Introduce F-35
Boeing and McDonald Douglas jointly developed the X-32. Now, the two companies have merged. Both X-32 and X-35 are proof-of-concept machines. After a comparative test flight, the US military will choose one of them to enter the engineering manufacturing and development stage.
JSF will match the F-22 fighter developed by Lockheed Martin of the US Air Force, just like the relationship between F- 16 and F- 15. In order to achieve low cost, its output should be large, so it should have a wider scope of application. Accordingly, JSF will have a variety of modes, namely: 1. Air Force conventional take-off and landing aircraft (CTOL), and the target purchase price is 28 million US dollars per aircraft (1.994 currency, the same below); Second, the US Navy's conventional take-off and landing aircraft carrier type, with a unit price of 34 million US dollars; Third, the short takeoff vertical landing model (STOVL) used by the US Marine Corps and the British Navy, with a unit price of 3 1 10,000 USD. Due to the limitation of the cost target, the Air Force indicated that it initially needed 1 763 CTOL models, and may also need 3 squadrons of STOVL models, so as to make a quick response to the close support mission. The us navy needs 400 ~ 500 JSF that can be carried. The Marine Corps said it needed 609 STOVL models. The Royal Navy first needs 60 STOVL models to replace "Sea Harrier" (whether it is 1 replacement 1 has not been decided).
For the US Air Force, JSF should not only replace F- 16 for air control and tactical weapon delivery, but also replace A- 10 for close air support. When replacing A- 10, the military hopes that JSF will not be destroyed by ground fire like A- 10, but it mainly relies on technical means rather than armor to achieve this goal. In addition, JSF will have a larger scope than A- 10. The expected weapon can be seen in the left picture. Including all kinds of ordinary bombs, laser-guided bombs, JDAM, JSOW, GPS-guided HARM anti-radar missiles, SLAM cruise missiles, Mavericks anti-tank missiles, all kinds of air-to-air missiles and 27mm Mao Se cannon (later changed to GAU- 12 25mm five-tube gatling cannon). In April, 2004, the U.S. military confirmed that all types of JSF will be able to load eight small-caliber bombs (SDB) developed by Boeing in the weapon cabin, or hang small-caliber bombs outside the aircraft. An official of the JSF project office of the U.S. military said that increasing the number of SDBs loaded in aircraft weapon cabins will be one of JSF's long-term goals to enhance its combat capability, but the specific increase number has not been disclosed.
For the US Navy, JSF will take over the air and attack missions of F/A- 18A/B, as well as the tactical weapon delivery and deep attack missions undertaken by the older A-6. The navy hopes that JSF and F/A- 18E/F will undertake the dual tasks of air control and attack together. The specific collocation of shipborne JSF and F/A- 18E/F is uncertain. When replacing A-6, JSF will be used as a medium bomber for night and low-altitude penetration, which is the same as the design task of A-6. However, JSF must also have the ability to attack during the day. When performing such a task, JSF must use advanced technology to avoid excessive losses in the battle. To this end, JSF will have stealth and long-range missile launch capabilities.
For the Marine Corps, JSF of STOVL will take over AV-8B, and use its short takeoff/vertical landing capability to perform short-range support, beachhead support and battlefield attack tasks. It will also replace F/A- 18 of the Marine Corps to undertake air control and attack tasks. The US Marine Corps hopes that the STOVL aircraft can have the range and load of F/A- 18, and the ability to quickly accelerate to supersonic speed. How to combine stealth, STOVL capability and supersonic capability into an airplane may be the biggest technical challenge that JSF plans to face. There are other factors to consider when designing marine corps aircraft. The tasks of the Marine Corps sometimes need to be completed alone, without the support of other arms, and they can only fight with relatively few resources. This makes the Marine Corps need an independent weapon system.
For the Royal Navy, JSF will be used to replace several existing Harrier fighters to perform air control and attack tasks, and it is required to take off from the existing light aircraft carrier in a short distance. Under the premise of not exceeding the weight requirements of the US Air Force, a unique aircraft/engine combination must be adopted to meet the requirements of the US Navy, Marine Corps and Royal Navy. At present, it is estimated that the JSF of the US Marine Corps and Royal Navy is 500~ 1000 pounds (227~454 kilograms) heavier than that of the US Air Force, while that of the US Navy may be 1500~2000 pounds (68 1~908 kilograms) heavier than that of the US Air Force.
