There's always a risk in flying, but the phase in which a plane is cruising at high altitude is widely considered to be safe. And that's what makes the mystery of what happened to so confounding.
飛行總是存在風險，但人們普遍認為飛機在較高的高度巡航的階段是安全的。因此馬航MH370的失聯(lián)才如此讓人迷惑。

"Whatever happened happened quickly and resulted in a catastrophic departure from the air," Mark Rosenker, former chairman of the National Transportation Safety Board who is now a consultant with CBS news, told NPR's Melissa Block.
美國國家運輸安全委員會的前任主席馬克·羅森克目前是CBS新聞的一名顧問，他對NPR的梅麗莎·布洛克表示，“不論發(fā)生了什么，一定是在瞬間發(fā)生，并且導致了飛機在空中發(fā)生了災難性的事故”。

There have been a number of cases in which planes have fallen from the sky — from factors that include catastrophic failure and sabotage. As Patrick Smith, a commercial pilot who runs the popular:
飛機從空中墜落曾經(jīng)有一些案例，原因包括嚴重故障和遭到蓄意破壞。民航飛行員帕特里克·史密斯的分析獲得了廣泛認同：

"All we know for sure is that a plane went down with no warning or communication from the crew. That the crash did not happen during takeoff or landing — the phases of flight when most accidents occur — somewhat limits the possibilities, but numerous possibilities remain. The culprit could be anything from sabotage to an in-flight fire to a catastrophic structural failure of some kind — or, as is so common in airline catastrophes, some combination or compounding of human error and/or mechanical malfunction."
“我們現(xiàn)在唯一清楚的就是飛機沒有發(fā)出任何警報或通信就發(fā)生了事故。而這個事故并沒有發(fā)生在起飛或降落的時候，這兩個階段是大部分航空事故發(fā)生的階段，所以可能性減少了，但依然存在許多可能。罪魁禍首可能是蓄意破壞，也可能是飛機起火，也可能是重大的結(jié)構(gòu)損壞，或者是許多空難當中的原因，即人為失誤加上機械故障?！?/div>

Here are some of the problems an aircraft can experience during flight:
飛機在飛行途中可能會遇到下列問題：

Stresses
壓力

An aircraft undergoes two kinds of routine stresses: a mechanical stress on the cabin caused by the pressurization and depressurization cycle that happens on each flight; and stress on the plane when it lands.
一架飛機會承受兩種必有的壓力：一是每架飛機中的增壓降低的循環(huán)導致的機艙機械應力，二是飛機落地時的壓力。

The structural fatigue and damage they cause "are typically taken care of by periodic maintenance," Todd Curtis, an aviation safety analyst who now runs the Foundation, said in an email.
由壓力導致的飛機結(jié)構(gòu)性疲勞和損失“一般都通過定期維護來解決”，航空安全分析員托德·柯蒂斯在一封電子郵件中說，他現(xiàn)在運營著航空安全基金會。

The Malaysian Airlines Boeing 777 was last inspected just 10 days ago and was said to be in proper condition. The 777 is a long-haul aircraft that is regarded as safe. , it's had about 60 incidents since it entered service in 1995.
這家馬航波音777飛機在10天前剛剛檢查過，而且據(jù)稱狀況良好。波音777是一種遠程飛機，普遍認為安全性很高。從1995年投入使用以來只發(fā)生過60次事故。

Takeoff and landing are typically the riskiest portions of the flight. A Boeing 777 operated by Asiana Airlines was involved in the crash at San Francisco Airport last year that killed three people.
起飛和降落通常是飛行過程中最危險的兩個時段。一家韓亞航空的波音777去年在舊金山機場降落時就發(fā)生了事故，造成3人死亡。

But the en-route portion of the flight, which the Malaysian Airlines flight was on, is seen as the safest. According to a Boeing analysis, only 9 percent of fatal accidents occur at cruising altitude.
但在飛行途中，也就是馬航飛機失聯(lián)的時段，普遍認為是最安全的。根據(jù)一份波音公司的分析，只有9%的致命事故發(fā)生在巡航高度。

