Seagul Edge 540 59"
 

I bought this model a couple of years ago and have recently commissioned it and wonder if any one has observations about the CG.

I balanced at the wingtips per instructions and a fair amount of up trim is required, perhaps 3/32". It is fairly sensitive on elevator but certainly not hyper sensitive. Last, it has a rather strange issue that when slowing, it actually reaches a point that it balloons. The ballooning is not a product of prop blast as it does it when it reaches a certain point in the off powered glide slope. It seems to me that the ballooning might be the up trimmed elevator gaining increased leverage as the plane slows.

Any experience with this plane?

With no suggestions, I ran the numbers on the aircraft CG calculator, which offer a 3" from LE CG for 15% static margin, 3.5" for 10% and 4" for 5%. Instructions call for 3.75" and I'm currently at 3 5/8" so, I'm thinking that the tail plane is settling with loss of stabilizer grip at slower speeds and causing the ballooning and will move the CG forward a bit to see if that stops it and desensitizes the elevator a bit.

That's pretty typical of a few of my planes. They'll slow to the point the tail is no longer providing enough lift to carry the back of the plane, so it starts settling. Will literally stop in mid air (usually without dropping a wing) if you don't give it a little bump of down as it slows to this point. The fact you still have "up" trim on it though, that's puzzling. When mine are like this, they've generally had CG trimmed for a flat elevator.

Haven't got this far with the Phoenix Edge yet. It's still flying on suggested (way forward of tube/spar). -Al

Hey Al..... The battery got pulled from behind the servo tray and moved forward of it, which moved the CG to about 3 1/4" or 3/8 further forward for test. I've experienced tail heavy before of course and the problems with wanting to fly till it stops in air... but frankly, I've never seen quite the issue like this one presented where the landing slope is perfect with hands off the elevator and then all of a sudden, it balloons and not just a little bit.