Turning

[_deltaV]

While doing some test flights the other day, after working out stalling issues I ran into a problem. After climbing and circling for a few turns, instead of circling the plane would begin to fly straight into the wall.
-the wings have wash-in and -out on the proper sides
-the tailboom is angled correctly to circle
-the vertical stabilizer is straight relative to the tail boom and vertical

Here's where the problem lies:
I believe the plane circles because the initial torque from the rubber is sufficient to overcome the plane's desire to circle right, but I can't seem to find why the plane circles to the right. Does anybody have any thoughts as to why this is happening?

[Chris_L]

Which way is the horizontal stabilizer tilted? You mentioned the tail boom but not the horizontal stabilizer so I just wanted a clarification?

[DoctaDave]

I believe this is how the circle is affected. In the initial high power portion of the flight, left thrust and torque will cause the model to turn. In the later portions the rudder and stab will be the main causes of turning. Angle the rudder and try tilting the stab some more. Also if you have no left thrust, your turn will suffer even in the later portions of the flight.

[bjt4888]

dfaris,

If you provide a more detailed description of your airplane structure and settings, we could give you very specific and helpful suggestions. Please include detail like: all dimensions and weights of the wing spars, stab spars, motor stick, tailboom and wingposts (if used); settings including: thrustline offset in degrees, amount of washin and washout on the wing panels in inches, stabilizer tilt in inches (stab tip relative to stab center), tailboom offset in inches, rudder offset (if any), stabilizer incidence in degrees, wing incidence in degrees, propeller type and pitch, etc. Include a description or a picture of your wingpost to motor stick attachment method (tissue tubes?). Additional info that could be helpful: weight of components (wing, stab, finished motor stick, tailboom, fin (if any), etc. What is the center of gravity location (distance from the trailing edge of the wing).

There are many possible issues that could be causing the flight pattern you are describing.

Brian T.
AMA member since 1968 (off and on)