i have a great plans 300 0.60 extra i have a problem when i do a loop it snap's to the left the plane is balanced bef & aft but i did not do lat. could this be the reason i've been told there's to much elv & the plane is to heavy.


need help please:

thanks

Have you tried it while holding less elevator?
That's a valid reason, and would be the simplest to check.


It could be too heavy, but since you aren't complaining about other
flight characteristics, or landings, we'll skip that for now.

You can check the lateral balance, of course. Better to be balanced than not.

But sight unseen, I'd probably guess 'too much elevator' too.

Reduce your elevator throw. Most aerobatic planes will snap with suffecient airspeed and elevator throw. My Giles will snap at full throttle when the throw is above 5/8 inch up or 3/4 inch down.

Well i can't check it anymore the same thing happened on a landing came in to fast the plane jumped down a little pulled back on the ele. and it snaped to the left and down she went.
i'am in the process of fixing it now and i don't want this to happen again. :cry:

thanks for the info

Aerobatic planes are designed to snap roll smartly. They must be flown with plenty of stall margin (speed) through loops and landing approaches. A cure to unwanted snaprolls (tip stalls) on landing approches is to equip the model with inboard flaps. When the flaps are deployed they produce tip stall fighting washout.

Decrease your elevator throw to 3/8 inch. Your problem will go away!

got the plane back up saturday and i set the low rate at 3/8 and 3/4 hi rate on the ele it was fine on low but snap out on hi

thanks for the help guys

Nature of the beast.... pretty much all aerobativ planes will snap with too much elevator. My Tip is to setup your low rates on your elevator so that the throw is low enough that even if you panic and pull full elevator it won't snap. Use your high rates when you're 3Ding the plane and remember to switch back to low rates when you build up speed.

Ollie,
Are you saying that inboard flaps will decrease the possibility of a tip stall, as opposed to flapperons?

Minn Flier,
When inboard flaps are lowered two things change. The camber of the airfoil increases at the flap which makes the zero lift angle of attack more negative and the chord line from the lead leading edge to the trailing edge changes along the wing at the flap in relationship to the chord line along the wing from the flap to the wing tip. The camber change causes aerodynamic washout and the chord line change causes geometric washin of the root which is equivalent to washout of the tip. The combined effect is so strong that the center of the wing must stall before the tip. Because the average decalage is greatly increase too, lots of down elevator must be applied symultaneously to prevent ballooning. With a computer radio it is wise to mix down flap to down elevator so that the pitch compensation is automatic.

My GP Extra .40 will snap when pulling too much elevator. Unfortunately, that means I have to fly the plane fast and with big maneuvers. To my eyes, the plane flies like it's two pounds too heavy even though it only weighs 6 pounds per specifications.

On the other hand, my CG Sukhoi will fly very tight maneuvers and never falters. It's very easy to land and gives you plenty of confidence to wring it out. I can do double snap rolls all day. I think the key is wing loading. I would wager that most .40 and some .60 size scale aerobatic planes are 30% too heavy.

If you're saying go with a REALLY low throw on the elevator, like the 3/8" I saw mentioned, I believe you are on target. I just sold a small .61 powered CAP 232 and the throws were tiny.

But the plane performed everything beautifully. With some thrust line adjustment and good balance it was a very neutral, good flying plane. It just couldnt do that "in front of your face" fun fly stuff so many people are trying now.

Cheech,
Something else I have seen but would NOT recommend is go with full 3D rate and 90% expo. I have seen a guy fly like this but to me, you can never get excited!

Agreed, Geistware. I have gotten to where I like the expo on high rate to be around 50%, but I don't really like any on low rate. At least on aerobats and fun flys this works good for me.

That little CAP I mentioned could still snap out of even that tiny low rate elevator if you stuck it to fast. That's the nature of the plane I guess. Fly it smoothly and with some speed and bad things don't happen.

Hi Guys,

I had (past tense, it met its demise due to dumb thumbs) a plane called The Flying Machine, very fast .45 size bird. With about 3/4 inch of elevator throw, if you pulled full up while straight and level at high speed, this thing would do the wildest manuever imaginable, I don't even know what to call it, but I guess it was something like a snap. So yes excessive elevator throw will cause a snap.

Jerry