After a while, this Airbus A330 came to a low-altitude stadium, its huge fuselage was completely displayed in the eyes of the audience, and even the height of its belly from the ground seemed to be only a dozen meters, which was too thrilling.
After a few thrilling maneuvers, the Airbus A330 also aligned with the runway and landed.
The next flight show was the turn of the Chinese planes, and these two performance planes were the Y-7 200A regional airliners that Shen Huan and the others took yesterday.
I saw several branch clerks, respectively, on two Yun-7 200A, and then the hatch closed, in the eyes of the public, the propellers of the two Yun-7 200A began to rotate, and even if they were closer, they could see that the air around the engine was pushed behind the propeller, making a buzzing sound.
The crews of the two planes, like the crew members of the Airbus A330, waved to the audience.
Although these two regional airliners are much smaller than the Airbus A330 just now, the audience is also full of expectations for them, because they are the latest regional airliners designed and developed by China itself.
In particular, Chief Engineer Tang Weiwen looked at the two Yun-7 with excitement, because this model was also designed by them 603, although it was not the chief engineer he served.
Although it is turboprop powered, the two Yun-7 are still under the pull of the propeller and begin to accelerate and slide continuously.
Chief Engineer Tang Weiwen also excitedly introduced to Shen Huan and them: "Our Yunqi 200A has a very excellent short-distance take-off and landing ability, and can even take off on a simple runway, and its gliding distance is only a few hundred meters, you can see it immediately." ” Although I experienced it in person, the feeling of sitting on the plane yesterday was still different, and now I was standing on the side and watching, Shen Huan, Lin Miaoyu and Fu Jianshe were all staring closely at the two Yun-7 passenger planes on the runway.
The first Y-7 200A quickly got out of the shackles of the ground, and then it also came to a large angle of attack climb, from the ground, it seems to be a vertical ascent, of course, in fact, its angle is much smaller than the previous Airbus A330, but because it is a turboprop aircraft, so this scene is even more shocking, and the audience can't help but let out a burst of exclamations!
Lin Miaoyu also lost her voice: "What?
The same can be said of propeller airliners?
And when we sat yesterday?
” Chief Tang Weiwen on the side hurriedly explained: "Lin Gong, this is not a real vertical climb, just like what Shen Gong said just now, in fact, its angle of attack is at most sixty degrees, but the visual error looks like it, but it is not." ” Then the second Yunqi 200A also came to the same action, which made the audience shout again!
…… Shen Huan couldn't help but admire: "Master Tang, our Yunqi regional airliner is not bad at all!"
It is really rare to fly at such a high angle of attack and challenge with a turboprop engine, which shows that this aircraft is very successful in terms of design and manufacturing, otherwise pilots would not dare to fly like this!
” Fu Jianshe also said in surprise: "Yes, this is simply flying a propeller airliner as a fighter jet, amazing!"
” Chief Engineer Tang Weiwen said proudly: "Yes, the large-angle climb of the aircraft is a high-risk flight subject, from the perspective of the aerodynamic principle of the aircraft, the elevation angle of the aircraft is large to a certain extent when flying, and the airflow separates, resulting in the pressure above the wing is greater than that below, and the lift coefficient is reduced, resulting in a stall.
Flying at large elevation angles places high demands on the aerodynamic layout and engines of the aircraft.
When this airflow separation develops to a certain extent, the aircraft will shake, and the heavy shake vibration will have a serious impact on the handling and stability of the aircraft, and there will also be loss of control phenomena such as upward tilt, wing shaking, wing downstroke and nose deviation, and even entering tail spin.
In aviation terminology, the elevation angle is generally called the angle of attack, also known as the angle of attack, which refers to the angle between the wingchord and the airspeed of the aircraft.
At the same airspeed, the greater the angle of attack, the greater the lift, and at the same time, the greater the drag.
However, the angle of attack is not always positively correlated with lift, when the angle of attack exceeds the critical value, the upper airflow of the wing appears turbulent, the laminar adhesion layer disappears, the drag increases, and the lift decreases, which will cause a typical large angle of attack stall, and even the aircraft will enter a tailspin.
Under normal circumstances, the angle of attack of an aircraft is limited to less than 30 degrees, and in special cases it does not exceed 50 degrees.
But this is an air show show, so it's different. ” At this moment, the audience shouted again.
At this time, I saw that the two Yun-7 200A regional airliners turned into a large slope and circled, and then entered a level flight state.
One wing of one of them suddenly sank, and then the whole plane flipped around the axis of the fuselage one hundred and eighty degrees, entered the upside-down state, and just under the belly of the other Yun-7, the two Yun-7 passenger planes came to a belly-to-belly stacked Arhat flight, this scene is really spectacular.
Although the distance between the two planes up and down is actually twenty or thirty meters, when viewed from the ground, it seems as if the bellies of the two planes are close together, and this stunt is even more shocking than when it took off just now!
Because under normal circumstances, only fighter jets can fly this aerobatic maneuver, I didn't expect Yunqi to be able to do it, so this is not something that ordinary people can imagine, and many viewers were so frightened that they reached out and covered their mouths.
Seeing that Lin Miaoyu and Fu Jianshe were shocked, Chief Engineer Tang Weiwen also hurriedly explained: "These two Yunqi are specially modified and use a pressure oil delivery device, so they can fly upside down, ordinary transport planes cannot, and there is no need to fly upside down except for performances."
In order for the aircraft to fly upside down, two must be met, first of all, the plane has an inverted fuel tank to fly upside down, if the plane can only rely on gravity to transport fuel when flying upside down, the aircraft engine will be shut down due to lack of fuel and crash.
There is a valve in the inverted fuel tank, when the normal flight, there is fuel in the inverted mailbox, which can be used to fly upside down for a short time, and when the aircraft resumes level flight, the valve of the main fuel tank and the inverted fuel tank is opened by using the principle of gravity, and the valve is closed after the fuel enters the inverted mailbox full.
The plane can fly upside down again, and so on. ” Shen Huan knew this, so he didn't look surprised.
After hearing this, Fu Jianshe said: "I see, it seems that it is really interlaced like a mountain, I really didn't know the truth of this before!"
” At this time, the two Yunqi made the next more thrilling action, only to see one of the Yunqi passenger planes, actually around another Yunqi passenger plane, into the state of spiral flight, although the spacing seems to be relatively large, but as far as those small propeller planes are concerned, they may not dare to do this kind of maneuver, like Yunqi This kind of regional airliner that is more than 20 meters long, actually did it, which makes people have to admire.
The crowd was boiling, many people cheered, and some people whistled to express their love for the air show!