The Zoomer Wrote:
>...the DF must tilt FIRST to accelerate. If the initiation of that tilt can be terminated, instantly, by sensors, back to level...there would be no acceleration.>

"...the DF must tilt FIRST to accelerate" sorry ... don't agree on this one.
The eqilibrium of the DF is feather touch sensitive and can be upset easily, like trying to balance a ball bearing on top of a pin.
Even if you could employ all of NASA's resources to come up with a tilt signaling device with an accuracy of a ten billionth of a degree tilt error, it still wouldn't give you a perfect hover.

The DF may BE perfectly level with no tilt whatsoever and it may still wander off in one direction or another. The eqilibrium imbalance could be caused by a single prop geometry difference or motor power difference .....and any number of electronic reasons also. So perfectly level doesn't mean perfect hover. It just means "perfectly level, but heading off slowly towards mums bloomers on the washing line"

Tilt sensors just tell you when you're in the ballpark. Any acceleration info that can be sensed after this will then tell you that your perfectly level status is not what's required to maintain a hover. So we'd better change it to an imperfect level if we want to save mum's bloomers.

It's annoying, the fact that the laws of physics dictate that gravity and acceleration are like Siamese twins.

Cheers ADI