KF iv- 1200 Classic trimming

[Iain Donnelly]

My Kitfox iv - 1200 Classic has the trimtab set into the right elevator, but isn’t very effective at the slow speed end, and with power of for glide approach I require a lot of back pressure on stick, I’ve extended the (electric) trim tab by about twenty percent which doesn’t make much difference, anybody got any ideas, would be appreciated.
Thanks
Iain d

[Ramos]

Not an authority. However, everything I have read suggests that the IV (and earlier) requires back pressure on the stick at approach speeds.

[Geowitz]

Look up "gap seal" and "vortex generators" (on the bottom of the horizontal stab) on this forum.



The gap seal will direct more flow over the elevator and the vortex generators under the stab help keep the air attached to the elevator too. You'll still need some stick pressure, but it should make the trim more effective as well as the elevator.

[jonstark]

There are larger elevators available for $500 uncovered.
I’m going to pass on them and deal with a little back pressure.
Coming in with some power at a higher deck angle is how I’m handling the marginal pitch authority experienced when flying power off slow and in the flare. Give the elevator some air to work with.

Jon

[Av8r3400]

You will not be able to trim away the stick pressure.

[jrthomas]

My Kitfox iv - 1200 Classic has the trimtab set into the right elevator, but isn’t very effective at the slow speed end, and with power of for glide approach I require a lot of back pressure on stick, I’ve extended the (electric) trim tab by about twenty percent which doesn’t make much difference, anybody got any ideas, would be appreciated.
Thanks
Iain d
It sounds like I have pretty much the same setup, a Kitfox 4/1200/912. I have the Ray Allen trim system with the trim tab built into the right elevator like you describe. I use full up trim with half flaps at idle on base and final and mine is very effective. I think gap seals are a must for the elevator to be fully effective. I installed VG's on the wings a few months ago but no VG's under the horizonal. I've never felt that I needed any more elevator. James Thomas

[Slyfox]

I have the same on my fox with the smaller elevator. I come in with no flaps and use full trim and there is basically no force on my stick. I never use flaps and can put her down and stop within 300ft easily.

[Iain Donnelly]

Hello all,
Thanks for your prompt helpfull response , I am working athe easiest job first and starting with gap sealing I’m going to use glider aeleron sealing tape, thanks again all.
Iain (Scotland)

[Slyfox]

just to help out with the tape. I used packaging tape clear, 2inch. what you do is stick to itself and leave 1/2 inch open on each end, that will be sticky. then you install by feeding a section you made between the hinges with the sticky on top first (installed on the horizontal) then raise the elevator all the way up and install on the elevator underside. then when all done I painted with a rattle can white. A good cheater here, cost real low and easy to do.

[Iain Donnelly]

I have sealed the tailplane to elevator gap , I can now trim back power off to fifty five knots.
Thanks everybody for all your interest and time.
Iain D