The flier is flying a new-type jet plane on trial.

飞行员正在驾一架新式作试验飞行。

Iraqi security forces were placed on high alert and American aircraft —unpiloted reconnaissance drones flying low, and fighter jets roaring high above —crossed the capital.

伊拉克安全部队处于状态，美国空军在首都上空穿梭，无人驾侦察低空飞行，战斗空呼啸。

Jets coursed the area daily.

每日飞经那地区。