This may be the wrong forum, but can anyone help me get a flat spin? I've got a Venus 40, and just can't seem to get the darn thing to do it. I've tried it right side up, and inverted. Any tips???

Well for starters if it's nose heavy it won't.

Folks around here enter a standard spin, and while holding full elevator and rudder in the original direction of the spin, add full opposite aileron. That tends to flatten the spin, but only if the CG is right.
HTH
Tom

See the thread at http://www.rcuniverse.com/forum/Flat...1695580/tm.htm

scoli121, not a great plane to try and do FLAT spins with, normal spins yes. To get a flat spin with this plane you are going to have to set the rates up real high on elevator and rudder and move the CG back. After doing all this I'm still not sure if it will go flat. If you do this don't expect it to perform good in its intended role as a 40 size pattern trainer and I feel knife edge will pick up so much coupling that it should be a bear to fly.

Ed M.

You can put the opposite aileron in too fast and ms the correct amount to flat spin some aircraft... Take it VERY HIGH, enter the spin and SLOWLY change to opposite aileron. When it flattens, don't add more opposite aileron or you can pop it out into an opposing direction spin or spiral.

As you gain skill in doing the flat spin you will increase the rate that you put in the aileron... and you will eventually learn how to put in the correct amount right as the aircraft initiates the stall and wing drop to be in the flat spin in less than 1/4 rotation of normal spin. (looks like it just goes directly to the flat spin)

You can flaten any spin... just if the plane is too nose-heavy, it never flattens well. Trainers rarely have both wings stalled so they pop out of the spin when you flatten it.

Wow, lots of good places to start. Thanks guys. I haven't moved my CG back yet, but I guess I should start there.

Many moons ago, I had a Venus 40... yes it is hard to get it to truly flat-spin correctly, as far as knife-edges go, It performed it pretty well with over 2" of throw, pull-pull cable, and a 106-oz torque servo. Also it did require a whole lot of rudder-elevator coupling to get it to knife-edge straight. Mine tended to fly towards the belly. Before I put the coupling in, I could perform a big circle in knife-edge flight. But that wasn't the intended flight characteristics I was looking for. Anyways, that's about all I've got to say about that. Have fun with your's and don't do like I did... Side-slip, think your going to run into the high grass, full throttle while still in side-slip flight. The end result is an amazing snap-roll into the lawn upside down. [:'(]

There are three things that tend to flatten the spin. Number one is the increased drag on the inside wing when you apply opposite aileron... this makes it spin faster, which in turn makes it spin flatter. Number two is gyroscopic reaction forces from the prop, in an upright spin to the left adding power will help flatten the spin. And the third is actually down elevator in an upright flat spin... once you have it pretty flat with opposite aileron and power pushing down elevator stalls the tail and blocks some of the rudder... the result is that the nose actually rises rather then falling with the application of the down elevator. To recover power off, ailerons neutral, opposite rudder, neutral elevator.... if that doesn't work add power while holding opposite rudder and full down elevator. I've had at least two models spin to the ground doing flat spins, sometimes you just don't have enough rudder to recover if the cg is too far aft.

Ty

Had two Chipmunks, one 25 size the other 60 size. Both would flatspin to the ground and nothing helped except maybe to tighten the spin. Must be something in the design too. I have a spad SPA3D that will, if you pull ut up into a good solid stall will go into a real slow decent flatspin only with the rudder, no other controls. Will pull out as soon as you let go of the rudder. To many design parameters i'm thinking.