At its first public appearance, Lei Feng's performance team brought eight sets of stunts including single machine, double machine and multi-machine subjects. That is, straight 9WA and straight 10 mixed five-machine dense formation low-altitude high-speed passing, straight 9WA double-machine "air ballet", straight 10 double-machine jumping and reversing, straight 10 single-machine left and right swinging, straight 10 single-machine forward and backward swinging, straight 10 single-machine rapid spiral lifting, straight Although the above stunts are called performances, in fact, all the movements are evolved from actual combat subjects, and they are real tactical movements, which are more powerful than tactical movements. During the flight, the distance between the two planes is smaller, the flight angle of attack is larger, the flight altitude is lower, and so on, thus making each action more ornamental.
Mixed formation stunt
In all the performances, the low-altitude and high-speed dense formation of two planes and five planes was quite shocking. The first three planes were straight 10, and the second two planes were straight 9WA, whizzing by at low altitude, which is also the most common prelude to the intensive fire suppression of armed helicopters on the battlefield. The next straight 9WA "Air Ballet" is the first of the Army Air Force. The whole set of movements consists of cross pendulum, flying around the head and flying around the point by single machine. In flight, the rotor spacing between two aircraft is less than 10 meter, which requires the pilot to judge the state and trajectory of the aircraft extremely accurately. In reality, the actions such as flying around the head and flying around the point by single aircraft also have strong practical value. It can be used for continuous attack and all-round reconnaissance of a certain target on the battlefield, as well as for air law enforcement and air rescue.
10 The seemingly simple actions of the left-right pendulum and the back-and-forth pendulum are great tests for the aircraft itself and the pilot. During the performance, the plane swung back and forth more than 30 degrees, and the helicopter itself needed enough power to support the plane to pause and turn at the top of the pendulum. Pilots need skilled operation skills to accurately judge whether the front, back, left and right vertices are consistent during the swing, so as to ensure the smooth trajectory of the aircraft. Especially the pendulum, the pilot can't see the ground at all, and controls the helicopter completely by feeling. This seemingly "swinging" flight action also has a brave place on the battlefield. It is one of the defensive actions of helicopter to avoid ground attack, and can be combined with other flight actions to complete the conversion of attack and defense.
Direct 10 double machine Levisman maneuver
Jump inversion, also called Levisman maneuver, named after the first pilot who completed the maneuver, is one of the internationally recognized helicopter difficult stunts. The so-called Levisman means that the helicopter pulls up and jumps at a high speed during the flight, climbs to a fixed point at a high angle of attack, adjusts the nose direction from top to bottom while keeping the rotor stable, and then the helicopter dives backwards according to the original flight trajectory. When a pilot parachutes, he will be overweight. The greater the angle, the more serious the overweight phenomenon will be, and the greater the pressure on his body will be, which will affect the accuracy of the pilot's operation of the helicopter, thus increasing the difficulty of operation. When reversing in the air, it is even more necessary for the pilot to operate accurately and timely. If the reversal action is too early, there will be a larger turning radius and the tactical effect will not be achieved. But if the reverse action is a little late, or the operation is wrong, the plane may fall soon. On the battlefield, the practical significance of Levisman maneuver is that it can quickly realize the second attack on the same target to ensure the attack effect.
If it is so difficult for a single machine to jump and reverse, the difficulty of double machine jump and reverse by Chi 10 will increase several times. First, after crossing the field, the two planes jumped high in the same direction. When the helicopter elevation is close to 60 degrees, they turn their heads synchronously and dive down together. Then, the two planes accelerated in the opposite direction, jumped and reversed in their respective directions again, and finally met in the air. In fact, this is a combination of two continuous Levisman maneuvers, and the two machines have to complete this action synchronously, especially the second Levisman maneuver, and the two machines are in opposite directions, so both the captain and the wingman need courage and skill, and they need tacit understanding.
Four-machine stunt
The four-dimensional diamond formation has blossomed, not to mention the first performance in China, which is the first time in the world. This stunt, in fact, is that four planes complete Levitsman maneuver at the same time, and then leave in four directions. During the performance, four helicopters first approached in a dense diamond formation, and then the diamond formation quickly pulled up and jumped in front of the crowd. When the formation jumped to the top, the four helicopters completed Levisman maneuver at the same time and dispersed in four directions. The whole action is done in one go, and there is no room for any mistakes. In this maneuver, four planes should always keep a stable dense diamond shape when assembling, and accidents may occur if the distance between helicopters changes slightly. When dispersing, all helicopters must turn at the same time, and the difficulty can be imagined.
Straight body 10 somersault
The somersault maneuver, a set of stunts from fighter planes, is the most difficult among helicopter stunts, so few helicopters can complete this action. But then again, the helicopter that completed this action is enough to win a place for itself in the industry. Apache, Tiger, Mi -28N, etc. All won praise through this action, and this time it's Zhi 10.
The so-called somersault is that the helicopter quickly pulls up the nose and climbs at a high angle of attack during the rapid level flight. When the helicopter climbed to the top, the pilot completed a 360-degree turn of the fuselage in a very short time, then the plane dived and flew forward along the original trajectory.
According to Li, the captain of the "Wind Thunder" performance team, the most difficult part of the "somersault" action is that when the helicopter is at the top of the "somersault", the rotor can no longer provide lift. The pilot must accurately judge the state of the helicopter according to his sense of space and the instructions of the reference instrument within 1~2 seconds, and continue to pull the rod under the action of inertia, gravity and rotor tension to make the helicopter complete 360 degrees in the vertical plane. If there is a slight mistake in judgment or control at the top of the somersault, the helicopter will fall vertically like a lead block. As mentioned above, when the helicopter somersaults, it actually completes an approximately circular flight in the vertical plane. In this process, the gravity of the fuselage and the direction of the rotor tension are constantly changing, especially when entering the somersault, the rotor tension is almost three times that of the helicopter to ensure that the helicopter does not fall, which is very difficult for many helicopters.
In the process of somersault flight, the helicopter fuselage itself has to bear all kinds of forces and moments that change at any time, which requires its fuselage structure to be strong enough, light in weight, high in strength and good in stiffness. At the same time, the pilot's control load increases during somersault flight, which requires the helicopter's control system to be flexible and reliable. In short, to complete the somersault maneuver, there are extremely high requirements for the aircraft itself and the pilot. Straight 10 can complete this maneuver, which is enough to prove that it has reached the level of advanced helicopters in the world.