Jet engine air intake fairing with de-icing device

There is presented an air inlet cowl for a jet engine provided with de-icing means comprising an air extraction opening (34) made in the partition (20), to put into communication the insulation volume (28) enclosing the hot pressurized air supply duct (10) with the internal peripheral chamber (21) of said leading edge (16) and the area of the flow passage section of said extraction opening (34) is chosen to ensure to the injector (12), in case of failure of said supply duct (10), a hot pressurized air flow rate at least equal to 50% of the hot air flow rate in said supply duct (10).