The plane gradually out of sight.

飞机渐渐远去看不见了。

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Overall, half of the respondents said they had been in the dust cloud from the collapsing towers;70 percent witnessed a traumatic sight, such as a plane hitting the tower or falling bodies;

总体来看，有一半的受访者称当时他们被笼罩在大楼倒塌产生的巨大烟尘中，70%的人亲眼目睹了飞机撞上大厦和尸体横飞的恐怖场景；

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And at the Pentagon the sight of the third plane attack.

在被第三架飞机撞击的五角大楼现场。

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The Lexington Institute's Loren Thompson says those mishaps usually result from a simple break in the line-of-sight connection between a plane and the satellite that controls it--often when one of the aircraft's own wings maneuvers into the path of the signal.

FORBES: Magazine Article

In contrast to past hijacking situations, Mr Learmount said it was unusual that police with weapons appeared in sight of the plane's cockpit.

BBC: How to negotiate with hijackers

The jumbo jet experienced turbulence on approach to Toledo and was within sight of the runway when the pilot pulled the plane up and circled the airport, according to reporters on board.

CNN: Air Force One aborts landing, second try successful