Trim Fo Take Off

[Brenton C]

After my last annual, my trim tab was moved. My mark for take off (made with a marker) is now decidedly "nose down."

I can still trim fine for all phases of flight. With 2 people on board anyway.

Can someone tell me what the trim tab configuration should be? Flat with the tail feathers, above or below?

[DeltaRomeo]

I'm not sure how to answer this as the take off is a dynamic process and one trim setting doesn't suit all phases. I fly largely trim neutral (centered), allowing maximum elevator availability. My CFI's liked to adjust it to provide assist while in the approach phase of landing. I never did because the amount of force it takes to manage the aircraft was not uncomfortable to me (I work hard, guys...), and I liked the idea of having more elevator available if wind gusts demanded it. I think of trim as a long term tool and adjust it mostly to fine tune cruise and ease pilot workload.

Another thing I do is carry some ballast. About 40 lbs in the cargo area (survival gear, tools, etc). What this does is balance the aircraft so that very little trim is required to keep the aircraft level and minimizes parasitic drag caused by a deeper set of the trim tab. In most aircraft designs the tail provides a down force in cruise flight; its why Rutan employed the canard wing to improve flight efficiency.

[Kirk]

With the indicator in neutral, the elevator trim tab should be flat with the elevator.

Is that what you were asking?

Kirk

P.S.
Degrees of travel are in the Type Certificate Data Sheet

[Brenton C]

Thanks for the input, Guys.

Yes, where the marking is placed for take off (and it's not a factory marking, but done by hand by a previous owner), about 2/3 of the way forward ( which worked for take off before), now this gives me a very nose down attitude. The trim tab is far from neutral with the trim control aligned to this marking.

So I'll just make a new marking corresponding to neutral trim.

Thanks for the reminder about avoiding drag, Dave. That's a great idea for flying "clean" with added weight in the rear cargo station. Doing this appeals to the obsessive part of me.