Page:Dictionary of aviation.djvu/103

 DICTIONARY OF AVIATION 79

dip dip n.

1. an act of dipping; a brief downward plunge thru the air, as of an aeroplane.

2. the downward inclination of the magnetic needle at any particular place ; the angle which the needle makes with the horizon.

3. the angular distance of the visible horizon below the horizontal plane thru the observer's eye; the depression of the horizon due to the observer's elevation, which has to be allowd for in taking the altitude of a hevenly bedy.

4. the angular depression or inclination of one or the other end of an airship; the downward slope of the craft, fore or aft.

dip dip intr. incline downward ; slope : as, to *dip and stwoop. dipping front edge, a form of front or fore aerofoils* edge which dips, slopes, or inclines downwards; the droop- ing front edge of a wing or other aerofoil; the archt ferm of wing-section.

dip-the-dip 'dip-d3,dip adj. characterized by the making of a sudden dip or downward dart in the air comparable to a shooting of the chutes or toboggan-slide en the ground.

dipper 'dipaz n. any stuimming bird which dips into or dives in the water with great ease and rapidity, as the grebe.

dipping 'dipirj n. the action of the verb dip; the process of sloping downward for a brief space of time.

dipping-needle 'dipin,nii-dl n. a magnetic needle mounted so as to be free to rotate in a vertical plane about its cen- ter of gravity, used for determining by its dip the direction of the earth's magnetism or magnetic pole; the needle of a dipping-compass.

dipter 'dipt3? n. one of the diptera; a two#wingd fly.

diptera 'dipta-za n. pi. the two-wmgd flies, a large order of insects having one pair of membranous wings, with a pair of halteres or poisers representing a posterior pair.

direction-maintenance di'erek$3n,meentn-3ns n. the main- tenance of the general direction of the course of an aero- done or aircraft; the keeping up, or persistence in, a given flight-path thru capacity to resist diverting forces, as by means of an abutment-fin; directional maintenance.

direction-rudder di'zekfen^Adaz n. a rudder used for con- trolling the horizontal direction of a flying-machine; a side-to-side rudder; a horizontal rudder for lateral steering.

dirigibility ,dizid&'bili-ti n. the quality of being dirigible or steerable.

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