First flight of new CAP

Today I finally got my Genesis CAP 232 in the air. Been real busy the
last couple of years with life and all, plus my other CAP been flying
fine. But, you can only have a plane lying around so long before it's got
to be finished.
So, I start it up, range test it on and off, GAS ZDZ 40, then do slow
speed taxi tests. So far so good. I decide to do a high speed taxi test
and it's here that I accidentally take off.
I'll have to double check my CG as the plane is very tail heavy, but I
thought I had it fine prior to flight. So at around 1/4 - 1/2 throttle
the she takes off very nose high, not enough field left to bring it down,
plus I'm already holding a lot of nose down. So I power up and get it up
high to try and trim this beast. It takes almost all the nosedown trim I
can put in, but finally I get it level, but it's very sensitive in regards
to the elevator. The good thing is that I've been flying a CAP for many
years now and so I fly it around for about 10 minutes to let my fingers
steady. I am curious as to what happens when I fly inverted so I try it,
it climbs rather well so I roll back level.
Landing was fun, when you reduce power it let the nose come up, so you had
to work with it, but I landed just fine. When I looked at my elevator
position you could see I had a large amount of trim in it to fly level, so
I moved my battery pack forward and tried again, but I couldn't move it
much, but I flew again. Better but still climbs inverted, so tonight I'll
remove the pack and remount it elsewhere to move the CG forwards. I
wouldn't have flown again if I didn't feel it was controllable, it was
just very touchy and required a light hand. The second takeoff was smooth
and behaved as expected, very pretty.
What amazed me though was how well this CAP flew, very clean and precise
in what little I tried. I didn't want to do anything involving stalls
with the CG so far back due to fears of unrecoverable attitudes. From how
it behaved I bet once I get the CG forward a bit more this will be one
sweet flying plane. It flew like it was on rails except for how it behave
to throttle and elevator, I was most impressed.
This reminded me the time when I tossed my Duraplane together after
many years of neglect to test a video cam system, didn't bother to check
the CG since it used to be right. When I pulled the power the nose went
to a 45 degree angle, but man, that plane actually did some respectable
aerobatics that it couldn't do before. Contrary to some, I found the high
wing loading fun, put another 2 lbs of camera equipment on it and it flies
like a real brick. It was fun for the challenge though. In retrospect,
the new battery pack I used was heavier than the original and I didn't
think about that until after.
I don't know how I mis-measured the CAP's CG yet, I'll look into it
tomorrow and see what I goofed up on. I did it like the manual said with
string, and then I put the scales under each wheel after making sure the
plane was level, did the math and it seemed close. The only mistake I
could have made was when I measured my main wheel position. Tomorrow I'll
reference it to the tip of the spinner against a wall so that I remove any
error of maybe the plane having moved and me not noticing it.
The scales bit is from full scale aviation, not the manual. It just gave
a position for the CG point. It come out to 12 lbs 7 oz. It could have
been lighter but I used lead to balance the tabs.
It's too bad Dani quit making this CAP, it's a very nice flying plane,
even with the CG so far back it responded well.
Reply to
Matthew P. Cummings
Loading thread data ...
I used lead to balance the tabs on a Giles 202 once and had a tail heavy problem. Moving the battery pack fixed it. When you calculate the location for the CG, remember the LE has a taper to it. That can make a big difference on your checking with string. Don't use the full scale trick with the math and weights at each wheel as the percentage of error in the distance might be enough to kill a Cap. Remember you don't have a perfect location for the center point of the wheel WHERE IT MEETS THE GROUND! That is probably the root of most of your problems. Rather calculate the distance back on Mean Aerodynamic Chord for the CG to be AND calculate the MAC. Measure the wing until you find the MAC and go from there.
Good luck
-- Jim Branaum AMA 1428
Six_O'clock_High Target
Reply to

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.