A mathematical model is developed to study the shimmy oscillations of aircraft nose landing gear with a dual-wheel co-rotation configuration. This model incorporates the dynamics of the torsional and lateral mode and the non-linear kinematics of the tire. The procedure of different types of shimmy bifurcation analysis is described in detail. The effect of the co-rotation configuration on shimmy oscillation is compared with non-co-rotation wheels. More specifically, the wheel separation distance and wheel moment of inertia are selected as important parameters to study the effect of the co-rotation configuration on the aircraft shimmy. It is concluded that as the wheel separation distance increases, the lateral shimmy becomes more stable, while the torsional mode become less stable. In comparison to the non-co-rotation configuration, dual co-rotation wheels have a petty effect on landing gear with small wheel separations. However, in the condition of a relatively large distance between wheels, the co-rotation configuration has a great positive influence on the anti-torsional shimmy. The wheel moment inertia, within a practical range, affects shimmy oscillation weakly for both the co-rotation and the non-co-rotation configuration
