四翼飞机
四翼机

Quadruplane \Quad"ru*plane\, n. [L. quadru- in comp. + E.
plane.]
An airplane with four superposed main supporting surfaces.
Contrasted with {triplane} {biplane} and {monoplane}. They
are now used only for hobbyist or historical activities.
[Webster 1913 Suppl. +PJC]