R

radar /re.dɑ/ noun a method of detecting distant objects and establish-ing their position, velocity, or other characteristics by analysis of very high frequency radio waves reflected from their surfaces
radar advisory service /re.dɑ .d va.z(.)ri sv.s/ noun an air traffic radar service which gives pilots advice on actions necessary to ensure that they remain at a standard distance from other aircraft that are also receiving the serv-ice. Abbreviation RAS
radar beam /re.dɑ bim/ noun a
shaft of radar waves directed towards a distant point
radar information service
/re.dɑ .nf.me..(.)n sv.s/ an air traffic radar service which gives pilots details of the positions, distances and levels of other aircraft to enable them to decide on any avoiding action which may be appropriate. Abbreviation RIS
(NOTE: An RIS is often provided when it is not possible or practical to provide an RAS.)
radar screen /re.dɑ skrin/ noun a
cathode ray tube screen on which radar information is displayed
radar vectoring /re.dɑ vekt.r../
noun the provision of navigational guidance to aircraft in the form of spe-cific headings, based on the use of radar
radial /re.di.l/ adjective referring to lines of radius having a common centre
. radial engine engine in which the pis-tons are arranged like the spokes of a wheel . noun a line of radio bearing from a VOR beacon . To get to a facility
you must track the reciprocal of the VOR radial.
radiate /re.die.t/ verb to send out rays or waves . The Earth radiates low intensity infrared waves. . Short bursts of energy are radiated from an antenna.
radiation /re.die..(.)n/ noun the act or process of sending out rays or waves
. terrestrial radiation radiation from the Earth
radiation fog /re.die..(.)n f./
noun fog caused by the cooling of the Earth to below the dew point, combined with saturation and condensation and a light mixing wind . Radiation fog can-not form over the sea.
radiator /re.die.t./ noun a liquid-to-air heat exchanger that transfers engine heat to the outside air . Anti-icing addi-tives are used in radiator coolants. .
coolant radio /re.di.υ/ noun wireless trans-mission through space of electromag-netic waves in the approximate fre-quency range from 10 kHz to 300,000 MHz . radio waves electromagnetic radiation waves . The atmosphere absorbs radio waves.
radio aid /re.di.υ e.d/ noun a navi-gation aid utilising radio waves
radio altimeter /re.di.υ lt. mit./ noun a device for measuring the height of the aircraft above the Earth using reflected radio waves