Up next, the U.S. Justice Department is trying to determine if any laws were broken in the certification process for certain passenger planes. The model is Boeing 737 Max series. One of these planes crashed in Indonesia last October. Another crashed in Ethiopia earlier this month. Everyone aboard both flights was killed, and the 737 Max jets have been grounded world wide. U.S. investigators are looking into everything from how the plane was certified as safe to how it was marketed. Meantime, Boeing has developed a software patch and a pilot training program to address some of the issues with the Max aircraft.

下则消息，美国司法部正在努力确定某特定型号客机的认证过程是否违反了法律。该型号是波音737 Max系列。去年10月，一架该型号客机在印度尼西亚坠毁。本月初，另一架客机在埃塞俄比亚坠毁。两起事故均无人生还。这导致737 Max喷气式飞机在全球被禁飞。美国调查人员正在展开详尽调查，包括该客机安全认证的过程以及宣传过程。同时，波音公司开发了一个软件补丁和一个飞行员训练项目，旨在解决Max系列飞机存在的一些问题。

OREN LIEBERMANN: One of the most important concepts in aviation is the angle of attack. In simple terms, it's the difference between the angle of the wings and the direction in which the plane is flying. Imagine a plane that's about to land. Its nose is pointed up, but the plane is still moving down towards the runway. That difference there is the angle of attack, sometimes called alpha. If the angle gets too big, if it exceeds a critical angle of attack, a plane stalls. Airliners have an angle of attack sensor. It's connected to the instruments and systems inside the plane.
One of these is Boeing's new MCAS system on its 737 Max series of airliners. MCAS is an automated anti-stall system. This system is the focus of the investigation into October's Lionair crash. And experts say there are similarities between it and the Ethiopian Airlines crash. If the MCAS system senses a high angle of attack, it will push down the nose to avoid a stall. But if the angle of attack sensor is malfunctioning, and gives a faulty reading, the system could force the plane to dive with potentially disastrous consequences.

奥伦·利伯曼：航空飞行其中一个最重要的概念是迎角。简单来说，就是机翼角度与飞机飞行方向之间的差值。想象一下，一架飞机正准备降落。其机头抬起，但是飞机仍在向跑道移动。这个差值就是迎角，有时称为α。如果迎角过大，超过临界迎角，那飞机就会失速。客机上搭载有迎角传感器。这个设备与飞机内部的仪器和系统相连接。
波音在737 Max系列客机上安装了MCAS系统。MCAS是一个自动防失速系统。该系统是去年10月狮航坠机事故的调查重点。专家表示，该事故与埃塞俄比亚航空坠机事故有相似之处。如果MCAS系统感知到迎角过大，就会自动下压机头以避免失速。但是如果迎角传感器发生故障，那就会造成读数输出错误，该系统可能会迫使飞机向下俯冲，导致潜在的灾难性后果。

来源：可可英语