New fatigue rules are here, and it can be a complex issue. How do you know if you are fatigued? How do you know if a crewmember is fatigued? How do you ask someone if they are fatigued? Some airlines have had robust fatigue rules for a while so much of the data available comes from airlines. Airline pilots might fly more hours and perhaps more days but, in my experience, fatigue can happen to you on your first day of work. Do a self-check and keep doing them.