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I always thought the Geebee Z was a beautifull plane, and since it is not
very common as a model (I don't like it when every other model-flyer has the
same plane, thats why I'll never design or build a Mustang), I thought it was
time I designed a plan for it.
Again I wanted to use my trusty OS-max 32 F-ABC engine, so after some
calculations i came to the following results:
Technical Specification:
Type:
Scale
Span:
1.26 m.
Wing area: 27.08 dm2
Length:
0.77 m.
Weight:
2450 g.
Wing loading: 90.5 g/dm2
Radio req.: 4-channel (elevator,
rudder, ailerons, throttle).
Engine:
.25 - .40 ci 2-stroke
     
After having covered the model, I spray-painted it in the
original colours. I decided that before I take all the trouble to minutely
detail it, I wanted to know if it flew.     
At
the field I checked the movement of the rudder, elevator and ailerons for the
third time, started the engine and tested it's capability to operate straight up
and immediately noticed that it generated more thrust than the plane weighed
(Very nice for vertical maneuvers).
So I set it down on the field, applied full power and took off.
And there it went straight and level and straight up and it kept going no matter
how much down or up elevator I put in.
So I reduced power and performed a controlled crash maneuver, where the Geebee Z
hit the deck hard, but luckily no damage whatsoever.
Not even the propeller was damaged.
A quick check taught me that the the cg was not at 4.5 cm. from the LE, but 13
cm.
So after moving the battery-pack from the back to the front, the cg was where it
was supposed to be and the next take-off was as it should have been the first
time, straight and level in a nice slow climb.
Even with "just" a OS-Max 32F ABC, the plane is very fast and it
responses very well to the large elevators.
I had to increase the aileron-throws to get a higher roll-rate (was approx.
180°/s, now is 360°/s).
The landing turned out to be quite a little adventure, even with idle power and
a very shallow dive, it just didn't seem to want to slow down and I used almost
150 m. of our 250 m. long flying field to get the Geebee Z to touch down at a
reasonable speed. All in all I am very pleased with the
performance of my Geebee Z, It's fast and maneuverable and attracts quite a
crowd at the field. |