I fly a 36# Ziroli Corsair. At times it exhibits a strong tendency for Dutch Roll.

All medium to large Corsairs that I've seen do the same thing. There doesn't look like much roll, just tail shimmy. Would a rate gyro on the rudder improve the situation or make it worse?

From : Don Stackhouse

The gyro would certainly help. What you describe is "dutch roll", which is the result of too much dihedral, not enough tail moment arm, and/or too much inertia about the yaw axis in particular.The Corsair does have the potential for all of these conditions. A gyro would act as a yaw damper and suppress at least some of this. I'd also recommend getting as much weight as possible out of the extremities, particularly the wingtips and the tail. For example, a lot of airplanes in that class use giant-scale sized servos mounted in the tail, which can easily add up to a half-pound or more of weight back there. Mounting them near the C/G and running carbon-tube pushrods back to the tail is a lot more work, but it saves a lot of inertia and could help your problem.

Of course as my business partner (who also flies giant-scale Corsairs) points out, this is a characteristic of all the giant-scale Corsairs he's seen, and some of the reports I've read suggest that it was characteristic to some extent of the full-scale Corsair as well. With that in mind, it's part of the plane's personality, and you might not want to remove it entirely. However, reducing it to a manageable level could certainly be a good move.

Do you like a particular brand and type of gyro?

Don Stackhouse
DJ Aerotech