Apteroid (Author), from the Greek α, πτερόν and ειδος, the converse of pterygoid. Thus apteroid aspect, with the greater dimension arranged in the direction of flight; the reverse to that which obtains in the wing plan-form of birds.
Aspect (Diet.), proposed by Langley in its present usage to denote the arrangement of the plan-form of an aeroplane, or other aerofoil, in relation to the direction of flight.
* Attitude (Dict.), used to denote the position of an aeroplane or aerofoil about a transverse axis relative to the direction of flight; analogous to the term aspect. The attitude of a given aeroplane or aerofoil is thus defined by its angle β: a change of attitude involves a change in β.
Ichthyoid (Dict.), fish-shaped, here applied to denote a body of practical stream-line form.
Peripteral. See Periptery.
Peripteroid. See Periptery.
Periptery (Dict.), proposed by the author in its present usage as denoting the region round about the wing or in the vicinity of the aerofoil (Greek, περι and πτερόν), § 107. Hence peripteral, as in peripteral theory, peripteral area; peripteral zone; peripteral motion, comp. Vol. I., footnote 2, p, viii. (Preface). Hence also peripteroid motion (Greek, περι, πτερόν and ειδος), the form of flow proper to the inviscid fluid in a doubly connected region, resulting from the superposition of a cyclic motion on one of translation. Resembling the motion in the periptery, lit-round-about-the-wing-like.
* Phugoid Theory (Author), from the Greek φυγή and εἶδος, lit. flight-like.[1] The theory dealing with longitudinal stability and the form of the flight path. Hence also Phugoid chart, Phugoid curve, Phugoid oscillation, etc. (Ch. II.)
- ↑ The appropriateness of the derivation is perhaps diminished by the fact that the word φυγή means flight in the sense of escape rather than the act of flying in the present signification.
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