trim

[shafs64]

Hi is it normal for the Savannah to run out of nose up trim in full flaps

[Blueadventures]

Hi may need to add the model and the asi that your at and wanting more nose up.  

 

Also I may be doing a fly Friday morning early, just need to confirm no work on.  Cheers

[shafs64]

it's 771 matts s model at full nose up trim you still need back pressure on the stick. just send us a text if you are going Friday.

[IBob]

Yep, that's entirely normal.

I have Mark Kyle's 3 position trim bracket. My trim tab swing was originally set by the book, I have now adjusted it to give more nose up. This now gives neutral trim at 33% flaps @ 50kts.

At 100% flaps I still get pronounced nose down trim. However, I am reluctant to adjust it further, as the full nose up trim for landing gives very strong nose up when taking off again (my routine for circuits is land, drop back to 33% flaps while trimming down as much as possible before taking off again).

[Kyle Communications]

I had my trim setup so that for level flight the indicator was the second top bar....you set the trim indicator where you want for level flight then adjust the antibalance tab position for level flight in that position. Then you get what you get. Always on full flap you (my indicator fully at the bottom) will need a good back pressure on my middle position of the flap lever then not so much and the first and most common position I used to use for general flying I basically needed no pressure on the stick

[IBob]

That's pretty much what I have too, Mark: my neutral trim for cruise is about 2 to 3 bars.

My instructor flies a VG, which originally had a smaller trim (not antibalance) tab. He converted it to the same tab as the S (full width on one side, but still trim, not antibalance), reckons it still pulls harder with full flaps than the S.

Some places (the UK?) seem to require tabs on both sides, so effectively twice the tab area. Presumably they are able to get closer to neutral trim at full flaps?

[shafs64]

Well that explains.

[facthunter]

A tab unloads the force on the Horiz stab ,Having it only on one side imposes a twisting force into the stabiliser and loads  the hinges. Nev

[IBob]

Yep, a more balanced arrangement would clearly be nicer. Having said that, apparently with tabs on both sides on the Savannah, there are 2 separate servos, which I think have to be synced prior to each flight by running them to nosedown limit.

[facthunter]

Or have a single servo with a linkage or cable to ensure symmetry. This is sometimes used with flaps for the same reason. Use care as exposed light  cable is easily damaged and a disconnect will guarantee flutter.   Nev