A method for operating a cooling unit on board an aircraft includes operating the cooling unit in a cooling mode and in a thawing mode. In the thawing mode, any thawed water in the cooling unit is drained off from a thawing element with the aid of gravitational force, and the thawing mode is prevented during specifiable flight phases and/or flight attitudes of the aircraft. A cooling unit configuration for an aircraft includes a cooling unit to be mounted on board an aircraft. The cooling unit can be operated in a cooling mode and in a thawing mode. The cooling unit has an element that thaws in the thawing mode, from which any thawed water can be drained off with the aid of gravitational force. A control device is configured to prevent the thawing mode during specifiable flight phases and/or flight attitudes of the aircraft.