Why was there a wall near runway at S Korea plane crash airport?
为什么韩国飞机坠毁机场的跑道附近有一堵墙？
Reuters 路透社济州航空飞机在木浦国际机场的残骸
Aviation experts have raised questions about an "unusual" concrete wall near the runway and its role in the South Korea plane crash that killed 179 people.
航空专家对跑道附近的一堵“异常”混凝土墙及其在导致 179 人死亡的韩国飞机坠毁事件中的作用提出了质疑。
Footage shows the Jeju Air plane coming off the runway before colliding with the wall and bursting into flames at Muan International Airport.
视频显示，济州航空的飞机在木浦国际机场滑出跑道，撞上围墙并起火。
Authorities investigating the cause of South Korea's worst-ever plane crash are considering the significance of the concrete wall's location about 250m (820ft) off the end of the runway.
韩国有史以来最严重的飞机坠毁事件的调查人员正在考虑跑道末端约 250 米（820 英尺）处混凝土墙位置的重要性。
Air safety expert David Learmount said that, had the "obstruction" not been there, the plane "would have come to rest with most - possibly all - those on board still alive".
航空安全专家大卫·利尔蒙特表示，如果没有那个“障碍物”，飞机“本可以停下来，机上大多数——甚至可能是所有乘客——都还活着”。
The pilot reported that the plane had struck a bird and then aborted the original landing and requested permission to land from the opposite direction.
飞行员报告称飞机撞上了一只鸟，随后放弃了原定的着陆，并请求允许从相反方向着陆。
The plane came down some distance along the 2,800m runway and appeared to land without using its wheels or any other landing gear.
飞机在 2800 米长的跑道上滑行了一段距离后降落，似乎没有使用轮子或任何其他起落装置。
Mr Learmount said the landing was "as good as a flapless/gearless touchdown could be: wings level, nose not too high to avoid breaking the tail" and the plane had not sustained substantial damage as it slid along the runway.
利尔蒙特先生说，这次着陆“对于没有襟翼和起落架的着陆来说已经非常好了：机翼水平，机头不至于太高以避免尾部受损”，飞机在跑道上滑行时没有受到重大损坏。
"The reason so many people died was not the landing as such, but the fact that the aircraft collided with a very hard obstruction just beyond the runway end," he said.
“他说，之所以有这么多人死亡，并不是因为着陆本身，而是因为飞机在跑道尽头刚好撞上了一个非常坚硬的障碍物。”
Christian Beckert, a Lufthansa pilot based in Munich, called the concrete structure "unusual", telling Reuters news agency: "Normally, on an airport with a runway at the end, you don't have a wall."
慕尼黑的汉莎航空飞行员克里斯蒂安·贝克特称这个混凝土结构“不同寻常”，他告诉路透社：“通常情况下，机场跑道尽头不会有一堵墙。”
The concrete structure holds a navigation system that assists aircraft landings - known as a localiser - according to South Korea's Yonhap News Agency.
据韩国联合通讯社报道，该混凝土结构内设有协助飞机着陆的导航系统——即所谓的定位器。
At 4m high, it is covered with dirt and was raised to keep the localiser level with the runway to ensure it functions properly, Yonhap reported.
据《韩联社》报道，这座高 4 米的建筑物被覆盖着泥土，目的是为了保持定位器与跑道平齐，确保其正常运作。
South Korea's transport ministry has said that other airports in the country and some overseas have the equipment installed with concrete structures. However officials will examine whether it should have been made with lighter materials that would break more easily upon impact.
韩国交通部表示，国内其他机场以及一些海外机场都安装了混凝土结构的设备。然而，官员们将审查是否应该使用更轻的材料制造这些设备，以便在受到撞击时更容易破碎。
Chris Kingswood, a pilot with 48 years' experience who has flown the same type of aircraft involved in the crash, told BBC News: "Obstacles within a certain range and distance of the runway are required to be frangible, which means that if an aircraft strikes them that they do break.
克里斯·金斯伍德，一位拥有 48 年飞行经验的飞行员，曾驾驶过与坠机事件中相同的机型，他在接受 BBC 新闻采访时表示：“跑道一定范围和距离内的障碍物必须是易碎的，这意味着如果飞机撞上它们，它们会断裂。”
"It does seem unusual that it's such a rigid thing. The aircraft, from what I understand, was travelling very fast, landed a long way down the runway, so it will have gone a long way past the end of the runway... so where will you draw the line with that?
这确实看起来很不寻常，竟然如此僵硬。根据我的理解，这架飞机速度非常快，降落在跑道很远的地方，所以它肯定会越过跑道的尽头……那么，你会在这方面划定界限吗？
That's certainly something that will be investigated.
这当然是需要调查的事情。
"Aeroplanes are not strong structures - they are, by design, light to make them efficient in flight. They're not really designed to go high-speed on its belly so any kind of structure could cause the fuselage to break up and then be catastrophic.
飞机并不是坚固的结构——它们在设计上是轻便的，以提高飞行效率。它们并不是为了在机腹上高速滑行而设计的，因此任何结构上的问题都可能导致机身解体，进而造成灾难性的后果。
"The fuel is kept in the wings so once the wing ruptures, then the potential for fire is significant.
燃料储存在机翼中，一旦机翼破裂，火灾的风险就非常大。
"So it's not a given that if the wall had not been there, it would have been a completely different outcome."
所以，如果没有那堵墙，结果会完全不同，这并不是一个必然的结论。
Mr Kingswood said he would be "surprised if the airfield hadn't met all the requirements in accordance with industry standards".
金斯伍德先生表示，如果机场没有按照行业标准满足所有要求，他会感到“惊讶”。
"I suspect if we went around the airfields at a lot of major international airports... we would find a lot of obstacles that could similarly be accused of presenting a hazard," he added.
我怀疑如果我们绕着许多国际机场的飞行区走一圈……我们会发现很多障碍物，这些障碍物同样可以被指责为存在危险。
Aviation analyst Sally Gethin questioned whether the pilot knew the barrier was there, particularly given the plane was approaching from the opposite direction from the usual landing approach.
航空分析师萨莉·盖欣质疑飞行员是否知道障碍物的存在，特别是考虑到飞机是从与通常着陆方向相反的方向接近的。
She told BBC News: "We need to know, were (the pilots) aware there was this hard boundary at the end?
她告诉 BBC 新闻：“我们需要知道，飞行员是否知道尽头有这个硬性边界？”
"If they were directed by the control tower to reverse the use of the runway the second time around, that should come out in the investigation of the black boxes.
如果他们在第二次使用跑道时被控制塔台指示改变跑道使用方向，这应该会在黑匣子调查中显现出来。
"I think there are so many questions."
我认为有太多问题了。
