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

ratio of input power to output power.                 以輸人與輸出功率的比率來推算的一個增量單位。分貝

                                                    通常表示兩個聲音信號或電力信號在功率或強度方面的

                                                    相對差別的單位，相當于兩個水平的比率的常用對數(shù)的十

                                                    倍

DECISION ALTITUDE/HEIGHT (DA/H), A specified        決斷高度/高（DA ／H），

altitude or height (A/H) in the precision approach at 在繼續(xù)進近必需的目視參考沒有建立的情況下開始復

which a missed approach must be initiated if the    飛的精密進近中的一個指定高度或高（A ／H）。

required visual reference to continue the approach has

not been established.

DECISION HEIGHT (DH) 1, With respect to the         決斷高（DH）1，

operation of aircraft, means the height at which a    就飛機操縱而論，指在使用儀表著陸系統(tǒng)或精密著陸雷

decision must be made, during an ILS or PAR         達引導進近時，必須要作出的是繼續(xù)進近，還是中斷進場

instrument approach, to either continue the approach or 復飛決定時的高。

to execute a missed approach.

DECISION HEIGHT (DH) 2, An altitude used during a   決斷高（DH）2，

precision approach to trigger the decision of either  精密進近時產(chǎn)生繼續(xù)著陸還是復飛決定的高。

landing or go-around.

DECOMPRESSION, The loss of internal aircraft air    失壓，

pressure.                                               飛機失去內(nèi)部空氣壓力。

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

                                                        關(guān)斷或使不工作。

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

using airplane fuel pumps or external suction.          用飛機的油泵或外部的吸油裝置將燃油從燃油箱排

                                                    出的方法。