All these types of JSF will be produced on the same production line, using the same engine optimized for CTOL and STOVL, and using as many common components as possible. In addition, all JSFs must use the same common support and maintenance system. JSF is not only the first fighter to meet the needs of multiple services for many years, but also the first fighter to produce multiple configurations on one production line. Moreover, the main driving force of the project is to reduce costs, which was not available in previous projects.
At present, both sides participating in the JSF competition have chosen the new modification of F- 1 19 produced by Pratt & Whitney as the power plant. According to the project manager of Pratt & Whitney's large military engine department, the improved JSF engine has greater thrust and better maintainability and support ability. The engine is designed to be managed automatically. It can not only feel the fault before it happens, but also compensate the damaged electronic components so as to continue working without these components. When there is a fault, the system will automatically send a signal to the aircraft base to report the fault, so that maintenance personnel can prepare spare parts and replace them immediately after the plane lands. In order to speed up the replacement work, the engine is designed so that all components installed outside the frame can be removed and replaced in 20 minutes or less.
Because the two competitors have different requirements for aircraft, Pratt & Whitney is required to develop two slightly different F- 1 19 improvements to meet the respective needs of each competitor. Boeing F-/KOOC-0//KOOC-0/9 engine code is JSF//KOOC-0/9-SE6/KOOC-0/4, and Lockheed Martin engine code is JSF/F/KOOC-0/9-SE6/KOOC-0//KOOC. The difference between these two engines is mainly due to the difference of vertical lift systems adopted by two JSF airframe manufacturers. Boeing adopts the guide groove layout, which is a bit like the lift system used by Haiyan engine (the picture above shows Boeing version F- 1 19). Lockheed Martin chose the lift fan system to achieve vertical flight. Boeing's engine has a nozzle similar to YF-22, and Lockheed Martin's engine uses axisymmetric nozzles similar to those used on F- 15 and F- 16.
JoeOberle, director of JSF business development department of Lockheed Martin, said: "The components used in the JSF verification machine are not necessarily the same as those used in the development of aircraft. Companies that provide aircraft parts now may continue to provide products for JSF in the future, but not necessarily as before. Soon we will ask for detailed information from various manufacturers and then choose suppliers based on the information we have obtained. " Among all systems, radar and airborne equipment are the most noteworthy. Blot said: "Now, microprocessors become backward every 18 months. We must not only make a system that will not fall behind quickly, but also make it have a lower life cycle cost. " Oberle said: "It is very important to choose the airborne equipment system to control the total cost of the aircraft. If an airborne equipment system can be adopted by various services, it can save 654.38+0.6 billion dollars every year. In addition, the airborne equipment system must be easy to upgrade. The simplest way is to design it into an open structural system so as to use various shelf products in the future. "
The partners of the X-35 project are Northrop Grumman and British Aerospace. They are chosen not only because of their business ability, but also because of their technology and experience. Northrop has rich experience in material technology, component manufacturing and molds. By developing the B-2 bomber, it has a strong ability in stealth technology. Grumman has the same experience in shipboard adaptability and shipboard use of carrier-based aircraft. The airborne equipment department of Grumman Company once belonged to Westinghouse Company, and it has profound attainments in system integration. BAE not only has advanced material manufacturing experience, but also has knowledge of system integration. Especially in the development and maintenance of STOVL fighter, the company's experience is unparalleled. Lockheed Martin aims to make all research and improvement projects available for JSF engineering manufacturing and development in 200 1 year.
In Boeing's design, the user can remove two annular nozzles and block the holes after the nozzles are removed with a flat plate, so that the STOVL engine is the same as the CTOL engine. Lockheed Martin JSF engine, as long as the rotating tail shaft is replaced by the non-rotating tail shaft, and then the driving shaft is removed from the lifting fan, the STOVL engine is exactly the same as the CTOL engine. On two F- 1 19 engines used in JSF, the low-pressure turbine was changed from one stage to two stages, and the cross-sectional area of the engine fan was increased by 10%~20% to increase the air flow. In these two types of engines, most components are common. In fact, 100% of the rotating parts of the turbine structure of JSF engines used by the US Air Force, Navy and Marine Corps are universal. The navy JSF is heavier than the air force JSF, because it enhances the structural strength and is used to bear the load of ejection and landing.
