Complete weight of the machine without pilot, fuel or oil.
O
Ornithopter.
A machine supported and propelled by planes moving in imitation of birds; a flapping wing machine.
A flight maintained by flapping wings.
P
Plane.
A surface or wing, either plain or flexed, employed to support or control an aeroplane.
One directing an aeroplane in flight.
Theoretical distance covered by a propeller in making one revolution.