This morning, in the waters near Tuandao Island in Qingdao, Shandong, my country’s self-developed large-scale firefighting/water rescue amphibious aircraft "Kunlong" AG600, witnessed by the blue sea and blue sky, took the wind into the sea, stepped into the sea and leaped into the air, successfully achieving its first flight at sea. This is the third maiden flight of the AG600 aircraft after the first flight on land in 2017 and the first flight on water in 2018, laying the foundation for the next step of the aircraft's maritime scientific research flight test and aircraft-related performance verification.
Before the first flight, Xu Chaoqun, Director of the Airworthiness Department of the Civil Aviation Administration of China, issued a chartered flight certificate to Bai Xiaogang, the on-site commander of AG600 and Chairman of Aviation Industry General Aviation. Subsequently, Zhao Jingbo, deputy commander-in-chief of the AG600 project site, reported the preparations for the first flight to Lu Guangshan, the administrative commander of the AG600 project, and applied for a release. Lu Guangshan ordered: "Follow the plan!"
At about 9:28, the first aircraft group composed of captain Zhao Sheng, co-pilot Liu Ruqin, mechanic Wei Peng and monitoring observer Jiao Lianyue, according to the scheduled subjects, piloted the AG600 aircraft to taxi from Shandong Rizhao Shanzihe Airport and flew in the air. About 28 minutes later, it successfully arrived in the waters near Tuandao Island in Qingdao, Shandong.
The wind is ninety thousand feet, and the water hits three thousand miles. I saw the distance between the water and the sky, the AG600 was like a vigorous and white seagull, coming through the clouds and breaking the fog, and instantly entered the sea in the field of vision. At 10:14, it lightly entered the water, sliding smoothly against the sea surface, aroused Blossoming spray. Turning, adjusting direction, accelerating, raising the nose... all in one go. At 10:18, AG600 was like a giant dragon from the east, once again flying into the sky against the waves, plunged into the sky, and successfully completed the takeoff at sea.
After safely flying for about 31 minutes and completing a series of scheduled flight tests, the AG600 aircraft returned to Rizhao at 10:49 and landed at Shanzihe Airport. It successfully completed the first sea flight test mission and made significant progress in model development.
Accompanied by the passionate melody of "Singing the Motherland", the AG600 aircraft returned to the rostrum through the majestic water gate. Captain Zhao Sheng reported that he successfully completed the first scientific research flight test mission for take-off and landing at sea.
As one of my country's "big aircraft family", the large-scale amphibious aircraft AG600 is the first large-scale special-purpose civil aircraft developed to meet the urgent needs of forest firefighting and water rescue. It is a major aviation equipment urgently needed for the construction of the national emergency rescue system.
The AG600 aircraft is developed in accordance with the design concept of "Amphibious Amphibious, One Aircraft and Multiple Types". Its biggest feature is that it can take off and land on land as well as on water. AG600 can repeatedly throw water back and forth between the water source and the fire site to extinguish the fire. It can not only draw water from the water surface, but also inject water at the land airport. It can carry up to 12 tons of water, and the single water throwing area can reach more than 4000 square meters.
The AG600 has a high wave-resistance hull design. In addition to low-altitude search on the water surface, it can also be anchored on the water surface to perform rescue operations. The water emergency rescue can rescue 50 people in distress at a time. While meeting the requirements of forest fire fighting and water rescue, necessary equipment can be modified according to the needs of users to meet the needs of other special tasks.
According to reports, the AG600 project was officially launched on September 5, 2009. On December 24, 2017, the maiden flight on land was successfully completed at Zhuhai Jinwan Airport in Guangdong; on October 20, 2018, the maiden flight by water was completed at Hubei Jingmen Zhanghe Airport. In order to verify the maritime characteristics of the AG600 aircraft, after the successful completion of the first flight on the water, a series of tasks including scientific research flight test and test pilot modification training were carried out in 2019.
2020 is a critical year for the development of the AG600 project and a crucial year for achieving the overall goals of the project. The development of AG600 overcame the impact of the epidemic, followed the annual development goals, and strictly followed the requirements of epidemic prevention and control. With the strong support of local governments and related parties such as Zhuhai City in Guangdong Province, Jingmen City in Hubei Province, Qingdao City in Shandong Province and Rizhao City in Shandong Province, Adopting a "point-to-point" chartered car to ensure that multiple teams go to the scientific research test flight and the first sea flight test site smoothly, and make every effort to ensure the successful completion of the first sea flight of the AG600 aircraft.
Decryption:
They all fly over water. What is the difference between the first flight at sea and the first flight over water?
On July 26, the large-scale firefighting/water rescue amphibious aircraft "Kunlong" AG600 successfully achieved its maiden flight at sea at Tuandao Airport in Qingdao, Shandong Province. This is the development of the project after the first flight on land in 2017 and the first flight on water in 2018. Another major breakthrough achieved.
From land to inland lake to sea, the AG600 aircraft perfectly interprets the characteristics of "amphibious amphibious". This "swimming aircraft" and "flying ship" has realized the dream of "flying into the sea" since ancient times.
The AG600 aircraft is the first large-scale special-purpose aircraft developed in accordance with the requirements of China's civil aviation regulations to meet the urgent needs of my country's forest fire fighting and water rescue. It is a major aviation equipment urgently needed for the construction of the national emergency rescue system. For the AG600 aircraft with maritime rescue and other functions, the first flight at sea is achieved, the aircraft's sea-fitness is initially verified, the sea test flight technology and flight test methods are explored, and the marine scientific research test flight is carried out to test the sea wave resistance, control characteristics and structure of the aircraft. Laid a foundation with the working characteristics of the system.
