时间:2011-08-28 11:47来源:蓝天飞行翻译 作者:航空 点击:次
D.C. Direct current. Dark adaptation. Physical and chemical adjustments of the eye that make vision possible in relative darkness. Deceleration error. A magnetic compass error that occurs when the aircraft decelerates while .ying on an easterly or westerly heading, causing the compass card to rotate toward South. Decision altitude (DA). A speci.ed altitude in the precision approach, charted in feet MSL, at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Decision height (DH). A speci.ed altitude in the precision approach, charted in height above threshold elevation, at which a decision must be made either to continue the approach or to execute a missed approach. Deice. The act of removing ice accumulation from an aircraft structure. Density altitude. Pressure altitude corrected for nonstandard temperature. Density altitude is used in computing the performance of an aircraft and its engines. Departure procedure (DP). Preplanned IFR ATC departure, published for pilot use, in textual and graphic format. Deviation. A magnetic compass error caused by local magnetic .elds within the aircraft. Deviation error is different on each heading. DGPS. Differential global positioning system. DH. See decision height. Differential Global Positioning System (DGPS). A system that improves the accuracy of Global Navigation Satellite Systems (GNSS) by measuring changes in variables to provide satellite positioning corrections. |