Elevator Trim Tab Position for Takeoff?

Helping a buddy with the initial SkyView setup for Elevator Trim indicator gauge prior to first flight on the RV-14A.

Any flying RV-14A pilots out there that can tell me where your Elevator Trim tab is for takeoff?

Thanks for your help.

This is what phase I testing is all about. Start out with neutral trim, and adjust from there.
My RV-6 without flaps requires the tab to be about 1/4" up (nose down trim). With one notch of flaps (13 degrees) neutral trim is just right.

Garmin G3X trim setting

I'm using the Garmin G3X EFIS and my trim tab on take off is, in a scale of 10, its position is at 8 towards nose down. In other words very close to nose down. It will be interesting to see the position in other flying aircraft.

Aussieflyer said:

I'm using the Garmin G3X EFIS and my trim tab on take off is, in a scale of 10, its position is at 8 towards nose down. In other words very close to nose down. It will be interesting to see the position in other flying aircraft.

Click to expand...

I would say mine is very similar.

We start with neutral trim and then adjust for nose up at liftoff. We use the same procedure with 10 degrees of flap as well as 0 flap.

The larger certified airplanes set their trim so as to be in trim for the climb speed. It usually varies with weight and CG. I guess the RV 6's CG doesn't change that much with weight, not like a 4 or 8. But if you put a bunch of baggage in the back and move it aft, the required tab position to trim at a given speed will be different. So what the bigger airplanes do is define a "green band", which is a range of trim setting for forward to aft CG, such that if you are set anywhere in the green band for takeoff the forces required to trim will be small. So that is usually the range between heavy weight forward CG and light weight aft CG. And it will change with flap as well. We are required to demonstrate that if you have the trim set for heavy forward (nose-up trim) and you are actually at light-aft, the resulting forces are not too bad. They call this test "mis-trimmed takeoff. This often defines the width of green band.

I know this stuff is all FAR25 (transport category airplanes) and there is no legal requirement that homebuilts conform, but these principles have been developed over 100 yrs and they work well. Somebody figured out a long time ago that 1.3Vs was a good speed for approach, and that works for homebuilts too - deviating significantly from this is probably not a great idea. And that there were certain things you should do and should not do in terms of cockpit design and human factors. All those lessons are written in blood - they mostly came out of the knowledge gained from accidents. Making your cockpit work differently than most other airplanes is probably asking for trouble. So these requirements provide very sound guidelines for setting up one's airplane in many areas IMHO.

I have the Ray Allen bar graph displays and I think that's 10 bars if I remember right. I find that I'm in the 2nd bar from the bottom on takeoff in the RV-14. On landing I'm usually somewhere in the top half of the range, maybe 3/4 nose up trim.