OneSky is a private aviation enterprise that encompasses a network of smaller aviation entities with a specific emphasis on enhancing private aviation through the development of advanced IT solutions. One of the challenges that they face is when the crews make fatigue calls. Crew fatigue calls result in disruption of scheduled flights which in turn costs money and results in damage to the company. Fatigue can also be seen as a major safety factor. To ensure flight safety and efficient flight and crew scheduling, this research will analyze the features that caused crew calling fatigue on a particular day. The analysis will be done based on the historical data of 1512 different crews with over 800 thousand crew trips and 258 fatigue calls from October 2018 to February 2023. Feature extraction will be used to determine the features that are most likely to cause fatigue calls in the past.