OPERATING ENVELOPE, Defines the environmental        使用包线，

limits of pressure altitude, temperatures and speed    确定飞机准予飞行的压力高度、温度和速度的环境极

within which the airplane is certified to operate.   限。

OPTIMUM ALTITUDE, The cruise altitude which results  最佳高度，

in the best fuel mileage.                              可获得最佳燃油哩程的巡航高度。

OR GATE, A device or circuit with two or more inputs of 或门，

binary information and one output. The output is 1 when 具有两个或两个以上二进制信息输人，和一个输出的装

any one or more of the inputs is 1. The output is 0 when 置或电路。当输人端有一个或多个为逻辑1时，输出为逻

all of the inputs are 0.                             辑1；当输人端都为逻辑0时，输出为逻辑0。

ORIFICE, A specified size hole in component for control 量孔，

of fluid flow from or to the component.                部件上用来控制流往或流出该部件的液流的尺寸已确

                                                     定的孔。

ORONASAL MASK, An oxygen mask covering only the      口鼻罩，

mouth and nose.                                        仅罩住嘴和鼻子的氧气罩。

OSCILLATE, To swing back and forth with a constant   振荡，

rhythm.                                                以恒定节律作前后的摇摆。

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英汉对照民用航空词典                                      BOEING

OUT OF DETENT, A condition away from neutral or a      脱离卡挡，

notched position.                                        操纵杆离开中立或槽口位置的一种状态。

OUTER LOOP CONTROL, For autopilot operation this       外回路控制，