The original idea of building the B-2A bomber began with 1975. At that time, the "Advanced Planning Agency" under the US Department of Defense released a project code-named "Harvey", which was implemented in the Air Force, from which the XST (Experiment, Stealth and Combat) plan was derived. In this plan, the idea of applying stealth technology to aircraft was first put forward. Lockheed, which has rich experience in military aircraft development, first won the military development contract and soon produced two full-scale XST prototypes, which initially proved the feasibility of stealth technology applied to aircraft. 1977, the "cold war" is still raging. In order to sneak into the Soviet airspace, discover and destroy the Soviet mobile intercontinental ballistic missile launcher and other important strategic targets in depth, the US Air Force proposed to build a new type of strategic bomber, requiring it to sneak into the enemy's depth, and the success rate of completing the task reached 80%. Therefore, the Air Force has drawn up the plan of "Saber Armor-piercing Projectile" and put the application of stealth technology on the concrete agenda. Because the prototype submitted by Lockheed was well received, the Air Force awarded the contract for the production of F- 1 17A stealth fighter to this company. With the production of stealth fighters, the US Department of Defense and congressional dignitaries also began to accept the concept of "stealth bombing alum", and officially approved the application report of the Air Force to develop such aircraft in 1979. The following year, the US Air Force held a public tender for the development of "Advanced Strategic Penetration Aircraft (ASPA)", and Northrop's proposal was approved. Subsequently, the US Air Force officially named the development project of the aircraft "Advanced Technology Bomber (ATB)", which is the original name of the B-2 stealth strategic bomber.
In the early 1980s, the design of B-2 underwent several major changes. For example, 1984, the design of the main wing of the aircraft has been greatly changed, because the air force requires the aircraft to penetrate not only from high altitude, but also from ultra-low altitude, which brings a series of problems, such as improving the lift of the aircraft, enhancing the strength of the mechanical structure and further reducing its radar reflection cross section. It took several years to finalize the design of this plane. 1On April 20th, 988, the US Air Force showed a hand-painted color picture of the B-2 aircraft for the first time, which shocked the world. People in the aviation industry and many military enthusiasts were amazed at its unique shape. In the same year,165438+1October 22nd, the B-2 prototype bomber with the number AV- 1 finally "only after we called for a thousand times, did she start flying towards us", which became a behemoth that the American public rushed to see, and military publications all over the world also rushed to report. But since then, B-2 has disappeared for several years. During this period, it experienced many secret flight tests and strict inspections by the military, and the manufacturer had to constantly make design modifications according to various opinions and harsh requirements put forward by the Air Force. Five years later, the US Air Force finally launched the first B-2A aircraft on June 5438+0993+February 17.
On April 2nd, 1997, the first batch of six B-2A stealth bombers officially served in the US Air Force, and another 15 will be delivered to the troops as planned.
keep secret
B-2 is an extremely dense weapon system in the United States. Since the Manhattan project to develop atomic bombs during World War II, no weapon system has been placed under such strict protection as B-2.
As early as1September 1980, the US Air Force asked Lockheed and Northrop to make suggestions on the advanced technology stealth bomber (ATB) plan from five aspects: performance, cost, logistics support, project management and safety. The top secret code of Lockheed's scheme is SeniorPeg, and the top secret code of Northrop's scheme is Seniorlce. 198 1 10 Northrop won the contract and changed the top secret code name to SeniorCJ to commemorate CJ Kelly, the deputy director of the US Air Force in charge of stealth aircraft who died of cancer not long ago. The main subcontractor is Boeing, which is responsible for the rear middle section, outer wing, fuel system, weapon launching system and landing gear of titanium alloy. To this end, Boeing employs-10/0,000 employees. LTV is responsible for the middle wing, aluminum-titanium alloy structure and composite structure, and employs 4000 people for this purpose.
General electric company provided f119-ge-110 turbofan engine with thrust of 84.5 kn (19000 lbs). Northrop's 12000 employees are responsible for manufacturing the front middle section, cockpit and final assembly.
