(under the class definition) Devices and arrangements for propelling aircraft in flight.
(1) Note. For propellers used only to steer or stabilize aircraft, see this class, subclass 92.
(2) Note. For reaction motors, per se, capable of propelling any type of vehicle, see Class 60, Power Plants.
(3) Note. For the combination of a motor driven propeller, per se, see Class 416, Fluid Reaction Surfaces (i.e., Impellers), appropriate subclasses.
(4) Note. Devices for cooling internal combustion engines by means of air are classified in Class 123, Internal-Combustion Engines, subclasses 41.56+, particularly subclass 41.7. This includes cowling devices for the engines to provide for directing the cooling air against the engine parts to provide for directing the cooling air against the engine parts to be cooled. Combinations of impellers with driving means are ordinarily classified in Class 416, Fluid Reaction Surfaces (i.e., Impellers), various subclasses but such combinations with modifications to assist in cooling the engine are classified in Class 123, subclasses 41.63+.
