Chapter 9

the paper airplane hovered in the air

“are you free on the 13th?”

on the way home, tang rui received a call from his classmate zhou tao.

they were like father and son in the same dormitory, and their relationship was excellent.

“if you’re married, you have time. if you’re not married, you don’t have time.”

tang rui replied afterward.

“get lost… you never wanted to get married. how could he get married?”

“haha.”

“let’s not talk about this. next saturday, which is the 13th, our alma mater’s aeromodelling club and china southern’s aeromodelling club will jointly organize an event.

china southern airlines applied for airspace at our alma mater’s venue. it’s a no-limits, fly-as-you-please session. our graduates can also participate. are you going?”

there was such a good thing?

he was worried that there was no place to test the various functions of the drone.

today’s test flight was only to test the electro-optical system.

as for the drone’s maximum altitude, maximum speed, stall speed, climb rate, and other performance parameters, there was no way to test it.

“go, where is the location?”

“over at the immortal grove purple gold academy.”

“i understand. kneels.”

“get lost.”

after hanging up the phone, tang rui still had a smile on his face.

although the two of them were very close, they didn’t usually communicate much.

after all, everyone had graduated.

each had their own matters.

he opened his own online store and engaged in self-media. it was still considered easy and free.

people like zhou tao, who didn’t come from a local family but chose to stay in jinling, were the most hard-pressed.

let alone the fact that work was extremely tiring; there would be little money left after paying the rent every month.

not to mention that he still needed to eat, drink, shop, and occasionally go out to relax.

it was good enough that he could earn enough. savings were out of the question.

everyone was usually busy with their own lives. only when they were in a bad mood and had too much negative energy accumulated in their hearts would they call for help and go for a drink.

under normal circumstances, tang rui would play the role of sprinkling salt on the other party’s wounds.

to use his words to describe the inner turmoil of the great… this was called fighting poison with poison.

although he would be forced to drink in the end, he was still very happy to have a venomous tongue.

back in the neighborhood.

after parking the car, she laboriously carried the aircraft model upstairs.

the first thing tang rui did after returning home was not pack his things but shower.

he was drenched in the rain.

he was sweating again.

her whole body was sticky and uncomfortable.

ten minutes later.

having just showered, tang rui sat on the chair with a towel draped over his shoulders. he crossed his legs and sipped the iced coke in his hand.

he finished half a bottle in one go.

burp!

it felt good.

however, his mood immediately turned sour when he saw the paper airplanes all over the ground.

“what should we do with these?”

throwing them away would be a waste.

he didn’t want to throw them away. there was no place to put it.

paper airplanes couldn’t be sold. at most, they could only be sold as waste paper.

wait a minute…

who said it couldn’t be sold?

tang rui picked up a paper airplane at his feet and looked at the system panel on it.

[item: paper airplane]

[experience: 0/20]

[origin: 0]

there was only very little exp needed for him to level up. he only needed 20.

he wanted to test the effects of the upgrade first.

“hah…”

he blew on the nose of the paper airplane and threw it out.

the paper airplane flew steadily in the air, its trajectory drawing a straight line in the air.

ding!

the paper plane crashed into the mirror of the shoe cabinet and landed on the ground.

tang rui got up, ran to the shoe cabinet, and picked up the paper airplane on the ground.

[item: paper airplane]

[experience: 6/20]

[origin: 0]

he gained 6 experience points in one go, and he could level up after three or four flights.

there was nothing much to say.

he continued.

with a light toss, the paper airplane flew out again.

this time, it might have been due to the collision of the nose, causing the flight path to be a little crooked, but it did not affect anything.

he picked up the paper airplane again.

this flight added 7 experience points. not bad.

whoosh…

after two more flights, the paper airplane gained 5 more experience points, reaching the level requirement.

tang rui directly clicked to upgrade.

swoosh!

a faint light flashed.

the paper airplane was upgraded.

