The "Feng Ru-3" drone that takes off in the car. Courtesy of Beihang
At 4 a.m., team members monitored the drone's flight status in the outfield. Courtesy of Beihang
80 hours, 46 minutes and 35 seconds. The world record was set again.
Not long ago, the news that the "Feng Ru No. 3" Phase II team from Beijing University of Aeronautics and Astronautics successfully refreshed the world record for the endurance time of 25-100 kg nitro fixed-wing UAVs has attracted attention. What is less well known is that the team members are 25 undergraduate students from 4 grades and different majors, with an average age of no more than 20 years old, and more than 90% are post-00s.
Previously, this record was maintained by the first phase team of "Feng Ru No. 3". In October 2019, the first team set a world record for the endurance time of an nitro fixed-wing UAV in the 25-100 kg range with 30 hours, 6 minutes and 42 seconds of flight time. Today, after two years of extreme challenges, the phase II team has successfully set a new record and topped the list of nitro fixed-wing UAVs in the world.
Standing at the top of the pyramid of the drone's endurance flight, this group of young people less than 20 years old did not stop exploring, and they were determined to let the "Feng Rusan" drone soar in the blue sky for 500 hours.
A box of screws that have been screwed
In the team, everyone's dream of flying points to one place: "Feng Ru No. 3".
This oil-operated fixed-wing drone, the whole aircraft is black, the wingspan is about 10 meters, the fuselage is in the shape of a submarine, made of carbon fiber composite materials. When it takes off, it spirals and roars, dusty, like an eagle that stands tall in the sky.
When I first saw it, Li Peishan, who was born in 2001, was just a recent student of Beihang. She had never been exposed to drones, and the first time they met, they just thought this big guy was "cool".
In the first class of "Feng Ru No. 3", this group of fashionably dressed and trend-oriented post-00s were pulled to a factory, which was a practical education base established by Beihang Airlines in cooperation with enterprises and institutions in the aerospace field. Here, the realization of all flying dreams starts with screwing a screw.
Li Peishan studied in the field in the factory and did not have any practical experience. When she was installing parts, she cracked the propeller and burned out the device because of the wrong battery, and the 19-year-old girl cried at once.
In 2018, as the first member of the "Feng Ru No. 3" team, Fu Ning of the large aircraft class entered the factory for the first time, looking at the tools held by the workers, not knowing the name, and not knowing how to start.
Taking the seemingly simplest bolt as an example, different bolts have different preloads, and loosening will cause the device to loosen, and too tight is easy to cause damage to the component.
What makes Fu Ning difficult is that when he first got started, he was not measured, often screwed and screwed, listening to the sound of "clucking", and the screw was broken. A week down, screwed up, enough to fill a small box. He stayed in the "Feng Ru No. 3" team for 3 years, and the "legend" of screwing a box is still circulating within the team.
Fu Ning said that this is a work that requires extreme precision, and the parts used in the drone must be weighed one by one, and even the amount of glue used has been digitally stipulated.
Zhang Yiquan, the captain of the first phase of the "Feng Ru No. 3" team, said that when the team members first arrived, they usually carried the "tiger spirit" of young people, dared to do anything, but inevitably made mistakes carelessly, and after a period of team tempering, everyone gradually learned a cautious and meticulous work attitude.
Zhang Yiquan once took a student to adjust the horizontal tail of the aircraft, at the beginning, the left and right horizontal tails always could not reach the same horizontal line, this young man dismantled and installed, installed and dismantled, until the first flight of the aircraft, the apprentice was still adjusting step by step.
"The requirements for flying are high, as high as every line, and you need to reach a preset position. Only in this way can the aircraft be prevented from abnormal situations. Zhang Yiquan said.
Overnight in vain for success
The "Feng Ru No. 3" team also has the tradition of "sitting on the cold bench".
