An aircraft engine, comprising: an inner casing extending circumferentially around a compressor section, a combustor, and a turbine section; an outer casing extending annularly around the inner casing; a duct defined radially relative to a central axis between the inner casing and the outer casing, the duct having an inlet and an outlet, the duct defining a bleed port through the outer casing between the inlet and the outlet; a bleed conduit stemming from the duct, the bleed conduit having a bleed inlet connected to the bleed port and a bleed outlet fluidly connectable to a fluid system; a first valve connected to the bleed conduit between the bleed inlet and the bleed outlet, the first valve having an open configuration and a closed configuration; characterized in that it further comprises a second valve connected to the bleed conduit upstream of the first valve and at or proximate the bleed port, the second valve having a second open configuration and a second closed configuration, and in that: when in the second closed configuration, the second valve blocks fluid communication between the bleed port and the first valve such that a portion of the bleed conduit between the first valve and the second valve is fluidly isolated from the duct; and the second valve being in the second open configuration when the first valve is in the open configuration to fluidly connect the bleed port to the bleed outlet through the first valve and through the second valve. an inner casing extending circumferentially around a compressor section, a combustor, and a turbine section; an outer casing extending annularly around the inner casing; a duct defined radially relative to a central axis between the inner casing and the outer casing, the duct having an inlet and an outlet, the duct defining a bleed port through the outer casing between the inlet and the outlet; a bleed conduit stemming from the duct, the bleed conduit having a bleed inlet connected to the bleed port and a bleed outlet fluidly connectable to a fluid system; a first valve connected to the bleed conduit between the bleed inlet and the bleed outlet, the first valve having an open configuration and a closed configuration; characterized in that it further comprises a second valve connected to the bleed conduit upstream of the first valve and at or proximate the bleed port, the second valve having a second open configuration and a second closed configuration, and in that: when in the second closed configuration, the second valve blocks fluid communication between the bleed port and the first valve such that a portion of the bleed conduit between the first valve and the second valve is fluidly isolated from the duct; and the second valve being in the second open configuration when the first valve is in the open configuration to fluidly connect the bleed port to the bleed outlet through the first valve and through the second valve. when in the second closed configuration, the second valve blocks fluid communication between the bleed port and the first valve such that a portion of the bleed conduit between the first valve and the second valve is fluidly isolated from the duct; and the second valve being in the second open configuration when the first valve is in the open configuration to fluidly connect the bleed port to the bleed outlet through the first valve and through the second valve.