1On April 8, 982, Northrop bought an idle factory of Ford Motor Company in Pi Corihuela, a suburb of Los Angeles, and transformed it into a windowless and strictly confidential factory. The whole company is under the 24-hour surveillance of the army and security personnel, and the planned expenditure for B2 aircraft security measures is as high as 2 billion dollars. For example, in order to prevent the former Soviet submarine from sneaking into the California coast, the computer software system of the B-2 project was detected by electronic technology, and the room where Picasso's CAD/CAM terminal equipment was located was surrounded by a special metal plate that could not be penetrated by electromagnetism. In addition, each computer is equipped with a special cover to prevent unauthorized people from seeing the information on the computer. Thousands of workers in key positions must pass the polygraph test to prevent spies from mixing with drug addicts. The requirements for senior managers are stricter, and only a few people know all the details of the plan. A vice president of Northrop was forced to change his nationality and become an American citizen before he was allowed to participate in the B-2 program. In order to better keep the secret of Bike Lavra, a fake company was set up in other areas, accepting parts from subcontractors and transferring them to Bike Lavra by unmarked trucks in the middle of the night. All air force officers have to change into civilian clothes before they can meet Picasso. And in Congress-* * only eight members know about it.
The stealth B-2A bomber has a fuselage length of 2 1.03m, a height of 5. 18m, a wingspan of 52.43m and a maximum bomb load of 22,680kg. This plane is equipped with four F 1 18-
GE- 100 turbofan engine. Without aerial refueling, the combat range can reach1.2000 km, and once aerial refueling, it can reach1.8000 km. The air flight time of each mission is generally not less than 10 hour, and the US Air Force claims to have the ability of "global arrival" and "global destruction". B-2A integrates various advanced technologies, and is praised by experts as "a milestone in the development history of military aircraft in this century" because of its outstanding stealth performance. It is reported that the radar reflection cross section of the B-52 bomber is 1000 square meters, that of the MIG -29 is 25 square meters, that of the B-lB is less than L square meters, and that of the B-2A is less than 0. 1 square meter, which is only equivalent to the radar reflection cross section of a bird in the sky, and it is difficult to find by general radar. So where does this invisibility come from?
The stealth performance of B-2 first comes from its shape. The overall appearance of B-2A is smooth and round, without "wrinkles", and it is not easy to reflect radar waves. The cockpit is curved, where lightning flashes.
Dabo will "crawl" around the shape of the hut without being reflected back. The sealed glass hatch cover is inclined, and all the glass is doped with metal powder during manufacture, so that radar waves cannot penetrate the hatch body and cause diffuse reflection. The wing is swept back 33 degrees, so that the radar waves incident from up and down cannot be reflected or refracted back to the direction where the radar is located. There is an irregular honeycomb cavity on the back of the coating on the leading edge of the wing, which can absorb radar waves. There are two W-shaped wings in the rear half of the wing, which can make the detection radar waves from the rear of the aircraft unable to reflect back. Moreover, the B-2A has no vertical tail, which greatly reduces the radar reflection cross section of the whole aircraft. There is no weapon cabin and weapon rack under the fuselage, and even the engine cabin and landing gear cabin are buried under the smooth wing to avoid the reflection of radar waves. The whole fuselage of B-2 aircraft is made of carbon fiber, graphite and other composite materials except the main beam and engine room, which is not easy to reflect radar waves. In addition, these different composite parts are not assembled by rivets, but by high pressure die casting. In addition, the leading edge of the alum wing is completely covered with a special absorbing material (RAM). The two square protruding parts located in the front of the wing and equipped with radar scanning antenna array also use special absorbing materials. In addition, B-2A is coated with special absorbing coating, which greatly reduces the echo of enemy detection radar.
