My brother is a commercial airline pilot who flies world wide and pilot fatigue is real and very common.
Airlines have been making bank for the last few years and all they need to do to prevent pilot fatigue is reduce hours for pilots and increase the number of pilots/flight, especially for international flights.
These simple measures (albeit costly), will overall help reduce commercial flight fatalities across the globe.
My father was an airline pilot for years (American, US Airways, and then Etihad) flying domestically and then internationally. I'd guess that if the airlines wanted to reduce pilot hours the pilot unions would have a lot to say about that.
Most pilots do earn an annual salary. I'm not sure what the previous comment meant. Pilots simply have to work minimum number of hours per month, but the issue is that most pilots are now working up to the maximum number of hours therefore there are actually pilot union striking because of overwork!
Airlines have been making bank for the last few years and all they need to do to prevent pilot fatigue is reduce hours for pilots and increase the number of pilots/flight, especially for international flights.
These simple measures (albeit costly), will overall help reduce commercial flight fatalities across the globe.