In this study, we investigated the rotational dynamics of airplanes at high angles of attack, where traditional decoupling of longitudinal and lateral flight dynamics becomes insufficient due to strong kinematic and aerodynamic couplings. At large angles of attack and sideslip, unconventional interactions (such as changes in rolling/yawing moments with angle of attack and non-zero asymmetric moments at zero sideslip) necessitate a more comprehensive stability analysis. Building on the existing literature, our study emphasizes rotational stability as distinct from translational stability, with the former governed by aerodynamic design and feedback control, and characterized by shorter time scales. A five-state dynamic model was developed, focusing on rotational motion under a constant velocity assumption, along with a trim tool for computing control deflections and stability derivatives. Linear stability analysis of the model reveals non-standard, highly coupled modes at extreme flight conditions, invoking the development of an algorithm to classify eigenvalues into Dutch roll, roll, and short-period modes. The findings contribute to improved understanding and predictive capabilities for stability and control under challenging aerodynamic conditions.