Monday, 10 August 2026, 12:11 PM
Site: Fitting Aviation Learning Center Online Nexus
Course: Fitting Aviation Learning Center Online Nexus (F.A.L.C.O.N.)
Glossary: Glossary
D
D.C. Direct current. |
DASee decision altitude. |
Dark adaptation Physical and chemical adjustments of the eye that make vision possible in relative darkness. |
Datum (Reference Datum)An imaginary vertical plane or line from which all measurements of arm are taken. The datum is established by the manufacturer. Once the datum has been selected, all moment arms and the location of CG range are measured from this point. |
Dead reckoning Navigation of an airplane solely by means of computations based on airspeed, course, heading, wind direction and speed, groundspeed, and elapsed time. |
Deceleration error A magnetic compass error that occurs when the aircraft decelerates while flying on an easterly or westerly heading, causing the compass card to rotate toward South. |
Decision altitude (DA) A specified 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 specified 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. |
DeiceThe act of removing ice accumulation from an aircraft structure. |
DeltaA Greek letter expressed by the symbol Δ to indicate a change of values. As an example, ∆CG indicates a change (or movement) of the CG. |