Nowadays most aircraft fly high,well above the clouds and weather,but their crews are still vitally interested in landing conditions at their destination,i.e. the cloud base and visibility there.

• 如今，大多数的飞机飞得很高，远在云层之上，不受天气影响，但是飞机的工作人员仍然非常关心目的地的着陆条件，也就是，云层底下的清晰度。