Correctly, a structure housing a falling weight used for starting an aeroplane, commonly a turning point in aeroplane flights.
The screw used for driving an aeroplane, plane.
R
Rudder.
A plane or group of planes used to steer an aeroplane.
Strip beneath an aeroplane used for a skid.
S
Scale Model.
A miniature aeroplane exactly reproducing the proportions of an original.
A mast, strut, or brace.