Before the real first flight, Pratt & Whitney tested each type of engine for 30 thousand hours. The initial test flight was conducted at Edward Air Force Base, and then the STOVL test was conducted by the US Navy. After the proof-of-concept stage is completed and the weapon system developer is selected, Pratt & Whitney will enter the engineering manufacturing development stage, during which it intends to produce about 30 experimental engines. This phase is planned to start from 200 1. Only considering the orders from the United States and Britain, the output of JSF engines will be close to 3000 units.
Boeing re-established its position as a fighter manufacturer by developing the F-22. In the initial concept development stage (CDP) of JSF competition, the company plans to prove not only the vertical lift system of its circular nozzle, but also its new design, manufacturing technology and its latest progress in aerodynamic research. Statkus, director of JSF project of Boeing Company, said: "At present, we are about to complete 25% of CDP phase. We are considering the technology that can be used for the preferred weapon system scheme, and we are also considering the technology that can be used in the concept development stage. "
Boeing is currently designing its preferred weapon system (PWS). Statkus said, "We have made great efforts to control the weight and cost of the aircraft in the conceptual development stage and the optimal weapon system scheme to ensure that the factory cost of PWS aircraft can be predicted reliably in the future.
Boeing is about to complete the tooling design of the X-32 proof-of-concept machine, many of which are produced in Boeing's Palmdale factory in California, and some processing machines are also installed here, and Boeing's JSF proof-of-concept machine will also be manufactured here. About the middle of this year, Boeing will begin to study two JSF schemes. Statkus said that the hardware design has been completed on time, and many major components are within the specified weight limit. Component processing of two JSFs is carried out simultaneously. Many of the hardware of these two concept research machines are the same, which is conducive to reducing costs. Perhaps more importantly, Boeing's research institutions have been put in place and the flight test institutions are being set up. The picture on the right is a schematic diagram of the component structure of the X-32.
Statkus said that in the concept development stage, we have obtained many improved shelf products from JSF suppliers. We have to make further choices on aircraft parts, but most subcontractors are waiting in line. For each option, Boeing tries to find the processing power that can be used in JSF already in the company. We use the processing capacity to control the weight, control the cost, select materials and determine the division of labor within Boeing. Boeing assembles its JSF proof-of-concept machine here, because the factory in Palmdale, California can provide lower production costs than other departments of the company. If Boeing can win the contract, JSF will also be produced here. There is an engine test-bed in Palm Valley, and now everything is ready. In addition, it is not far from the Edward base of the US Air Force, where JSF's proof-of-concept machine will be tested.
The design idea of Boeing X-32 is based on the dual consideration of economic affordability and the ability to meet various operational needs. Strother, commercial development director of X-32 project, said that although there are several types of JSF, they all have the same mold line, that is, their external dimensions are the same. X-32 hopes to use two deflectable nozzles located in the middle fuselage to make the exhaust of the engine downward to obtain STOVL capability. The X-32 uses a deflectable nozzle similar to that used by Harrier. With the acceleration of the aircraft, the lift generated by the wing will replace the lift generated by the engine, and the nozzle can gradually turn to the rear. During STOVL flight, the X-32 needs to be balanced by the airflow at the tail of the aircraft, which rotates downward through a two-dimensional vector nozzle. The nozzle is integrated with the fuselage structure and bears the load. With the acceleration of the aircraft, the airflow of the engine will gradually turn to the nozzle at the tail of the engine and be discharged from the circular nozzle in the middle of the fuselage. Flight control and pitch control during hovering or STOVL flight will be provided by deflected airflow from different nozzles. Roll control is provided by small vents on the wing. When these nozzles discharge hot air downward, a vertical baffle will rotate downward from the front fuselage to prevent the hot air discharged from the engine from being sucked into the engine intake. When the annular nozzle is completely backward and the thrust is distributed to the rear exhaust pipe of the engine, the nozzle in the middle of the aircraft will be covered by the small doors around the nozzle. High priority is given to the consideration of weight, and neither the STOVL JSF nor the Navy JSF (which needs to be strengthened to meet the landing requirements) has greatly changed its weight because of the additional system. However, compared with the other two JSFs, STOVL JSF still reduces the internal weapon loading. Other types of JSF can carry weapons loads similar to A-6.