The AG600 aircraft has the particularity of "amphibious amphibious, multi-type" multi-purpose, which determines that it has three first flights different from other land-based aircraft. What is the difference between the first flight over water and the first flight at sea?
According to reports, the "water" of the two first flights was different. The location of the first flight at sea is in the waters near Tuandao Island in Qingdao, Shandong. Compared with the inland water environment, there are three differences, which will make the test flight of the aircraft difficult.
First, the salinity of water is different. The first flight over the water is carried out on the lake, where the lake is natural fresh water, and the water salinity is relatively low; while the marine environment requires higher corrosion resistance for the testing machine.
Second, the density is different. The density of sea water is high, and the density of lake water is small. There will be differences in the buoyancy of the aircraft in the water and the "stickiness" of the water that needs to be overcome when taking off. And this difference will be more obvious when the aircraft is taxiing at high speed, especially when it is landing, under the same flight conditions (flight weight, flight attitude, flight speed, descent rate, etc.), the seawater density is 2.5% higher, and the aircraft is landing on the sea The reaction force of seawater on the aircraft is larger than that of lake water. This difference will make pilots feel that it is "harder" than fresh water.
Third, the waves are different. Inland lakes are generally wind waves formed by the wind, which are short and broken waves with relatively small wave heights, and the wave propagation direction is generally consistent with the wind direction. When planes take off and land on the lake, they usually choose to take off and land in the wind and waves. As the saying goes, "three-foot waves without wind on the sea", there are many types of waves on the sea (wind waves formed by wind, swells formed by overall underwater movement, large boat waves, etc.), waves are high and have high energy, and different types of waves may be at the same time Exist, and the direction of propagation is inconsistent. At the same time, the sea surface is also accompanied by ocean currents and wind, which will make the flight environment more complicated.
In addition, the visual experience and control requirements of the pilots were different in the two first flights over water.
On the one hand, the sea is more open than the lake, and it is not as easy for a pilot to choose a reference point when landing.
On the other hand, the sea environment is relatively more complicated than the lake environment. During the flight test, the wind direction, wind speed, ocean currents and surges, as well as the combined effects of high temperature, high humidity, and high salt environment, need to be fully considered during the flight test. Take off and landing at sea will stabilize the plane's wave and sea taxiing. The requirements for performance, handling characteristics, wave resistance, splashing characteristics, and anti-corrosion characteristics are higher, and the professional operation requirements for pilots are also more stringent, and the corresponding sea test flight support is more complicated.
In the two first flights on the water, the operating environment of the aircraft was different. Although the first flight at sea is also on the surface of the water, there is a big difference between the surface of the sea and the surface of the inland lake, which will test the aircraft's performance even more.
First, the content of the aircraft test flight verification is different. The wind and waves on the lake are small and the energy is small. The first flight on the water is mainly to verify the working conditions of the aircraft's various systems on the water surface, and to initially check the aircraft's water surface take-off and landing stability characteristics and performance, for subsequent aircraft to use for forest fire fighting and natural disaster prevention system construction provide support. Splashes will inevitably occur when the aircraft is accelerating and taxiing. If it wants to take off and land in a "turbulent" sea, the splashing will become more serious, which may cause deformation or damage to structural components such as flaps and propellers. However, the AG600 aircraft adopts measures such as V-shaped hull, installation of suppression grooves and deflectors, which effectively suppresses splashing, and controls the water flow into the suppression groove, effectively reducing the height of splashing and reducing the impact of splashing. The energy guarantees the safety of aircraft taking off and landing on the wavy sea. The first flight at sea is to focus on testing the aircraft's splashing characteristics, wave resistance, acceleration characteristics and surface control characteristics, checking the operation of the aircraft's various systems in the marine environment, and collecting sea flight data to provide support for subsequent related work.
Second, the airplane landing on water and the takeoff environment are different. When taking off and landing on land, the aircraft relies on a hard and smooth runway, and the aircraft relies on a cushioning landing gear system, which is relatively more secure for the safety of the aircraft. Both the first flight over water and the first flight over sea include the two stages of "landing from the air to the lake or the sea" and "accelerating taxiing from the lake or the sea into the air".
Especially in the process of taking off and landing on the sea surface, due to the greater fluctuation of the surge, it is more likely to cause the aircraft to bump and sway up and down. The technical term is "pitch". If the pitch diverges, the plane will jump up and down like a dolphin, which is the so-called "dolphin jump". In severe cases, the plane will lose control and dive into the water. In addition, the density of sea water is about 800 times that of air. If an aircraft wants to accelerate to the speed of leaving the water when taking off on the water, the hydrodynamic drag characteristics of the aircraft must be better designed to reduce the drag coefficient as much as possible to make the aircraft pass the drag peak. There is still enough acceleration at time to ensure that the aircraft accelerates to the water speed for takeoff in a short time. The difference between the density of sea water and the water density of Neili Lake is also more obvious here.
Whether it is the first flight on land, water or sea, it is the only way for the AG600 to change from a drawing to a test machine, and from a test machine to the customer market. It is to verify the different flight characteristics of the aircraft and ensure the performance of the aircraft. Achieving, safe and reliable key flight test subjects.
Reporter Pan Fuda