inertia coupling
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inertia coupling


When aircraft is rolled in a pull-up maneuver, it acts as a gyroscope and yaws to the right while rolling to the right. Higher the rate of roll, higher is the rate of yaw. As it passes through 90 degree bank angle, the yawing action dominates the directional stability. As the aircraft becomes inverted, the longitudinal stability of the tailplane becomes dominant in pitching moment. Once aircraft is rolled through 270 degrees, the pitching moment is translated into yawing moment. At this moment, yaw divergence may take place if the aircraft does not have sufficient directional stability.
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