The present work proposes a simple technique for the derivation of Euler's equation for a rigid body rotating about a fixed point, which is often overlooked in standard texts. This work considers the moment due to inertia forces as an external moment and uses static equilibrium equations (D'Alembert's principle) for obtaining Euler's equation. The present method is adopted as a part of a graduate course on flight mechanics, where a short introduction to the mechanics of rigid bodies is required by a cross-section of students from diverse backgrounds.
