專家：導彈擊中馬航飛機 機上人員只能絕望等死

The explosion captured in a video likely didn't happen until the Boeing 777 aircraft crashed into the ground, Timothy Holt, a professor at Embry-Riddle Aeronautical University told ABC News.

"In this case, it looks like most of the aircraft disintegrated upon impact [with the ground]," he said.

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What happened to the aircraft depends on where the missile struck, he explained, saying that if it pierced the wings -- where the fuel is located -- the plane might have exploded mid-air.

But with this explosion, "it looks like most of the gas was still contained," Holt said.

"You don't see a fireball in the sky ... you see the flame when it hits, you see the black clouds coming out."

Commercial planes like the one that was taken down today in eastern Ukraine carrying 295 people don't have the equipment that lets crews know if a missile is tracking the aircraft. The only way a pilot might know is if he saw the missile fired from the ground.

"If you had some warning in a commercial aircraft, if you see a visual, the best you could hope for is maybe doing a quick descent, taking it into a turn," said Holt, who flew surveillance aircraft in the U.S. Navy for about 15 years. "But we're not talking a high-performance jet that's going to try to out-maneuver a missile. I don't see a way pilots really could have avoided it at that point. And commercial pilots aren't trained for missile strikes."

It's not yet clear if passengers, whose remains are scattered in Hrabove in eastern Ukraine, died immediately when the missile struck or possibly minutes later, when the plane crashed to the ground.

"A lot depends on missile type and where the missile impacts," Holt said.

A U.S. official told ABC News that a surface-to-air missile struck the Boeing 777 that went down today in Ukraine near Russia's border. It is unclear whether the missile was fired from inside Ukrainian or Russian territory and who fired it, the official added. Debris and remains are spread across 10 miles in the area.

The flight, carrying 280 passengers and 15 crew members, was traveling from Amsterdam to Kuala Lumpur.飛機被導彈擊中，究竟會發生什麼？美國廣播公司（ABC）就此採訪專家後指出，馬航MH17航班遭此橫禍時，機上的人們不知道導彈來襲，即使知道也無力阻止慘劇發生。

當地時間7月17日，馬來西亞航空公司一架波音777客機在靠近俄羅斯邊界的烏克蘭東部地區墜毀，機上298人全部遇難。

烏克蘭內政部長顧問安東•傑拉申科宣稱，客機在1萬米的高空飛行時被一枚導彈擊中，而這枚導彈是由巴克（Buk）導彈發射器發射。美政府官員也表示，是一枚地對空導彈導致了這場災難，但尚無法確定導彈是來自烏克蘭還是俄羅斯境內，以及導彈的發射方。

美國安博瑞德航空航天大學教授蒂莫西•霍爾特表示，從事發視頻中可以看到，這架波音777客機是撞向地面時才發生了爆炸，“在這種情況下，像是飛機受地面撞擊的影響而解體”。

霍爾特進一步解釋稱，至於飛機究竟遭到何種損壞，則取決於其被導彈擊中的具體位置。“如果導彈穿過裝有燃油箱的機翼，飛機會在半空中爆炸。但在視頻裏，馬航客機沒有在空中變成一個火球，而是待其墜至地面時，纔看見火焰和濃煙。”

霍爾特還表示，受機載設備侷限，駕駛波音777之類商用客機的飛行員無法知曉是否有導彈正在追蹤飛機，假如他知道了，唯一的解釋就是他透過窗戶玻璃看到了導彈。

“即使收到了預警、發現了導彈，飛行員能夠採取的最佳避險措施可能只是操縱飛機快速下降、急轉彎……”霍爾特曾在美國海軍服役，擔任偵察機飛行員長達15年，“但民用客機不是高性能噴氣式飛機，它無法應對導彈。我認爲，在當時的情境下，馬航飛行員根本無法避開導彈，畢竟他們也沒有接受過導彈襲擊相關培訓。”

目前，還不清楚遇難人員是在客機被導彈擊中後立即喪生還是死於幾分鐘後的地面撞擊。“諸如此類的許多細節問題，要由導彈類型、擊中位置等事故要素來決定，”霍爾特說。