If you haven't read my update in the other thread, you should check that out before reading any further



So I've got a Phoenix Super Decathlon with an OS 55AX. It's definitely not what I was expecting out of my inexperience in flying, but I'm starting to think the plane is underpowered.

I need full throttle to take off, and fly at over 3/4 throttle. I am able to land the plane at half throttle. I've tried a 13x5, 13x6, 12x6, and 12x8 prop, with the 13x6 being the best so far. I feel like I am flying just above stall speed at 7/8 throttle.

The plane is heavy. People have logged there's in at weighing 7lb and over. I've got as 12oz tank, painted the gear and struts, added about 18" of 1/2x1/4" balsa, and added 5/4 oz to the tail and 1/2oz to one wing tip, and the plane is balanced very well. I haven't had the chance to weigh the plane yet.

I feel that the plane is severely under powered. The recommendation is for a .46 to .51, but I don't know how the plane could fly with that size engine. My 55AX is brand new, so maybe I'll get some more power out of it down the road, but I'm not enjoying flying the plane at all (except when it's inverted - it flies GREAT upside down) Coming out of an Immelmann the plane will stall if not perfectly level, and turns are VERY wide regardless of the bank angle.

I think the plane needs more speed. The 12x6 was really loud as RPM's were getting up there, but it was still really lacking. The 13x6 is a bit slower, but has the ability to maintain altitude and pull itself around corners with the extra diameter.

I'm feeling that I will have to keep this plane flying with the current setup, but will be stripping the engine and gear over the winter for a .40-.50 pattern plane. I think this plane needs something like a .61 or even a .75 two stroke, or an .80-.90 four stroke. Could this really be? It seems like a lot since the plane is suggested to run with a .46-.51 two stroke or a .52 four stroke.

Please offer any suggestions or advice as it is a beautiful plane and I would love to have a bit more fun with it. Right now I am afraid to try any aerobatics as the plane seems to be flying so close to stall speed (weight?)