Before the plane could fly, team members had to do a lot of refueling and pumping. Among them, refueling is the last step before take-off, starting refueling and weighing at 11:30 p.m., often until more than 4 a.m. the next day; at the same time, they also have to measure the fuel consumption of the engine, the speed, the temperature of the cylinder, everyone takes turns to work in 4 hours, taking turns on duty records.
Li Xuhang, a 2019 student of Beihang FengRu College, still remembers that there was a test flight, although it was August, but the dew was heavy at night, the temperature was low, sitting near the engine, the propeller blew a cold wind, they had to put the down jacket on the body as a quilt; occasionally the electric pump "strikes", the battery is out of power, Li Xuhang will work on his own, relying on the hand oil pump, fueling the drone.
Liu Yaxi, a student from the School of Reliability and Systems Engineering, was initially in the take-off and landing group, and later transferred to the control group, responsible for the sensor part, and it was more than 7 hours to do the test, and staying up all night was a common thing.
One year, on a Chinese New Year's Eve night, the team members had only one down jacket, and they took turns putting it on their bodies for experimentation. Liu Yaxi remembers that sometimes it was too cold to bear, and some of them drank the counselor's wine to keep warm.
Still, the 19-year-old never felt bitter, just thinking that she could serve the country with what she had learned.
"Feng Ru No. 3" team instructor Wang Yaokun explained that once the aircraft flies into the sky, it will face many unknown factors, and there may be a situation such as engine shutdown at any time, and the team members can only monitor the flight data through the ground station at all times to judge the flight status of the aircraft and deal with it at the first time. As a result, team members often stay up late together according to the needs of the task.
Wang Jiqin, a young man born in 2001, remembers that when he entered the school, his teacher said that he would find something he liked. Now, he felt that he had found it, and this matter was "Feng Ru No. 3".
Once, Wang Jiqin found that after the plane was refueled, there was a problem with the relevant parameters. Together with the team members, he pumped out the oil, reworked and modified the power plan, and debugged it a little bit. Staying up until more than 4 a.m., when he accidentally looked in the mirror, he suddenly found that his beard had suddenly turned white.
Since then, the story of "one night must be white" has also spread in the team. But Wang Jiqin felt that it was "worth it", and in the process of the death test, he said that he had become more courageous and rigorous.
No one gave up "Feng Ru No. 3" because of hardship. On December 27, 2020, Fu Ning had just finished taking the graduate school admissions exam and when he left the examination room, he received a call from a team member. The other end of the phone said that the research and development time of the new power system of "Feng Ru No. 3" is tight and the task is heavy, and it is necessary to carry out power tests by hand. Without saying a word, Fu Ning took the high-speed train the next day and went straight to his destination.
Later, a team member asked him if he hesitated. Fu Ning replied no, in his opinion, since this matter has begun, it is necessary to continue to do it, "'Feng Ru Iii' is not only a drone, but also carries everyone's dream of flying." ”
A fallen drone
This "Feng Ru-3" drone was also scarred.
Zhang Xiuhui, a student of the Academy of Astronautics born in 2001, first saw a drone crash in Hainan. After eating at noon, everyone was preparing for a lunch break, only to hear someone outside shouting: "The plane is in an accident, the plane is in an accident." He immediately ran out and watched as the plane spiraled down and eventually disappeared into the woods.
Everyone was frightened, and more than 20 people went out en masse, carrying carts, pliers, scissors, and fire extinguishers, and the soldiers went in two ways to find them. The place where the plane fell, in the middle of the rainforest, the road was covered with bushes, the branches of the trees were torn, and they could not take care of it, and they used their hands to remove all obstacles to find the wreckage of the plane.
When I saw the drone, it was a mess. Zhang Xiuhui remembers that part of the drone fell into the ravine, and the other part of the fuselage disappeared. Wang Yousheng, who was traveling with him, felt distressed, every part of the plane was installed by everyone's own hands, and in their hearts this was a priceless treasure.
After the crash, the team members of "Feng Ru No. 3" moved the wreckage back to the laboratory, dismantled it little by little, and analyzed the cause of the failure.