In order to meet the need of stealth, the engine inlet of B-2A aircraft is placed above the wing in an S shape, which makes the incident detection radar naturally attenuate after repeated refraction and cannot be reflected back. The nozzle of the engine is deeply placed in the wing, which is also honeycomb-shaped, so that radar waves can enter but not exit. In addition, the engine assembly is also equipped with an airflow mixer, which can guide the cold air flowing through the airfoil into the engine and continuously reduce the outer temperature of the engine. The nozzle part is wide and flat, so people can't see the nozzle at the tail of the plane. Especially, due to the nozzle temperature adjustment technology, the infrared exposure signal of the nozzle part is greatly reduced, and the stealth performance of the aircraft is greatly enhanced.
mobile system
There are many advanced airborne electronic systems on the B-2A aircraft, such as detection, navigation, aiming, electronic countermeasures and other systems, each with its own advantages and extraordinary functions. As far as detection radar system is concerned, it usually plays the role of "eyes" for aircraft. An /APQ- 18 1 radar is used on B-2A, which is made by Hughes Company and has the advantages of narrow frequency spectrum and difficult signal interception by the enemy. This electronic scanning phased array radar system has two radar antenna arrays, and its characteristic is that it can scan in different angles and directions only by changing and combining the positions of signal arrays without additional rotating or swinging antennas. Its working frequency is 12- 18GHZ, with small sidelobe and strong anti-electronic interference ability. There are 2 1 working modes * *, among which the most prominent are synthetic aperture radar working mode and anti-synthetic aperture radar working mode. The former is mainly used to scan the land landforms, and can clearly obtain the land radar scanning images with the distance of 1, 6 1km, so as to be used by aircraft when bombing ground targets; The latter is mainly used to identify and capture maritime targets, and the longest effective distance can reach 128 km. In addition, these working modes also allow the B-2A bomber to use terrain matching and terrain avoidance technology, so that it can penetrate enemy airspace at low altitude and carry out bombing missions.
The B-2A is also equipped with an advanced NSS navigation system. Two kinds of navigation devices are installed in the system, one is inertial navigation device, and the other is NAS-27 astronomical navigation device. They can provide advanced automatic navigation and the most commonly used constellation positioning navigation for B-2A respectively to ensure flight safety.
The target aiming system on the plane adopts the global positioning auxiliary aiming system, which can lock the selected target and enlarge it by 4 times, which greatly facilitates the crew to identify and aim the target, thus greatly improving the hit accuracy of the bomb. According to the United States, with this positioning auxiliary aiming system, the error of a bomb hitting the target is usually less than 6 meters.
The B-2A is also equipped with an electronic warfare system of APQ-50 model. The system can not only provide radar early warning for aircraft, but also quickly detect the azimuth coordinates of enemy radar. The ZSR-62 active electronic warfare system on the plane can quickly and actively interfere with and suppress the enemy.
There are also some other electronic systems on the plane, such as communication management system and various display systems in the cockpit, which can display the information and images obtained by all sensors in combination for the crew to judge the processing situation and contact with relevant departments on the ground. In front of the seats of the two crew members, there are four full-color multi-function display screens with the size of 15.2 cm respectively, which makes the situation clear at a glance.
Bomb carrying capacity
The B-2A bomber can carry 16 AGM- 129 cruise missiles, 80 MK82 or 16 MK84 ordinary bombs or 36 CBU-87 cluster bombs. When using the new TSSM long-range attack ammunition, the carrying capacity is 16. When using nuclear weapons, you can carry 16 B63 nuclear bomb. In addition, AGM- 129 cruise missiles can also carry nuclear warheads.
According to the actual situation of the Gulf War, the US Air Force calculated the bombing capability of B-2A. Take the "attack task force" commonly used by the US military to bomb Iraqi targets as an example. It usually consists of 16 attack planes carrying precision guided bombs, 16 escort fighters, 4 accompanying electronic jammers, 8 ground attack planes suppressing ground air defense firepower and 7 KC- 135 tankers. The bombing effect of these 49 planes can be achieved with eight F- 1 17A and two KC- 135 tankers. If you change to B-2A, you don't need to refuel in the air. You only need two planes and four crew members to take off from Diego Garcia base in the Indian Ocean.
