Volume One, Chapter 36: Hold Steady

Wang Zhen’s response was as steady as ever, like a pebble dropped into a deep well, failing to stir the slightest ripple.

"Received. Preparing to break the sound barrier."

In the control room, the air that had just grown heated due to the "staggered PRF" cooled down once more, and everyone’s nerves tightened again. This was a dual test. The radar was the eyes, and the engine was the heart of this bird of prey.

On Du Yuze’s screen, the engine data streams flowed like two steady green brooks, trickling quietly by. He did not issue specific instructions, merely saying, "Wang Zhen, it’s in your hands."

"Understood."

A slight sound of a control stick being pushed came over the radio. On the screen, the numbers representing engine RPM began to climb. 80%, 90%, 100%. Immediately afterward, the afterburner ignited. The two green brooks instantly transformed into surging red rivers.

"Altitude 11,000 meters, speed Mach 0.8," Wang Zhen’s voice remained calm.

"Mach 0.9."

The airframe would encounter violent buffeting in the transonic region; this was the air issuing a warning to the steel body. On Du Yuze’s data panel, dozens of parameters flickered frantically, but all fluctuations remained within the pre-set "safe envelope."

"Mach 0.95, buffeting has begun."

"Steady," Du Yuze said, only one word.

"Mach 0.98..."

The control room was deathly silent. Factory Director Zhang gripped his fists, leaning forward as if he could help the aircraft exert more force by doing so.

Suddenly, a report came in from the ground monitoring station: "Sonic boom cloud detected! He’s through!"

Almost simultaneously, Wang Zhen’s voice sounded: "Sound barrier broken. Aircraft attitude is stable, flight control system response is normal."

"Good!" Director Zhang slapped his thigh again, this time with a much louder sound. "Our engine held up!"

"Test continues." Du Yuze cut short his excitement. "Wang Zhen, climb to 15,000 meters. Prepare for high-G maneuver testing."

"15,000?" Director Zhang was stunned. "At that altitude, the air is so thin; performing high-G maneuvers will place an immense load on the engine and airframe structure..."

"Testing the limits is the point." Du Yuze did not look at him; his entire focus was on the data.

Director Gao stood to the side, remaining silent. He simply watched Du Yuze, like an examiner scrutinizing his student.

On the screen, the aircraft turned into a light point, climbing steadily. A few minutes later, Wang Zhen’s voice came through.

"Reached the designated airspace. Ready to begin."

"Proceed as planned," Du Yuze ordered. "Left turn, 5G load, hold for ten seconds."

"Received. Commencing maneuver."

On the screen, the number representing G-force jumped abruptly from 1 to 5.0. The data stream turned turbulent in an instant; structural stress, hydraulic system pressure, engine intake pressure—all parameters danced wildly near their critical points.

Everyone in the control room held their breath.

Ten seconds felt as long as a century.

"Maneuver complete. Aircraft status is good," Wang Zhen reported.

***

Du Yuze’s brow did not unfurl. Everything was too perfect. The data was perfect, the operation was perfect, and the feedback was perfect. It was as standard as a textbook—so standard that it felt unreal.

"Wang Zhen, prepare for the next item: right turn, 7G."

"7G?" This time, even Wang Zhen hesitated on the radio. "That will exceed the design limits."

"I know," Du Yuze replied. "I need the most authentic data."

Director Zhang grew anxious. "Little Du! This is too risky! If something happens..."

"There are no 'ifs'," Du Yuze interrupted. "All risks have been simulated by computer. I need to verify the accuracy of the simulation."

Director Gao remained silent.

"...Received." Wang Zhen ultimately chose to obey. He was a soldier; carrying out orders was his duty.

"Begin!"

The aircraft banked sharply to the right. The G-force jumped from 1 to 7.2!

At that very moment, in the center of Du Yuze’s console, a red master warning light illuminated without warning, emitting a piercing buzz!

Almost at the same instant, a cold, emotionless synthetic voice exploded deep within his mind.

[Warning! Abnormal temperature spike at the turbine inlet of the right engine! Safety threshold of 1750K exceeded! Supercritical risk exists!]

Du Yuze’s body jolted.

He looked at his main data screen. The parameter bar representing the right engine's turbine inlet temperature (T4) was still green. The reading showed 1600K—an absolutely safe value.

What was going on?

