otrcman

Reply to Burkhard Post #50, Off Topic.

Yes, a gyro works very well in yaw for a taildragger. My first experiment with a yaw rate gyro (mechanical gyro back in the 1980's) was to see if the gyro might help with spiral stability. Turned out that the yaw rate in the spiral mode was so slow that the gyro didn't sense the movement. But it sure did help with directional control on takeoff ! This gyro was a yaw damper only, with no heading hold. But it made takeoffs amazingly easy. I left the gyro in place for it's takeoff improvement and found that I had soon grown so lax that I could hardly manage if the gyro were turned off.

I have since adopted yaw rate gyros for most of my taildragger models. For the people who say that the gyro is a crutch, I say rubbish. The inertia of a model airplane is so much lower than a full scale that the divergence rate in a ground loop is far greater than on full scale. The rapid divergence of a model, plus the inability of the pilot to see or feel the initial stages of a ground loop, makes the model most unrealistic compared to full scale.

When we consider the feedback loop between airplane and pilot, the model is quite different from full scale. In full scale, we are flying primarily by attitude reference and accelerations. In a model, we are flying primarily by flight path direction. Two very different feedback schemes. Flight path is the integrated result of changes in attitude and acceleration, so the model pilot is always in a delay loop. Ever see a model pilot standing directly behind his model for takeoff? He is instinctively trying to see yaw angle changes so he can quicken his responses.

Especially in a fast model, the pilot is basically flying a projectile.