In the original design, the X-32 had a large wing-body composite delta wing. In order to reduce the manufacturing cost, a monolithic structure is adopted. The wing tip has an extra part that can be removed when performing tasks on board. However, in the detailed design, Boeing thought that this scheme was not enough to give the X-32 enough maneuverability, so it added two tails. Compare the left picture with other pictures, and you can see it. But what remains unchanged is that all the fuel except the US Navy model is installed in the wing. The upper and lower surfaces of the wing are covered with a symbol and a material respectively. In addition, the X-32 is designed with high fuel efficiency and long range. Moreover, its signal feature design is relatively balanced, and Boeing attaches as much importance to JSF's infrared signal feature and visible signal feature as to its radar signal feature.
All JSF models of Boeing will have the same airborne electronics and cockpit at least in the initial stage. The fuselage is designed into three parts, and the tail part includes an integrated engine nozzle, but there is no separate tail flight control surface. When the navy JSF lands on the ship, a vortex generator fence will appear on the upper surface of the wing to help the aircraft maintain a high angle of attack. Boeing also designed the middle of the fuselage to adapt to three types of aircraft. The front fuselage can be used for single-seat and two-seat models. Although no one has considered two-seat JSF yet, Boeing predicts that there may be a demand for two-seat coach JSF in the future.
Boeing has won many points by using its rich experience in manufacturing, maintaining and supporting civil aircraft around the world. This also enabled mcdowell to quickly and comprehensively join the research project of JSF, so as to make use of the company's rich experience in fighter development. Because Boeing airframe manufacturers have participated in most military aircraft projects including mcdowell in the past 20 years, they have accumulated rich experience and test data. One of the innovations is the automatic numerical control coding technology, which enables designers to embed instructions into automatic processing machines for blank cutting and forging at the initial design, and also enables one machine to process two identical parts at the same time. In the test, the parts that used to take 30 days to process took only 8 hours to complete.
Boeing has recently successfully developed a low-profit titanium processing technology, which can reduce the amount of titanium used in production, so that some parts can be cast with a titanium ingot, and then only a small amount of processing is needed. In addition, the possibility of developing large military spare parts storage and transportation equipment is also studied. At present, its civil aircraft support equipment in Seattle can deliver any parts of any Boeing aircraft in service to its destination within 2 hours after receiving the application.
Let's take a look at Lockheed Martin's JSF development plan -X-35. In the past 30 years, the company has produced a variety of high-performance fighters. Lockheed Martin decided to use lift fans in JSF based on the data they obtained in past research projects. HarryBlot, deputy manager of JSF project of Lockheed Martin, said that the design of lift fan can transform enough air into vertical airflow needed for aircraft hovering without increasing the cross section of engine fan, thus avoiding the drag generated during supersonic flight. The fan can be regarded as a horizontal turboprop engine. When the aircraft hovers, double airflow is generated below the aircraft, so that the front section of the aircraft does not exceed the design level of the traditional aircraft, so the ability of the aircraft to fly at supersonic speed is not affected.
There are other advantages to adopting the lift fan scheme. It can reduce the downward deflection air velocity of 33% and the air temperature of about 250 F. The fan driven by the main engine of the aircraft can generate a cold air thrust of 18000 pounds (8 172 kilograms), which reduces the possibility of the forward inlet sucking hot air from behind the engine. Lockheed Martin believes that the lift fan scheme is the only feasible lift system for aircraft like JSF, which is larger than Harrier and has greater load and range. The company believes that the lift fan layout has three obvious advantages in providing vertical lift for JSF: first, it provides greater load under certain thrust; Second, improve the impact of downward airflow on the ground; Thirdly, the forward cross-sectional area of JSF inlet is reduced, thus reducing the windward area of the aircraft, which is beneficial to supersonic flight.
Blot said that in order to inhale enough air for vertical flight, Harrier has two huge air intakes protruding from both sides of the plane, which makes it difficult for the plane to reach supersonic speed. Lockheed Martin's JSF design not only has a small air inlet, so that it can be used at supersonic speed, but also can suck in the surrounding air when the valve at the top of the fuselage is opened. When the airflow flows through the fuselage, it can be accelerated by the lift fan, so as to obtain the airflow needed for hovering flight. This downward airflow formed by ambient air can completely block the forward hot airflow. And it can provide enough lift at the front of JSF to balance the thrust generated by the downward deflection of the hot gas nozzle at the tail of the aircraft. The development of this new lift fan used in the X-35 was jointly completed by Lockheed Martin's Skunk Task Force, Lockheed Martin and Allison. The next step of the X-35 is to verify the maneuverability of the aircraft and the acceleration of radar, airborne equipment and aircraft.
