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Stabilator Trim Tab Setting for Takeoff

C

Catbird

Well Known Member
As first flight of N562E approaches within the next few weeks, I'm becoming more curious about the stabilator trim tab. I'll calibrate the trim tab in Skyview tonight along with setting the potentiometer to 27 seconds for full stroke, but haven't found any information specific to the trim tab setting for takeoff. The POH simply states, "Trim - SET for takeoff." The PAP seems to be silent on trim tab setting for takeoff.

Can anyone who has been flying his or her RV-12 provide some information on where the trim tab should be for takeoff? Should I just set it at the center of stroke go with it?
 
Do a search for 'trim setting' and follow Marty Santic's post #4. It should get you very close to what you need. This is for D180 but I think the Skyview should be same.
 
Hal-san said:
Do a search for 'trim setting' and follow Marty Santic's post #4. It should get you very close to what you need. This is for D180 but I think the Skyview should be same.
Click to expand...

Yes, for the D-180. Takeoff setting (Green line 1/3 the way down in the lower half of the bar. The lower half of the bar being that portion of the bar below its midpoint).

Ensure you followed the entire calibration procedure. And double check the indicator is moving the correct direction when commanding full up trim and full down trim. (If miswired, the indicator could move in the wrong direction). A mis-calibrated trim indicator was a contributing cause to a RV-12 mishap.
 
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It is better to have too much nose down trim rather than too much nose up trim on the first flight. And it is better to require a little more force to lift the nose wheel rather than to have the airplane jump into the sky unexpectedly and stall. That happened to one RV-12 on its first flight and resulted in a damaged airplane. After a few takeoffs, you will find the setting that is best for you.
It might be possible to takeoff and land no matter what the trim setting. But nobody wants to fight the controls, especially on the first flight. Error on the side of nose down.
Joe Gores
 
What is the trim position indication on G3X Touch to set for takeoff, in G3X Touch equiped RV-12 aircraft?
 
I have a D180. I just set mine at mid travel on the first flight and after several flights zeroed in on a slightly nose down trim as best suiting my technique. My recommendation would be to do this with your G3X and find the setting you like.
 
rjtjrt said:
What is the trim position indication on G3X Touch to set for takeoff, in G3X Touch equiped RV-12 aircraft?
Click to expand...

If you haven't done the trim calibration routine, do that first. It is very easy.

There is a small green tick mark on the trim indicator (lower left side of display). I have found that the trim needs to be set below the tick mark.

I usually take off with flaps fully retracted and the trim set so the point of the little triangle is a bit below the tick but the upper point of the triangle pointer is still above the center tick mark. I usually have to add down trim as I get to about 80 knots on climb out.

I'll take a picture and post it tonight.
 
Trim indicator set-up and takeoff position calibration for the RV-12 is covered by the PAP document.


In Section G1 - Systems Check of the PAP document. Line item 8 says...

Use the corresponding “Read me” file and set up your EFIS per the manufacturer’s instructions: http://www.vansaircraft.com/public/downloads.htm
This explains the process of downloading Van’s Aircraft factory settings for the RV-12, including TRIM take off and AP servo configuration, etc.

If you down load the appropriate presets file (whether you have Garmin or Dynon) from the support section of Van's web site into your EFIS, and then open the "read me" file that is part of that down load (you can also download the .pdf of the read-me as a separate document), it will take you step by step through the entire firmware loading and set-up process.

The reason it is done this way, is it avoids updating the PAP document every time Garmin or Dynon issues a firmware update. Instead any required changes induced by that update can be made in the read-me file that goes with the update.

I highly recommend builders use the provided PAP document for final inspection. Including following the step noted above of installing the presets file and then using the steps in the read-me file to finish all of the set-up and calibration.
 
G3X Picture

Here's a picture that shows my typical trim setting for a 0 degree flaps takeoff. I followed the trim calibration procedure in the PAP
This setting gives me excellent control during the takeoff roll and initial climb but a bit more down trim is required as speed increases during the climb.

IMG_0905.JPG
 
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