"Now the airplane is the most economical cruising speed, 90 kilometers per hour is the best speed, at this speed the plane flies the most fuel-efficient, and the speed is not slow, but the maximum speed can reach about 140 kilometers, but the fuel consumption is too great!"

As he spoke, Chen Wei pushed the throttle, and Yun Yi immediately heard the roar of the engine outside the cockpit a little louder, and the scenery on the ground swept back a little faster.

"The maximum altitude of this aircraft is much higher than the 3,000-meter elevation of an ordinary aircraft due to its unique and huge lift, and according to my calculations and that of the students, the maximum elevation is about 5,000 meters.

However, during the last test flight, I only flew over the height of the north main peak of Qingyun Mountain, and I never dared to fly high again, for fear of being scanned by radar. ”

Chen Wei shouted at Yun Yi a little louder, compared to the ultralight plane last year, the noise of this plane in the cabin is much smaller, and the two of them can hear it clearly when they talk a little louder.

"Brother Chen, how far can this plane fly with a full tank of fuel?"

After the plane is built, it will definitely fly to the Evenki grassland, Yun Yi asked after thinking about it.

"There are two ways, one is to rely on the fuel tank of the aircraft itself, and the aircraft can fly 600 kilometers when it is fully filled, and if the fuselage is filled with one and a half tons of water, it can fly 250 kilometers.

The second way is to fill the one-and-a-half-ton water tank in the fuselage with gasoline, and then use the supercharger to go to the fuel tank through the tube, so that it can fly about 4,000 kilometers at a time! ”

Chen Wei pointed to the cabin behind his fingers and shouted to Yunyi:

"I know that you want to get the plane to Hulunbuir, so I specially designed this fuel supply method."

After trying to fly two laps in the sky, Chen Wei let Yunyi feel the indicators of the plane, and then landed the plane slowly, and someone below had already dragged a water pipe over, which was to add water to the plane's water tank, and this was to test the plane's ability to fly with water.

"Here you go. Carry this on your back just in case! ”

Before the plane started the engine, Chen Wei threw a parachute backpack to Yun Yi, which immediately made his forehead full of sweat.

"Okay, you kid don't have to be so scared, although the plane hasn't taken off with water yet, but with the strength of the wings, it's absolutely fine!"

Chen Wei originally comforted Yun Yi, but he didn't expect that this sentence of flying with water for the first time made Yun Yi feel a little more nervous.

"Buzz!"

The plane's engines roared again, only this time the fuselage was noticeably heavier, and both engines were working at full capacity. Still let the plane taxi at first very slowly, very slowly.

"Brother Chen, there's no problem with the plane carrying so much water, right?"

Yun Yi asked Chen Wei nervously and loudly, and Chen Wei waved his hand indifferently;

"Don't worry, according to the results of the design calculation, this cabin can fly even if it is loaded with two tons of water!"

Sure enough, as soon as Chen Wei finished speaking, the plane taxied a lot faster with the increase of accumulated power, and after thirty seconds. After taxiing a distance of 500 meters, the plane swayed towards the sky and soared into the sky.

"The plane has to be loaded with one and a half tons of water, and the flight speed must be maintained at more than 90 kilometers per hour to ensure that it does not stall. Otherwise, the wings of the aircraft will not provide such a large lift! ”

Seeing Yun Yi frowning slightly, Chen Wei explained loudly to Yun Yi and asked him to turn on the water spray switch behind him.

"It's beautiful!"

When the water spray switch is turned on, a series of water mist erupts from both sides of the wing. As the plane whizzed through the air, it left two long white mist behind it.

After five minutes in the air, about one-sixth of the water sprayed out. When there was about 1.2 tons left, Chen Wei was full of nervousness and prepared to land, this is to test whether the aircraft landing gear is qualified or unqualified, so as to ensure that the landing gear will not break when the aircraft has to make an emergency landing in the air in the future.

"Whew!"

The plane is getting closer and closer to the ground with a whistling sound, and the speed is slowly decreasing, from 90 kilometers to 70 kilometers, when the plane is about to contact the ground, Chen Wei gently pulls the handle, and the nose of the aircraft lifts a lift to the ground, and then lands on the ground because the speed is too low.

"Bump!"

After a very loud sound, the five wheels of the plane were firmly attached to the ground, and then Chen Wei was about to release the accelerator, one foot gently stepped on the brake, and the plane quickly landed smoothly, Yun Yi quickly ran out of the cockpit with a pale face, and the sudden resounding made his heart almost stop beating.

"Ha Lu Ha, the test is perfect!"

Chen Wei walked out of the cabin with excitement on his face, and after looking at the landing gear, he smiled from ear to ear.

"Brother Chen, the low-speed performance of this aircraft you made is really good, the speed of seventy kilometers before landing, the tail and horizontal rudder can still play a role!"

Long Xiaotian, who had been watching on the ground for a long time, immediately greeted him with a smile, and Chen Wei smiled modestly.

"No, Brother Long, I almost didn't scare me to death when I landed just now, why do you still say it?"

Yun Yi said in surprise on the side, while a group of students immediately ran up to check the parts of the plane very professionally after the two of them got down.

"Uncle Chen, all parts of the plane are intact and normal, and there is no loosening of the landing gear at all!"

A high school student ran over and handed the inspection report to Chen.

"Yunyi, this aircraft can be regarded as a successful research!"

Chen Wei gave the inspection report to Yun Yi with a proud smile, Yun Yi took it and looked at it twice, nodded, took out a check for 100,000 yuan from his pocket and handed it to Chen Wei, and said with a smile:

"Brother Chen, don't shirk this, the performance of this aircraft you built is not bad at all compared with the Y-5 agricultural aircraft, although the comfort and appearance are not as good as it, but this low altitude and low speed, and the unique design method is better than the Y-5!"

"Of course, my aircraft is not only better than the Y-5 in low-altitude performance, but more importantly, it is more practical and fuel-efficient, and its Y-5 is also improved from the transport aircraft, compared with my aircraft that has been committed to agriculture and practicality from the beginning, it is really too far behind!"

Chen Wei looked at the check, took it after a little hesitation, and immediately waved the check and shouted at the seven or eight students who had been helping:

"Hey boys, today your Vice Dean Yun sent me money, wait for one of you to come over and get five thousand yuan!"

"Whoa!"

A group of high school and junior high school students were immediately excited, although this money was nothing to them, but this was the first money they earned for their interest, which was of great significance!

Looking at their excited eyes, as well as some knowledge that the science teacher on the side took the opportunity to tell, Yunyi's heart moved: Maybe these children can become excellent aircraft designers in the future! (To be continued......)

PS: Thanks to the 'wdid007, free old otaku, Gao Shu, yogo' folks for their tips and support

Thank you to the 'Bookworm 810627' brothers for their monthly ticket support