Grade 5 requires 150.000 XP and 250 hours.
My average XP/Hr is around 1200.
That means I’ll reach 150K XP in 125 hours. Half the hours needed for Grade 5.
After 250 hours I’ve reached 300K XP. Twice the XP needed for Grade 5.
I guess the flight hours requirement is high for grade 5 because it gives everyone something to aim for rather than lots of pilots being grade 5 too easily. I have like 170 hours to get there!
I think that’s fine, but maybe the argument would be to increase the XP requirement to match the hours. People who exploited the bug to hold throttle up outside of region boundaries could easily be over the hours requirement just by letting the plane fly on autopilot overnight for a few days.