To prove this argument, the American Rockwell and the German MBB Company based on a joint plan of the US and German governments,
The US Defense Advanced Research Agency (DARPA) and the US Navy Designed the X-31, a demonstration aircraft to enhance fighter maneuverability. The design of the aircraft began at the end of 1986 and was completed in August 1987. Two aircraft were produced in Japan, called X-31A and X-31B respectively, and they first flew in 1990 and 1991 respectively. In 1993, a helmet-mounted visual/audio display was installed on the aircraft to enable pilots to understand their position when fighting at high angles of attack. During the test, the X-31 controlled flight to reach an angle of attack of 70°, and completed a controlled roll around the velocity vector at this angle of attack. The second aircraft used its post-stall maneuverability to complete a rapid, small-radius 180° turn. The X-31 can fly normally beyond the aerodynamic limits of any conventional aircraft. One of the maneuvers it can perform is called the Herbst maneuver, which is a maneuver that pulls the X-31 to an angle of attack of 74°, rolls around the velocity vector and glides in reverse to accelerate flight. This action greatly reduces the turning radius of the fighter jet and can quickly point the nose of the aircraft towards the rear target.
The X-31 completes a 180-degree turn within a radius of approximately 149 meters and takes 12 seconds. With conventional maneuvering (without thrust vectoring), the X-31's turning radius is approximately 823 meters.
The X-31 has conducted many one-on-one air combat test flights with the F/A-18. The F/A-18 aircraft used for countermeasures has been modified with aerodynamics and flight control systems, and its conventional turning performance is close to that of the X-3l. As a result of air combat, X-31 won 78 times, drew 8 times, and lost 8 times in 94 exercises. Using the NASA air combat simulator to fight 71 times under the same conditions, the X-31 won 56 times, drew 7 times, and lost 8 times. Of course, these air combat and combat simulations are conducted under certain constraints and are limited to visual combat.
In the past five years, the two aircraft have conducted 538 test flights. On January 19, 1995, the X-31A crashed at the NASA Dryden Flight Research Center. The research project was completed in the same year. Later, the X-31 conducted flight verification research on tailless aircraft technology. Although the vertical fin was not actually removed, after the flight control system was reprogrammed, other rudder surfaces on the aircraft were used to offset the stability function of the vertical fin, making the aircraft appear as if there was no vertical fin, and then thrust vectoring took over the role of the vertical fin. To simulate tailless flight. On March 17, 1994, the X-31 successfully conducted a test flight at an altitude of 11,600 meters and a speed of M1.2. During high-speed level flight and turns, test pilots successfully demonstrated flight stability and maneuverability using only engine thrust vectoring technology. Achieved unprecedented supersonic flight without vertical tail.
In 2002, the United States and the United States wanted to use the X-31B to conduct extremely short takeoff and landing research (ESTOL) called the VECTOR project. They planned to fly 45 times and prepared to rely on thrust vectoring to increase the landing angle of attack from the current 12 The temperature increased to 24 degrees. Preliminary test flights showed obvious effects, with the landing speed reduced by 31 and the rolling distance reduced from 2,400 meters to 520 meters. Later, the project was canceled due to funding cuts.
With the development of medium-range air-to-air missiles, there is a great debate on whether future air combat will be based on beyond visual range combat or visual combat. Therefore, research on over-stall maneuvering technology has come to an end for now.
This X-31 was taken by Pingp at the Berlin International Aerospace Exhibition in May 2004. This is the latest modified X-31, called X-31 VECTOR, which is Vectoring Extremely short takeoff and landing Control, and Tailless Operations Research. , unlike the first phase of the X-31 EFM (Enhanced Mobility Fighter) to study super maneuverability, VECTOR studies extremely short takeoff and landing technology under thrust vector control, and the research results can be applied to future UAV projects.
VECTOR is developed by the U.S. Navy and Boeing, together with the German Federal Office for Defense Technology and Procurement (BWB), the 61st Test Center of the German Air Force (WTD), the German EADS Military Aircraft Company, and the German Aeronautical Research Agency (DLR) Flight Systems Technology Institute*** Same implementation, can be seen on the VECTOR project badge. When talking about the maneuverability of fighter jets, it includes conventional maneuverability and unconventional maneuverability. If we talk about conventional maneuverability, of course it refers to the thrust-to-weight ratio, wing load, turning speed, etc. of the aircraft. Unconventional maneuvers include over-stall maneuvers and direct maneuvers. An unconventional force-controlled maneuver, a stall-passing maneuver is to raise the aircraft's elevation angle far beyond its stall elevation angle, and rapidly change the direction of the aircraft's speed vector and nose pointing when the speed is very small. For example, there are several typical actions of the American X31 demonstrator aircraft's over-stall maneuver. A. Pull the stick to bring the aircraft to an elevation angle of 70 degrees, then perform a stall loop with a heading of 150 degrees, and then perform a 150-degree circumscribed roll around its speed vector; B. First pull the lever to an elevation angle of 70 degrees, then make a left turn at an elevation angle of 50 degrees to complete a 150-degree turn. C. The lever is overloaded at 3G at an elevation angle of 15-17 degrees to fly inverted. In this state, the aircraft passes 180 degrees to the left at an elevation angle of 70 degrees, and then turns 90 degrees again.
What is different from the traditional conventional design of modern fighter jets is Active Control Technology, but don’t forget that Active Control Technology is an aircraft design and control technology first proposed by the United States. From the perspective of aircraft design, active control technology is a flight control technology that takes into account the impact of the fly-by-wire flight control system on the overall design in the initial stage of aircraft design and fully utilizes the potential of the flight control system. For example, the F-16 is the world's first aircraft designed with active control ideas. For example, using active control technology: 1. Relax static stability 2. Realize direct force control 3. Controlling maneuverable loads 4. Control gust loads 5. Control body vibration 6. Adopts integrated fire control/flight/thrust control system.