It remains to be seen how weather conditions affect the air flows that make formation flight more efficient.

天气状况如何影响使编队飞行更高效的气流，尚待观望。

Earlier this year, the country's Defence Advanced Research Projects Agency announced plans to pay Boeing to investigate formation flight, though the programme has yet to begin.

今年早些时候国防高级研究计划局宣布了将调拨资金以供波音公司研究编队飞行的计划，尽管这一项目还未开始。

It might also be hard for airlines to co-ordinate the departure times and destinations of passenger aircraft in a way that would allow them to gain from formation flight.

除此之外，各航空公司也很难协调其客机起飞和降落时间同时又能使他们从编队飞行中获益。

Sunny spring weather along the east coast brought out spectators in droves Saturday to watch the Blue Angels and Thunderbirds conduct formation flights in Washington, Baltimore and Atlanta.

星期六东海岸阳光明媚的春天天气吸引了成群结队的观众观看蓝天使队和雷鸟队在华盛顿、巴尔的摩和亚特兰大进行编队飞行。