Propeller Thrust Important.
There is one great principle in flying machine
propulsion
which must not be overlooked. No matter how
powerful the engine may be unless the propeller thrust
more than overcomes the wind pressure there can be
no progress forward. Should the force of this propeller
thrust and that of the wind pressure be equal the result
is obvious. The machine is at a stand-still so far
as forward progress is concerned and is deprived of the
essential advancing movement.
Speed not only furnishes sustentation for the
airship,
but adds to the stability of the machine. An aeroplane
which may be jerky and uncertain in its movements, so
far as equilibrium is concerned, when moving at a slow
gait, will readily maintain an even keel when the speed
is increased.
