黑匣子的秘密：空難的真相記錄者

On the minds of many these days is the mystery of Malaysia Airlines lost flight MH370， a Boeing 777 that disappeared on March 8th. How does a plane just disappear into thin air？ Recovering the flight data recorder （FDR）， otherwise known as the flight’s black box （even though it is really orange）， might be the only way to solve the plane’s mysterious disappearance. This got me wondering： just how does a black box containing 1）electronic circuit boards remain intact during a 2）catastrophic airplane crash？ The truth is that the electronics are likely destroyed， but the recorded data is recoverable.

In fact， there are two data recording devices on-board an airplane： the cockpit voice recorder（CVR） that records dialogue in the cockpit such as communications between the pilots with air traffic control， and the FDR that records hundreds of different 3）parameters about the airplane while in flight. Both devices are located in the tail of the plane to increase the chances of survival following a crash. Although earlier black boxes were in fact painted black， they are now painted bright orange to make them easier to locate in a plane’s wreckage.

A solid state flight data recorder （SSFDR） can store up to 25 hours of flight data. The main 4）components of an SSFDR are an interface and controller board （ICB）， power supply， crash survivable memory unit （CSMU） and an optional under water locator beacon （ULB）. The ICB is a single circuit board that controls the SSFDR and provides data processing capabilities. It enables front-end data conditioning， recording， and monitoring and ensures that up to 700 different parameters associated with an airplane’s operating conditions are recorded by the CSMU.

The CSMU of the FDR is often the only device that survives a plane crash and holds the secrets of what went wrong. The CSMU is designed to be resistant to shock， 5）temperature extremes， and pressure according to the 6）EUROCAE ED-112 standard for Minimum Operational Performance Specifications for Crash Protected Airborne Recorder Systems. Even so， if investigators cannot find the FDR， it is of little use.

The ULB will send out a ping signal for at least 30 days that can be detected from up to two miles away. However， there have been several instances where the flight data recorders were never recovered， such as the ones from the Boeing 767s that hit the World Trade Center in New York on 9/11. This leaves many people wondering why， given all of our technological advancements， flight data is not uploaded in real-time.

In fact， all airplanes do have an Aircraft Communications Addressing and Reporting System （ACARS） that sends critical information about the airplane to the ground in real-time. However， only basic information is sent such as whether or not the doors are closed and the plane’s altitude and location. Plus， ACARS data is typically only sent during events such as takeoff and landing and not continuously during the entire flight. The amount of data recorded by the FDR during the entire flight that would need to be uploaded in real-time would be immense. While I think we have the technology required to support the necessary 7）bandwidth and storage capacity， the real question is at what expense？

It is well known that traveling by plane is far safer than driving in a car. According to the National Safety Council （NSC）， the lives lost on US roadways each year 8）are equivalent to the lives that would be lost from a 100-passenger jet crashing every day of the year. Is the extra expense of having real-time data transferred from a plane in flight really worth it？ I am sure that if we asked that question to those waiting to find out the fate of their loved ones on Malaysia Airlines flight MH370， they would say that it is.

Unfortunate events such as these are prompting people to rethink airplane communications and tracking. For example， a Canadian company named Flyht has developed a portable satellite communications device， based on a global positioning system （GPS）， to monitor and stream critical data in realtime from anywhere in the world. Makes sense to me since GPS signals are already found in many devices that we use everyday such as our cell phones and cars. Do you think that with continued improvements to GPS systems， they will finally devise a viable alternative to the infamous black box？ Only time will tell.

