China’s purchase of VTOL aircraft available only Jacques -141
data for: conventional takeoff Jacques -141 VTOL aircraft
data for: Jacques -141 VTOL aircraft
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during the Cold War, vertical takeoff and landing aircraft was subjected to a high degree of attention. Because nuclear war conditions, the airport and aircraft carriers are vulnerable to devastating blow, so to lose fixed-wing aircraft taking off and landing sites. Beginning in the 1950s, the air power solutions for a variety of vertical takeoff and landing attempt. But limited to the technical conditions, most of the programs and test machine without success, only a few enter the military service, such as the Soviet Union and the United Kingdom Jacques -38 “Sea Harrier” fighter. The aircraft performance there is much more problematic, mainly low speed, short combat radius, payload is small, poor reliability. VTOL aircraft in the formation of air weapons not mainstream. But the inherent advantages of vertical takeoff and landing aircraft still continues to attract various military power, weapons and equipment makers. For example, in the U.S. JSF fighter program, the Marine Corps specifically reserved for the design of the vertical takeoff and landing F-35B, shows the U.S. military VTOL aircraft is still very seriously.
because the accumulation of previous decades and the recent aviation technology in the engine, flight control and other aspects of the significant progress made before the vertical takeoff and landing aircraft is expected to overcome the shortcomings in performance close to the conventional takeoff and landing of aircraft . On the other hand, due to long-range precision-guided weapons, the rapid development, making conventional war under the conditions of the airport and the aircraft carrier the ability to damage greatly increased, conventional takeoff and landing combat aircraft in the war once again facing the threat of loss of landing sites. Technological advances and the needs of traction is likely to bring another VTOL aircraft development boom in China in this regard should also be a difference. In particular, China is faced with the choice of developing aircraft carriers. In the choice of carrier-based combat aircraft on the one hand, of course, to follow the traditional model, the development of slip or jump off and landing of aircraft carrier catapult, on the other hand should also be concerned about the vertical takeoff and landing aircraft carrier. Because for a long period of time, China can not have a greater number of medium-sized aircraft carriers, amphibious ships and can be modified at public boat landing vertical takeoff and landing aircraft carrier-based aircraft can make up the number of deficiencies. VTOL aircraft carrier in amphibious operations, shore support, etc., are sent fast, responsive, able to follow-up support and other advantages. China in the VTOL fighter and almost no foundation, but had failed in the early exploration, if we do nothing, will be the world’s advanced level of technology widens. It should take this opportunity to begin the development of vertical takeoff and landing aircraft carrier. I hang the advantages and limitations of aircraft taking off and landing vertical takeoff and landing aircraft generally have a vertical takeoff/vertical landing or short takeoff/vertical landing capability, which means relative to the takeoff of the aircraft through the roll is a great advantage. First and second fighter take-off roll distance is greater than 500 meters from the landing roll at 1000 meters. Third-generation fighter aircraft take-off roll distance can be less than 500 meters, but the landing roll distance is still close to 1,000 meters. 1000 meters above the runway of the airport, complete confidentiality can not be in nuclear war conditions, these airports can easily be destroyed. In the precision-guided weapons, before the widespread direct hit the runway more difficult, and in the popularity of precision-guided weapons, is very easy to hit the runway. Therefore, if there is parity of modern warfare, these combat aircraft is likely to face the danger of war is hors de combat. Many countries have adopted measures to solve this problem, such as the airport quickly repair technology, caves airports, roads airports. The vertical takeoff and landing aircraft from the fundamental solution to this problem, vertical takeoff and landing aircraft can be just tens of meters of space, vertical takeoff/landing, short takeoff roll, only hundred meters away, so there is no loss of airport dangerous.
for carrier-based aircraft, if the take off roll the way, you need a longer deck, the modern medium-sized aircraft carrier deck is longer than 300 meters. But it also will face two problems: First, the high cost of large tonnage of aircraft carriers, most of the country or can not afford to build a small number made while several. The second is the carrier of large tonnage target too obvious, while several small aircraft destroyed in combat or wounded once, carrier-based aircraft that lost its combat effectiveness. The vertical
takeoff and landing aircraft is not the limit, you can 37Y tons of light aircraft carrier and amphibious landing ship, even the people on board can also be modified to use, which broke through the large tonnage of aircraft carriers in the number of restrictions in the use of more subtle and flexible.
but to make the aircraft jet engine can be equipped with vertical takeoff and landing, there are many technical difficulties, is summed up in four areas: lift, balance, control and security.
fixed-wing aircraft, mainly from the aerodynamic lift, the aircraft high-speed flight, high-speed air flow over aircraft surfaces, the wings generate lift, the aircraft can fly. The vertical takeoff and landing, the aircraft relative to the air base is stationary, there will be no aerodynamic lift, lift only from the aircraft’s own power plant. As engine technology limitations, this lift is not enough. Starting from the third-generation fighter aircraft’s thrust-weight ratio was slightly more than 1, and the weight of the aircraft when the machine is generally only 2 to 4 fuel and air to air missiles. In real conditions, the aircraft will carry fuel and weapons more than this. We F-16 Block20 aircraft, for example, the aircraft to carry two air to air missiles, with no auxiliary fuel tanks weighs 10,800 kg, 10,800 kg thrust engine. If we carry two 1400 l tanks, take-off weight of about 13,000 kg. At this point lower than the weight of the aircraft engine thrust, thrust down even with all of the jet can not support vertical takeoff aircraft. Therefore, the vertical takeoff and landing aircraft vertical takeoff at the time of the weapons and fuel are very limited, bring a combat radius of the defect is too short. For example, AV-8B aircraft, vertical take-off weight of the aircraft shall not be more than 9342 kg, and the aircraft will have its own weight 6336 kg, the aircraft can not even machine with full fuel. Jacques -38 Russian aircraft carrier, vertical take-off mode, the combat radius of less than 200 km. Vertical takeoff and landing aircraft generally use the short take-off, vertical landing model, such as AV-8B using short take-off mode, the maximum takeoff weight of up to 14 tons. But this time, run distance of 435 meters, and the conventional takeoff and landing of the third-generation fighter aircraft also no differences.
