Hi Buddah! I know you are a bit confused with WW2 planes in this game (I saw your comment in
this video
lol). In this game you can find 2 servers: World War I and Mixed Wars (WW1 + WW2). EVERY PLAYER under rank 15 will be playing in WW1. However, the game can sometimes spawn you in the Mixed for some reason, even if you are under 15. That's what happened to you the times you saw Mustangs, Me 262s, etc.
When you reach rank 15, you will ALWAYS be spawned in the Mixed server, unless you subscribe and pay Premium (rank 15+ Premiums can choose between WW1 and Mixed). I recommend you to enjoy WW1 while it lasts, because when you join the mixed games you'll face LOTS of WW2 planes, which are faster, more agile and can carry more bombs than yours (to sum up, you are undefended against them). I forgot to say that they are damn expensive, so you'll stay a lot of time stuck with your little and slow WW1 plane (most players leave the game at this moment).