[item: stable paper airplane +1]

[experience: 5/40]

[origin: 0]

he picked up the paper airplane and looked at it carefully. it didn’t seem to have changed, but it seemed to have changed a little.

he really couldn’t tell exactly what had changed.

the word “stable” appeared on the system panel.

after tang rui frowned, he threw out the paper airplane again.

he wanted to see the effects of the paper airplane after it was upgraded.

whoosh…

the paper plane drew a standard horizontal line in the air and flew straight towards the window.

it didn’t seem to have changed much.

the paper airplane from before was also flying in this manner.

just as he was feeling a little disappointed, a gust of wind suddenly blew in through the window.

the paper airplane that was flying toward the window suddenly stopped at this moment and slowly retreated.

f*ck!

tang rui was dumbfounded.

as he stared in shock, the paper airplane slowly flew backward and stopped after rising ten centimeters. it hovered steadily in the air.

ten seconds passed.

the wind blowing in through the window decreased.

the paper plane that was hovering in the air flew forward again. as it flew, it slowly descended.

however, before the paper plane landed, a gust of wind blew in through the window.

following this wind, the paper plane slowly retreated and rose again, finally hovering in the air.

the corners of tang rui’s mouth twitched unconsciously.

was this magic?

that’s right.

this was a spell unique to the field of aerodynamics.

at this moment, tang rui already understood why the paper airplane would appear to reverse, rise, and hover.

theoretically speaking, in order to make the paper airplane achieve such an effect, one had to first ensure one thing.

that was the folded paper airplane. the two sides of the central axis were completely balanced by gravity.

in other words, the weight on the left and right sides of the central axis was absolutely balanced and completely identical.

furthermore, the weight, shape, and angle of inclination of the wings had to be the same.

secondly was the center of gravity.

he folded a canard plane. normally, the center of gravity of a canard plane was between the canard and the wings.

but the problem was that this was a paper plane.

its center of gravity was at the nose of the plane, very close to the front.

as everyone knew, the closer the center of gravity of the plane was to the front, the more stable it was, and the easier it was to fly in a straight line.

in such a situation, the balance would be perfect, where the center of gravity was in the front. there would be the same amount of lift on both wings. the body of the plane would be in line with the ultra-lightweight of the paper plane itself.

all of this added up to a perfect balance between lift, drag, and gravity.

that was why the paper airplane could hover in the air.

tang rui picked up a paper airplane that he had folded himself and hadn’t been upgraded by the system, and threw it toward the window.

whoosh…

at first, the paper plane could still draw a straight line, but as it approached the window, it immediately began to deviate from the direction of the wind blowing in through the window and finally hit the wall.

he was not surprised by this situation.

paper airplanes that had not been optimized by the system panel could not reach that ideal state.

after all, it was handmade.

it was impossible to achieve a perfect balance.

after a while.

the wind blowing in through the window stopped.

the paper airplane hovering in the air also slowly glided down.

tang rui walked over and picked up the paper airplane.

[item: stable paper airplane +1]

[experience: 58/40 (upgradeable)]

[origin: 0]

he didn’t expect that this wind would not only let him discover the awesomeness of the paper airplane but also filled up his experience points.

there was nothing to hesitate about.

he directly clicked on the upgrade button.

swoosh!

a faint light flashed.

the shape of the paper plane had become more in line with the air dynamics. there were even two gaps at the tail. together with the curvature of the wings, it even became two horizontal tails.

[item: stable paper airplane +2]

[experience: 18/? (cannot be upgraded)]

[origin: 0]

tang rui finished looking at the upgraded panel and found that the paper airplane could no longer continue upgrading.

there was nothing wrong with thinking about it.

after all, it was just a paper airplane. the first upgrade optimized the overall structure, and the second adjustment adjusted the body shape.

without strengthening it, there was no room for improvement.

as for strengthened paper airplanes?

it was impossible.

source points were still very precious, he could not waste precious source points on paper planes.

the paper airplane in front of him was stunning enough.

tang rui picked up a few paper airplanes that hadn’t leveled up from the ground and threw them toward the window.

he planned to get a few more upgraded paper airplanes and then shoot a video of the paper airplane hovering in the air.

even if the videos were fake, many people would still like to watch them.

needless to say, he was telling the truth.

when the time came, he would upload the video and put the paper airplane on the shelf. there would probably be many people who would buy it.