Thread:Kololz/@comment-749631-20150830154650

..Try sortie with mltiple unused (brand new) fighter planes of same type at places where there are no enemy air power and then you can see they gain rank at different speed which make it hard to tabulate the levelling speed of planes. Even more, in this scenario some plane on smaller slot can gain rank faster than planes from larger slot. Thus I think it isn't really possible to tabulates the levelling speed. 