"Du Yuze, what’s wrong? Your warning light is on!" Shen Qingyun was the first to notice the anomaly.

"Wang Zhen!" Du Yuze ignored everyone else and roared into the microphone, "Report your right engine T4 temperature immediately!"

"T4 is normal!" Wang Zhen’s voice was distorted by the immense G-load, but his words were clear. "The gauge shows 1600K, everything is normal! All parameters are in the green!"

Director Zhang’s face turned deathly pale. "A false alarm? Little Du, turn it off! Don't distract the pilot!"

A false alarm?

Du Yuze clenched his jaw. The "symbiotic" data monitoring system he designed—using micro-probes and data models outside of the hundreds of conventional sensors—had constructed a digital twin. Its perception and predictive capabilities far surpassed the aircraft's onboard instrument system. It could not be wrong.

[Warning! Temperature continuing to rise! 1820K! Risk of turbine blade creep surging!]

The alarm in his mind grew sharper.

"Wang Zhen!" Du Yuze called again, his words coming out like a machine gun. "Don't look at the gauges! Trust your instincts! Tell me, what does the plane feel like now? Is there anything wrong at all?"

There was a second of silence on the other end of the radio. Under seven times his own body weight, any minor anomaly would be magnified.

"...Power," Wang Zhen’s voice came through. "The power output has a lag. Very slight, but I can feel it. On the right side... it feels like something is dragging on it."

That was it!

***

Du Yuze did not hesitate any longer. The pilot’s intuition was the final piece of the puzzle he needed.

[Warning! Blade fatigue limit approaching! Risk of structural failure within three seconds!]

"Abort the test!" Du Yuze issued the command into the microphone, his voice loud enough for the entire control room to hear. "Wang Zhen, abort the test immediately! Return to base at once!"

He paused, adding, "Shut down the right engine, prioritize safety!"

"What?" Director Zhang shouted. "Du Yuze! Are you crazy? Returning on a single engine? Just because of one of your alarms and a pilot's 'feeling'? The aircraft's gauges are normal! Do you know what shutting down the engine means? This is a Class A accident, the most severe kind!"

Wang Zhen waited for final confirmation over the radio. He heard the argument in the control room.

Du Yuze stood up abruptly, facing Director Zhang. "Director Zhang, if the gauges were always correct, why are we sitting here? Why do we even conduct test flights?"

He pointed at his screen, even though the T4 data on it was still green.

"My system tells me that in a few seconds, that engine will disintegrate in mid-air! By then, what we lose won’t be just a test flight mission, but a multi-billion [currency] prototype and China’s top test pilot!"

"You're gambling!" Director Zhang’s hands were shaking with rage.

"Yes, I am gambling," Du Yuze’s voice turned cold. "I am betting that my design is correct. If I’m wrong, you can have me shot. But what if I’m right?"

The air in the room seemed to have been sucked dry.

Director Gao, who had remained silent throughout, finally moved. He did not judge who was right or wrong between Du Yuze and Director Zhang; instead, he picked up the communicator in front of him.

"Tower, this is Gao Jianjun. 'Sword One' is experiencing an emergency; declaring a Level 1 status. Clear all approach paths, prioritize 'Sword One' for landing. All fire, medical, and emergency repair units, standby at the runway immediately."

His instructions were clear and calm, leaving no room for negotiation.

This decision was the most direct support for Du Yuze.

Director Zhang opened his mouth, then slumped back into his chair in defeat.

Du Yuze sat back down and reconnected to Wang Zhen’s channel.

"Wang Zhen, execute the order."

"Received." Wang Zhen’s response was without a hint of hesitation. "Right engine shut down. Aircraft attitude controllable. Preparing to return."

On Du Yuze’s screen, the data stream from the right engine, after a brief, violent fluctuation, turned into a gray straight line. And in the final moment before it went dark, the T4 reading from the official sensor jumped abruptly from green into the yellow warning zone, finally settling at 1760K.

The sensor had sounded the alarm eventually, but it was seventeen seconds too late.

In the rapidly changing conditions of the sky, seventeen seconds was enough to decide life or death.

Du Yuze did not look at the people behind him. He knew the real test was only just beginning.

He asked into the microphone, word for word, "Wang Zhen, how does it handle?"

"Asymmetric thrust is a bit heavy, but it’s still controllable," Wang Zhen’s voice remained steady. "This bird is pretty tough. I’m bringing her home."