When she first experienced the failure of the test flight, Tian Ge was still a little girl who loved to shed tears. Today, this student of the School of Aeronautical Science and Engineering has seen too many test flights, and once she encounters an emergency, she can calmly analyze the cause of the failure, "These failures have given me the strength to resist setbacks, even in the face of other difficulties, I am not so afraid." ”
During the development of the UAV, in order to verify the performance, the "Feng Ru No. 3" team conducted thousands of hours of tests and dozens of rounds of test flights; in order to test the extreme flight time of the aircraft, they took the aircraft to Zhengzhou, Xuchang, Jiaozuo, Anyang, Haikou, Wuhu, Tianjin, Nanjing...
On May 18, 2021, the team officially launched the test flight tour of the "Feng Ru-3-100" UAV in Xuchang, Henan.
A blue sky where you can soar freely
On the day of the test flight, the group of students kept staring at the weather forecast, afraid that the wind direction was not appropriate, afraid of sudden wind and rain.
Feng Jiarui, a student from the School of Aeronautical Science and Engineering, stood in the safe area next to the runway, watching the car carrying the drone accelerate in a straight line, and with a "take-off", the aircraft was released instantly, "jumped up" from the car, and gradually spiraled up along the gradient until it entered the reserved route.
It worked! Everyone cheered, and their eyes stared at the "Feng Ru No. 3" in the sky for a long time, unwilling to move away.
After the test flight is successful, the challenge really begins.
The drone, powered by a gasoline engine, has since begun to hit the world record for endurance flights. When fully loaded, it weighs about 60 kg in total, carrying a simulated payload of about 3 kg during the flight.
What impressed Feng Jiarui was that once, "Feng Ru No. 3" encountered a strong wind of about eight levels, and a heavy rainstorm occurred, the tents of the monitoring points were blown out of shape, and the railings of the outfield were also blown away. Everyone held their breath, stared at the data, and accompanied the "Feng Ru No. 3" drone to survive this difficulty.
By the next day, the weather had improved and the drone was still flying in a designated orbit. This is beyond Zhang Yiquan's imagination, "Which shows that in the environment of strong winds and heavy rainfall, the wind resistance of 'Feng Ru No. 3' is very strong." ”
On May 21, the "Feng Ru-3" UAV completed its mission and successfully landed on the runway. Zhang Xiuhui carried the camera out to take pictures for the first time, recording the moment it landed. The group of students, whose average age is less than 20, cry with their heads in their hands and cannot suppress tears.
"It's a heartfelt love for aerospace." Zhang Xiuhui said.
"'Feng Ru No. 3' is to gather a group of people who can shine and heat, and fly into the blue sky together with everyone's ideals and pursuits." Member Wang Lanchen said.
"Only by constantly pursuing the ultimate can we become a champion one day." Member Zhang Yaohui said.
On October 1, 2021, on national day, the International Aviation Federation officially certified the new world record created by the "Feng Ru No. 3" team.
"We feel the students' love for aerospace from the bottom of our hearts." Zhuang Yan, secretary of the Youth League Committee of Beihang Airlines, said that in the traditional classroom, many students in related majors do not know how to fly the aircraft to save fuel, and even some students do not know the principle of take-off. But in the "Feng Ru No. 3" team, students are independently learning knowledge, doing mechanical design, and asking their predecessors for advice, "We must completely integrate scientific research and teaching, and cultivate the vanguard and vanguard of scientific and technological talents." ”
Looking to the sky, the "Feng Ru No. 3" team has a more ambitious goal. Team member Lin Zhaoru set the direction of his doctoral thesis as the overall design of the ultra-long time-of-flight UAV, which mentioned that the "Feng Ru-3" UAV flight target should reach 500 hours. They want to aim for the highest level of aviation technology in the future.
China Youth Daily, trainee reporter Yang Jie Source: China Youth Daily
Source: China Youth Daily