Chain Of Command
Starts with Private at the bottom (above anyone in the RAF, clearly) and goes through all the ranks up to Field Marshal.
Bear in mind, your chain of command is the one that starts within your Section, works its way through your Platoon, Company, Battalion, Brigade and Division.
Going to a higher rank outside your own CoC is frowned upon unless there are extenuating circumstances. If you want sensible advice on this, speak to the Padre, not the Barrack_Room_Lawyers.