H
Hangar—A structure for the housing of aeroplanes.
Head Resistance—The resistance encountered by a surface moving through the air.
Heavier-than-air—A term applied to flying machines whose weight is not counterbalanced or buoyed up by the lifting power of some gas lighter than air; and which weigh more than the volume of air displaced.
Helicopater—A type of flying machine in which propellers revolving horizontally lift and sustain its weight in the air.
Horizontal Rudder—The rudder surface which is used to steer an aircraft upward or downward: so-called because it lies normally in a position parallel to the horizon; that is, level.
Horse-power—An amount of work equivalent to the lifting of 33,000 footpounds in one minute. See [Footpound].
Hyperbola—The outline formed by the cutting of a cone by a plane passing one side of its axis at such an angle that it would also intersect another cone placed apex to apex on the same axis.