An aircraft incorporating a bleed system for extracting compressed air from the aircraft main engines to be used as a source of pressurized air for the aircraft. The bleed air system includes a first pre-cooler installed at one of the main engines nacelle and coupled with the bleed duct, and adapted for cooling down the bleed air extracted from the main engine, and a second pre-cooler installed at the pylon and coupled with bleed duct and downstream the first pre-cooler. The working temperature of the aircraft bleed system is reduced, down to max 200° C., so that the dimensions of an Over Heat Detection System (OHDS) is reduced.