light there is not enough lift, vertical takeoff and landing aircraft will also be required in the force balance. General aircraft engine nozzle mounted on the tail, if the downward thrust, the aircraft is clearly not balanced. So for the vertical takeoff and landing aircraft, the engine installation is a luxurious.
in the early exploration there are many options. Such as design and installation of the engine on the wing, near the center of gravity, and is rotating, turn the engine on take-off time, down to the vents, then turn the aircraft off the ground after. This program is very difficult on the machine. Another solution is to jet aircraft can be rotated in the take-off when the nozzle down, back after take-off nozzle, such as the Harrier aircraft is to take this program. Such programs must be arranged in the very front engine, so that vents located near the aircraft center of gravity, the drawbacks is the air intake must be large, increasing the resistance of the aircraft, but can not install the engine afterburner. Adopt such a program aircraft, maximum speed is limited. The third program is also equipped with jet aircraft engine and nozzle down the lift backwards (or rotating) of the main engines. Disadvantage is that the lift in level flight the engine not have any effect, as excess weight.
in vertical takeoff and landing, the aircraft’s aerodynamic control surfaces basically useless, how to control the aircraft to become a problem. Now generally taken to reflect nozzle to solve this problem. Several catheter leads from the engine, the air directed to the nose, tail and wing parts, through the jet down to control the aircraft attitude. Aircraft took off from vertical to horizontal flight mode switching mode or flight mode from horizontal to vertical landing mode conversion, you need control
system vents the engine or the rotation. This process is also more complex, can easily lead to flight accidents. Now generally used telex flight control system automatically, in order to reduce pressure on the pilot’s control. There is a jet engine down when the heat flow on the ground or deck will have a serious erosion, making the aircraft under field conditions can not take off vertically from the ground, took off from the flight deck, also requires a lot of maintenance. Down the exhaust circulation will be formed around the aircraft, the engine has been inhaled. This gas can cause loss of engine thrust, the aircraft crashed in the hover state. This is a threat to the safety of VTOL aircraft is an important factor.
VTOL aircraft development opportunity
precisely because of these technical difficulties, so far from the 1950s, developed the program are numerous, successful example is very small. Jacques officially entered service only a 38, “Sea Harrier” and so few. And the performance is far and compared to conventional takeoff and landing of aircraft, can only appear as a special role.
but the technology is always in development and progress, for vertical takeoff and landing aircraft is also true. On the one hand due to the elimination of decades, not appropriate program be eliminated, a viable solution is retained. Partly because the engine and flight control technology, making the vertical takeoff and landing aircraft performance may be a breakthrough. For example, now push more than the latest model of the engine can reach 10, while only 7 to 8 before. We are still in F-16block20 example, assume that it is equipped with a push of more than 10 F-119 engine thrust of 15 tons. When the aircraft to carry two AIM-9 and two AIM-7 air missiles, two 1400 l tanks (the real needs of this state have been met), take-off weight of about 13.5 tons of thrust to meet the needs of vertical takeoff aircraft. Suppose in the near future, the development of the engine thrust to push more than 15, the engine can reach 20 tons of thrust, even at maximum takeoff weight, but also to meet the needs of vertical takeoff aircraft.
other technical issues are also many years of accumulated technology to be addressed. For example, lift the engine layout problems, Yakovlev Design Bureau designed the tail pipe can be rotated 95 degrees downward. In the vertical takeoff mode, the main engine nozzle down to the approximate vertical rotation, and lift the front of the aircraft engines and jointly promote the aircraft vertical takeoff, the aircraft is in equilibrium. In level flight, the nozzle and rotated to the horizontal. F-35B also used a similar layout, but instead of using the lift engine lift fan, the fan exhaust is cold air downward, a partial solution to the problem of hot air and exhaust gas recirculation ablation problems. Fax flight control system development, to achieve automatic control of vertical takeoff and landing, to avoid accidents caused by pilot error operation.
Therefore, since the development of vertical takeoff and landing aircraft, was given a new opportunity for development. The development of the Soviet Union in the 1970s, Jacques -141 VTOL aircraft, and conventional takeoff and landing aircraft on a close performance. Only because the Soviet Union, this scheme can not continue. The F-35B’s technology solutions have more similarities with Jacques -141, F-35B’s birth, vertical takeoff and landing aircraft can be regarded as an epoch-making progress, indicating the VTOL aircraft is expected to enter combat aircraft “mainstream” list. With the further development of engine technology, such as pushing the emergence of more than 15 engines, vertical takeoff and landing aircraft is expected to fully meet the performance levels of conventional takeoff and landing aircraft, there may even be vertical takeoff and landing transport aircraft. These aircraft will enable the integration of space combat to a whole new level.1 2 Next
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