Tuesday, December 15, 2009

Special report: China's carrier-based fly-by-wire jet aircraft flight in the Varyag

With China's "large surface combat ship," began approaching, who will become China's first fixed-wing carrier-based trainer has become a massive numbers of visitors concerns. In fact, this problem has been quietly resolved - most suitable for the Chinese carrier's trainer jet, is Hongdu L-15.

China's aviation industry can provide to the Chinese trainer aircraft carrier of choice very few options currently available for only eight coaches, coaches, 9, FC1, and L-15.

Eight low-altitude performance, a good coach, taking off and landing distance is short, manageability in hydraulic models are also considered good, but its design too early, without considering the demand on the aircraft carrier, body structure, strength enough room for modification. Its single, hydraulic characteristics and objectives of the carrier-based fighter aircraft flying a great distance. The possibility of its last ship was the first eliminated.

Coach 9 from the FT-7 modifications from high-altitude high-speed performance, low-altitude low-speed performance is poor, as a land-based third-generation advanced fighter trainer aircraft, can still be used, but the prototype FT-7 has always been "the most not suitable for flight "The models, teachers are difficult to master, although the change on both sides of the intake and double-delta wing, but on the ship when the low-altitude low-speed control performance is limited, depending on the next difficulty. Land-based runways is 2000 meters, the aircraft carrier landing runway, a short 100 meters, the aircraft but also the rise of the ship, the front and rear seat 9 coaches could not see the runway, followed by feeling of flying on the ship is very risky. Similarly, it is its single, hydraulic flight characteristics and objectives of the carrier-based fighter has a great distance, thus trained pilots to go through a lengthy two-seat target machine modification training, a great waste of time and money. L-15 design is to adopt a beginning serial two-seater design, the rear 30 cm higher than the front seat, and the two-seater single-seat fighter to change compared to the rear field of vision was good at 6 °, the front seat even up to 16 °, which in the trainer in both domestic and foreign advanced level. China's use of aircraft carriers lack of experience, a good view of aircraft can significantly reduce the accident rate.

L-15 trainer aircraft is specially developed low cost (relative fighter), with a whole long life, suitable for short-haul flights, taking off and landing characteristics of frequent, and there is "rugged." China in the early nineties the introduction of three generations of aircraft from Russia Su-27SK, the Chinese Air Force has new equipment across the times. However, we also found that long-term with the two-seat Su-27UB training pilots, just "squat ups and downs of" sufficient injury to the body, while the Su-27SK / Su-27UB design is a large-scale fighting consumables, the body life of only about 3000 hours is used to make frequent ups and downs of short-haul flight training trainer, wasting enormous. In our equipment, the introduction of Su-27 after the flight took place excessive consumption of valuable life lessons.

The truth is that an aircraft carrier at sea in a very small high-risk airports shaking incessantly. The course of the world's ships are all a large number of crashes. If the rash with the two-seater advanced trainer aircraft carrier-based fighter to risk directly as training of ship undoubtedly inappropriate. When an aircraft carrier pilot training courses need to take off and land and infrastructure far exceeds the amount of training Air Force pilots, if an expensive two-seater fighter aircraft used to train, too expensive. It is worth noting that the land-based aircraft carrier loaded planes taking off and landing approach and a great difference. Land-based aircraft in the 23 km of straight track on their own take-off aircraft carrier containing machine is more than 100 meters of the deck by steel cables pull the wings wing root or with front-wheel traction bar grabbed violence thrown to (catapult take-off) , or the opening of afterburner "hit" springboard to fly (Yue-fei), in particular the former a great impact on the life of the aircraft. Land-based aircraft approach for a long period of decline in low-altitude small angle, in the 23 km-long runway there is still a "flat Gone with the Wind," the flight of the process, the final landing point as small as possible to "shoot down" the impact of the landing minimized to "press ahead." Small body and landing gear force. However, the aircraft carrier deck landing runway is often less than 200 meters, but also about rocking up and down, obviously, the aircraft carrier landing point set to be large, there will not be a "flat Gone with the Wind." Often people will look at the video found in the military, aircraft carrier ship method contains a "beat", down at a large angle, it is violently break on deck, and then rely on landing to block Sok Shenglayingzhuai stop. F/A18 Hornet carrier landing rate of decline of 6 m / s, is the real "beat" on the ship. Aircraft-carrying body and the landing gear must be strengthened, each time taking off and landing are the obvious damage to the structural life. Contains aircraft carrier landing training, life contained aircraft destroyed far more than land-based aircraft taking off and landing training.

Can be seen, only the rugged specialized trainer, is suitable for use as a trainer on the ship. Once the L-15 mass production, cost reduction after every hour of training costs will be lower than the target machine an order of magnitude. Is expected to increase training costs as low as 3-4 in thousands of dollars / hour (land-based type). Equipped with the right trainer, a large amount of valuable fighters freed for combat readiness and new tactics research, will bring very significant economic, readiness for combat.

