The increasing prevalence of semi-autonomous aerial platforms, commonly referred to as ``drones”, coupled with rising demands for autonomous operation, has accelerated the development of advanced sensing and situational awareness technologies. One persistent challenge is achieving reliable navigation in the absence of Global Navigation Satellite Systems (GNSS), particularly for airborne platforms constrained by Size, Weight, and Power (SWaP) limitations. Optically Pumped Magnetometers (OPMs), in conjunction with magnetic map matching, offer a potential solution; however, their effectiveness is degraded by magnetic interference originating from the host platform. We report the hard-iron and soft-iron distortions inherent to a multi-rotor drone and quantify the magnetic noise introduced by its motors. We observe that motor-induced noise frequency exhibits a linear relationship with throttle input, whereas the overall noise magnitude does not. Further, interactions among multiple motors produce modulated noise components. Additionally, this noise correlates strongly with pilot control inputs and appears consistently across different sensors, enabling improved identification and mitigation of platform-induced magnetic disturbances.