In the future, as the US military gradually equips its troops with the Joint Direct Attack Ammunition weapon system, B-2A aircraft may also carry this weapon. At that time, B-2A only played the role of ⑸ ⒀ ⒀ ⒀ ⒀? You can go home or go on the next mission, because the JDAM weapon itself carries the last bomber. In America, B-2 always seems to be the focus of media attention. Once upon a time, journalists trumpeted it and crowned it as the "ultimate weapon"; In recent years, it has been criticized as an "expensive high-tech toy". However, whether it is good or bad, there is an undeniable fact that B-2A is good, but expensive.
1978, when the manufacturer won the contract to develop B-2, the quotation for producing 132 aircraft was $36.6 billion. By 1984, the manufacturer's total offer had risen to $42.5 billion, which forced the US Air Force to reduce the number of orders. 1987, the us air force decided to buy only 75 aircraft, but it still had to pay $35 billion.
1993, when the us congress decided to buy only 20 B-2A aircraft, the research and development expenses paid in advance by the air force and the start-up manufacturing expenses of the manufacturer amounted to $44.4 billion. In this way, even if the development cost is deducted, the cost of each aircraft is 840 million US dollars. 1995, according to the final contract, the manufacturer manufactured 20 B-2A aircraft at a production speed of 3 per year, and each aircraft cost about 600 million US dollars. Even so, if the development cost is added, the cost of buying a B-2A will exceed $2 billion!
Another important reason for making the B-2 channel sick is the difficulty in maintenance. A few years ago, when the B-2A was first equipped with troops, the maintenance tasks were basically completed by technicians from major companies, and the maintenance time per flight hour was 132 hours. After each flight mission is completed, the high-speed airflow will cause wear on the surface of the aircraft. In order to ensure that the stealth performance of the aircraft will not decrease, technicians need to repair the radar absorbing material on the surface of B-2A with a method similar to painting after each flight. The newly sprayed radar absorbing material must be dried and solidified at a certain temperature and humidity. Due to the lack of sufficient spare parts and perfect maintenance equipment, B-2A has been unable to be deployed in overseas bases, which is an unbearable regret for the US troops deployed around the world. Although the US military has used force overseas many times since the B-2A was equipped with troops, the B-2A has never appeared on the battlefield.
The high cost and complicated maintenance make it uninterested in any country outside the United States. Even in the United States, the production line of B-2 has been closed, and 90% of the more than 4,000 suppliers who provide accessories for B-2 have also used the production line for other purposes; Even Brigadier General Thomas Gosling, commander of the 509th bomber wing of the US Air Force equipped with B-2, has to admit that there will be no B-3 or B-4 in the next 20 years. Maybe 30 years later, people will find that the B-2 is just a brilliant afterglow in the history of bomber development.
The 1 unit equipped with the B-2 stealth bomber is the 393rd squadron of the 509th bomber wing. Now it has been equipped with the 20 th batch of 8 aircraft, which has initial combat capability.
The B-2 bomber was originally designed as a nuclear weapon carrier, and its basic weapons were B83 and B6 1 nuclear bomb. The maximum bomb load is 22,700 kilograms (50,000 pounds). It can also mount a variety of weapons such as short-range attack missiles, GPS-assisted guided bombs, joint direct attack ammunition, joint defense off-site attack missiles and conventional bombs such as MK82.
Operational mode and effectiveness evaluation
Can carry out multi-target attacks.
1June, 997 12, during the operational test at Baisha missile range in New Mexico, B-2 bombers dropped 16 JDAM guided bombs at a time. 16 bombs are aimed at the target groups respectively. The target group includes 8 targets in 2 areas, and 2 JDAM bombs attack one target.
B-2 stealth bomber has high comprehensive operational efficiency, and it is usually unnecessary to escort and suppress the support aircraft of the other side's air defense system when performing combat tasks by using its own stealth characteristics. The U.S. Air Force estimates that if two B-2 bombers use non-stealth fighters, they need 32 F- 16 fighters, 16 F- 15 escorts and several EF-11and EA-.
1On March 25th, 999, NATO bombed Yugoslavia with B-2.