"Cruise is generally a pretty good place," says David Ison, assistant professor at Embry-Riddle Aeronautical University, who was a transport pilot with international and transoceanic experience. "There's stable conditions. The weather at higher altitudes is generally better. The only issue is turbulence and sometimes thunderstorm activity."
埃姆伯里-利德爾航空學院的助理教授大衛(wèi)·艾森說，“巡航通常是一個非常不錯的階段”。艾森曾經(jīng)是一名運輸機飛行員，有過國際以及跨洋飛行的經(jīng)歷。“這個階段條件很穩(wěn)定。高度越高，天氣狀況通常越好。唯一的問題是氣流，偶爾會有雷暴活動?！?/div>

Weather
天氣

While weather is a factor at higher altitudes, Flight MH370 was traveling in good weather conditions.
雖然在較高的高度飛行時天氣也是需要考慮的因素，但是MH370航班當時的天氣狀況很好。

Referring to the Malaysian Airlines flight, Curtis said:
關(guān)于馬航失聯(lián)航班，柯蒂斯說：

"Weather can be a factor, but it is unclear if it was a factor in this event. One factor that was happening during this event was that the aircraft is flying over the ocean at night. Under these visual conditions, the crew may not be able to look out the window and use the horizon as a sort of backup aircraft altitude indicator. This may make it harder for the pilots to recover the aircraft if it gets into an unusual attitude."
“天氣會有影響，但在這次事件中還不清楚這是否是其中一個因素。這次事件有一點，飛機當時是在夜間在海洋上空飛行。在這種視覺條件下，飛行員也許無法看清窗外，利用地平線作為飛機高度的參考。這樣一旦飛機的高度出現(xiàn)異常，飛行員想要做出調(diào)整難度就會加大?！?/div>

Technical/Catastrophic Failure
嚴重的技術(shù)故障

Catastrophic failure can affect one or more critical aircraft structures or systems, making it difficult or impossible for the crew to safely land the aircraft.
嚴重的故障可能會對一處或多處飛機結(jié)構(gòu)或系統(tǒng)造成影響，從而導致飛行員難以甚至無法讓飛機安全降落。

There are exceptions to this, of course. The most famous being the "miracle on the Hudson" in 2009, when U.S. Airways Flight 1549 took off from LaGuardia Airport in New York, struck some birds on its way into the sky, lost both engines and was then successfully guided to a safe landing.
當然也有例外。最著名的一次是2009年的“哈德遜河奇跡”，一家全美航空1549航班從紐約的拉瓜迪亞機場起飛，升空后遭遇鳥擊，雙引擎失靈，最終依然成功平安降落。

Curtis says, "Because many aircraft systems have backup systems or backup procedures, it usually takes multiple failures to occur before those failures are considered catastrophic or potentially catastrophic."
柯蒂斯說，“因為很多飛機系統(tǒng)都有后備系統(tǒng)或后備程序，如果發(fā)生嚴重的毀滅性的故障，那么一定是發(fā)生了多重故障?！?/div>

One example of this is Air France Flight 447 that crashed over the Atlantic in 2009. An accident report blamed faulty air speed sensors and pilot error for the crash that killed 228 people.
比如2009年在大西洋墜毀的法航447航班。事故調(diào)查報告認為，飛行速度傳感器和飛行員操作失誤共同導致了這次造成228人死亡的空難。

Ison of Embry-Riddle notes that aircraft today are so reliable that technical failures are highly unlikely in regular operations. In 75 percent to 80 percent of such cases, he notes, the error is human — either by the pilot or by air traffic controllers.
埃姆伯里-利德爾航空學院的艾森認為，今天的飛機都非?？煽?，正常操作下不太可能出現(xiàn)技術(shù)故障。他認為75%-80%的飛行事故都是人為原因造成的，要么是飛行員的失誤，要么是空中交通管理員的失誤。

Sabotage
蓄意破壞

Sabotage is the single-biggest reason for en-route accidents, writes Max Kingsley-Jones, a reporter for Flight Global, an aviation magazine.
飛行途中發(fā)生的事故，蓄意破壞是最大的原因。一家航空雜志《環(huán)球飛行》的記者馬克思·金斯利瓊斯在報道中這樣寫。

