Test flew my Kougar the other day and man does it fly nice right side up. Rolls nice and smooth, PLENTY of power (Rossi 60) and unbelieveable verticle.

The only problem I have found so far is wen I go to fly inverted it starts DROPPING. Not sure what the final weight of the plane is but I can def say it is not a light plane. Any help regarding this would be grate.. Thank you

The most usual reason for this is that the CG is too far forward.

It could be a wing incidence problem - do you have much elevator trim set to fly s&l? Also, check it in a vertical power off dive, if it pulls to the canopy there is too much incidence.

Assuming that this is ok it is a case of trying to shift backwards as much weight as you can, batteries etc. Once that is done if it still drops its nose inverted all you can do is add weight to the tail.

Best of luck.

James

Wing incidence, balance and thrust all play a factor in this. Start by double checking your CG (You do NOT want to get a Kougar tail heavy!) and then check your wing incidence. Make sure you don't have a ridiculous amount of positive. Lastly if you've checked everything else, do a thrust line check.

A Kougar needs a good bit of down elevator inverted, but not an excessive amount. It doesn't like to slow down though.

Have fun,
-Mike

Just a note about the Kougar: that's a tip stalling sob. Don't get that CG too far back or it'll snap over hard on T/O and landing, usually just a few feet off the ground where you have no chance of recovery. Don't ask me how I know this (twice).

-Mike

I noticed the tip stall on the first landing that i did. It was about 5 feet up... Lucky for me I saw it coming and was not suprised as I did have it flying a little to slow. Little bit of power and aileron and it came out good. I do think my CG is a bit far forward. It balances just a hair back at the wing tip. I will add tail weight little by little.

How do I check the thrust line check?

A few ways will work. A "coarse" check would be to trim for level flight at full throttle, and then chop the throttle to idle in s&l. If the plane zooms on a bit and then starts to gently drop it is ok. If it tucks down in a dive you need more down thrust. If it tries to climb slightly before the speed drops off you have too much.

To fine tune the thrust line you need to make sure the wing incidence is correct - first do a power off dive and make sure that the model drops vertically hands-off without pulling out or tucking in (corrections as in my post above). If it does this ok then do a full power vertical climb. It should go vertically up hands-off without pulling onto its back (not enough down thrust) or pushing down (too much down thrust).

Trimming is difficult in that changing one thing almost always affects the way the plane responds to another thing. It's an iterative process, with the "error" getting less (hopefully) with every iteration through the process.

There is an excellent trimming chart around, can't remember what the link is but I am sure someone more organised than me can supply it . It gives all of the methods above, plus checks on dihedral, side thrust etc.

If the model already tip stalls on landings then be careful pushing the cg back, do it a bit at a time. It does sound a bit heavy but that doesn't mean you won't be able to get it flying better with a bit of trimming.

best of luck and have fun doing it!

regards,

James

The recommended cg is 1/2" back from le, measured at the wingtip. I fly mine 1.5" back, very little change (flying inverted) from 1.2" cg setting. I suspect it has to do with wing incidence (engine thrust is at 0,0 and flies fine upright), maybe even that built-in washout at the wingtip.

Its a fun little sport plane. It is heavy though, and tough as nails. I have never tip stalled this plane (unless it was on purpose), not sure why you guys are having such issues.

Go to the NSRCA website for a good trimming chart.

http://www.nsrca.org/trimA.htm

Wildloose,

The start of the tip stall on landing was my own fault. I did not do any HIGH slow speed test and was taking it way to slow to start. Just a leason learned to test the slow and high speed charactoristic of the plane a little higher next time. Here is a pic of my baby.