(单词翻译:单击)
One thing a black box isn't is black.
“黑匣子”并不是黑色的。
They're painted bright orange and often covered with reflective tape to help investigators find them, especially when they're lying in deep water.
它们的外表会被涂成明亮的橙色，并经常会贴有反光带，这样调查人员就能很快找到它们，尤其是掉落在深水中的时候。
And a black box actually refers to two separate pieces of equipment,
“黑匣子”实际上指的是两个独立的设备，
both of which help air accident investigators learn what happened in the final moments before a crash.
它们都能帮助航空事故调查人员了解坠机前的最后时刻发生了什么。
The first of these is a flight data recorder, it stores information like the altitude and direction of a plane, but other details too:
第一个是飞行数据记录器，它会存储诸如飞机的飞行高度、飞行方向等信息，此外还有其他细节：
how much fuel is on board, whether the autopilot is on or not, the cabin temperature and pressure, and so on.
飞机上有多少燃料，自动驾驶仪是否开启，座舱温度和压力等等。
It stores around 25 hours of data.
它可以保存25小时的飞行数据
The second is a cockpit voice recorder.
第二个是驾驶舱语音记录仪。
This not only records the crew's conversations but also other sounds in the cockpit: engine sounds, stall warnings, emergency alarms and the like.
它不仅能记录机组人员的谈话，还能记录驾驶舱内的其他声音：引擎声、失速警告、紧急警报等等。
Skilled investigators can sometimes work out what caused an accident purely from the sounds in the cockpit.
经验丰富的调查人员有时可以仅从驾驶舱的声音中就能找出事故的原因。
So the most important data is stored in the crash survivable memory unit,
所以最重要的数据都存储在事故数据存储单元里，
a small stack of memory boards, protected from heat by a layer of insulation, and from impact by a hardened steel or titanium shell.
事故数据存储单元就是一叠存储板，有一层绝缘层隔热，外部还有硬化钢壳或钛壳，以保护其不受冲击。
And to make sure the memory boards inside survive, the units are put through a brutal test regime.
为了确保里面的存储板能够保存下来，这些存储单元都经过了严苛的测试。
Crash tests subject the boxes to 3,400 Gs, that's the kind of deceleration that happens when an airliner crashes.
碰撞测试会让这些匣子承受3400G重力的冲击，这就是飞机坠毁时的负加速度。
They can withstand an hour in a fire held at 1,100 celsius,
此外，它们还要承受持续一小时的1100℃的高温，
and they must also survive long periods under pressure, in salt water and in fluids like aviation fuel.
还必须在有压力、有盐水、有航空燃料的液体中保存很长时间。
And the black boxes are usually fitted at the very back of the aircraft to give it the best chance of surviving the crash.
黑匣子通常安装在飞机的最后面，这样能尽可能地使其在坠机事故中保留下来。
On the outside is an underwater locator beacon that doubles up as a handle.
在其外部有一个水下定位信标，可以兼作手柄。
If the device falls into water the beacon starts to transmit pulses of ultrasound.
如果装置落入水中，信标就会开始发射超声波脉冲。
It works down to depths of 14,000 feet and can send out pulses for up to 30 days.
在14000英尺的深处，它依然可以工作，并能发出长达30天的持续3脉冲。
A black box doesn't give the whole picture.
一个黑匣子无法展现事故的全貌。
It can take weeks or even months for investigators to piece together precisely what happened to an aircraft.
调查人员可能需要数周甚至数月的时间，才能准确拼凑出一架飞机究竟发生了什么。
But what is clear is that without black boxes, countless aircraft disasters would remain unsolved mysteries forever.
但可以肯定的是，如果没有黑匣子，无数空难将永远是未解之谜。
