Flyboywbl

i told the guy who flew it the response about the air speed and this is what he said back.
Matt,

I think the engine had sufficient power and we had plenty of airspeed (except for the turn where it stalled and fell out of the turn). After that stall, I kept more airspeed than I thought the plane needed and did a very "hot" landing. I was actually adding down elevator to level the plane and get airspeed, but we weren't up in the air long enough to "trim" it out so I couldn't say for certain if it was an "off trim" down or if down trim was required to fly level. It was stable enough that we probably should have taken it higher and played with it a little to evaluate the balance and trim. Since it was a first flight I felt we needed to bring it down and look for problems first. With a 4-stroke a higher pitch prop would probably be better since they turn at lower RPM, so I would recommend the 14/8. I have a tach that we can use to check the RPM.

It is possible that the plane is nose heavy vs tail heavy - either condition can cause instability, however since I was adding down elevator to get it level it seemed to me like it was tail heavy. Planes that are nose heavy are generally more forgiving than tail heavy ones. If your directions are the same as mine, I would move the CG back to spec and try again. We might have my son, Ron, fly it and give his opinion, he likes to balance his planes tail heavy to get "snapper" maneuvers and is therefore used to flying planes that are less stable.

Their "steep dive" maneuver assumes the plane has been trimmed for straight and level flight. If normal trim requires down elevator (to hold up a heavy tail) then an increase in speed will cause the nose to drop due to the down trim. Conversely up trim will cause the nose to rise with increase in speed.

In short - we weren't "wallowing around" at stall speed so I still think it is a "balance/trim" problem.

Chuck

what do you guys think could this be true?
-matt