Not long ago, Mr. Chen saw a novel thing on the Discovery Channel: Americans put a blocking bed at the end of some airport runways, which actually prevented planes from rushing off the runways. On the TV screen, the materials paved at the end of the runway successfully prevented a Boeing passenger plane from rushing out of the runway, which protected the plane and ensured the safety of passengers.
The technology presented in the picture is called Engineering Material Arresting System (EMAS), which has long been monopolized by foreign companies. On July 12th, 2012, EMAS, developed by China Civil Aviation Science and Technology Research Institute and with completely independent intellectual property rights, officially passed the qualification examination of Civil Aviation Administration of China and was approved for engineering application. This is an important progress made by China Civil Aviation in the research and development of major systems related to flight safety, and it is also the second EMAS in the world to be approved by government civil aviation authorities. The achievement of this achievement will greatly reduce the cost of installing the system in airports, thus promoting the effective improvement of safety and security capabilities of many plateau airports and airports with special terrain in China.
How to stop the plane from running off the runway?
With the rapid development of the world’s civil aviation industry, the number of take-off and landing flights has increased significantly, and the number of aircraft rushing off the runway has shown an upward trend. How to avoid serious accidents after the aircraft rushing off the runway has become an important issue for civil aviation safety. In order to solve this problem, as early as the 1960s, the British began to research and develop related technologies to stop planes that ran off the runway, but failed to form products for various reasons. By the 1980s, the Federal Aviation Administration (FAA) and an American company began to jointly develop the EMAS system.
In fact, EMAS is a kind of foam concrete with specific mechanical properties, which is laid on the ground of the runway extension line with a thickness of several tens of centimeters to form an arresting bed. Its width is consistent with the runway, and its length is between tens of meters and more than 100 meters. Once the plane rushes out of the runway, it enters it, and the foam concrete is crushed under the rolling of the wheels, so as to absorb the kinetic energy of the plane, and on the premise of ensuring the safety of the plane and the people on board, the plane will gradually slow down and finally stop in the arresting bed.
In 1990s, FAA approved the design method of EMAS system. In 1996, the first trial laying was carried out at Kennedy Airport in new york, and three planes were successfully stopped. Subsequently, the FAA issued a license for it and promoted it in civil airports in need in the United States. Up to now, 55 sets of EMAS systems have been laid in 35 civil airports in the United States, and 8 planes have been successfully stopped. At the same time, the United States promotes the EMAS system on a global scale. In recent years, the system has been installed at Jiuzhai Huanglong Airport in Sichuan and Songshan Airport in Taiwan.
Can solve the problem of running off the runway.
Sichuan Jiuzhai Huanglong Airport was built by cutting mountains, surrounded by mountains on three sides. Due to the influence of complex terrain and high altitude, pilots often feel that the runway is short during the flight mission of Jiuzhai Huanglong Airport, especially in rainy and snowy weather. Once the plane lands and stops taking off, there will be back spraying, brake failure or rushing off the runway, and the consequences will be unimaginable. Therefore, in 2006, when Jiuzhai Huanglong Airport carried out the second phase expansion project, two sets of EMAS systems were installed at the north and south ends of the runway respectively.
In China, a considerable number of airports are built by cutting mountains, commonly known as "desktop airports". Although these airports have established runway-end safety zones according to the standards, there are often steep slopes or cliffs outside the safety zones. Once the plane rushes out of the runway-end safety zone, the tragedy of plane crash and death will inevitably be staged. In addition, some airports in Linjiang, Linhai and residential areas also have such problems.
With the rapid development of civil aviation in China, the number of flights has increased dramatically. In order to maintain the past safety level, we need updated safety measures. According to the statistics of ICAO, the number of runway accidents in the world ranks first in the statistics of civil aircraft accident types. In recent years, the number of incidents of civil aviation rushing off the runway in China also ranks first in the statistics of serious accident symptoms of civil aircraft. It can be seen that the installation of EMAS system in the airport where the safety zone at the runway end is not long enough can solve the problem of the plane rushing off the runway and obviously improve the safe operation level.
Technical problems of
Before the EMAS developed by the China Academy of Civil Aviation Science and Technology was approved by the Civil Aviation Administration of China, there were no similar products in China. If we want to install it in our airports, we need to face three problems: high product price, long transportation distance and difficult system maintenance.
It is reported that in 2010, Taiwan Songshan Airport plans to lay a set of this system, with a budget as high as NT$ 430 million. Compared with 2006, when the system was laid at Jiuzhai Huanglong Airport in Sichuan, the price has increased significantly. Such a high cost, even if the government gives most subsidies, it is difficult for small and medium-sized airports in China that need to install EMAS system most.
China needs its own EMAS system! In 2010, under the direction of Li Jian, deputy director of the Civil Aviation Administration, the Academy of Aeronautics and Astronautics organized a research and development team headed by its main leaders and attended by dozens of scientific research backbones, and relevant units in the United Nations invested tens of millions of yuan. After more than two years, the technical problems of material production and system design methods have been overcome. In order to effectively verify the performance of the product and the safety of the system, the Institute of Aeronautics and Astronautics designed and built a special test bench, conducted dozens of tests on the process of wheel rolling materials, and obtained a lot of valuable data, and finally established a set of perfect simulation calculation model and design method for the blocking process. The Academy of Aeronautics and Astronautics also specially purchased a Boeing 737 aircraft from Air China. Since the fourth quarter of 2011, it has carried out six large-scale real aircraft verification tests using the second runway of Tianjin Airport. The test results show that the EMAS system developed by the Institute of Aeronautics and Astronautics has an effective blocking effect and can ensure the safety of the aircraft and the crew.
Development prospect of
"For China’s civil aviation, the EMAS project is a brand-new and groundbreaking project, and only the United States has mastered this technology in the world. We don’t have any experience to learn from. Doing this project well is of great significance for China civil aviation to export standards to the international civil aviation community, to enhance the international status of China civil aviation, to enhance the safety margin of complex airports, and to build a strong civil aviation country. " Li Jian, deputy director of CAAC, has repeatedly emphasized the importance of China Civil Aviation in developing its own EMAS system.
The responsible person of Academy of Aeronautics and Astronautics (Beijing) Science and Technology Development Co., Ltd. revealed to the reporter that the successful research and development of domestic EMAS system has greatly reduced the laying cost, and provided reasonable engineering solutions for many plateau airports, airports with complex terrain and other airports that are difficult to extend the runway safety zone for special reasons. It has a very broad market prospect. Tengchong Airport has decided to install EMAS system, and many airports at home and abroad have also shown strong interest in this product. "We have more than 10,000 square meters of production workshop in Tianjin Airport Economic Zone, which can meet the environmental requirements for the production and maintenance of blocking materials, and can ensure the stability of material performance, and can produce one set of materials required for EMAS system every month."
This year, ICAO will put forward the standard of increasing the length of the safety zone at the runway end in the "International Standards and Recommended Measures" to reduce the serious flight safety accidents caused by running off the runway. However, due to geographical or other environmental constraints, many airports are difficult to meet the new requirements for the length of runway safety zone. EMAS has been written into Article 3.5.5 of Airport Design and Operation, Volume I, Annex 14 of ICAO Convention on International Civil Aviation, which has become an internationally accepted equivalent safety measure.
It is understood that although the price of domestic EMAS system has dropped significantly compared with similar products abroad, it is also a huge expense for many airports, especially small and medium-sized airports. In view of the purpose of laying EMAS system to improve the safety of airport operation, CAAC is working on formulating relevant subsidy policies to support the popularization and application of EMAS system.