Successful first flight of large amphibious aircraft Kunlong ag600

 Successful first flight of large amphibious aircraft Kunlong ag600

On July 26, 2020, Kunlong ag600, a large-scale amphibious aircraft for fire fighting and water rescue, developed by China, successfully made its first flight at sea near Qingdao, Shandong Province, which laid a foundation for the next flight test training and verification of aircraft performance.

At 9:28, the first aircraft group composed of Captain Zhao Sheng, CO pilot Liu ruqin, mechanic Wei Peng and monitoring observer Jiao lianyue took off from shanzihe airport in Rizhao, Shandong Province. After about 28 minutes of flight, we arrived at the sea near Qingdao.

Ag600 gradually lowered its altitude and entered the sea smoothly. It entered the water at 10:14 and took off at sea at 10:18.

After completing a series of movements, such as turning, adjusting direction, accelerating and nose up, it was like an Oriental Dragon again, soaring into the sky against the waves, and successfully completed the sea take-off.

After completing the established flight test subjects, ag600 successfully landed at Rizhao shanzihe airport at 10:49, successfully completed the first sea flight test mission, and made significant progress in model development.

As one of Chinas large aircraft family, large amphibious aircraft ag600 is the first large-scale special-purpose civil aircraft developed to meet the urgent needs of forest fire-fighting and water rescue. It is a major aviation equipment urgently needed by the construction of national emergency rescue system.

At present, the ag600 aircraft has completed more than 360 hours of scientific research flight, accumulated and obtained a large number of flight test data. Combined with the ground test verification, the research team has revised and improved the key design theory, design method and verification method of the amphibious aircraft, such as the air and water integration, and further broke through the key technology of amphibious aircraft design.

Ag600 project was officially launched on September 5, 2009. On December 24, 2017, the first flight on land was successfully realized at Jinwan airport in Zhuhai, Guangdong Province; on October 20, 2018, the first flight on water was completed at Zhanghe airport in Jingmen, Hubei Province. In order to verify the maritime characteristics of ag600 aircraft, after the successful completion of the first flight on water, a series of work such as scientific research flight test and pilot modification training were carried out in 2019.

What does ag600 have?

Ag600, also known as Kunlong, is the largest amphibious aircraft under research in the world. It adopts the layout of cantilever type upper single wing, front three-point retractable landing gear and single hull amphibious aircraft. It is equipped with 4 domestic turboprop 6 engines, with a length of 37 meters, a wingspan of 38.8 meters and a height of 12.1 meters (the external dimension is equivalent to that of Boeing 737), and the maximum take-off weight is 53.5 tons.

Whats the difference between the first flight at sea?

On October 20, 2018, the first flight over water was completed at Zhanghe airport in Jingmen, Hubei Province. So, what is the difference between the first flight on water and the first flight on the sea?

The water of the two first flights was different.

First, the salinity of water is different. The first flight on the water is carried out on the lake. The lake is natural fresh water, and the water salinity is relatively low, so the corrosion protection test of aircraft systems is small; while the first flight on the sea is carried out on the sea, the salinity of sea water is significantly higher than the fresh water in the lake, so the corrosion resistance of the test machine is higher in the marine environment.

Second, the density is different. Due to the high density of sea water and the low density of lake water, the buoyancy of aircraft in water and the viscosity of water to be overcome during takeoff will also be different. This difference is more obvious when the aircraft taxis at high speed, especially when landing, under the same flight conditions (flight weight, flight attitude, flight speed, descent rate, etc.), the sea water density is 2.5%. When the aircraft lands on the sea, the reaction force of sea water on the aircraft is larger than that of the lake water. This difference will make the pilot feel that it is harder than the fresh water surface.

Third, the waves are different. Inland lake is generally formed by wind waves, short breaking waves, wave height is relatively small, and the wave propagation direction is generally consistent with the wind direction. When aircraft take off and land on the lake, generally choose to take off and land against the wind and waves. As the saying goes, there is no wind on the sea, three feet of waves, there are many types of waves on the sea (wind waves formed by wind, swell waves formed by the overall underwater movement, traveling waves of large ships, etc.). Waves of different types may exist at the same time with different propagation directions. At the same time, the sea surface is also accompanied by ocean current and wind, which will make the flight environment more complex.

In addition, the pilots visual perception and control requirements were different in the two first flight on water. On the one hand, the sea surface is more open than the lake surface, so it is not as easy for pilots to select reference points when landing. On the other hand, the sea environment is relatively complex than the lake environment, so the comprehensive influence of wind direction, wind speed, ocean current and surge, as well as the high temperature, high humidity and high salt environment should be fully considered in the flight test process; the requirements for the stability, handling characteristics, wave resistance, splash characteristics, anti-corrosion characteristics of the aircraft on the sea surface are higher, and the professional operation requirements for pilots are also higher Severe, the corresponding support of sea test is more complex.

For the first flight on water and the first flight at sea, the contents of aircraft flight test verification are different.

The first flight on the water is mainly to verify the working conditions of various systems of the aircraft on the water surface, and preliminarily check the stability and performance of the aircraft taking off and landing on the water surface, so as to provide support for the follow-up aircraft to be used in forest fire-fighting and natural disaster prevention and control system construction.

The first flight at sea mainly tests the take-off and landing characteristics of the aircraft under sea conditions, the working conditions of various systems of the aircraft in the marine environment, and focuses on the verification of the performance of the aircraft at sea, such as anti wave ability and corrosion prevention and control. At the same time, in view of the corrosion protection problems caused by the high salinity and high humidity environment, the anti-corrosion effect of the aircraft is evaluated, and preparations are made for the future aircraft to carry out ocean cargo transportation, water emergency rescue and other tasks.

(CCTV reporter Cui Xia, Li Xia, Li Ning, Tao Jiashu, Wu tianbai, Shi Xia, Dai Haibin, Wu Bingqi, Qingdao Taiwan aviation industry group)

Source: CCTV news client editor: Wang Fengzhi_ NT2541