Propeller Shaft—A piece of wire which is run through the hub of the propeller and tubing in mounting the propeller.

Pylon—Correctly, a structure housing a falling weight used for starting an aëroplane, commonly a turning point in aëroplane flights.

Pusher—An aëroplane with the propeller or propellers situated in back of the main supporting surfaces.

Q

Quadruplane—An aëroplane with four wings superposed.

R

Rudder—A plane or group of planes used to steer an aëroplane.

Runner—Strip beneath an aëroplane used for a skid.

Running Gear or Landing Gear—That portion of the chassis consisting of the axle, wheels and shock absorber.

Rib—Curved brace fastened to the entering and trailing edges of a wing.