Order 7110.65P, Air Traffic Control, with changes

2/19/04Pilot/Controller GlossaryDDA [ICAO]−(See ICAO Term DECISIONALTITUDE/DECISION HEIGHT.)DAIR−(See DIRECT ALTITUDE AND IDENTITYREADOUT.)DANGER AREA [ICAO]− An airspace of defineddimensions within which activities dangerous to theflight of aircraft may exist at specified times.Note: The term “Danger Area” is not used inreference to areas within the United States or anyof its possessions or territories.DAS−(See DELAY ASSIGNMENT.)DATA BLOCK−(See ALPHANUMERIC DISPLAY.)DEAD RECKONING− Dead reckoning, as appliedto flying, is the navigation of an airplane solely bymeans of computations based on airspeed, course,heading, wind direction, and speed, groundspeed,and elapsed time.DECISION ALTITUDE/DECISION HEIGHT[ICAO]− A specified altitude or height (A/H) in theprecision approach at which a missed approach mustbe initiated if the required visual reference tocontinue the approach has not been established.Note 1: Decision altitude [DA] is referenced tomean sea level [MSL] and decision height [DH] isreferenced to the threshold elevation.Note 2: The required visual reference means thatsection of the visual aids or of the approach areawhich should have been in view for sufficient timefor the pilot to have made an assessment of theaircraft position and rate of change of position, inrelation to the desired flight path.DECISION HEIGHT− With respect to the operationof aircraft, means the height at which a decision mustbe made during an ILS, MLS, or PAR instrumentapproach to either continue the approach or to executea missed approach.(See ICAO term DECISIONALTITUDE/DECISION HEIGHT.)DECODER− The device used to decipher signalsreceived from ATCRBS transponders to effect theirdisplay as select codes.(See CODES.)(See RADAR.)DEFENSE VISUAL FLIGHT RULES− Rules applicableto flights within an ADIZ conducted under thevisual flight rules in 14 CFR Part 91.(See AIR DEFENSE IDENTIFICATION ZONE.)(Refer to 14 CFR Part 91.)(Refer to 14 CFR Part 99.)DELAY ASSIGNMENT (DAS)− Delays are distributedto aircraft based on the Ground Delay Programparameters. The delay assignment is calculated in15−minute increments and appears as a table inETMS.DELAY INDEFINITE (REASON IF KNOWN)EXPECT FURTHER CLEARANCE (TIME)− Usedby ATC to inform a pilot when an accurate estimateof the delay time and the reason for the delay cannotimmediately be determined; e.g., a disabled aircrafton the runway, terminal or center area saturation,weather below landing minimums, etc.(See EXPECT FURTHER CLEARANCE (TIME).)DELAY TIME− The amount of time that the arrivalmust lose to cross the meter fix at the assigned meterfix time. This is the difference between ACLT andVTA.DEPARTURE CENTER− The ARTCC having jurisdictionfor the airspace that generates a flight to theimpacted airport.DEPARTURE CONTROL− A function of an approachcontrol facility providing air traffic controlservice for departing IFR and, under certain conditions,VFR aircraft.(See APPROACH CONTROL FACILITY.)(Refer to AIM.)DEPARTURE SEQUENCING PROGRAM− A programdesigned to assist in achieving a specifiedinterval over a common point for departures.DEPARTURE TIME− The time an aircraft becomesairborne.DESCENT SPEED ADJUSTMENTS− Speed decelerationcalculations made to determine an accuratePCG D−1