opjose

The problem is not with the plane, but rather with the longer battery packs you tried.

The "standard" 1800-2200 sized battery puts the bulk of the mass too far backward to hit the recommended C.G. with ease.
It wasn't designed for that type of battery.

So the packs you used put the C.G. too far back of the recommended.

BTW: It DOES fly this way just fine as I've tried it.

However if you wish to get the C.G. right on the money, use smaller or thicker packs.

I've used 3S2P 2800mAh 11v 12C packs which not only fit perfectly but bring the C.G. forward more than the recommended.

Of note is that these were actually fairly inexpensive when I purchased them, because they use two 1400mAh packs in parallel in the same package.

I've used 1200 through 1800 packs that were a bit shorter than say 2100mAh packs, ( typically these are 15C or less in rating ) and these also bring the C.G. in line. NP sellls serveral that are perfect.

And of course you can also use a heavier motor.

There is nothing "wrong" with the plane per-se and there have been several reviews of it in it's various forms that like it a lot... a return is unwarranted IMHO as this is not a defect.

It's a great flyer when properly configured. See the other threads here about setting it up.

It is a good idea to alert anyone who purchases one that they need to be aware that to get the C.G. right, that they must choose the right components, that's all.... e.g. use the shorter battery packs.