Boeing will complete the operation test of the X-32 engine in the near future, thus making the proof-of-concept machine of the X-32B fighter another step towards the first flight. As part of the construction of short takeoff and vertical landing (STOVL) aircraft, Boeing's test team carried out the transition of airflow, that is, the reverse test of engine thrust. The engine used in the test is Pratt & Whitney F 1 19-6 14 engine, and various power settings are tested to verify the completeness of the system. The power setting range simulates the representative thrust diagram required by the normal flight of the aircraft. More than 500 tests were carried out on the short takeoff and vertical landing engine test-bed. The transition time from normal horizontal thrust to vertical thrust or from vertical thrust to conventional horizontal thrust is always 1 ~ 3 seconds. All components of the propulsion system work normally as designed and predicted. In addition to the running test of the engine, another working group of Boeing is conducting a series of durability tests at Pratt & Whitney test station in West Palm Beach, Florida, to obtain the certificate of short takeoff and vertical landing flight of the engine.
The four verification machines currently being produced-two X-32s and two X-35s-are only aircraft in the conceptual development stage (CDP), and the airborne equipment of aircraft entering the EMD stage may be quite different from it. On the other hand, however, modern computer technology enables people to develop and verify many systems used on EMD aircraft in CDP stage. At present, some system manufacturers have made choices, and these choices cannot be changed in the future unless they spend a lot of money. Therefore, some CDP aircraft system and component manufacturers will also become the final manufacturers of aircraft.
On Lockheed Martin's X-35, the lift fan will be designed by Allison Advanced Development Company and produced by Allison Engine Company. Rolls royce, the parent company of these two companies, will produce the rotor of lift fan, the vector nozzle at the tail of engine and the rolling nozzle of suspension flight control system, which are also developed by rolls royce.
In addition, after Boeing or Lockheed Martin entered the EMD stage, other companies were striving for equipment development contracts:
Raytheon Texas Instruments is designing and developing a central processor for Lockheed Martin's EMD JSF.
General Electric Aircraft Engine Company in Ohio is developing the next generation engine, and plans to start advanced testing or put it into use before 2007.
Moog company in New Jersey has signed contracts with Boeing and Lockheed Martin to produce JSF actuators for CDP phase. Later this year, Moog will also deliver weapons doors, leading edge flaps and generators to two major contractors;
EDO company in New Jersey is developing a hydraulic drive arm, which can move the weapons carried by JSF from the inside of the bomb bay to the external launching position.
Sanders Electronics of Lockheed Martin is developing electronic warfare systems for Boeing and Lockheed Martin ·JSF. No matter which company wins, this electronic warfare system will be installed on JSF prototype in EMD stage. Saunders is also a member of the Lockheed Martin ·JSF fighter CPU development team. TRW Airborne Equipment System Company participated in the development team of communication, navigation and identification of friend or foe (CNI) systems of Boeing Company and JSF Lockheed Martin Company.
Northrop's Electronic Sensors and Systems Division (ESSD) is developing integrated RF systems and multifunctional sensor arrays for Boeing and X-32, including active electrical scanning arrays for multifunctional radars, electronic warfare systems and CNI systems. In addition, Northrop has developed several photoelectric systems for JSF, including multifunctional infrared distributed aperture system.
MPC products will produce electromechanical actuation systems and motors for opening weapons doors, measuring the movement of engine nozzles, driving flight control systems and providing power for cooling and environmental control systems;
TEAC USA will provide durable miniaturized airborne video recorders for Boeing and Lockheed Martin JSF in CDP phase to record the data obtained by TV and other sensors;
Selma is designing the canopy for the X-32. This integral canopy is improved from the canopy developed for the F-22.
Hamilton Standards and Honeywell are cooperating to develop the X-32 airborne management system. Hamilton Standard Company develops the environmental control system, and Saunders Chuangde Company is responsible for the secondary power supply system and power distribution system of the aircraft.
Lianxinnan Bender is leading several other companies to design, manufacture and assemble landing gear systems for the X-32.
BFGoodrich Aerospace Company in Ohio is conducting comprehensive research on fuel management, thermal management, fire source detection and other systems for the X-32.