I took my new Xterminator out for a test flight yesterday evening (I found a
field with well packed snow that I could walk on)... First off I have to
say that it floats like a dandelion (and this was in VERY still air which
was giving me air times of ~12 seconds with my 11.5oz Zagi THL)... The
first throw, it glided out nicely but started trying to porpoise... I
brought it back to me and checked the CG... It was in the dead center of the
recommended CG. I added pushed the battery pack to the very front of the
nose (moving the CG forward about 1/8") and gave it another toss... it still
porpoised so I brought it back and added a couple of coins to the nose
(bringing the CG about 1/4" ahead of the recommended CG)... gave it another
toss and it flew fine (although wasn't as responsive as before.
I added the weight to the front to correct the porpoising, because in the
past when my planes have done this, everyone at the field said to just add
nose weight. I always end up with my CG's in front of the recommended CG's
because of the porpoising, but then I read about people flying with cg's
behind the recommend placement. This has made me wonder if moving the CG
forward is truly the correct correction for the porpoising. Is there
another correction for this porpoising tendency other than CG movement?
Thanks, Daniel
BTW: I only got to toss the Xterminator about 5 times b/c on the 5th time I
decided to give the launch preset a try, so I switched to the model memory
that I thought I had programmed with the latest launch preset setup... Gave
it a toss, saw the plane starting to loop backwards so I switch the preset
switch back in the opposite direction to which it responded by doing a nose
dive (despite giving it full up elevator... I could see that the elevator
was still showing down, so this was not a stall...) it hit the ground and
cracked the fuse in numerous places (I have since fixed it w/ about and hour
of work)... I assessed the damage and determined that it wasn't anything
major, then I tried to figure out what happened... I checked my mixing and
quickly realized that I had chosen the wrong model memory and that the
switch had been having no effect, but instead my throttle stick was in
control (I was apparently hitting the throttle stick in my paniced state
causing the down elevator input). ie: ALWAYS DOUBLE CHECK YOUR MODEL MEMORY
SELECTION!!! ;-) I'm going to try to give it another try this weekend if
the snow holds off.
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