The instrument is used when fly overwater in the daytime.

那仪器是在白天飞越使用。

According to some pilots, members of crews have even been known to play DVDs on laptops in the cockpit to pass the time on particularly long overwater and international flights.

据一些飞行员说，在特别长越洋飞行和国际班，机组人员甚至有在驾驶舱通过笔记本电脑看DVD消磨。