Built in the 1950’s as a small trailer-able Artillery spotter
with minimum maintenance, the “Hornet” utilized ramjet engines
to power the rotor blades. The ramjet engines have no moving
parts and develop their thrust from the expansion of the burning
fuel. Since the engines cannot power themselves to start the
rotor spinning, a hand-held two-horsepower drive unit is
attached to the right side of the cockpit that gets the rotor's
speed up to 150 rpm. The pilot then turns on the igniters, which
are small spark plugs in each engine, with a switch on the
control stick. At this point the fuel is slowly turned on and,
hopefully the fuel ignites to begin the process of allowing the
expansion of the gases to propel the engines to a faster comes
from a 45-gallon tank located under the pilot and It is pumped
through the rotor mast to the rotor blades where the centrifugal
force then drives the fuel out the blades to the ramjets. When
the rpm begins to increase, the starting unit is disengaged and,
by the addition of mo