飞机场———占据中心城市周围大量的宝贵土地 ,由于散发噪音而令人越来越难以忍受—正在变成空中运输的最薄弱一环 ,欧洲尤其如此。由于机场的能力难以改善 ,运量增加和起降次数有限的矛盾便突现出来。航空先驱者的时代恍如隔世。那时 ,大城市的郊区还是农田一片 ,只需将一块 Airports, which occupy a large amount of valuable land around central cities and are becoming more and more unbearable due to noise emissions - are becoming the weakest link in air transport, especially in Europe. Owing to the difficulty in improving the airport capacity, the contradiction between the increase in traffic volume and the limited number of take-offs and landing movements came to light. The era of aviation pioneers seems like a world. At that time, the suburbs of the metropolitan area is still a farmland, just a piece