O

O-RING, A circular shaped rubber or synthetic material O形圈，

sealing device for pneumatic and hydraulic systems.   用于气源和液压系统，圆形的橡胶或合成材料制成的密

                                                    封装置。

OAT, SEE - OUTSIDE AIR TEMPERATURE                  外界大气温度，

                                                        见Outside Air Temperature．

OBSTACLE, An obstruction protruding into the airspace 障碍物，

in the path of flight.                                进人飞行航径上空域里的障碍物。

OBSTACLE CLEARANCE, The process of flying the       越障，

aircraft over all obstructions under the flight path. 飞机飞越其航道上所有障碍物的飞行过程。障碍物的选

Which obstructions are considered and the amount of 择和飞机距离障碍物的高度要求由当地有关管理机构决

vertical altitude required above the obstructions are 定。

determined by local regulatory agency.

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英汉对照民用航空词典                                 BOEING

OEW, SEE - OPERATING EMPTY WEIGHT                 使用空重，

                                                    见Operating Empty Weight．

OFFSIDE, Opposite side.                           反面，

                                                    相反的一面。

OIL COOLER, A heat exchanger for cooling engine oil 滑油冷却器，

by fuel flow or airflow.                            利用燃油或空气的流动来冷却发动机滑油的热交换器。