This paper summarizes the use of a small, low cost, versatile, easy-to-program, and off-the-shelf autopilot system, called the Pixhawk Mini, to fly and validate a student-built RC aircraft in the aerospace engineering senior design class at Wichita State University. The goal of this paper is to obtain data from flight testing an aircraft and to use that data to validate the aircraft design. In the senior design course, a physics-based model is developed in the conceptual and preliminary stages of design and consists of aerodynamic, stability and control, and structural estimates for the aircraft and in detailed design, the model is manufactured and tested for validation. In this thesis, a simple test plane is designed, manufactured, and flown. With the Pixhawk Mini in the aircraft, the plane goes through several flight-tests in a simulated environment such as X-Plane and in real life to obtain data used to better understand the design choice, validate the physics-based model and verify the aerodynamics, stability and controls, and structural parameters obtained in the early stages of design.