Improvement of operational efficiency and realization of autonomy in spacecrafts and ground facilities are required. The model-based digital twin of the 6.5 m×5.5 m Low-speed Wind Tunnel of the Japan Aerospace Exploration Agency (JAXA) that enables real-time simulation is developed. Validation of the digital twin is conducted using the experimental data of a generic aircraft model under a varying angle of attack. Real-time fault detection with the present digital twin and Unscented Kalman Filter is demonstrated using the sensor fault data obtained in the wind tunnel.