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Old Aug 26, 2013, 11:26 AM
"Get off the runway!"
Da Big_G's Avatar
United States, TX, Hutto
Joined May 2012
544 Posts
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Trimming planes

Trimming my Airoso. Looking for backup on my procedure....making sure I have the order right. The problem is my power off down lines the plane pulls slightly to the canopy. Also climbs a bit on full throttle and dives slightly inverted. I will start adding weight to the tail until inverted flight is almost hands off. Then if it still pulls a little to the canopy add a little up-thrust to the motor. Do I have this right?
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Old Aug 26, 2013, 12:50 PM
Registered User
Northern CA
Joined Feb 2005
111 Posts
Take a look at your elevator position after you've trimmed the plane for hands-off level flight. If it's too nose heavy, it'll likely be carrying some up trim.
Adding up thrust may help, as you'll have to feed a little down trim to keep level flight. The down trim will help the power-off down lines.
I would add a bit of weight to the tail first. You could also reduce the wing incidence, but you definitely want to get the C.G. where you want it first.
The trouble with trimming is that each little change will affect many other things, it's easy to start chasing your tail (or the planes)
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Old Aug 26, 2013, 06:38 PM
KE your cub.
Curare's Avatar
in the gutter, again....
Joined Jun 2005
4,126 Posts
I don't necessarily agree with that, but then again trimming is an interesting thing, some say one thing, others say another.

First things first, I don't trim for straight and level flight, for the simple reason that I'm rarely in that position for long, and trimming for that means that every other position is affected by that trim setting.

I set mine for 'zero G' flight. That is: straight down. I trim the plane until it flies exactly vertical, no push, no pull. I then turn around and fly straight up, if the plane pulls to the canopy, add upthrust, and if it pushes to the belly, add downthrust.

After that you'll find that you need to fly holding the nose up, either upright, inverted, or knife edge or a combination of two. How much you have to pull is determined by your cg, the more forward it is, the more you'll be hanging on the up stick. As for determining the correct cg, that's a matter of taste and to a certain extent spin entry, and knife edge flight.

For a slightyl different approach, try using the trimming chart from Peter Goldsmith, it's the bible for most guys wanting to start trimming their planes out.

Here's the link to it.

http://www.flyinggiants.com/forums/s...ad.php?t=32733
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Old Aug 26, 2013, 07:26 PM
"Get off the runway!"
Da Big_G's Avatar
United States, TX, Hutto
Joined May 2012
544 Posts
Thanks guys...I've seen those charts. Looks like I'm on the right track. Can't wait until Saturday comes to do the final trimming.
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Old Aug 26, 2013, 11:07 PM
KE your cub.
Curare's Avatar
in the gutter, again....
Joined Jun 2005
4,126 Posts
Hehe, in pattern it seems you stop trimming the aicraft when you total it.

Even after hundreds of flights, I still end up tweaking my planes, a little at a time, then go too far, mess it all up, and start right back where I began knowing that wasn't the way to do it LOL!
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