The objective of this project was to investigate experimental methods for estimating rotational moments of inertia. The moments of inertia of an aircraft are important in understanding its aerodynamic properties and thus its translational and rotational motion during flight. A current method used in the Unmanned Aerial Vehicle (UAV) Laboratory to estimate moments of inertia includes a bifilar pendulum, which will be described in this report. An investigation of the bifilar pendulum includes determining the accuracy of the experiment and understanding its experimental process. It was found that the variance for ten experiments was small, allowing confidence to be had when estimating moments of inertia of a given aircraft. However, it should be noted that uncertainty in aircraft properties could affect the comparative analysis between analytical values and experimental results. Additionally, this investigation provides insight into the experimental process of moment of inertia estimation and motivates future research in the area.