In the late 1960s when I received a Cox Sky
Copter free flight helicopter for Christmas, there was very little in the way of
commercially available flying model helicopters. It was modeled after the Bell 47−G,
which was later made famous by the M.A.S.H. television series. Victor Stanzel sold its tethered
ElectroMic "Copter" that
was powered by a pair of "D" cell batteries. As far as I know, Cox made the only
nitro fuel powered free flight helicopter, named "Sky Copter." It was powered by
a Cox .020 engine mounted to the top-center of the main rotor shaft, and caused
the rotors to turn due to the counter torque cause by the propeller on the .020.
It worked very well. After getting the engine started, you would give the rotors
a spin in the clockwise direction (looking down from the top), and the gently push
the model straight up. My guess is that most of the lift was provided by the engine's
propeller pushing air down, and that the spinning rotors served primarily to stabilize
the model during powered flight. Once the engine quit, the spinning rotors essentially
went into a counter-rotation mode to gently bring the Sky Copter back to terra firma.
As was the tradition, our family went to my grandparents' house for a big Christmas
dinner, and with the tradition came us kids whining about having to spend so much
time away from home with all our nifty Christmas presents there. We knew the presents
that would come at grandma's house would only be clothes and other practical things.
I took the Cox Sky Copter with me. Upon finally having the opportunity to give the
copter its maiden flight in her yard, I discovered batteries were not included for
use in the glow plug battery box. Turns out grandpa wasn't very diligent about keeping
fresh batteries on-hand. It took probably half an hour to finally get the Cox .020
engine started. After adjusting the engine for peak RPM (I had no concept of breaking
in an engine at the time), I gave the rotors a gently twirl and launcher her skyward.
It went up, and up, and up, nearly out of sight. I was in a panic. The engine finally
quit and she came safely back down, as advertised. After about another half hour
the engine was going again, and another perfect flight was logged. By that time
the snow had been falling at a pretty good rate, so my parents wisely decided to
pack us back into the old Rambler and head for home. I don't recall what happened
with the Cox Sky Copter after that. See the
newspaper edition from the Christmas I received the Cox Sky Copter.
This model is in like-new condition and does not appear to have ever been flown.
It still has the fuel bottle (empty), starting battery box (empty), and engine wrench.
It would probably fly today as it would have when fresh off the department store
Cox Sky Copter
Cox Sky Copter Box
Posted July 27, 2016