ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / This paper describes the design and construction of a semi-autonomous quadrotor aircraft approximately 1 meter in diameter. Because of the mechanical simplicity of the aircraft, the design challenges primarily centered on the electrical and computer engineering (ECE) tasks, and was used as a capstone design experience in an undergraduate ECE program. An onboard microcontroller based system uses a network of digital sensors and differential thrust for autonomous attitude control. A wireless telemetry and command link allows a user to monitor the vehicle, control its direction of flight, and for flight safety control.