I wouldn't recommend trying any aerobatics on a glider that wasn't built strong enough (wing and fuselage) to handle the G forces of a steep dive or loop (which can be the result of an aborted roll). Given this warning, there are many polyhedral/rudder/elevator gliders capable of rolling. I've seen a few floaters where flying inverted (from a half roll) was used to lose altitude, but these could be rolled fairly quickly (a bit risky since some of these floaters could not handle steep dives). With a polyhedral setup, your rudder is used as an aileron, due to the yaw/roll coupling with polyhedral (or large dihedral) wings. (The yaw aspect of the rudder is basically ignored on a polyhedral glider). Yaw/roll coupling explanation: If you hold your polyhedral (right side up) so that a cross wind blows sideways across the wings, you note that the wind blows under the up-wind wing (pushing it upwards), and over the down wind wing (pushing it downwards), creating a rolling force on the glider. Applying the rudder causes the glider to "yaw" the fuselage, so that the glider is flying slightly "sideways", and the result is that some of the air flow is now "sideways" with respect to the wings. With a polyhedral setup, this "sideways" component of air flow causes the same rolling reaction I just described. When used as an "aileron" (polyhedral setup), the sense of the rudder remains the same whether inverted or right side up. With normal or up elevator, the result is a "skid" (excessive or proverse yaw); and with down elevator (inverted flight), the result is a adverse yaw (or a very sick "slip", the yaw is in the wrong direction. For example, the glider is banked "right", but down elevator causes it to go "left", and the tail is pointed into the turn (severe slip), instead of out from the turn (skid)). RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
