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RV 12 Trim tab

Allan Stern

Well Known Member
I have the Dynon Skyview system and am setting up the trim tab scale. When setting the tab to take off is the tab level with the stabilator in forward/take off position? On the scale where is the take off position? The center or somewhere else? Where is the info in the plans?

Thanks
 
Hi Allan,
All the -12?s that I know of, including mine, wind up with the takeoff position mark on the indicator somewhere below the center. There are some good threads on this forum that will help you set things up properly. Try searching on ?AST measurement? or similar.
Alex
 
Allan,

With the control stick in the full aft position, move the anti servo tab until it is approximately 1 7/8" higher than the stabilator .... measured from trailing edge to trailing edge. Then tell the SkyView this is the take off position. This should get you in the ballpark for a safe first flight.

This link is to a photo that was posted here by another poster.
https://2.bp.blogspot.com/-1FdMcom3UcY/V_e6sygnLfI/AAAAAAAAMbI/sKahPD-dmzozmo1Ezl7divfVueYdiYhhgCLcB/s1600/image_zps7a46c741.jpg
 
The trim takeoff position on the EFIS display is about 1/3 of full scale. It is better to error on the side of nose down trim. At least one RV-12 has crashed on first flight because of too much nose up trim. The plane jumped into the air, stalled, and hit the runway.
 
The trim takeoff position on the EFIS display is about 1/3 of full scale. It is better to error on the side of nose down trim. At least one RV-12 has crashed on first flight because of too much nose up trim. The plane jumped into the air, stalled, and hit the runway.
Wow.

I have inadvertently (checklists are a Good Thing) taken off with a good fist-full of UP trim still set from landing. It will get your attention, but is certainly nothing some forward pressure on the stick can't overcome.
 
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INTERESTING THOUGHTS - -

I actually like to take off with the takeoff trim set the same as landing. I just look to see the trim indicator is lined up and go. Yes, you need to trim down shortly after takeoff, but I guess you can get use to doing it either way huh ?
 
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If the RV-12 PAP (production acceptance procedure) document is utilized for final inspection, on the very first page it 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 use/load the appropriate downloads file it will automatically load the take-off position in the trim indicator. Then use the information in the downloads read-me file to confirm that all of the settings are correct (it includes photographs showing how to confirm proper travel using measurements, etc.
 
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