(under subclass 4) Aeronautical machines having provision for sustentation in part or entirely by aerodynamic action on airfoils in fixed relation to the machines, having also provision for sustentation or vertical lift by the downward thrust developed by flapping or reciprocating blades attached to the machines. These blades may also be the propelling agents.
(1) Note. For machines sustained by beating wings alone, see this class, subclass 22.
(2) Note. For lighter-than-air craft partially sustained by beating wings, see this class, subclass 28.
(3) Note. For beating wing construction, per se, see this class, subclass 72.
