A propeller system includes a propeller located at a tail section and a drive shaft operably connected to the propeller to drive the propeller about a propeller axis. A propeller gearbox connects the propeller to the drive shaft and a propeller gearbox lubricant cooler is operably connected to the propeller gearbox and disposed circumferentially about the drive shaft. The propeller gearbox lubricant cooler transfers thermal energy from a flow of lubricant flowing therethrough to a flow of air flowing through the tail section across the propeller gearbox lubricant cooler. A method of cooling a gearbox for a propeller includes circulating a volume of lubricant through a propeller gearbox and flowing the lubricant into a propeller gearbox cooler. Thermal energy is transferred from the lubricant to a flow of air flowing across the propeller gearbox cooler and the flow of air is vented from the tail section of the rotorcraft.