L-15 also has an excellent three generations of fighter aircraft fly-by feature and part of Asia, transonic flight performance, we can better simulate the flight characteristics of a new generation of fighter aircraft. Capacity of its stable hover 6G, while the third-generation fighter is also the maximum is only 9G, fully capable of flight simulation to the general requirements. Its aerodynamic shape determines its low-altitude low-speed flight performance and stability, very good, very suitable for ship-borne aircraft taking off and landing requirements of low-speed flight. Its twin-engine characteristics, which can simulate single parking accident, the event is really the sea single accident, are better able to return to the vicinity of an aircraft carrier or landing parachute alternate airport.

L-15 has more than one design of the lift thrust-weight ratio and good performance, but also make it in medium, large carriers have to meet the flight and the ejection slide leaps off Shihai can carry enough fuel and payload training. The minimum take-off speed of 240 km / hour, the minimum take-off distance of 300 meters, the minimum landing distance of 400 meters. L-15 short take off and land a good ability to modifications on the ship taking off and landing room, no major changes in it. Similarly, as a light aircraft, L-15 aircraft carrier on the ease of use and carrying capacity are better than two-seat carrier-based fighter. Particularly in the design at the beginning, L-15 dual-fat means more than a single fat increased by 10% -15% of the structural weight and great shape of the resistance. If we adopt the FC1 fighter RD33 afterburning turbofan engine type, it means to extend the fuselage length (17.32 meters MiG-29 pilot, FC1 captain of 14.30 meters, L15 is only 12.27 meters). Now L-15 to shorten the overall length of the engine compartment as well, just to get on an aircraft carrier - as a carrier-based aircraft, five short stature can be cramped for space savings on the flight deck.

L-15 in the country's first on the initial design used in the engine Full Authority Digital Control System (FADEC). Before the aircraft engine throttle operation most have some limitations, different height, speed may have different restrictions, there are some special conditions, such as restrictions on the engine when the high angle of attack. Landing in a complex tense flight, in general, pilots are often easy to forget some of the engine restrictions, misuse is likely to bring the air parking and other serious consequences. FADEC for the pilot to lift the emergence of the ideological burden, to reduce pilot fatigue and reduce errors. FADEC system uses a computer to monitor and adjust the engine to maintain optimum engine work, and at the same time to provide a safe diagnostic and inspection. FADEC technology has been widely used in civil aircraft, the future of new fighter will also be used in all FADEC control technology.

L-15 engine compartment below the "big off Cap" design, can be very simple to open repair, which is cramped in a small aircraft carrier on the commissioning, maintenance particularly convenient. Good maintenance feature allows L-15 can achieve a very high attendance. L-15 has an outstanding expertise: up to 4 hours of blank time. Blank means that can reduce the length of time set to take off the oil also has a very good left blank time for a take-off also means that more subjects can be trained to reduce the rise and fall times increase economy. Aircraft carrier often deliberately set out to reduce fuel load and save take-off weight easy to take off, but also frequently encountered "aerial line" to wait for landing conditions, as when the L15 could easily circled the deck, leaving the runway and other aircraft to land urgently needed. Long blank time for the L-15 in the carrier have a better user flexibility. L-15 before the forward landing gear incorporated into the nose and main landing gear kneeling flinching incorporated into the body, this design allows front and rear landing gear have left room for strengthening the transformation, but also under the wings of liberated space. In the future, whether by cable or a front-wheel traction catapult ejection traction, are convenient. The strengthened structure, then, can adapt to the aircraft carrier takeoff and landing gross requirements.

In addition, User request to change FC1 seat on the ship. FC1 fighter with a good low-altitude performance, three-axis four-redundant fly-by at low altitude performance make it a very good result of the planned mass production, its costs can also be diluted. It would have been thrust-weight ratio is small, the body interior space is relatively small, as a single-seat fighter to meet the needs of the future to increase the resistance of two-seat modification to increase the carrier landing equipment, and strengthening the structural strength to bring the weight, and make these issues more prominent , the required changes in volume over. It does not change any value and technical feasibility.

L-15 currently plaguing the biggest problem is the engine. As a carrier-based aircraft carrier training aircraft, L-15 demand is much less than the air force, naval land-based trainer, the engine can not be made in the issue is not so serious: a limited number of equipment, as long as the appropriate accumulation of a number of spare engines can deal with. Only because the production volume is small, it will be the cost of abnormal high, but can still afford. With the future, AI-222-25F turbofan localization after 11 were expedited, and catch up with the ship, it is probably too late. With the L-15 on the ship, China will usher in the first carrier-based fixed-wing trainer. It can simulate the third-generation fighter aircraft took off, Landing, but also simulate long-range raid on the ship-to-ground attack, air combat, is a true multi-purpose carrier-based trainer.