The Federal Aviation Administration (FAA) shares the Environmental Protection Agency's (EPA) concerns about lead emissions from small aircraft. Owners and operators of more than 200,000 piston-engine aircraft operating in the United States rely on aviation gasoline (avgas) to power their aircraft.
Symmetry (noun). a due proportion of the several parts of a body to each other; adaptation of the form or dimensions of the several parts of a thing to each other; the union and conformity of the members of a work to the whole. Symmetry (noun).
Medical Definition of BILATERAL SYMMETRY. : symmetry in which similar anatomical parts are arranged on opposite sides of a median axis so that one and only one plane can divide the individual into essentially identical halves.efinition of BILATERAL SYMMETRY. : symmetry in which similar anatomical parts are arranged on opposite sides of a median axis so that only one plane can divide the individual into essentially identical halves. See bilateral symmetry defined for kids. ADVERTISEMENT.