馬來(lái)西亞航空公司失聯(lián)的MH370航班——在3月8日失蹤的一架波音777飛機(jī)，在這段時(shí)日里成為許多人心中的疑團(tuán)。一架飛機(jī)怎會(huì)就這么在空中消失了？尋回飛行數(shù)據(jù)記錄儀——也就是大家所熟知的飛機(jī)黑匣子（盡管其實(shí)它是橙色的），或許會(huì)是解開(kāi)這個(gè)謎題的唯一辦法。這讓我不禁產(chǎn)生疑問(wèn)：一個(gè)裝有電子線路板的黑匣子究竟如何能在毀滅性的墜機(jī)情況中保持完好無(wú)損呢？真相是：電子部件很可能會(huì)被毀壞，但記錄的數(shù)據(jù)卻可以被恢復(fù)。

其實(shí)，飛機(jī)上裝有兩個(gè)數(shù)據(jù)記錄裝置：一個(gè)是駕駛艙話音記錄儀，用來(lái)記錄駕駛艙里的對(duì)話，如飛機(jī)師與空中交通管制站之間的通信，而另一個(gè)就是飛行數(shù)據(jù)記錄儀，用來(lái)記錄飛機(jī)在飛行中數(shù)以百計(jì)的不同參數(shù)。兩個(gè)儀器都安裝在飛機(jī)的尾部以提高在飛機(jī)墜毀時(shí)被完整保留下來(lái)的幾率。盡管早期的黑匣子的確是被漆成黑色的，但現(xiàn)在被漆成了鮮艷的橙色，目的是使其在飛機(jī)殘骸中更容易被發(fā)現(xiàn)。

一個(gè)固態(tài)飛行數(shù)據(jù)記錄儀能夠記錄25個(gè)小時(shí)的飛行數(shù)據(jù)。其主要的部件包括有：一個(gè)接口與控制板、供電電源、耐沖擊記憶單元，以及可選配的水下定位信標(biāo)。接口與控制板是一個(gè)單一電路板，負(fù)責(zé)控制固態(tài)飛行數(shù)據(jù)記錄儀以及提供數(shù)據(jù)處理功能。它能夠進(jìn)行前端數(shù)據(jù)的處理、記錄和監(jiān)控，并確保多達(dá)700項(xiàng)與飛機(jī)運(yùn)行狀況有關(guān)的不同數(shù)據(jù)被記錄到耐沖擊記憶單元上。

飛行記錄儀中的耐沖擊記憶單元通常會(huì)是飛機(jī)墜毀事故中唯一幸存的裝置，而且它保存著事故原因的秘密真相。依照歐洲民用航空設(shè)備組織的ED-112文件標(biāo)準(zhǔn)所制定的《機(jī)載事故記錄設(shè)備最低操作性能規(guī)范》，耐沖擊記憶單元被設(shè)計(jì)成具有耐沖擊、耐極端溫度和耐壓性能。即便如此，如果調(diào)查人員無(wú)法找到飛行記錄儀的話，它還是發(fā)揮不了什么作用。

水下定位信標(biāo)能夠在至少30天內(nèi)持續(xù)發(fā)射出聲脈波信號(hào)，并能在兩英里范圍內(nèi)被探測(cè)到。然而，也有過(guò)好幾例飛行記錄儀無(wú)法被恢復(fù)的情況，例如“9·11”事件中撞擊紐約世貿(mào)中心的波音767飛機(jī)上的飛行記錄儀。這讓好多人感到疑惑：既然我們的科技都已如此先進(jìn)了，那為何飛行數(shù)據(jù)不實(shí)時(shí)上傳呢？

事實(shí)上，所有飛機(jī)上確實(shí)都備有一個(gè)飛機(jī)通信尋址與報(bào)告系統(tǒng)來(lái)完成空、地間的實(shí)時(shí)數(shù)據(jù)通信。但是，傳輸?shù)闹皇切┗A(chǔ)的數(shù)據(jù)，如機(jī)艙門是否關(guān)閉了，飛機(jī)所處的海拔高度和位置。另外，飛機(jī)通信尋址與報(bào)告系統(tǒng)數(shù)據(jù)通常只會(huì)在某些情況下才被發(fā)送，如飛機(jī)起飛和降落的時(shí)候，而不是在整個(gè)飛行過(guò)程中持續(xù)地發(fā)送。在整個(gè)飛行過(guò)程中，飛行記錄儀所記載的數(shù)據(jù)如果全部實(shí)時(shí)上傳的話，那將會(huì)是極其龐大的數(shù)據(jù)傳送量。雖然我認(rèn)為我們已具有支持該做法的技術(shù)，包括所需的帶寬和儲(chǔ)存能力，但真正的問(wèn)題是所需費(fèi)用會(huì)是多少？

