I was thinking mostly out of ground effect although I should have thought that most folks think of ballooning in the landing phase, I need a better title.

The balloon, nose up with speed increase, is there at any altitude. But coming into landing if the speed gets higher than a nicely trimmed landing speed (which indeed is a beginner's problem as Tom mentioned) the trainer airplane will trade the speed for a nose up attitude and potential problems.

I guess in that respect the trainer isn't a good trainer in the landing process.

At altitude it can save a potentially bad death dive caused by disorientation by zooming upward as the speed increases. I know the effect has saved my airplane many times in the good old days (I learned to fly on my own, not a really good approach).

Ken - I think our pitch damping is fairly high in most of the airplanes we fly. Our horizontals are large and we do have a reasonably high static margin. The ballooning is mostly a dCm/dVelocity effect.

Certainly when in the ground effect there can be some effects. One of the interesting tests we did on our airplanes at McDonnell Douglas (before Boeing) was the slow speed ground-effect testing. They would insert a "board" and them take data. There is a variation in downwash and lift due to wing-board interaction and lift on the tail due to downwash and tail-board interaction.

If you come in at a good (+ or -) landing attitude the overall effect with a trainer configuration would seem to be that the tail, regardless of whether lifting up or down, would get an incremental up load due to ground cushion effect. It would stop the ballooning very close to ground (maybe).