Time passed day by day, and the progress of the test flight was also very fast, on this day, Qin Feng came down from the sky, looked at the flight log, and the subject of his own test flight was already the last page in the small book.

"We're moving so fast." Wang Gang said: "I didn't expect to successfully complete all the test flight tasks so quickly, tonight, let's go out and celebrate!" ”

The entire test flight team, a total of five test pilots, Wang Gang is the team leader, now it is he who speaks, since the test flight, Wang Gang is responsible for formulating the daily test flight plan, and now, he is also very happy in his heart.

It's not easy, look at the J-8 of the brother unit, after so many years, how much progress has been made in the test flight? It's still a test flight in the subsonic range!

Of course, this is also because the aircraft we are flying is a full-fledged aircraft.

The J-7 II fighter is an improvement on the basis of the J-7 I fighter, mainly changing the previous rather unreliable ejection survival device that ejects with a hatch cover to an open ejection life-saving device, and redesigning a new type of rocket ejection seat that is easy to use and maintain, safe and reliable; It has been replaced with a new type of engine, which has improved the performance of the aircraft and increased the thrust-to-weight ratio of the aircraft; With the newly developed 720 liters of auxiliary fuel tank, replace the original use of 480 liters of auxiliary fuel tank, increase the fuel capacity, improve the endurance, move the drag parachute cabin seat up, increase the parachute speed, increase the parachute resistance, thereby significantly improving the landing performance of the aircraft, the aircraft can be parachuted in time and space not more than one meter from the ground, and the landing and running distance is shortened to less than 800 meters.

It can be said that the general direction has not changed, and this aircraft is equivalent to a slightly improved model, so the test flight is also very smooth, and there is no need to go to the test flight institute, as long as it is in the 132 factory in Chengdu, you can test the flight yourself.

The test flight subject is progressing very quickly, and now it is about to be completed, and it has reached the level of equipping troops.

"Really?" Qin Feng casually picked up the test flight logs recorded on the table, looked at them one by one, and looked at their flight records, Qin Feng continued to praise: "It's so fast, we finally finished flying." ”

flipped to the end, Qin Feng suddenly remembered something: "By the way, why didn't our stall tailspin subject fly?" ”

Hearing Qin Feng's words, all of a sudden, the faces of several people were ugly.

"This subject is not mandatory by superiors." Wang Gang said: "After all, I flew this subject on the J-7 I. ”

Hearing Wang Gang's words, Qin Feng was also silent for a moment, he knew that when he flew this subject on the J-7 I a few years ago, there were senior test pilots who sacrificed, so even if it was a superior, he had concerns about this project.

After all, this is a no-go zone for delta-wing aircraft.

Pilots flying fighter planes and soaring into the blue sky look very chic, but the risks of flying are everywhere, and among all the risks, stall tailspin is the most terrible one, and it is definitely the highest level of accidents.

In fact, in the early days of the advent of the aircraft, there was a mysterious flight phenomenon: in the flight, sometimes the aircraft suddenly lost control, while falling, while flipping sideways, it is difficult to deal with, often the result of ineffective control and the death of the aircraft. This phenomenon is known as stall tailspin.

Stall and tailspin are actually two different aspects.

Stall is a phenomenon that occurs when the angle of attack of the wing increases to a certain extent, and the airflow on the upper surface of the wing separates, resulting in a decrease in lift. To put it simply, the speed of the aircraft is low, and the lift cannot drag the aircraft, at this time the aircraft will lower its head and sink until it has enough lift to fly.

Tail spin is caused by stalling, and it is a special case in stalling, that is, when one wing stalls before the other, the aircraft will rotate along the longitudinal axis of the aircraft in the direction of the wing of the side that stalled first, which is called spiral or tail spin.

In normal flight, the pilot should be careful not to let the aircraft enter the stall tailspin, but for the test pilot, it is necessary to fly the aircraft to the tailspin, and it is necessary to experiment with what to do after entering to change it.

The risk of this subject is very great, and even in the later period, in the nineties, there was a time when this subject was abandoned for more than ten years, and no one dared to fly this subject.

What if the plane goes into this state? Then there's only skydiving.

At the same time, in the West, stall tailspin has been trained as a normal flight subject, and the average pilot has flown and knows how to change it, but in China he has given up training in this subject because of safety concerns.

Now, everyone knows that this stall tailspin subject is very dangerous, anyway, it has been flown on the J-7 I, and this subject is not listed as a subject that must be tested.

"Although our plane has not changed much, it has been changed after all." Qin Feng said: "The engine, parachute position, etc. have been changed, and the tail spin may be different, if we don't test the flight, once the fighter is finalized into the army, what should we do if we encounter this situation?" ”

After encountering problems, pilots will deal with them according to the flight manual they are familiar with, and how to do it under what circumstances, this flight manual is written by test pilots with their own test flight experience.

If there is no test flight, just copy the previous flight manual, isn't it fooling? What if things are different?

Qin Feng looked at everyone's eyes and said, "I have been delayed for a long time and have not participated in our test flight subject, so this stall tailspin, let me fly." ”

"What are you messing around?" Wang Gang couldn't help but say, "Do you think everyone is afraid? Do you think you're alone? None of us have ever flown a stall tailspin, what if the change fails and the fighter falls? That's the property of the state, and the superiors have agreed, what are you shouting here? ”

Everyone is not afraid of death, but the plane is the property of the state, what if the property of the country is wasted for a subject that is not necessary?

"Team leader, you said it all, what if it fails? We test pilots here have to mention the word in case of failure, then what about the troops below? ”

Wang Gang stopped speaking for a moment.

At this moment, there was the sound of footsteps behind him.

Old Tu is here.

After coming back, it was already the morning of the next day, Tu Lao couldn't take a break, first looked at the mapping progress of the MiG-21MF, and then came over to see the progress of the J-7 II test flight, of course he was also worried about this matter.

Who knows, after he came over, he heard the sound of Qin Feng and several other test pilots arguing. Hearing everyone mention the stall tailspin, Tu Lao also frowned.