Then the errors start—and not just one error.
问题往往从这里开始，通常单个错误不会造成重大事故。
Typical accident involves seven consecutive human errors.
典型的事故都会涉及七个连续的人为失误。
One of the pilots does something wrong that by itself would not be a problem.
某个飞行员造成一个失误不是问题，
Then one of them makes another error on top of that, which combined with the first error, still is not amount to catastrophe.
但机组其他人员会在此基础之上，出现另外一个失误，两个失误仍然不能够构成大灾难。
But then they make a third error on top of that, and then another and another and another and another, and it's the combination of all those errors that leads to disaster.
但在此之上，他们又会出现第三个失误，然后一个接一个，最后所有的失误叠加在一起，大灾难就发生了。
These seven errors, furthermore, are rarely problems of knowledge or flying skill.
再进一步讲，这七个失误完全与知识和飞行技巧无关，
It's not that the pilot has to negotiate some critical technical maneuver and fails.
也非飞行员们必须进行讨论的重大机动问题。
The kinds of errors that cause plane crashes are invariably errors of teamwork and communication.
造成飞机坠落的问题无一不与团队合作或沟通相关。
One pilot knows something important and somehow doesn't tell the other pilot.
某个飞行员得知一件重要的事情，但不知为何，他不愿与其他飞行员分享；
One pilot does something wrong, and the other pilot doesn't catch the error.
某个飞行员操作失误，但其他飞行员却不肯当面指出；
A tricky situation needs to be resolved through a complex series of steps—and some-how the pilots fail to coordinate and miss one of them.
类似这种微妙的情况需要一系列复杂的程序予以解决，但很多飞行员并不擅长进行协作来解决此类问题，而且还会遗漏其中一些程序。
"The whole flight-deck design is intended to be operated by two people, and that operation works best when you have one person checking the other,
“整个驾驶舱是为两个人操作飞机设计的，一人驾驶飞机，一人在旁协助；
or both people willing to participate," says EarlWeener, who was for many years chief engineer for safety at Boeing.
或两个人一同参与飞行。这样，飞行工作会进行得非常顺利。”波音公司负责安全工作多年的总工程师厄艾尔·卡卫涅说，
"Airplanes are very unforgiving if you don't do things right.
“如果你做错了事，可不要期待飞机会原谅你。
And for a long time it's been clear that if you have two people operating the airplane cooperatively,
很久以来的事实证明，如果两名飞行员一起合作飞行，飞机会更安全。
you will have a safer operation than if you have a single pilot flying the plane and another person who is simply there to takeover if the pilot is incapacitated."
若只由一名飞行员飞行，另一名飞行员只是简单坐在一旁，直到无法继续飞行时才来接替，那么安全系数就会小得多。”
Consider, for example, the famous (in aviation circles, anyway) crash of the Colombian airliner Avianca flight 052 in January of 1990.
航空界里最着名的坠机事件，是1990年哥伦比亚航空公司阿维安卡52号航班的坠机事件。
The Avianca accident so perfectly illustrates the characteristics of the "modern" plane crash that it is studied in flight schools.
阿维安卡事故非常完美地演绎了“现代”飞机坠落事件的一系列特征，因而被飞行学校作为教学案例。