documentation /d.kjυmen
te..(.)n/ noun a collection of letters, memos, reports, etc. . Flight crews are provided with a full meteorological briefing, backed by documentation, a short time before ETD.
domestic /d.mest.k/ adjective
referring or belonging to inside a coun-try . Domestic flights usually leave from Terminal 1.
dominant /d.m.n.nt/ adjective
main or most influential . Both pres-sure and temperature decrease with height but the pressure change is the dominant one and so, as pressure decreases with height, so does density.
dominate /d.m.ne.t/ verb to have the most effect or influence on .
Because the chart time and the depar-ture/arrival times differ, it is necessary to consider the movement of any weather system which will dominate the route.
Doppler radar /d.pl. re.dɑ/ noun
radar which can distinguish between fixed and moving targets or provide ground speed and track information from an airborne installation
Doppler VOR /d.pl. vi .υ ɑ/
noun an adaptation of VOR to reduce
errors caused by location dot /d.t/ noun a small circular mark on paper . The highest point in a locality is marked by a dot with the elevation marked alongside.
downdraught /daυndrɑft/ noun 1.
cool air which flows downwards as a rainstorm approaches. Opposite updraught 2. air which flows rapidly down the lee side of a building, moun-tain, etc. (NOTE: It is also written down-draft in US English.)
77 drive
downstream /daυnstrim/ adverb
in the direction of flow, or further along the line of flow . Internally driven superchargers are generally used on medium and high powered engines and are fitted downstream of the throttle valve.
downward /daυnw.d/ adjective
moving to a lower level . When flying in turbulent air conditions, an aircraft is subjected to upward and downward gust loads.
downwards /daυnw.dz/ adverb to
a lower level, towards the bottom . Pull the toggles downwards to inflate the life
jacket. Opposite upwards (NOTE: In US English, downward is used as an adverb and as an adjective.)
downwind /daυnw.nd/ adjective, adverb in the same direction as the wind is blowing . turn downwind turn the aircraft so that it is flying in the same direction as the wind is blowing. Oppo-site upwind
downwind leg /daυnw.nd le/
noun part of the airfield traffic circuit which runs parallel to, but in the oppo-site direction to, the approach to land which is made into wind
DR abbreviation dead reckoning draft /drɑft/ noun US same as
draught . a down draft or an updraft
drag /dr/ noun the resistance of the air created by moving the aircraft through the air . To reduce the effect of drag on an aircraft by the fixed under-carriage a retractable type was intro-duced. . If an engine failure occurs, the windmilling propeller may cause con-siderable drag.
COMMENT: There are two basic types of drag called parasite drag and induced drag. Parasite drag is caused by friction between the air and the aircraft surface, aerials, landing gear, etc. Induced drag is produced by lift.