Sky Star Series 7 Builders Manual

[Dave S]

Alex,

There have been a few variations of trim mechanisms on the kitfox. The early S7s came with a manually controlled trim tab on the elevators; and, no jackscrew - in place of the jackscrew, there is a tube with rod ends used to rig, not trim the HS. The S5s had the jackscrew, and, since John M picked up the company they went back to the jackscrew on the S7s which John M explained to me was to provide a bit of additional elevator authority because the solid elevator resulted in a little less blanking out of the airflow compared to the trim tab version. The manual trim tab vs electric jackscrew is an either or - not both.

The manual trim tab has a couple advantages, IMHO, even if not in anyone elses Humble Opinion: 1) no electrical stuff to crap out, 2) Instantaneous trim change - a person can throw full up to full down or back in the blink of an eye with the drag adjustable lever. Folks with a back country mission trying to eke out the last bit can probably benefit from the jackscrew system. In my case, I elected to keep the manual trim tab system and have done just fine with fields of 800 feet, in spite of the fact that I had to donate the first 250 feet to the tall corn at the threshold.

FWIW - I have the trim assist kit which Kitfox sells; and, from what I have observed, it functions the same on both the jackscrew and manual trim tab versions. A useful addition.

[alexM]

Alex,

There have been a few variations of trim mechanisms on the kitfox. The early S7s came with a manually controlled trim tab on the elevators; and, no jackscrew - in place of the jackscrew, there is a tube with rod ends used to rig, not trim the HS. The S5s had the jackscrew, and, since John M picked up the company they went back to the jackscrew on the S7s which John M explained to me was to provide a bit of additional elevator authority because the solid elevator resulted in a little less blanking out of the airflow compared to the trim tab version. The manual trim tab vs electric jackscrew is an either or - not both.

The manual trim tab has a couple advantages, IMHO, even if not in anyone elses Humble Opinion: 1) no electrical stuff to crap out, 2) Instantaneous trim change - a person can throw full up to full down or back in the blink of an eye with the drag adjustable lever. Folks with a back country mission trying to eke out the last bit can probably benefit from the jackscrew system. In my case, I elected to keep the manual trim tab system and have done just fine with fields of 800 feet, in spite of the fact that I had to donate the first 250 feet to the tall corn at the threshold.

FWIW - I have the trim assist kit which Kitfox sells; and, from what I have observed, it functions the same on both the jackscrew and manual trim tab versions. A useful addition.

Good input Dave, thanks. I'm a big fan of manual trim myself. I'm also a fan of the horizontal stab doing the trim instead of a tab. My Citaria cruised with significant down elevator (normal because they're just overpowered Champs). A moving stab would be less induced drag.