How Can Air Traffic Controllers Lose a Plane? 马航370航班失联事件仍无进展（在线收听）

How Can Air Traffic Controllers Lose a Plane? 马航370航班失联事件仍无进展

From VOA Learning English, this is In the News.

这里是美国之音慢速英语新闻报道。

The search for a Malaysia Airlines passenger jet expanded this week. The airplane, a Boeing 777, disappeared last Saturday on a flight from Kuala Lumpur to Beijing. It was carrying 239 people. At first, the search was along its expected flight path. But by week's end, crews had expanded the search across parts of southern Asia for any evidence of Malaysian Airlines Flight 370.

本周，马航客机的搜寻范围已经扩大。上周六这架波音777航班从吉隆坡飞往北京时失踪，机上载有239人。最初是沿着它的预期飞行路线搜寻。但到了周末，由于马航370航班的一些迹象，人们已经将搜寻范围扩大到南亚部分地区。

With satellites and other technology available, how can a plane as large as the "Triple-7" just disappear? Air safety expert  says it is easier than you may think.

随着卫星和其它技术投入使用，像波音777这么大的飞机怎么会凭空消失呢？航空安全专家约翰·麦格劳（John McGraw）表示，其实这比你想象的简单。

"People are under the impression that every airplane, even when it's flying across the ocean, is observed on some kind of radar scope, with a human being looking at that scope. And it's just not the case. Radars don't reach that far."

麦格劳说，“人们都认为所有航班，甚至当它在跨越海洋时，都能在某类有人值守的雷达屏幕上被看到。但事实并非如此，雷达管不了那么远。”

But John McGraw says there are also a lot of devices inside the Triple-7 that can help searchers follow its movement. Systems in the aircraft send altitude, weather conditions, position and speed to air traffic controllers. There are also at least three ways the pilots can communicate with controllers. Another tool is the flight data recorder or "black box." If the plane is downed in the ocean, the black box sends out a signal that can travel up to three kilometers away.

但麦格劳表示，波音777上有很多设备可以帮助调查员追踪它的移动。机载系统会向空管发送高度、天气状况、位置和速度。此外飞行员至少有三种途径同空管联系。另一个工具是飞行数据记录仪，也被称为黑匣子。如果飞机坠入大海，黑匣子会发送信号，三公里外都能追踪到该信号。

Many people remember when a French passenger jet disappeared five years ago. Air France Flight 447 went missing as it flew from Brazil to Paris. Its wreckage was eventually found in the Atlantic Ocean.

很多人还记得五年前法航一架客机失踪。法航447航班从巴西飞往巴黎时失踪，它的残骸最终在大西洋被发现。

Air safety expert John McGraw remembers the National Transportation Safety Board taking action after the French jet went missing. He says US officials called for continuous download of an aircraft's flight data recorder information in case of emergencies.

航空安全专家约翰·麦格劳记得美国国家运输安全委员会在法航客机失踪后采取行动。他说，美国官员呼吁采用在紧急情况下能连续下载数据的飞行数据记录仪。

"In the past they haven't been able to justify installing that kind of equipment, because it's expensive, and because there hadn't been that many accidents where it would have come into play. This will certainly provide some additional motivation and there may be calls to do that."

他说，“在过去他们一直没能安装这类设备，因为它太贵了。而且因为也没什么事故让它有用武之地。这次肯定会提供一些额外的动力，可能会要求那样做。”

Malaysia Airlines Flight 370 was last seen on radar above Vietnam and Malaysia. Air traffic controllers in both countries say they did not receive any message that the plane may have been in trouble. On Tuesday, Malaysian media reported that the Malaysian military had noted the aircraft flying toward the country's west coast. That is far from where controllers lost contact with the plane.

马航370航班最后一次出现在雷达是在越南和马来西亚上空。两国的空管都表示，他们没有收到任何表示该飞机遇到麻烦的信息。上周二，马来西亚媒体报道，马来西亚军方曾注意到该客机正飞向该国西部海岸。那里距离空管与该客机失联的地方很远。

The next day, China released satellite images showing three large objects floating in waters between Malaysia and Vietnam. But China later said it could not confirm the objects belonged to the missing aircraft. 

第二天，中国公布的卫星图像显示在马来西亚和越南之间水域有三个大的漂浮物。但中国随后表示没法确定该物体是否属于该失联航班。

The Wall Street Journal reported that the plane could have stayed in the air for several hours past the time of its last confirmed location. The newspaper later said that the plane continued to send information about its engines and performance to satellites for five more hours. That suggests Flight 370 could have remained in the air or was on the ground somewhere. Why the signals stopped is unclear.

华尔街日报报道称，该客机在最后确认位置的时间后可能在空中还停留了几个小时。该报后来表示，这架飞机继续向卫星发送其发动机和性能信息并持续了五个多小时。这表示370航班可能当时可能仍在空中，或在地面某处。该信号为何终止尚不得而知。

This is a developing story. For the latest news on the Malaysian airliner, go to 51VOA.com. 

事态仍在继续发展，有关马航客机的最新消息，请访问51VOA.COM。