can receive it.

Improvements relating to the furtive coating of B-2 making it more resistant to moisture and requiring a reduced maintenance, grace in particular to a system of diagnosis of the furtive coatings, are currently in hand.

Its heavy maintenance makes that to the maximum the half of the fleet of B-2 can be used at the same time in operations.

At the time of the reception of the first planes, it was necessary to carry out a general revision every 200 hours of vol. In 1999, this time was increased to 600 hours.

Operations of combat

Its baptism of fire took place during the Guerre of Kosovo where on the 21 apparatuses, a pool of 9 took part in the operation '' Allied Force '', and a maximum of 6 simultaneously.

The March 24th 1999, two B-2 released their bombs on Yugoslav targets during a 31 hours mission.

After 11 weeks of operations, they carried out a total of 49 exits while taking off and landing of their base of Whiteman without stopover for missions from 28 to 32 hours, 45 droppings with approximately 700 missiles and bends S JDAM guided by GPS of which it was the first use with the combat, that is to say 11% of the ammunition released for less than one percent of the whole of the raids of Bombardement S carried out by NATO. 80% of the targets would have been destroyed as of the first master key.

Its targets were varied: terrestrial air bases and, bridges, administrative buildings but this countryside was marked by the bombardment of the Ambassade of the Popular republic of China to Belgrade on May 7th at midnight (local time); officially, this bur would be due to an error of address, the building having belonged before to the ministry for Yougoslave defense.

Six B-2 took part in the first three days of the operation Enduring Freedom , the American intervention in fine Afghanistan 2001, carrying out strike as of the first hours of the conflict Sunday October 7th 2001.

A mission lasted 44 hour S, the longest exit of combat in the history of the air war for a plane (a Zeppelin carried out a mission of 95 H in 1917), with the flight of B-2 de Whiteman as far as Afghanistan, the attack of its targets, a landing on the island of Diego Garcia in the Indian Ocean to restock with fuel, to rearm, take a new crew while the engines remained with the idle. This made, B-2 again went on Afghanistan to drop its loads, and finally returned in Whiteman.

The majority of the missions took off however this island.

Four B-2 also took part in the Opération release of Iraq in 2003 or they released 583 JDAM.

Alternatives and order of combat

Alternatives

Block 10

Apparatuses AV-7 with AV-16 were built according to the standard configuration Block 10 (B-2A-NO). This configuration limited B-2 to transport 16 bombs B83 or Mk 84, and restricted its use with missions from 2 to 3 apparatuses on the basis of Whiteman, but with the option to regain another base of the Air Force. The AV-12 until the AV-16 was put at the standard Block 20 into 1996/97.

Block 20

Apparatuses AV-17 with AV-19 were built with the standard Block 20. The configuration Block 20 made it possible the apparatus to carry 36 bombs or 16.900 kg of bombs JDAM. In parallel with the JDAM, GPS-Aided Targetting System (GATS) was also installed.

Block 30

The AV-20 and the AV-21 were built according to the final configuration, Block 30. This last allows the carrying of 80 bombs Mk 82 of 225 kg and mines Mk 62 or 37 Mk 117 of 340 kg. A satellite communication system by (Milstar) was added, and the system of planning of mission is entirely functional there as well as a Liaison 16 (military Intranet). From 1995 in November 2000, all B-2 were carried on this level, including the prototype which is since operational and can carry out missions of combat.

B-2C

A new version of the B-2A, known under the name of B-2C (C for conventional) based narrowly on the B-2A Block 30 was proposed fine 2001, it would have new current computers and radar much less expensive than those and its electronic would be replaced by the commercial Processeur S available immediately. This plan would imply the production of 40 additional B-2C over one 10 years period for total costs of 28 billion dollars. It has very few chances to be born.

List B-2 bombers

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