That's the reaction torque from the engine, not precession.
Brett
Ok, I'll re-visit the theory to make sure I've got this straight. Assuming we are talking about Torque Induced procession or Gyroscopic procession, not Classic or Torque-free procession: If the engine is spinning along in a clockwise direction, as seen looking from the back of the plane, when the plane is turned to the right (and here is where I’m adding the supposition that the GeeBee is in a tethered turn to the right in constant yaw in relation to the tow location of leadouts, towards the outside of the circle, not straight ahead as we ideally trim for) forces are applied to the structure of the plane forcing the front end of the plane down and the back end up. If the plane is turned to the left (towards the pilot, not very practical, heh) then the front end of the plane is forced up and the back end forced down. If the engine is spinning in the opposite direction then the reverse applies. If the reverse applies, and you trim for a lot of yaw, you get something that feels like up-thrust, and this could make our e-power bretheren very unhappy in level flight and perhaps why some complain of something that resembles a hunt?
Then taking it further, if the plane was moved without change of angle, by say a thermal, or whatever, directly upwards, downwards, forwards, or side-to-side the gyroscopic effect would not apply any extra forces, right? OK, But… what I’m thinking here, is if the engine only applies extra forces when the plane is moved at an angle (rotational turning left/right) then it also applies forces when the front/back of the plane is rotationally turned up/down via elevators.
Even though the shot of the GeeBee is in level flight, it was in a mild climb as it went by, (probably at 10ft elevation when I snapped the picture, and at 25ft as it went by me in the span of less than a 1/4 lap) and so this mild climb would create a procession to the outside of the circle in addition to the torque induced by the engine and perhaps result in the twist seen in the front end?
I know this is all pretty basic, and why a Rabe Rudder exists for outside turns, but all I was trying to show in the pic in a humorous way was that not only does it effect the flight path, but puts stresses on the airframe as well, that some might not have been aware of, and that maybe the distortion of the airframe could add other trim issues to deal with as well.
EricV