After entering a brief stall tail spin, the aircraft quickly dropped altitude in a tail spin attitude. After two and a half rotations, the left aileron and flaps had restored some of their aerodynamic effects in the dive state.
At this time, the situation of No. 121 improved, but No. 109 driven by Zhou Hai fell into a fatal vicious circle.
Due to the influence of the central area of the jet airflow, the L-15C Falcon entered a stall tail spin. Not only did its own rotation accelerate, but it also suffered from the dual effects of strong vertical wind shear and horizontal wind shear. The fuselage was like falling and rotating leaves. Change from a nose-down tailspin attitude to a horizontal tailspin.
In the aviation field, pure vertical wind shear is enough to cause fatal effects on aircraft during the takeoff and landing stages.
Now, Zhouhai is affected by two different types of wind shear, both of which are strong levels, with wind speeds as high as more than 20 meters per second.
"I'm in the center of the flow, can't recover, repeat, can't recover."
Zhou Hai held the joystick tightly with his right hand, his brows furrowed, his expression unchanged, and while sending a message to Yang Xiaolong, he operated to forcibly turn off the stall and spin warning prompt.
The situation seems a bit dangerous.
In an instant, the high-speed rotating narrow cockpit returned to silence, and the current flight parameters were displayed on the left screen.
The true airspeed is 19 kilometers per hour, the altimeter is lowering at 89 meters per second, the aircraft is completely out of control, and the spin frequency has reached three revolutions per second, and is still increasing.
The average flight overload has reached 7g, which is only 5g away from the maximum overload of the L-15C Falcon.
"No. 109, change out! Change out immediately! Your rotation speed is too fast!" Yang Xiaolong's anxious roar sounded on the radio channel.
The L-15a Falcon, with 121 white numbers painted on its nose, dropped to an altitude of about 1,300 meters. The six aerodynamic rudder surfaces and left and right main wings of the fuselage have regained their effect under dive, providing lift and the turbofan engine is stable. Output the power, level out and fly into a stable circle, avoiding the airspace encountered before.
Yang Xiaolong stared at the L-15C spinning and falling at high speed in the distance, like an ant on a hot pot, his eyes full of anxiety.
Spin!
Stall spin recovery not only has strict requirements on height, but also has requirements on rotation frequency. The ultimate recovery condition is a rotation frequency of 5 revolutions per second.
If it exceeds this limit, it means that it cannot be corrected.
"I'm trying!"
Zhou Hai's voice was steady and powerful, his eyes were clear, his right hand moved forward to keep the lever pressed, and he turned the rudder to the right, trying his best to control the war eagle under him.
However, the L-15C Falcon High School, which was completely out of control, had all six aerodynamic rudder surfaces and left and right main wings completely disabled. The two WS-17 Minshan engines were at idle speed and did not output any power.
It is taboo to add fuel when stalling and spinning. Not only will it not be effective, it will actually be a hindrance.
Spin!
Falling!
As precious seconds passed by, under the influence of two types of wind shear and the center of high-speed jet airflow, the condition of the L-15C Falcon did not improve. The rotation speed continued to increase and the flight altitude decreased crazily.
eight thousand meters,
seven thousand meters,
It was falling about 100 meters per second, and its stalling tail spin showed no sign of improvement. Below it was the vast northern land, surrounded by endless urban agglomerations.
"109, make a correction quickly!" Yang Xiaolong's eyes were fixed on No. 109, which was spinning at high speed and falling high, and he was even more anxious.
The L-15A Falcon is flying in circles, lowering its head and heading towards the vast land.
"No. 109, this is the college airport control tower. How is the situation?"
At this time, the female airport controller connected to the encrypted communication channel, her voice was quick and solemn.
"Report to the tower, 121, I want to try to recover at medium and low altitudes to avoid the influence of two kinds of wind shear. I am now out of the range of high-altitude jet airflow." A series of information about high-altitude jet airflow came to Zhou Hai's mind, and his eyes were like As deep as the starry sky, the words are understated and show no hint of panic, which is in sharp contrast to the anxious Yang Xiaolong inside.
calm,
Stablize,
You must not mess up your position.
"No. 109, your rotation speed is too fast, and the risk of recovery at medium and low altitudes is too high." Hearing Zhou Hai's answer, Yang Xiaolong breathed quickly and felt even more anxious.
Zhou Hai kept pressing the pole and stared at the altimeter data: "No. 121, there is no choice now. Please answer from the tower."
Recovery at medium and low altitudes is the only way to save the fighter plane.
Zhou Hai will never watch No. 109 fall to the earth, and will never give up until the last moment.
Because this is his number 109, and today is the first day of solo flight.
At an altitude of 6,230 meters, the fall rate has increased to 110 meters per second under the acceleration of gravity, and there are only 56 seconds left before touching the ground.
After deducting about three seconds of buffering time, it is only 53 seconds.
"No. 109, medium and low-altitude recovery is allowed." The female controller obtained permission from the superior commander next to her, speaking quickly and quickly, and immediately agreed to the plan given by Zhou Hai.
"Received on the 109th."
Zhou Hai responded.
six thousand meters.
Five thousand meters.
As its flight altitude rapidly decreased, the density of the air gradually increased. After passing the dividing line at an altitude of five thousand meters, the heavy and sluggish body suddenly became lighter, and the nose of the aircraft was slightly pressed down, as if it was freed from invisible and powerful constraints.
Now, the entire War Eagle has escaped from the main influence areas of strong vertical wind shear and horizontal wind shear, and has completely said goodbye to the terrifying high-altitude jet stream belt.
However, the main crisis has not been resolved.
The body of the aircraft was still in a stalled tail spin and falling state. Zhou Hai's eyes were solemn, and he kept the pressure lever and full right rudder. The l-15c adjusted the angle and the nose of the aircraft gradually downwards.
At a height of 4,000 meters, the nose of the aircraft was facing the ground below. A straight and long highway came into view, with heavy traffic and various vehicles.
At an altitude of three thousand meters, the L-15C Falcon's dive speed has increased to 60 kilometers per hour. The top of the right wing of the fuselage and the ailerons have restored a certain degree of aerodynamic effects, slowing down their own rotation tendency and speed.
This is a good start, but as the distance from the ground gets closer and closer, the rotation frequency of the body is still uncontrollable.
The altitude was two thousand meters, and the dive speed was 120 kilometers per hour. In just a few seconds, the aerodynamic rudder surfaces of the left and right main wings and flaperons of the aircraft recovered to a certain extent one after another. The rudder, which was as stiff as death, gradually came back to life, thereby generating more lift. Resist rotational moments.
The rotation frequency is reduced from three revolutions per second to two revolutions per second.
There are signs of recovery from the stall and tail spin, but the flight altitude has dropped to 1,500 meters.
"No. 109, eject! Eject!"
Yang Xiaolong, who was covered in sweat, saw that Zhou Hai still failed to recover. He couldn't wait any longer. He shouted hoarsely and issued a forced ejection order.
Words, extremely anxious.
Although an L-15C Falcon high-education aircraft worth tens of millions of dollars is expensive, it must not cost Zhou Hai's life again.