眾所周知，搭乘飛機(jī)旅行的風(fēng)險(xiǎn)要比開(kāi)車低得多。根據(jù)國(guó)家安全委員會(huì)所述，每年在美國(guó)路面喪生的人數(shù)，與每天撞毀一架承載100人的飛機(jī)所導(dǎo)致喪生的人數(shù)相當(dāng)。為了實(shí)時(shí)上傳飛機(jī)飛行中的數(shù)據(jù)而額外增加這些費(fèi)用，這是否真的值得呢？如果這個(gè)問(wèn)題用來(lái)問(wèn)那些仍然在等待馬航MH730航班上親人消息的人們，我肯定，答案絕對(duì)是值得的。

此類不幸事件正促使人們重新考慮飛機(jī)通信和追蹤的問(wèn)題。例如，一家名為Flyht的加拿大公司，已經(jīng)開(kāi)發(fā)了一款便攜式的衛(wèi)星通訊裝置，該裝置以全球衛(wèi)星定位系統(tǒng)為基礎(chǔ)，能夠在全球任何地方實(shí)時(shí)地監(jiān)控和流出關(guān)鍵數(shù)據(jù)。我覺(jué)得這辦法可行，因?yàn)槿蛐l(wèi)星定位信號(hào)已經(jīng)被廣泛應(yīng)用到我們?cè)S多日常設(shè)備當(dāng)中了，如手機(jī)和汽車。隨著全球衛(wèi)星定位系統(tǒng)的不斷改進(jìn)，人們會(huì)否最終設(shè)計(jì)出一個(gè)可行的替換方案來(lái)取締聲名狼藉的黑匣子呢？看來(lái)只能等時(shí)間去證明了。

小鏈接

Air France Flight 447 法航447航班

此次馬航事件讓很多人想到了2009年發(fā)生的法航447航班失事事件。當(dāng)年6月1日，法航447航班墜入大西洋，導(dǎo)致機(jī)上228人全部遇難。盡管在事發(fā)后第二天就有部分飛機(jī)殘骸浮上大西洋海面，但整個(gè)事故的調(diào)查花費(fèi)了幾乎兩年時(shí)間，在黑匣子被成功從海底打撈起來(lái)進(jìn)行分析之后才告完成。2012年7月，法國(guó)官方正式公布了此次事故的調(diào)查報(bào)告，此時(shí)距離空難已經(jīng)過(guò)去3年時(shí)間。報(bào)告認(rèn)定技術(shù)故障和人為操作失誤共同導(dǎo)致了災(zāi)難的發(fā)生。

9/11 Attacks “9·11”恐怖襲擊事件

美國(guó)東部時(shí)間2001年9月11日，恐怖分子劫持四架民航客機(jī)撞擊美國(guó)紐約世界貿(mào)易中心和華盛頓五角大樓。其中一架波音767客機(jī)撞向世貿(mào)中心大樓北樓，一架波音757客機(jī)撞向世貿(mào)中心大樓南樓，一架波音767客機(jī)撞向首都華盛頓美國(guó)國(guó)防部的所在地五角大樓，另一架波音757客機(jī)則在距匹茲堡東南130公里處墜毀。此次事件造成5400多人失蹤，450多人死亡，全球經(jīng)濟(jì)損失超過(guò)一萬(wàn)億美元，而在事件中墜毀的飛機(jī)是唯一保留著黑匣子錄音的。