DECIBEL (db), A unit of gain derived by computing the 分贝，

ratio of input power to output power.                 以输人与输出功率的比率来推算的一个增量单位。分贝

                                                    通常表示两个声音信号或电力信号在功率或强度方面的

                                                    相对差别的单位，相当于两个水平的比率的常用对数的十

                                                    倍

DECISION ALTITUDE/HEIGHT (DA/H), A specified        决断高度/高（DA ／H），

altitude or height (A/H) in the precision approach at 在继续进近必需的目视参考没有建立的情况下开始复

which a missed approach must be initiated if the    飞的精密进近中的一个指定高度或高（A ／H）。

required visual reference to continue the approach has

not been established.

DECISION HEIGHT (DH) 1, With respect to the         决断高（DH）1，

operation of aircraft, means the height at which a    就飞机操纵而论，指在使用仪表着陆系统或精密着陆雷

decision must be made, during an ILS or PAR         达引导进近时，必须要作出的是继续进近，还是中断进场

instrument approach, to either continue the approach or 复飞决定时的高。

to execute a missed approach.

DECISION HEIGHT (DH) 2, An altitude used during a   决断高（DH）2，

precision approach to trigger the decision of either  精密进近时产生继续着陆还是复飞决定的高。

landing or go-around.

DECOMPRESSION, The loss of internal aircraft air    失压，

pressure.                                               飞机失去内部空气压力。

DE-ENERGIZE, To turn off or cause to not operate.   断开，

                                                        关断或使不工作。

DEFUEL, A method for removing fuel from the tanks   排油，

using airplane fuel pumps or external suction.          用飞机的油泵或外部的吸油装置将燃油从燃油箱排

                                                    出的方法。