Under F. A. A. guidelines, recreational fliers like Mr. Anderson and his customers must keep unmanned aircraft lower than 400 feet, away from other aircraft and within the operator's sight.

在联邦航空局的准则里有，像安德森先生和他的客户们娱乐飞行，必须使无人机在400英尺以下高度飞行，远离其它飞机而且在操纵者的视线之内飞行。

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On the Gulf Test Range near Eglin Air Force Base, Fla., an F-15 Eagle fired two missiles at two QF-100 drones at 10,000 feet and two more at two drones at 5,000 feet.

在佛罗里达州埃格林空军基地附近的湾试验靶场，一架F-15鹰式战斗机在10000英尺的高度、在QF-100drone上发射了两枚导弹，并在5000英尺高度发射了另外两枚。

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Pointed nose-down and hurtling toward the ground at 8, 400 feet per minute, F-16C fighter jet pilot Chris Stricklin came to a terrible realization: I'm not going to make it.

就在F-16C型喷气式战机机头朝下、以每分钟8400英尺（42.5米/秒）的速度呼啸着向地面冲去的时刻，特技飞行员克里斯·斯特里克林猛然意识到：表演无法完成！ 恐怖的时刻到了……（注：事后事故调查表明，他错把飞机显示的海拔高度当成飞机与地面之间的实际距离——可地面本身还有将近200米的海拔高度！

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When the F-18 dropped to 50 feet the crew ejected.

CNN: F-18 crash attributed to rare dual engine failure

The IPCC Panel's near-consensus was that human activity is having some discernible impact on climate, and that by 2100, a warming earth could result in more frequent storms and droughts, sea level rise of up to three feet, and up to six degrees F. in temperature rise.

CNN: Selected Web sites on climate change

Now, Bezos Expeditions also an investor in space research firm Blue Origin will attempt to bring the five F-1 rocket launchers up from 14, 000 feet below.

FORBES: Jeff Bezos' Apollo Mission: Amazon Chief Joins The Billionaire Daredevils Club