Naval Tactical Data System
During 2005–10, "São Paulo" underwent extensive modernization. The upgrade included inspection and repair of the steam turbines; maintenance of the surface condensers; retubing of boilers; repair of two high-pressure compressors; revision of the AC electrical generator; purchase of spare parts; maintenance of pumps, valves, and structural items; addition of two API oil-water separators; installation of two water cooling units; upgrade of the chemical oxygen generator; repair and treatment of oil tanks; substitution of the Naval Tactical Data System, installation of a closed-circuit television system; installation of an IFF transponder; installation of a MAGE system (ESM), flight deck inspection, repair, and painting; upgrade of the Optical Landing System processing unit; and revision of the aircraft catapults. The upgrade was completed in July 2009, and the "São Paulo" was initially due to be fully operational by August 2010.