With his elbows on the lower edge of the car window and his wrist supporting his chin, Xia Yu tilted his head and looked at the scenery outside the car window, he had not looked at the scenery so leisurely for a long time. Although there is not a lot of free time, most of the time, Xia Yu spends his time studying in the space of consciousness.

It's been a week since he left the aircraft carrier, and after handing over the J-31 to Shen Fei, Xia Yu stayed in Shen Fei for two weeks, making improvements, making written and oral reports, and holding research meetings, which is more troublesome than him flying in the sky, but this is the job of a test pilot, and test pilots also need to participate in the actual design of the aircraft.

Fortunately, the 31009 does not need to make more changes in the aerodynamic shape design, and the proposed construction has also been proposed in the meeting and written report, and the next thing to do is to wait for the improved 31009 to be built, continue to test flight, and see if the effect of the new design can be achieved. However, it will take at least two to three months, so during this time, Xia Yu will not have any flight missions.

Thinking that more than half of this year has passed, and he hasn't gone home to see his parents once, Xia Yu made a report to apply for a vacation, and it was quickly approved, so Xia Yu will sit in the taxi to the airport at this time. This is a month-long vacation, enough for Xia Yu to do something he wants to do.

came to the airport, got the ticket, passed the security check, and Xia Yu entered the waiting hall. Today's weather is very good, the sun is shining, and the plane is not late, so Xia Yu can enter the boarding gate without waiting too long. I found my seat, and just as I sat down, someone next to me suddenly asked, "Young man, can I switch places with you?" ”

Xia Yu turned his head, he was an old man with a very healthy mental outlook, although his hair had completely turned white, his face was very ruddy, he was wearing a multi-bag vest, he looked like a director, and he was looking at Xia Yu with a smile at the moment.

"Oh, okay." Xia Yu stood up and moved inside, his original position was against the aisle, but the old man's position was against the window. The space between the economy class seats is very narrow, and it is not much better than the bus, and it is estimated that the elderly are worried about the inconvenience of going to the toilet.

It was very simple to get Xia Yu's consent, the old man naturally thanked him very happily, Xia Yu saw that the old man was still carrying a travel bag in his hand, and simply helped the old man put the travel bag into the luggage rack on his head, and then sat down in the position by the window. This is where the tail of the plane stands, and in the front row are the emergency escape doors, and when you look out the window, you can see the wings and huge jet engines.

This is the Boeing 737, a well-known short- and medium-range twin-engine commuter airliner, one of the most successful models in the aviation industry, and the main aircraft in China's civil aviation industry. Nowadays, all over the world, there are more than 1,000 Boeing 737s flying in the sky at any given time, which is quite a remarkable number.

Xia Yu sat in the seat, the seats in the economy class are a little narrow for people who are slightly fat, and the comfort of the seats is naturally not as good as the first class, but compared to the first class, which is several times more expensive, even if it is a little uncomfortable, it is not a big problem for ordinary people, as long as the plane can reach the destination safely.

Buckle up and Xia Yu quietly waited for the plane to take off. Once the flight attendant has confirmed that the passengers have boarded the aircraft, they begin the instructions that must be made before each take-off, such as turning off the mobile phone, anti-impact posture, etc. However, with the exception of first-time flyers, most frequent flyers basically don't pay attention to what flight attendants say, which has long lost their novelty, and they prefer to pay attention to what they are doing rather than listen to the same words.

The engines of the Boeing 737 also began to run, and unlike the fighter jets, the sound insulation of the civil airliner was quite good, although the sound of the two huge jet engines when running could reach about 120 decibels, the sound that could be heard in the aircraft was not loud, and if you were not careful, you would even ignore the past. Taxiing, raising heads, getting off the ground, climbing, this set of take-off actions Xia Yu has long been familiar with, but the comfort of a fighter is far less than that of a civil airliner. When the fighter took off, Xia Yu could feel the huge inertial force pressing himself down on the seat, but now, Xia Yu felt that he had no problem dancing in the aisle.

It takes about three and a half hours to fly from Shenyang to Guilin, and Xia Yu has no habit of sleeping during the day, so when the plane climbs to the cruising altitude, Xia Yu gets up and opens the luggage rack, takes out a book from his travel bag, and prepares to kill time.

The old man next to him saw that Xia Yu was about to read, and he didn't plan to disturb Xia Yu, but at a glance, the book Xia Yu was holding in his hand was actually the latest issue of an American science magazine, and he couldn't help but be curious.

"Science" is a natural science weekly created by Thomas Edison, with high academic value, but in China, unless it is a scientific researcher, few people generally go to see it, the old man himself also subscribed, I didn't expect to see a young man reading this kind of magazine, the old man asked: "Young man, are you engaged in scientific research?" ”

Xia Yu was stunned for a moment, turned his head to look at the old man, shook the magazine in his hand and replied, "No, I'm just using it to pass the time." ”

Kill time? The old man was stunned for a moment, and then looked at the page number that Xia Yu was looking at just now, this is obviously a scientific paper, how can anyone use reading papers to pass the time. The old man stepped forward and took a few looks, this is a research report on pulse detonation engines, which is of a very professional nature, and it is full of all kinds of real numbers and conjectures of the author, the old man was a little skeptical, and asked directly: "Can you understand?" ”

When Xia Yu heard this, he was immediately happy, and said with a smile: "What am I doing with it if I don't understand it?" ”

"That's right." The old man nodded, and then asked: "Then you can tell me about the ideas and theories mentioned in this paper, don't try to lie to me, I also study aero engines." ”

It can be seen that the old man is very proud of his identity and status, even if he does not clearly state his position, the confidence revealed in his eyes makes Xia Yu believe what the old man says, besides, the old man does not need to lie to himself. However, since the old man wanted to take the school and test himself, Xia Yu didn't mind, lowered his head and organized the language slightly, and began to expound his views.