There is nothing wrong with doing negative G aerobatics with a gravity fuel
system or float type carb. The engine quits as soon as you go negative and
starts as soon as you go positive. I did them for years in my modified
Startduster. Most pilots mistake getting light in the seat for negative Gs.
If you really want to experiment, see how long it takes for the oil pressure to
bleed down to -0- while inverted with the engine windmilling. Having said
that, I have never turned my KR upside down. I have terribly bad habits from
doing aerobatics in a draggy biplane.
Regarding the stability of the various tails and wings. Since my -2S was
started before the release of the -2S plans, it has the smaller stock KR-2 tail
married to a 14" stretched fuselage. There are two issues at work here that
tend to get mixed together and called stability. One is the actual stability
of the plane. The second is the sensitivity of the elevator controls.
I would term my KR as reasonably stabile since in smooth air, I can fly 30
minutes or so at a time with my hands off the stick. If I bump the stick to
upset it, the plane will return to it's original speed and very close to it's
original altitude. I attribute that quality to keeping my CG well forward in
the CG range.
However, as others that have flown with me can attest, the elevator is very
touchy. That goes back to the argument as to whether it feels like a little
fighter and you get used to it, or that you're not a real KR pilot if you don't
like the touchy elevator. In my opinion, the more horizontal stab you add to
the plane, the less touchy it will be. After 8 years and 500+ hours in my KR,
I think I have enough time in the plane to declare myself an official KR pilot,
but I can't help but think that the plane would be safer for me or the next
owner if I add some horizontal stab to the plane to reduce the pitch
sensitivity.
-Jeff Scott
