If they lose power while flying, they can autorotate down and land without sustaining any damage due to their flexible structure that deflects upon impact.

如果在飞行中它们失去了能量，它们可以自旋下降并着陆而无需承受任何伤害，因为它们弹性构造可以使伤害转向。

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Headwinds and downdrafts meant flying at a lower altitude than planned, which used up power too quickly.

大风和下降气流使得飞行高度比计划低，这样耗电也更快。

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But building a tiny, lightweight flying robot is tough when you need a power supply — like an onboard battery — to keep the MAV flying.

然而研制这种微小、轻型的飞行器是很困难的，因为必须要有如板载电池这样的电源供电才能维持它的飞行。

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The report says up to one billion birds die each year from flying into objects like power lines, windows and tall buildings.

VOA: special.2009.05.12

The project started with attempts to charge by simply flying near power lines, but when that method yielded only micro-watts of juice, focus shifted to actually landing on the lines.

ENGADGET: Air Force developing UAVs that can recharge on power lines

Hargrave's aeronautical journals and drawings illustrate his lifelong project to develop a practical flying machine and power plant in Australia.

UNESCO: Communication et information

In 2010, fire caused a 787 test flight to lose primary electrical power while flying from Yuma, Arizona, to Laredo, Texas.

CNN: Fire aboard empty 787 Dreamliner prompts investigation