DICTIONARY OF AVIATION 199
air, as an aeroplane flyer does, or seems to do, tuhen net
wholly under the control of the operator.
2. move along en a skid or en skids, as a flying^machine
does in landing; slide en the landing^skids or runners. skid-strut 'skid,stAt n. one of the struts or braces of the
landing^skid of a flymg^machine. skid-wheel 'skid,iuiil n. one of the landmg#u>heels attacht
to or taking the place of a skid in a flying^machine. skim skim v.
1. glide aleng upen; soar close to.
2. glide or dart aleng in a smooth even course thru the air; soar.
skimmer 'skimaz n. a bird that skims or shears the water, as any member of the genus rhyncheps; a cutwater, shear- water, or scissorbill.
skin-area 'skm,e:-zi-a n. the area of the portion of the sur- face of a selid bedy which is immerst in a fluid.
skin-fold 'skm^oold n. the fold or fly in the skin forming the patagium or flymg^membrane of a flying animal : as, the *skin?fold of the flying^squirrel.
skin-friction 'skin,fsik$9n n. [also spelt skin friction] the friction between the skin or immerst surface of a selid bedy and a fluid, such as the air, in which the selid bedy is immerst and thru tuhich it is moving; skm^resistance.
skin-frictional 'skin,f5ik$9-nl adj. ef or related to, skin* friction : as, the influence of *skins:frictionai error.
skin-resistance 'skm-zi,zistns n. the resistancce efferd to the air or other fluid by the skin or surface of a moving aerof eil ; skm^f riction.
sky skai n. [ploral skies'] the region of clouds; cloudland; the hevens ; the firmament : ef ten used in the ploral : as, to sail the *skies.
clear sky, a sky markt by the absence of clouds; the sky characteristic of a clear day; specifically, in the United States Wether^Bureau, a sky in tuhich the obscuration is about 3 en a scale of 10.
green sky, a sky which is green in color, usually occur- ring at sunset.
lamb'sfwool sky, a sky characterized by white fleecy patches of cloud against the blue.
livid sky, a sky overspred by clouds of a livid hue; a blackish^blue or leden sky.
mackerel sky, same meaning as mackerelzsky. red sky, a sky which is red in color, usually occurring at sunset.
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