It's been a while since I posted to this...

My four star has been lots of fun until two weeks ago. The tucking with rudder has been reduced, although I have not tried a slip lately.

It did have some glitches, including a tendency to severely balloon when pulling out of a loop. I was playing with the CG to try and correct this.

Two weeks ago, I ran into a snag in my redesigned built-up hstab. Turns out, it wasn't strong enough. I was coming out of a split S and half the hstab ripped off. Fortunately, it was the side without the control horn, and I pulled it to the fastest, smoothest landing I've ever done. My plane was flying at least 2x my normal landing speed, and I greased it in!

I repaired this and a week later (last Saturday) I took it out with a stronger hstab. I took off, came around a couple times, then realized I was hearing vibration and flutter. I come in, and it is flying fast. Waiting for the flare, I'm thinking one more second, one more second. I pull back for the flare, and nothing. No flare, nothing. Smack, the plane slams into the ground. I see the mains rip off (common on a four star), then I see the tail separate. It ripped the light ply apart.

After bringing the plane back in, I was talking to others at the field, and they said it looked tail heavy.

So, I finished the repairs, rebalanced the plane, which required the battery to move up 6 inches.

I flew yesterday. The plane now tends to buck over as the speed increases on the ground. Okay, I can deal with that. The plane seems faster in the air. Okay, I can deal with that. Wait. What's that? I hear vibration. Ugh. Time to bring it in.

I start thinking, OK I'll float it in like I used to. The thing starts falling out of the air. That's interesting, it didn't do that before. So I bring it around, keep some power on it, and fly it to the ground. Ugly landing, but everything is still intact. I taxi it back to me and notice the vibration still occurs on the ground, so I don't shut it down. I then go through some tests, and note that the vibration occurs at 1/3 to 1/2 throttle, but not at idle, nor at full throttle.

I hold all of the control surfaces to see if that is the issue. Nope. No flutter. Something else is causing it. (BTW, I have a different thread discussing this issue.) After playing around a bit more I decide to fly it again, as it appears that the vibration is engine related, and I want to fly. Takeoff was the same, tends to nose over. Liftoff was fine, bring it around to land, and I now need about 1/8 throttle to keep it in the air, which I like. Not time to do touch and goes, as I need to catch my breath after every landing. Land, taxi, then decide to go home.