Included in the "dull" and the "difficult" categories were surveillance missions requiring time and a degree of persistence that crews of manned aircraft could not provide.

“枯燥”“困难”分类内的任务包括需要时间和相当程度的耐久性的监视任务，这是人工飞行器不能满足的。

youdao

Work hours management is divided into four parts: work categories, statistics, data processing, feedback of results, and permeates in all aspects of the aircraft maintenance production organization.

工时管理分为工时分类、数据统计、数据处理、结果反馈四个部分，渗透于飞机维修生产组织的各个环节。

youdao

In general, the control methods of the aircraft 's landing gear shock absorbers are classified three categories: a passive type, an active type, and semi - active type.

一般地说，飞机起落架缓冲系统的控制方式有三种：被动控制、主动控制和半主动控制。

youdao

However, that position is dictated by the small number of system integrators who have managed to survive since the Cold War ended in military aircraft, armored vehicles and warships, making any further consolidation a step toward monopoly in some weapons categories.

FORBES: Wave Of Consolidation May Be Coming In Military Electronics