Page:Dictionary of aviation.djvu/107

 DICTIONARY OF AVIATION 83

2. lateral deviation, as of a projectil from its path; ten- dency to move sidewise.

3. the force with which a fluid, as the air, presses hori- zontally upon an aerofoil, either backward or forward, as the case may be; the horizontal component of the air-pres- sure on a kite, aeroplane, or airship; the backward posh or thrust (or, sometimes, the forward poll) of the atmosfere or wind upon an aeroplane or aerocurv: distinguisht from lift, compare head-resistance.

drift drift intr.

1. float or be driven along, as an airship, by a current of air; be carried at random by the force of the wind.

2. tend, move, or be posht or thrust horizontally back- ward (or, less usually, forward) somewhat, relativly, by the pressure of the air.

drifter 'drifter n. any aerial craft of the type which tends to drift or float along with the air, rather than actually fly or move under the complete control of the operator; a lighter-than-air machine.

drifting-force 'driftirj,fo:zs n. the force or strength of the tendency of an aerofoil to drift, see drift (verb, sense 2).

drive draiv n. a driving or propelling mechanism; also, the mode of being driven : as, a flexible *drive ; the direct
 * drive of a helicopter.

chain drive, transmission of power from the motor of an airship to the driving-apparatus or propeller by means of a chain.

driver 'drai-vaz n. one who drives or operates a flying-ma- chine; an aviator.

driving-power 'drai-vin,pau-9z n. the motory power em- ployd or kept in reserv for driving or propelling an air- ship; power or capacity to drive; propulsiv power.

drome droom n. an aerodrome; a flyer; an aero.

droop droup n. a downward bend; the curvature, cer-"" downward, of the margin of a wing; the hanging cu the archt form of a wing-section; the dipping edge a sustaining-surface; the arch of an aerofoil, compar (verb) and arch.

drop drop intr. fall, sink, or descend, as thru the air to or toward the ground.

drop drop n. the action of dropping, sinking or falling thru the air; a descent: as, a long *drep, a corkscrew *drep.

droplet 'droptat n. a little drop, as one of the water-particles of a water-cloud.

drosometer dra'somi-taz n. a weighing*instjument for mes- unng dew.

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