So recently, I just reached Grade 3. It was hard… I had to do some long-hours of grinding. Let me show you the best ways to Grade-up! Remember to do this on a Casual Server!
So the first way if for landings and XP. Grab any small plane! I would recommend a Citation X or an A318. These planes can reach high-speeds in a matter of time and rarely stall while doing sharp turns. Next thing is to get in an airport with parallel runways like Heathrow. You can do any airport of course! After that, taxi to the runway and take off. As soon as your airborne, then make a sharp turn onto the other runway that’s parallel to the one you just took of from. I recommend using some flaps as well. You can get 10 landings and 1000+ XP in under 15 minutes if you do it properly!