Here's more from his story:
下面的內(nèi)容也來自他的報道：

"Including the MAS 777, Ascend Online shows that a total of 46 western-built jet airliners have crashed with the loss of all on board while in the en-route phase. Of these, 13 were caused by sabotage, two more by hijacks and one was shot down. Three more were caused by undetermined causes where flightcrew suicide is suspected."
“包括這次馬航777飛機，Ascend網(wǎng)站顯示，總共有46架西方生產(chǎn)的飛機在飛行途中完全墜毀。其中13起事故是蓄意破壞導致的，兩起是劫機，一起是飛機被擊落。還有3起原因不明，飛行員自殺也被懷疑是原因之一?！?/div>

And, he notes, "In some cases, in-flight events happen so rapidly that the flightcrew are unable to issue any form of mayday, but it is extremely" unusual.
他還注意到，“在某些案例中，飛行中的狀況發(fā)生的太突然，以至于飛行員來不及發(fā)出任何警報，但這種情況非常少見?！?/div>

Pilot's Role
飛行員的角色

When faced with a crisis, the main job of the pilots is to maintain control of the aircraft. That may explain why there was no communication from the Malaysian Airlines plane.
面臨危機時，飛行員的主要任務就是保持對飛機的控制。這也許可以解釋為什么馬航客機沒有和地面聯(lián)系。

"If the pilots are distracted doing something else, then talking to air traffic controllers is not a priority," said John Cox, a former commercial airline pilot who is now CEO of Safety Operating Systems.
“如果飛行員因為做其他事情而分心，那他就不會優(yōu)先選擇和空中交通控制員通話，”安全操作系統(tǒng)的CEO約翰·考克斯說，他曾經(jīng)也是一名民航飛行員。

Ison notes that in the event there's no communication, it could mean that something catastrophic has happened, or simply that the crew was unaware of what was happening. That was the case, he says, with Air France Flight 447. The pilots "didn't communicate [with air-traffic controllers], even though they had an opportunity to," he said.
艾森注意到，在這起事故中沒有任何通信，這也許意味著發(fā)生了某些毀滅性的的事故，或者飛行員根本不知道發(fā)生了什么。他說，法航447航班事故就是這樣。飛行員“并沒有和空中交通控制員聯(lián)系，即使當時他們還來得及這么做?！?/div>

The black box recordings in that case showed that the pilots seemed unaware that the plane was going to crash until just seconds before they hit the water.
這起事故中的黑匣子錄音表明，飛行員似乎直到飛機墜入海中的前幾秒才意識到飛機即將墜毀。

What's Next
接下來該怎樣做

The black boxes on that Air France flight were found two years later, and it took investigators until 2012 to piece together what happened on Flight 447. That may also be what's in store for Malaysian Airlines Flight 370.
法航事故中的黑匣子兩年之后才找到，調(diào)查人員直到2012年才推斷出447航班上到底發(fā)生了什么。也許馬航MH370這次也會面臨同樣的情況。

"Of course, once this plane is found, it'll be much more clear what may have happened to the aircraft," Curtis said. "In any case, it may be months or years before the true nature of this event is understood."
“當然，一旦找到飛機，查明真相會更加清楚，” 柯蒂斯說。“在任何空難中，都需要花上數(shù)月甚至數(shù)年才能弄清事故的真相?！?/div>

Ison, however, said there's no reason why it takes so long to locate an aircraft after it goes missing.
然而，艾森認為飛機失聯(lián)后要花如此長的時間來確定位置，是沒有理由的。

"In this day and age, having no ability to pinpoint these aircraft is really not acceptable," he said. "We have technology to make it happen. We really need to do something ... so we can prevent the loss of aircraft."
“今時今日依然沒有能力定位飛機，這簡直不可接受，”他說?！拔覀冇屑夹g(shù)做到這一點。我們真的需要采取行動，避免這種空難的發(fā)生?！?/div>

The holdup, said Rosenker, the former NTSB chair, is cost. One recent study said a U.S. airline with a global network would have to spend at least $300 million per year to transmit its flight data.
美國國家運輸安全委員會的前任主席馬克·羅森克說，這種事故代價高昂。一項最近的研究表明，一家有全球航線的美國航空公司每年至少需要花費3億美元來發(fā)送它的飛行數(shù)據(jù)。