In the north, the temperature is still a little cold in the morning of March.

The wind was blowing gently.

"Zhou Hai, have you remembered all the information you gave you yesterday?" Yang Xiaolong stood in front of the door of the flight simulation room, his face was calm, and asked Zhou Hai.

Zhou Hai held an introduction to the technical performance of the L-15C Falcon in his hand and reported: "Report to Instructor Liu, remember. ”

"That's good, practice today, go to the crash course in the afternoon to report, my teaching method is the same as the old squad leader, theory and practice are carried out simultaneously, your talent is very good, three days later, flight simulation and aviation theory assessment." Instructor Yang Xiaolong heard this and responded: "Give me the information, what is the ceiling of the L-15C Falcon?" ”

Handing the information to Yang Xiaolong, Zhou Hai looked calm and replied, "Seventeen thousand meters." ”

"What is the maximum controllable angle of attack and instantaneous angle of rotation?" Yang Xiaolong nodded and continued to ask.

"32° and 22°."

"What is a three-axis, four-redundancy fly-by-wire digital flight control system?"

"This is an advanced electronic flight control system, based on electrical signals as the core, which is composed of sensor groups, various gyroscopes, accelerometers and other inertial measurement devices, angle of attack sensors, input devices, flight control computers, steering gears and electrical transmission lines, that is, fly-by-wire control systems in the popular sense."

Zhou Hai's voice was calm, and he slowly said the definition of the entire telex system: "The so-called three axes refer to the longitudinal axis, the roll axis and the yaw axis, and the four redundant degrees refer to three digital channels and one alternate analog channel, which are controlled by computer. ”

Yang Xiaolong nodded with satisfaction: "What is the empty weight of the L-15C Falcon?" ”

"5800 kg." Zhou Hai replied.

"How much is the flight performance of the L-15C better than that of the B type?"

"The overall flight performance is increased by 8%."

"What is the maximum usable overload and the maximum ultimate overload of the L-15C, respectively? What are the effects of overloading beyond the maximum limit? ”

"8.7G and 9.5G, the impact is to damage the load-bearing structure of the airframe, and eventually lead to disintegration in the air."

"The last question, what is the basis for the existence of modern jets?"

"Classical mechanics of physics, based on Newton's third law – that the forces of action and reaction between two interacting objects are always equal in magnitude and opposite in direction, acting on the same straight line."

After the test, Yang Xiaolong became more and more satisfied in his heart, and said to Zhou Hai: "Okay, come in with me." ”

The words fell, and he turned and walked forward.

Zhou Hai followed closely behind, followed Yang Xiaolong into the flight simulation room, entered the building that was not good-looking but was guarded by two air force soldiers, went up the stairs, came to the second floor, and entered Room No. 1.

The whole room is about 300 square meters, the ground is clean and tidy, the lights are bright, there are four six-degree-of-freedom flight simulators, each machine is painted in white, the surface is clean, and the white energy-saving light is reflected.

On the right side of the room is the console, in which a second lieutenant officer sits upright, in charge of the console.

Zhou Hai stood in the center of the room, looked around, left and right, the flight simulator of the Shicheng Flying Courtyard was a little different from the sky from the perspective of appearance, each simulator was equipped with a teardrop-shaped glass cockpit, which highly simulated the configuration of a real fighter.

"Let's go up, Simulator One." Yang Xiaolong gestured to the second lieutenant officer in charge of the console, and then gestured to Zhou Hai.

"Okay."

Zhou Hai responded, came to the bottom of the No. 1 flight simulator, climbed the escalator skillfully, and entered the front seat of the teardrop-shaped glass cockpit.

Yang Xiaolong followed behind, stood next to the simulator, and introduced to Zhou Hai: "This is the latest flight simulator, the avionics system and fly-by-wire control system are the same as the L-15C, highly simulated, we will contact in the morning, and go to the class in the afternoon to report and learn the theory." Let's start by learning how to start the engine. ”

Sitting on the flight seat, Zhou Hai's eyes showed curiosity and listened quietly.

"The jet engine is different from the piston engine in the propeller era, its starting characteristics and principle are that the air flow must flow first, and then ignite and burn, that is, the engine must first rotate and then start. However, this creates a contradiction, the engine has not started yet, it has not yet ignited, but it has to turn first. ”

Yang Xiaolong's voice was calm, and he slowly explained: "Such starting characteristics and principles determine that the aviation turbofan engine cannot be ignited and started independently like a car engine, Zhou Hai, what kind of consequences will it cause if it starts like an engine?" ”

"It burns the combustion chamber and the turbine guide vanes, and destroys the engine." Hearing this, Zhou Hai naturally had knowledge about aero engines in his mind and replied.

"Why?" Yang Xiaolong smiled.

"In the stationary state, the engine is directly supplied with oil for ignition, because the compressor does not rotate, and there is no pressure to inhale the air, the high-temperature gas cannot flow backwards and spray out, and then the turbine blades cannot rotate and work." Zhou Hai did not pause at all, and slowly revealed the principle.

"Yes, it is precisely because of this starting feature and structural characteristics that we generally use other auxiliary power to drive the main engine to rotate before the pre-ignition combustion step."

Yang Xiaolong nodded and continued to explain: "Now the mainstream way is power start, the ground provides a high-power power vehicle and a high-power engine, drives the main engine turbine to rotate, and the pilot then presses the start button to make the engine enter the slow car and maintain a stable working state. However, in case of emergency, it can also be activated by the on-board battery, have you made a note? ”

"Got it." Zhou Hai nodded, with a sincere attitude, and responded.

Although, Zhou Hai has long known about the starting process of aviation turbofan engines, and has recorded all these important knowledge in his mind.

"Okay, we've explained the situation, and then you control the simulator and demonstrate the process of starting the plane to the state before takeoff." After Yang Xiaolong finished explaining, his mouth was a little dry, and he gave new instructions.

"Da!" A crisp sound of a switch flicking sounded.

Zhou Hai's face was calm, his dexterous hands jumped and danced, skillfully turned on the main power switch, the 'EZVIZ' airborne avionics system started to operate, the head-up display and the two multi-function displays in front of him were energized and activated, and the dark screen was bright.

Skillful and fast, as if it had been operated countless times.

Then, turn on the engine power switch, press the engine start button, then the on-board battery supplies power to the right engine, and after a few seconds, the right multifunction display gives the engine parameters, showing the simulated turbine blade rotation.

Zhou Hai was not in a hurry, turned on the oil supply switch, and connected the oil supply pipeline.

"Drop!" Fifteen seconds later, the multifunction display on the right gives a hint of a successful engine start.

After successfully simulating the start of the right engine, Zhou Hai immediately relied on the gourd to draw a scoop, accurately replicated the operation process just now, supplied power to the left engine, drove the turbine blades to rotate, and pointed to achieve the stable working state of the slow car.

"Drop!" The left engine has been successfully started.

The whole start-up process took Zhou Hai about 40 seconds.